uOVS-SASOL-BIBLIOTEEK 0124622 111087449201220000019 A SEDIMENTOLOGICAL STUDY OF THE CONGLOME- RATES IN THE ELSBURG STAGE ON THE WELKOM AND WESTERN HOLDINGS GOLD MINES. by ,JACOB JOHAlTNES KLEYNHAlTS THESIS SUBNITTED IN PARTIAL FULFILNENT OF THE REQUlRENENTS FOR THE DEGREE OF MASTER OF SCIENCE IN THE FACULTY OF SCIENCE, UNIVERSITY OF THE ORAlTGE FREE STATE, 1970. -~ DiS BlEU _ :; l\EIB i ABSTRACT A sedimentological description of the layers of conglomerate in the Elsburg Stage of the Witwatersrand System, as disclosed by 23 boreholes and underground development on the Welkom and Western Holdings Gold Mines in the Orange Free State Goldfield, is given. The palaeocurrents in the Elsburg Stage as inferred from pebble-size distribution and preferred pebble orientation, were from two different directions. On Western Holdings Limited and the Welkom Mine area west of the Ar-r-art-aFault, the layers of conglomerate were derived from the north-west. On the Welkom Mine area east of the Arrarat Fault, the direction of transport was from the south-west. These two different palaeocurrent directions can be explained by lateral movement along the Arrarat Fault. Thus, the eastern block of the lease area of the Welkom Gold Mining Company, which was formerly situated on the north-eastern flank of a delta fan, was displaced along the strike of the Arrarat Fault for a distance of approximately 6 000 m towards the south, while the western block (Welkom No.3 Shaft and ii"esternHoldings Limited), vas displaced towards the north. A detailed analysis regarding the composition, roundness, shape, orientation and sorting of the pebbles in the layers of conglomerate was undertaken. The sorting and roundness of the pebbles increase towards the centre of the basin, while the majority are orientated with their long axes parallel to the palaeocurrent direction. The percentage of non-durabIe pebble types also decreases in a down-current direction, while the durable types remain constant. The pebbles are mostly spheroidal, although oertain types show a strong tendency to disc shaped. These features indicate that the layers of conglomerate were probably deposited on an alluvial fan bordering an inland lake or sea. ii CONTElJTS Page INTRODUCTION 1 A. HISTORICAL REVIEW 1 B PREVIOUS GEOLOGICAL WORK 2 C. PRESENT IlJVES'rIGATION 5 II. GENERAL GEOLOGY 7 A. PRE-WITlfATERSRAlJDROCKS 7 B. WITWATERSRAND SYSTEM 7 L Lower Division 7 2. Upper Division 7 (a) Main-Bird Series 7 (i) Bird Group 10 (b) Kimberley-Elsburg Series 11 (i) Kimberley Stage 11 (ii) Elsburg Stage 11 C. VENTERSDORP SYSTEM 15 D. KARROO SYSTEN 16 E. INTRUSIVE BODIES 16 nl. STRUCTURAL GEOLOGY 17 A. GENERAL 17 B. STRUCTURE OF THE PRE-KARROO SURFACE 17 C. FAULTING 19 IV. SEDIMENTOLOGY 22 A. GENERAL 22 B. PEBBLE LITHOLOGY 23 1. Description 23 (a) Durable Types 23 (i) Pebbles of Quartz 23 (ii) Pebbles of Chert 25 (iii) Pebbles of Jasper 26 iii Page (b) Non-durabIe Types 26 (i) Pebbles of Quartzite 26 (ii) Pebbles of Slate 27 (iii) Febbles of Yellow Silicified Shale 27 (iv) Pebbles of Quartz Porphyry 27 (v) Other Pebble Types . 27 2. Ratios 27 C. PEBBLE-SIZE DISTRIBUTION 29 Size Variation 29 (a) Method Applied 29 (b) Determination of Regression Lines 32 (i) Mathematical Method 39 (ii) Determination by means of a computer 39 (c) Hean Size and Its Significance 40 (d) Conclusions 43 Sorting 47 Skewness and Kurtosis 49 D. FABRIC 51 Method of Determination 51 Statistical Analysis 53 Pebble Clusters 55 E. Pb13BLE SHAl"'E 58 Roundness 58 (a) Durable Types 62 (i) Quartz 62 (ii) Chert 63 (b) Non-durabIe Types 63 (i) Quartzite 63 (ii) Slate and Shale 64 (iii) Porphyry 64 Spherici ty 64 MORPHOLOGY OF THE PEBBLES 72 VARIATION Dl THE PEHCEl'1'l'AOGFE CONGLO~!EHATE 75 v ILLUSTRATIONS Pigures Page 1- Locality map. 6 2. Generalized geological section of the Orange Free 9 State Goldfield. East-west geological section through surface 18 boreholes TR 3 to MB 6. 4. Plan showing the main shafts and surface boreholes 24 on which observations were taken. The change in pebble lithology along an east-west 28 section based on surface boreholes JR 1 to U 2. 6. Illustration of the method applied in the 31 determination of the pebble area on the borehole core. Scattergram for pebbles of quartz with the 33 regression line defined by means of a computer. 8. Scattergram for pebbles of quartzite with the 34 regression line defined by means of a computer. Scattergram for pebbles of chert with the 35 regression line defined by means of a computer. Scattergram for pebbles of shale with the 36 regression line defined by means of a computer. lL Scattergram for pebbles of slate with the 37 regression line defined by means of a computer. 12. Scattergram for pebbles of porphyry with the 38 regression line defined by means of a computer. 13. Transport directions during sedimentation. 44 14· Graph for the conversion of values calculated 50 by the computer to sorting values after Inman (1952) and Folk and Ward (Folk, 1966). vi Page Block diagram illustrating the positions of the 52 three axes of pebbles viewed from different angles. 16. Histogram showing the orientation of the long axes 54 of pebbles. 17· Illustrations of pebble clusters in a horizontal plane. 55 18. Section through a pebble cluster. 56 19· Rose diagram showing the orientation of pebble clusters. 57 20. Roundness chart for pebbles of 16 - 32 mm (after 60 Krumbein, 1941). 21- Roundness grades (after Sames, 1966). 61 22. Shape classification of pebbles (after Zingg). 65 23· Shape classification of the pebbles of quartz, 71 quartzite and chert according to calculated parameters. 24. Model illustrating the relationship between broken 74 rounds and pebble size (after Pittman and Ovenshine, 1968). Plates I- Specimen of typical Elsburg conglomerate. 84 II. Specimens of Elsburg conglomerate 'tii th one sample 84 showing the greenish tinge due to metamorphism. III. Greenish coloured conglomerate near the top of 84 Zone VS 1. IV. Specimen showing pebbles of red jasper and maroon 85 slate present in the conglomerates. V. Method applied in the determination of pebble sizes 85 on a borehole core. Vr. Specimen of borehole core with large pebbles showing 85 cuts parallel to the apparent c-axis. VII. Large pebbles of milky quartz orientated with their 86 long axes parallel to the bedding-plane. vii Page VIII. Pebbles depesited with their a-axes parallel to the 86 bedding-plane. IX. Specimen showing large pebbles of quartz and 86 quartzite. X. Specimen showing large pebbles of quartzite in 87 comparison to other pebble types. XI. Preferred orientation of rod-shaped pebbles (bettom 87 view). XII. Pebble cluster with the arrow indicating the direction of the current. Plans (in folder) 1. Geological map of the Pre-Karroo surface and the suboutcrop of the Elsburg Stage. 2. Structural plan of Hestern Holdings and lielkom Gold Mines. 3. Isopleth map of pebble size. 4. Plan showing the percentage of conglomerate in the Elsburg Stage. viii TABLES Page 1. The main schemes of correlation and terminology 8 of the Upper Division of the Wi twa tersrand System (after Sims, 1969). II. Subdivision of the Elsburg Stage (after Sims, 1969). 12 III. The differences in mean pebble size in the layers 42 of conglomerate intersected in borehole ME 5. IV. The differences in mean pebble size at different 42 underground localities. 33 East-west Haulage at No.2 Shaft, Western Holdings Limited. V. The mean diameters of the different types of 46 pebbles at randomly selected stations. VI. The ratios botwoen the longest, intermediate and 68 shortest intercepts of the pebblos of quartz. VII. The ratios between the longest, intermediate and shortest intercepts of the pebbles of quartzite. VIIL The ratios between the longest, intormediate and 70 shortest intercepts of the pebblos of chert. - 1 - 1. INTRODUCTION During the years 1933 to 1949, a successful exploration oampaign for gold in the Orange FroG State, revealed a tremendous amount of stratigraphical data which are being recorded and safe-kept in the form of borehole core. Geological data from this borehalo core disclosed a sequence of sedimentary rocks below the Ventersdorp System which has boon correlated with the Witwatersrand System. The layers of conglomerate in tho Elsburg Stage of the Witwatersrand System on which this investigation was f'ocussed , wore discovered in thG doep boreholes drilled for thG locating of the gold-bearing Basal Heef 0 The coros from all the surface boreholes are stered in tho core-shed of the Anglo American Corporation at Western Holdings Limited, or have been safe-kopt in tho core yards of tho athol' gold minus in the Anglo Group. With the kind approval of the Consulting Geologist in the Gold Section of tho Anglo American Corporation, Dr. IL C.Mo Whiteside, and the Managoments of the Welkom and Hestorn Holdings Gold Mines, the author was able to submit a thosis on the sedimontation of the Elsburg Stage in the Witwatersrand System in tho area embracing the Welkom and Wostern Holdings Gold Mines. A. HISTORICAL IlEVIEH Almost 37 years havo passed sinco the first borehole was drilled for the exploration of gold illthe Orange Free State. This historical borehole, VIE 1, which Has drilled in 1933 on the farm Aandenk, near Loraine, proved the presence of gold-bearing conglomerates of the Witwatersrand System below the overlying rocks of tho Vontersdorp and Karroo Systems. In 1937, borehole rl.E. 4 intersected sedimentary rocks which were recorded as "Upper Witwatorsrand Quartzites, presumably of the Elsburg Series" (Coetzee, 1960, po 57). - 2 - Diamond drilling commenced to radiate from Aandenk and was located on relatively low gravity areas whore it was anticipated that the Vontorsdorp lava below the Karroo System would be thin. The African and Luropean Investment Company Limited, commenced drilling in 1938 in such an area of low gravity. This area comprises the present Welkom, President Steyn and President Brand Gold Mines. Up to that stage, conglomerates yielding only very low values were intersected. Afto r Harld lelarII, drilling activities increased, until such a woal th of geological information rogarding the gold-boaring roofs has boon obtained, that mining activities oould be commenced in 1946. B, PR8VIOUS GEOLOGICAL WORK Since the Basal Roef has boen encountered in surface borehole No. 7 on St. HGl()J1a,in April 1939, many authors have made contributions rGgarding tho geolo€,-y of tho Orange Free State Goldfield. There havo beon diffGront opinions as to the mode of deposi tion cf the great thickness of sodimonts in the vIi twators- rand Systom.. Strong arguments have b80n submittod in favour or against tho theorios regarding the propos8d sedimontary environments. Hhoroas this research is mainly focussed on tho palaeocurrent analysis of the conglomerates in the Elsburg Stage, it would bo of groat importance to discuss some of tho theories closely related to th0 sedimentation and structuro of the Wit"latersra.Yld Basin in the Pr-co Stato Goldfield .. Sharpe (1949) rocog~iscd a cyclic periodicity in the deposition of tho Witwatersrru1d rocks, each cycle ending with a diastrophic culmination. Borchers (1950) doscribes the formation of a border fault parallol to the western margin of the Witwatersrand Basin, which was contemperaneous with doposition of the 3 - sedimcnts cast of the fault scarp, According to Borchers, it appears that sediments had boon discharged into tho basin from the north, north-west and west. 'rho layers of conglomerate in the Upper Division of the Hïtffatersrand System are coarser in those directions ",ith a thickening of tho sediments towards the centre of tho basin. Borchers visualisod tho deposition of tho sedimonts as follows,- At tho outsot of the Wih'fCtorsrand pori.od, tho Archaean land surface in the vicini ty of the present goldfield consisted of a barren penoplano of rocks of tho Primitive System and granite. Hivers from distant mountains north and wost of the Wit",atersrand basin, discharged fine sediments into this inland sea. A change in climate, combi.ncd possibly w i th slight elevation of tho surrounding country, caused the rivers to transport coarSQr sodimonts which woro depositod in tho basin as layers of conglomorato intorbodded with quartzites. Simpson (1951) supported tho thoory of Borchers. He found that tho sediments of tho iiitl'latorsrandSystem aro characterised by a series of uraniferous cycles which arc separated by poriods of lessor activity. Those cyclcs proved helpful in problems of corrolation. Brock (Cootzee, 1960) postulated that in the ",estom soctor of tho Orango FroG Stato Goldfield? the auriferous roefs have beon preservod in a graben. According to Brock, the sediments of the Upper Division of the lhtwatersrand System ",,,redeposited in a continontal basin. The periphory of this basin was surrounded by elliptical faults along which the source rocks were uplifted, while tho basin itsolf was not affected by tho faulting. Antrobus (1956) is of tho opinion that the sedimonts of tho Witwatersrand System are the rosuIt of deposition in a continental basin surrounded by land surfaces. The whole sequence maintains the same lithological character. According to Antrobus, two types of conglomerate can bo recognised in the - 4 - Upper Division of the Witwatersrand System. Normal conglomerates possess a pol~nictic pebble assomblage and are characterised by drab matrix material. Auriferous conglomerates are composed of well rounded chemical stablo pebbles, usually sot in a clean matrix of orthoquartzite. Coetzee (1960) is of tho opinion that tho Witwatersrand System as found in the Orange FroG Stato Goldfield, is part of a marine sequence laid dovm in a shrinking basin. Coetzoe statod: "Many of the conglomeratos probably arc dcpositod on a transgressive boach over a surface of low relief" (Coetzee, 1960, p. 51). Winter (1964) postulates that the formation was deposited in a marginal synclinal trough formod by prominent folding along an axis parallel to the elongation of tho Wit"o1atersrandBasin. The folding continued during the deposition of the bods and was particularly prominent when tho Elsburg Stage was laid down. Tho shoroline was not far distant from the present posi t i on of tho suboutcrop of tho Basal Roef. 'Therising of the sourco area to the west had a profound influence on tho sedimenta- tion in tho basin, and as the sourco aroa advanced eastwards, tho removal and rodeposition of previously accumulated sediments took place. In studying tho Elsburg Huofs in tho Loraine area of tho Orange Froe State Goldfield, Olivior (South African Mining and Engineering Journal, 1960) felt that Hinter's idea of a synclinal trough is somewhat over-emphasisod. Olivier describes the pr'o- Vontersdorp structure as a stoop marginal limb and a relativGly flat area eastwards towards the centre of tho basin. In tho aroa investigated, however, thore is evidence of regular sedimentation during the deposition of the Bird, Kimberley and Elsburg Stages in the Witwatersrand Basin. The results obtained by Sims (1969) in his study of the stratigraphy and palaeocurrent history of tho Upper Division of the Witwatersrand System on Fresident Steyn Mine and - 5 - adjacent areas, strongly suggost the arrangement of a fan del ta about at the peint of entry of a fluvial system into tho marginal environment of'a continental sua. c PRESE]Tr n:V~STIGATION Tho study of sodiments, both pruscnt day doposits 08 woII as anciont sodimGntary procGSSOS; has Grown enormously during the past fenl yoar-s , 'l'od.ay, much sGdimcntological r-osc.ar-ch is just a refinomont of provious Kork already dono. In a study of the sedimuntoloE;"Y and palaoocurT'onts of tho conglomerates in the Elsburg Stage, tho author -bcncfittod from t.ho rosul ts obtained and techniquos used during research donu by his predecessors. Encour-aged by tho succo ssf'u I r-oau l ts obtainod by similar projects (Winter, 1957; Coetzoo, 196c, Hodgson 9 1967 ~ Piouaar1 1969 and Sims j 1969):, this investigation was undertaken to assomble and int(Jgrato s orne sodimuntological information 1•.;;ith tho 'i,fishthat the r-osu Lts rm gh t bo a u ae f'u l contribution to tho study of tho Elsburg Stago~ All the w or-k d on c by thu author Has on a macroscopic scalG~ 'I'h e investigation commcncr.d at th0 b0ginning of 1968 ana consisted of detail ad goolog'iaal logging of soma 23 bo.rohol cs . the measuring of the pebble sizes on tho borehole core) and the determination of pebble paramcturs such as pubblo composition;; r-oundrioae , shape; or Lcnt.at i on , ot c, J dUI'ing ob ae r'va.t i.one and measuroments underground. 'Irio aroa of detailed analysis covered by this treatise oomprises tho Welkom and Western Holdings Gold Mines whioh are situated in the centre of the Welkom section of the Orange Pree Stat" Goldfield. Tho area is bounded on the south by the lease areas of Presidunt stoyn, Prosidunt Brand and St. Helena Gold MinGS and in tho north by tho Free State Geduld Mine (Fig. I). LOCATI N OF MINING AREAS THE O.F. S. GOLDFIELD. AREA OF DE TAILED ANALYSIS. o SOO 1000 r17 &:,INECSONSOLIDATEDLTD. ~ ODENDAALSRUS ,REE ~TATE GEDULD MINES ~TD. ST. HELENA [j.M. LTD. FREE STATE SAAI PLAAS G.M. CO. L PRE.SIDENT BIlAND G.M. CD. LTIl. VIRGINIA (0 F. s.i G.M cO. LTD. VIRGINIA. M(IHIIESPRUIT (0. F. S.I G. M. CO. LTD. - 7 - II" GENI;RAL GEOLOGY The stratigraphical succession in the Orange Fr-ee State Goldfield is interpretod in tho geological column as recognised by the Anglo .American Group Minos ('Pa'bloI and Fig. 2). The description, subdivision and correlation of tho Witwatersrand System and other formations in the Orange Free State Goldfield, as describod in this troatise, arc based on contributions by Borchers (1950), Van der Vyvor (1956), Antrobus (1956), Coetzee (1960), Hinter (1964), rftcKinneyet al. (1964) and Sims (1969). These authors provided comprehensive descriptions of the gBological column in this arGa. A. PRE-HITWATERSRAND ROCKS Surface boreholes wh i ch ponetrated the rocks of the 'ditvld.-t,arsrand System provod tho pr-osonco of gr-ana to , diorite, rhyolite and andosite belo" tho Hitwatorsrand Systom. The lavas prebably beleng to t.h o Deminion Roof System (Cootzee, 1960, p. 25 - 27). B. WITl-lATERSRAl!DSYSTEM 1. Lower Division The scdimen t s of thG Lower Division of'the Witwatersrand System consist mainly of'shalo and quartzites belonging te the Jeppesto>Jll,Govornrni}ntRoof'and Hospital Hill Serios (Ceetzee, 1960, p. 50 - 53). 2. Upper Division (a) Main-Bird Series The rocks stratigraphically underlying tho Basal Reef are referred to as the f'eot"all bods. Lithologically these rocks are quite variable. Conglomeratos and quartzites "ith pebble bands are subordinate te a "ido varioty of quartzite types belonging to the Livingstone and Main Reef Stages. - 9 - FI G. 2 - (;EN£RALISED GEOLOGICAL SECTION- -OF OF"S GOLDFIELDS - -SCALE 1 : 10.000- COd! U'dm& n J;;~Jd_trn» 0'112/77 o -JO veatersaor: (/Pj-U L.Ut1 0-862171. o= Ze35 Ventcr.Jdcrp S~dlme.·Jts /27217? 0-4000 (}-/2/9m. Pu. r ~-{'nr IQI19m Low« ...71·'<:1 785m, NOI1TJ, ·~.'ES""Ef"1 4fU,A ':"P •."".;: "ANBCU' rs rrs: 72.dn>, v en './l.Ifur D.rLUI'9 .... ~'<.. Cong om~r4~"~ V, (U ..... "'l ~ ~/9m. ~ ';;) r,Sbur9 ~ ~ O"hlr;n!e ~ '-.-J 'A·dd/l'Q f.,n17 Q.7I€" 515177 r.... ~ r I _ewe!' .,.: ~ hot i/val' 744m ~ " 2 r' 1070 .9.16 rn . (! ree:' Quar:::ule I -l..: ItJ7óm. /?24-rn. 3andu! R Quar:ztlc ,... I 4-.70 I.JG2m,ArqJ 'i/-"OU$ l2uÓ'rt 71'(' 447C 1484rn .dt(i "OS'~ 1586177 ~_,'J1-/779/17, !r-:------- 6J60.-" 19~5mg'J .-.,., ,;,_,,,, -6:.r:" .., _'.: --=-~ ~ -~ 2IJ.98m " " "- IlJ [.-.i!'r rt«, I I?.... r ......:..0..& ~ ,j U~() - !219mt::: H';',7('- t I:;:) t-) [_ ~~ ..... 1 76J5 l.J?1 IT]........ I "l'S..... U7Jm <. v , ...... ..... ' m ~oos 244tJ m ... '" -, I~,~ .... ~ ~ /'~rc.7d{ rotr OI/.1r/1.Jte::. \:) ~ ,'()rqr",: ,. .,,.?uf ........_. "~~~ 11'30 lóóO m'7 F~ 6840 U9 m. ea/c(/;;;' 1/017 S Prom/oS!' ]"e! '/7 It' lo I7tZaresl me/r'e - 10 - (i) Bird. Group This group oomprises the Basal Reef and Loader Reef Formations. Tho Basal Roef is oharacterised by an intermi ttent thin oarbon scam at its baso with ODc) er more layers of small pebbles varying in thiokness from 25 to 50 mm or from 0.3 to 1 m. This is tho most important gold-boaring conglomerate in tho Free State Goldfield. The reof usually contains muoh pyrite in a finely disseminated ferm or as crystalline nodules and also oarbon in tho form of soattered fine granulos. Tho Basal Reef is overlain by a thin layer of Basal Quartzite. Tho Khaki Shale overlying tho Basal Quartzite and Basal Roof ranges in thickness from less than 30 cm in the north-eastern portion of tho area, to more than 150 om in the extremo south-west of tho area. Tho Loador Roof Formation rosts unoonformably upon tho Leador Quartzites. These quartzites oonsist of several layers of oonglomerate and quartzite and attain an average thiokness of approximately 18 m. The Loader Roof is a fairly compact small pebble conglomerate about 30 Col in thickness. Mineralisation of' pyrito occur quite often, but tho carbon content is normally low compared with tho Basal Reef. Tho Lcador' R00f has consistantly low gold valuGs. Tho quartzites of the Upper I-Iain-BirdS.tage aro do scribed as coarse-grainGd impure argillacGous rooks overlying the yellow grey micaceous quartzites of the Loader Reef Zone. The Upper Shale Marker, unconformably overlain by the I' Kimberley-Elsburg Series, overlies the quartzites of the Upper Main-Bird Stage and attains a thickness of a few metres to approximately 30 m. The composition of this member in the • Leader Reef Formation varies slightly, but is commonly described as a dark grey arenaceous shale, - 11 - (b) Kimberley-Elsburg Sories The Kimberley-Elsburg Series is subdivided into the Kimberley and Elsburg Stages. (i) Kimberley Stage Tho stratigraphic break between the Kimberley-and 1·3 Elsburg Stages is based on a sharp sedimentary chang~"where the Lower Elsburg Conglomerate (Zone VS 5) is overlying the relatively even-grained sedimonts of the Uppo r- Shale l'!arker. The stage comprises three horizons of conglomerates intercalated with varying thicknesses of impure quartzite. These conglomerates are the so-called "Gold Estates R8ofs" ("A" Reef, Big Pebble Con- glomerate and "B" Reef respectively) whieh attain a thickness of approximately 120 m. (ii) Elsburg Stage This upper group of sediments in the Witwatersrand System, which is everlain by tho Leifer Volcanic Stage of the Ventorsdorp System, consists of a succession of conglomerates and quartzitos with an avorage thicknoss of approximately 500 m. This thickness is mainly basod on intersections in surface boreholes, and faulting mi@lt thorefore influence tho thicknesses. Plan 1 is a map of the pro-Karroo surface showing the suboutcrop of the Elsburg Stage in tho contral part of the ,Telkom Geld Mine and tho wGstorn portion of wostorn Holdings Limited" In tho aroa invostigated, Borchors and Whito (1943, p, 137 - 143) havo subdivided tho sod i.rnon t s of tho Elsburg Stage into a number of zones which are indicated by symbolsc Zono VS 1 Zone VS 2 Zone VS 3 Zone VS 4 Zone VS 5· - 12 - A subdivision of tho Elsburg Stage into threo substages based on genetic and cyclic affinities is described by Sims (1969, p, 138) (Tablo II). TABLE II. - A subdivision of tho Elsburg Stage after Sims (1969) AVERAGE THICKNESS: ZONE' UTl!OLOGIC AT lfELKOM AlTD SYMBOL: COMPOlJENT \mSTEill'HJOLDINGS ' SUBSTAGES GOLD MINES ., • VS 1 ,'Upper Elsburg Cong'lomcr-ate 300 m --+ Upper ElsburG , VS 2 ,Middlu Elsburg Quartzite 75 m + ' ) , i ) Middlo Elsburg VS 3 ;Middle Elsburg Con gl.omc r-a to 15 m + : ) VS 4 ,I Lowor Elsburg Quartzite 75 ra + , ): ) Lower Elsburg VS 5 : Lower Elsburg Conglom"ratc 30 m + : ) ------------------'------------------- .... Tbo Elsburg Stage is unconformably ovorlain by tho Lower Volcanic Stago of tho Ventorsdorp Systom with further probablo uncenformities at the base of the Upper Elsburg Conglomerate (VS 1), the Middle Elsburg Cong.lomer-etc [lhddling Conglomorato (VS 3a)], as WGll as, at thc basG of tho Lowor Elsburg Conglomerate (VS 5). Tbe rocks of thu ]nsburg Stage arc subjoct to pronounced changos in facies in tho arGa invcf5tigatod.. The ana extrome occurs near tho westorn sector of ~IQstorn Holdings Limi tod, whore tho VS Zones arc reprcsc.mted by Laycr s of conglomerato with occasional thin intercalations of quartzito. In the central area, the succession is represented by variable amounts of quartzite and conglomerate. Further to tho east and north-cast, the layers of conglomerate become subordinate and the succession is largely represented by dark and light grey quartzites. Only a few layers of conglcmerate are invariably doveloped at the top of Zone VS 1 and in Zone VS 5. Tbe layers of conglomerato in the Elsburg Stage differ strikingly from other conglomurates within tho Upper Division of the Witwatersrand System. The conglomorates are of a ver! mixod, - 13 - ill-sorted type, which gave riso to tho term "agglomerate - conglomerate" to distinguish thom from tho eleanor more typical types o~ conglomerate enceuntored lower dow~ in the Witwatersrand System. Pettijohn (1957, p, 2:14 - 259) has deseribed a genetic classification of conglomerates, according to which they are dividod into tho following types: Olimictic conglomerate Polymictic conglomcrat~ Intraformational conglomerato. The principle foatur-::sof a polymictic conglomerato are~- (a) A high r-ange of pobb Le sizes with poor sorting. (b) Subroundod to subangular pebbles. (c) Varied lithology \'lithmany rock types repr0sontod~ (d) Crude bedding of the coarsest phases. (e) Subordinate matrix. (f) 'mo groat thicknoss of tho deposits. 1~o layers of conglomerate in the Elsburg Stage aro not idoal polymictic conglomorates, but could bo rogarded as a varioty of that typo. Lower Elsburg Substage ('IS5 - vs 4) ,- This substage consists of a basal momber of conglomerate followed by a phase of quartzite. The conglomorate occurs as a polymictic ill-sorted type which forms a distinctivo marker and normally ranges between 10 and 20 m in thickness, but may, togother with the intorvening quartzite, attain a thickness of about 30 m. Tho rock varies from a small pebble to a boulder conglomerate. It is poor to woII packed, while the pebbles are usually fairly well roundod to rounded. In order of predominence, the pebbles of Zone VS 5 consist of white and smoky quartz, - 14 - massive black chert, greon and grey quartzites, pale yellow sericitic silicified shale, blue and blue-grey slate, buff and banded ehort, and decomposod porphyry. 'rhopresonco of such a variety of pobbles causod a colourful effect (Pl. I). The matrix of tho conglomerate in Zono VS 5 consists of dirty, black and yellow speckled quartzi to Hhich is typically ill-sortod and generally dark grey in colour. 'I'ihs congl omer-ato (VS 5) grados upvaz-d.sinto a acqucnco of quartzi tos (VS 4), wh i ch rango in thiokness from an avorage of 3 m on Hostorn Holdings Limitod to 70 m on Welkom Gold Mine. Those quartzitos arC)usually modium to fino-grained, groy to dark grcw in colour and subglassy, Hith fino-grained argillaceous intercalations. Mi.dd.LoElsburg Substage (VS 3 - VS 2) ,-- This eub stago is mostly composod of quartzitos Hith an avorage thickness of 20 ID on l-IestornHoldings Limited and 110 Dl on l-lelkomGold Mine. A conglomorate consisting of small pobbles occurs afton at tho basG of this substago ',rtih a t.h i cknc ss of about 10 to 30 m and has boon designated as Zone VS 3ao This zone consists of a porsistont dovelopmont of typical conglomerates of tho Elsburg typo. The coarse f'ac i os grados upwa.rds into a sequonco of dark grey quartzito (VS 3) which passc:s through a transition zonG of altornating light grey (almost Hhitish bleached), ooar80- grainod glassy quartzi to, 'I'ovrar'ds t.ho vTOst lonticular and wodgo- shapod layers of conglomorato incroase rapidly so that almost the ontire sequence on tho W0stOTIl portion of ~fostorn HoLdi.ngs Limited consists of conglomorato~ Uppor Elsburg Substago (VS 1) ,- 'Thobase of the Uppor Elsburg Substago is afton gradational, thus eausing miscalculations in estimating tho thicknoss of this zone. This, oombinod Hith faulting and subsoquont erosion causos thicknesses to be erratio, Zono VS 1 oonstitutos the upper 220 m of tho sucoossion; it is charaoterised by a thick conglomerate interbedded te a - 15 - variablo extent with dark grey impure quartzites. The composition of tho Upper Elsburg Conglomorate is eventually similar to that of tho Lowor Elsburg Conglomerate" Tl1';_s;arno range of pcbb l e typos occurs and a dark grey of tcn pyr i tic mat r-i.x is typical" Although thoro is a good r0scmblanco botwOOD Zonas VS 1 and VS 5, Zono VS I can bo distinguished from tho lower conglomorato by tho prcsonco of a higher proportion of woII roundod pebbles of milky quartz in a dark grey groundmass consisting of impuro yellow specklod quartzite. Tho colour of tho scdimcn t s in Zono VS I changos from dark greem in tho upper portion, to dark groy and light grey shades lowar down. Tho greenish colour of tho upper portion is thought to bo the rosuIt of metamorphism causQd by tho lavas of tho Ventersdorp System which d.ir-cctLy ovorlio Zono VS 1 of tho ;;:lsburgStago (Pl. II and rIr)e C. VElTTERSDORP SYSTEM Thoro is no apparent unconformity botwoon tho 1iitwators- rknd System and tho overlying Vontorsderp System. The Vontersdorp System is ropr,,:;scntod by an Upper and a Lowor Volcanic Stage fparatod by a scd imcnt.ar-y scqucnco , The lava of the l!O'0ICr Volcanic StaSG rangos in thicknoss from 200 to 650 m and consists of a thick sori os of dark groen, decomposod, intormediate te basic amygdaloidal and non-amygdaloidal typos. llioscdimonts of tho Ventersdorp Systom are poorly sortod, with woII rounded to subru1gular pebbles in a matrix of dark grey, grooD to almost black quartzites. Pebblos of its"TIOOUS rocks arc relativoly rare, wheroas pebbles of black and dark groy shale and ohert arc numorous with an abundanco of da.rkgray pebbles of quartzite. Fairly fine-grained grey-groan ~~dGsitic lava of the Upper Voloanio Stage overlies the Vontorsdorp acdi.ment s, Gonerally this lava is not distinguishable from that of the Lower Volcanic Stage. - 16 - D. KARROO SYSTEM The Karroo bods arc fairly flat lying in this area and vary in thicknoss betwoen 300 and 350 m. Although sandstonos in the lower portion of tho Beaufort Sorios aro found to tho south- east of Wolkom, tho Karroo Systom is mainly reprosented by the Ecca and Dwyka Sories, which arc the two lowest sequences in tho Karroo System. Tho Ecca Sorics is composod of blue-black soft arenaceous shales and some gritty sandstonos, while tho Dwyka Scrios is represontod by tillito. 'rho tillito consists of an unsortod assemblage of pobblos and boulders in a groundmass of sandstone er mudstone. Tho Dwyka tillite occurs intermi ttontly at the baso of the Ecca Sories. E. DlTRUSlVE BODIES Locally discordant shoots of intrusives ara common on Welkom Gold Mino and Westorn Holdings Limitod. Thoso transgrossivQ sills havo considerablo economic significanco. Difficul t mining conditions are cmcountored when tho plano of tho intrusion is along the basal roof parting .. .Antrobus (1956) describos Karroo doloritos and lamprophyros of post-Vontorsdorp ago. Tho dykes of Ventersdorp ags ara subdivided by him in yellow porphyrios and acicular lava. - 17 - III c STRUCTURAL GEOLOGY Ac GEIfERAL From tho intGrprotation of the: succussion of rock typos found in boreholos as well a8 tho analysis of structural problems oncountered in underground mining oper-at i orrs , tho gonoral str-ClO- tur-o of the 1'1e:lkomGold Mino and Wi~storn Holdings Limited can bo r-epr-oscntod by an oast-wast goological soetion (Fig. 3). It is advisablo to compare Plan 2 with this figuro so that tho roador can casily inturprot the influonce of faulting in this aroa. Comparing those tvlO diagrams ~ a number of interesting points arise from thc; discussion of the different aspocts of faulting in this area .. B~ STf{UCTTJRE CF TEE FRE-KARROO SUnFACE Proviously it was as ourncd that tho Karroo Systom was laid down on a smooth ponc p'lanc d surface. Boroholes af t er-wa.rds proved that this statement is not t ruo , Borchors (19509 d i agr a-: 10) indicatos that tho pr-c+Ka.r-r-o surface: Lr; the Orange Fr0c State Goldfield was fairly decply dissected. Pig. 3 illustratos that the; sodimonts of the Ka.rroo System Wr,:::rc do posLtud on <::111 undulating surface aftorthe Lowor Volcanic of tho Vcmtorsdorp System has boon eroded. The sedimentary layers of tho Upper Division of the ItJi twatorsrand System wc:rc d oposi ted on a surface w i.th a gontlo gradiont. Tho strata in tho central part of Western Holdings Limitod and Wolkam Gold Mino havo an average dip of 15 to 22 dogreos to tho oast1 whilst the sod.imentary layers noar tho woster-n boundary of Westorn Holdings Limitod and cast of the Arrarat Fault on Welkom Gold Min" havo dips of 25 to 52 degroes. This can bo attributed to tho intcnsivo faulting near the margin of tho basin and tho influenco of tho Do Bron Fault immodiately Gast of tho Leaao ar-ca of tho ,[olkom Gold Mine. .." G) o '0 W I,.., o o o o 00 :h"') '0 ,., Ir ..., .0 ti '0 0o '.) ";'~IJ 'Jl , , o o T-J')-,-/ 0 Of" o .) o I', . . o • t I • o ') " / 0 o, I t> ' < ~ i, : ~0 ~ s , (> ",/ < r , h "'Jp) < ef'i .,6; f:," < r- o o '0 ~'r::.,C) , ~f rn po OJ I ':> ,< G) o rn C J o ' or -f.0 z :::0 CJ w or-+- .)', o .) ' cf., lJ'rJo ,! . ,1:3, CJ> bO::> 1<, n» r tv" ,-c:) : 0 o o <. rn o h ,.,- " ~ '0 ~. :::J o ,r ,:.) .) 0 0 ...- /) c- o 00<' tv r- b ::) o " o o o( 0 A o 0 0< < o •.t.__ , (f) ,; z ~ o o.., C.., Jr'1 • ._._' ..-+ .0 0 o O<_ ....... " . :Y n" :> 0 < < () P ij o 0 ('i) o d' ,,' o o .p 0 <, < Q OJ o , 0 ° ::>'< P " 0, o, .oI P, 0/ o ~ o .) '. o ° 0 -c :Y o ° 0< < o o ° .._ ( -'i) 0 < (/) o "0 < < < o o o '-4< < < o o" ? ,- o fo .) .) ..)r o o .) o o o p p o :-.~ '" :." o .:J ••• : o o <" t't..,{, ;:> (}~.... ;:: D.., < _c- ,~~\ ,'I.r- , r I ) I) , • , I I • ol, . , '0 . < o ~ ,.It< S-o < ,J < o o t) :):> <-"o I o , I ' " .. . 0 0 :> < < .:.{ . 'Tl I :) < I .) 1 < .) < < '/ < ~I ---\l < I ;1 IJ to - ... , z: o l " r- a o o 6 -" k < o ) < o ,< -0 ,.., o ) '::;;I/Q.· /.6 r- << I o j ., <)< < o o ,r.. - < Jhich trend north-south. From t.ho ao fault sys tams , tho following are of major importancog- The throe major faults rGcognisod on 1'lclkomGold Mino and Wustorn Holdings Lind tod? arc tho Do Bron Fault) Arrarat Paul t and tho Dagbreok FauI t. Those thT00 faults arc all normal gravity faul ts >Jith dips varying from 55 to 70 degrees and they trond roughly north=nor-th+vcst (P18.l12), Tho Do Bran Fault cuts acrOGS tho horizon of tho Basal ReG±~noar' tho castorn boundary of irJolkomMino , In a dcfloction of bor-oholo HB 6 and in boreholo U 3 tho position of tho Do Bron Fault waS locatod as a fracturo Z011(.; of intonsive faulted rocks associated iii th rnagnct i c shales of the J'oppc s t own S6ri08, According to Cootzee (1960, p. 122) two phasGs of faulting exist. During tho first phaso of faulting (about 2 40C m to the wost), the eastern block >Jas elevated and subjected to erosion which r omovcd in places tho Lowor Stage of tho Vontorsdorp System as woI I as sed i.mcnt s of tho Upper Division of tho Witwatersrand Systom dovn to bc l.ow the horizon of tho Basal Rouf" '_fhc second ph aso had a dovrit.nz-oowf about 600 rn to tho cast. Tho Arrarat Fault is one of t.he major foaturos against which the sodiments of the -HitWEl,tGrsl'and orn have boon d ownth r-own on Wolkom Gold Mino. rrllisfault is situated DoaT the contral part of Welkom Gold Mino and the nor t.h+ca s t cr'n portion of 1'iustorn Holdings Limi tod .. It has a vertical down tr.r-ow of approximately 950 m in tho Welkom Mining Aroa, but the amount of displaoemont incroasos to 1 500 to 2 000 rn to,iards t.ho nor th , Noar tho northern boundary of tho vlolkom Gold Mine; tho Arrarat Fault is displaced to tho cast by an oast-1rIGi;t tr()nding toar fault. Tho rusults obtainod from pebblo-sizo distribution and pebblo orientations) provod that tho Arrarat Fault is - 21 - associated with a north-south tear action. Tho block of ground to tho cast of tho fault has a lateral displacement of approximatoly 6 000 lil to tho south. Tho Dagbruek Fault occurs in tho east orn portion of Western Holdings Limited and is also encountered in the south- wostorn corner of tho ~'lclkomGold Mine.. It has an average vertical displacemont of 400 nl with a downthrow to tho wost. The minor faults which appear or-os swi ao over tho ar-oa , can bo tentativoly joined up with tho major faults. Tho structural implications of tho many intrusives oncountorod in the surface boreholes aro not thought to bo of great goological significance as far as the layers of conglomerate in tho Elsburg stage aro concGxTIod, but theso intrusivo 'oodi.oe have consti tutod a hazard in the mining of tho Basal Roef whon tho plano Ol the intrusion is along thG Basal HGef par-ti.ng, - 22 - IV. SE1JIMENTOLOGY A. GENERJ~ Sodimontation r0fors to the process responsible for the formation of sodimGntary rocks, including tho transportation and deposition of tho rock-forming materials, their diagenesis and lithification. Commonly impliod, sedimentation comprisos sodimentary potrology and sedimentary pctrography~ which togother covor tho study, description, classification and interpretation of sedimentary rocks. ThG study of sGdimcnts and sedimentary procossus has mad.ogroat strides in tho recent yc~ars., lIow techniques have beon doveloped for tho analysis of tho behaviour of sodimentary materials during transport and after doposition. These advances have boon par-a'LloLcd by tho rofincmunt of methods for tho invostieation of a wido variety of physical and chemical attributos of sodiments. The investigation and analysis of a stratigraphic uni t , thus, begin Iii th the systomatic obsorvation of tho basic coraponont s of the ob ject 9 which in this caso 9 az-c tho pz-opc r-t i.os Ol' tho Layo r-s of conglomerate in tho Elsburg StGgo. Tho na tUT'C of tho conglomera te layc:rs 1iBS macroscopically oxaminod rogarding the composition) sizo'} sorting and oriontation of tho pcbbLcs in ardor to compile an 20nalytical t r-oa't i sc on tho palaoocurront history of the rocks. The ar-ca Lnvcs t i gat cd COVOl'S 57 km 2 b ound od by tho lease aroas of -Wostorn Holdings Limi tod and tho Wolkom Gold Mining Company (Fig. 1). Jh thin tho above+ montioned aroa, tho author had to mako uso of tho information obtained from 23 surfaoo boroholos. Tho research has largely boon carried out by moans of dotailod logging and measurements on tho boreholo core as wall as mOaSUI'Officnts and obsorvations underground. Whon solocting tho 23 boroholos, tho author has kopt in mind that certain rostrictions \)ould bo inevitable, i.o. distances botween tho bor-oho Lcs and tho tr-ornondousamount of' - 23 - faulting in tho aroa. Tho boroholes woro choson in ardor to givo a rogularly spacod grid whon dotormining tho properties of tho conglomoratos and comparing thoir rolationships to onG another. Bearing in mind that vory little is known about tho differoncos betwoon tho conglomoratos of the Upper Elsburg Substage (Zono VS 1) and theso of tho Lowor Elsburg Substago (Zono VS 5), tho boroholos woro soloctod in such a way that tho CDQploto succession of tho Elsburg Stage is r-o pr-oscnt cd in the c orc. Undurground obsorvations and mca aur-omcnt a havo boon carried out on both mines whore conglomorates of tho Elsburg stage aro exposod. Tho surfaco boroholcs and undorgTound localities are indicated in Fig. 4. B PGBBLE LI'rHCLCGY 1. Doscription A wide r-ange of pcbbLc t.Y1lCSconstitutus tho pebb'Lo assemblage of the conglom0ratos, which can be divid0d in durablo and non-durablo typos. Th0S8 az-o : i Whito milky quartz ( Smoky quartz ( Durable typos ( Massive black chert ( ( Barïd cd ch cr-t ( ( R~d Jaspor ( Yc;llow silicified shalo ( ( Slate (blue, groy, olivo groon and purplo) Non-durablo typos ( ( Quartzi to (grey and light groen) ( ( Quartz porphyry (a) Durablo Types (i) Pobbles of Quartz 'TI1C pobblos of quartz pr0sent in tho layors of conglomerato consist mainly of tho following typos,- MH 4 MH o TR 5 o 2 MH 3 o o TR 1 o EF 2 FH o o 2 N~Shaft TRo 2 FIG. 4 WELKOM AND WESTERN HOLDINGS No.2 Shaft GOLD MINES @ BO 1 Plan showing the main shafts and surface boreholes on which obser- vations were taken. DG 1 o SCALE: 40000. No4Shaft. ® MTK 3 ENK o AL 4o 8 3> NORTH MBo 8 No; I Sha.ft AR 1o Wo5 MB 4 @ tl No 2Shaft 0 ® MB 3 M~ 2 MS 1 DH 1 o Wo3 WOl Uo2 - 25 - (1) Milky whito pobblos arc the most abundant. ('2) CIGar transparent glassy pcbb.Lee , (3) Smoky quar t z - th0SG pob bLos arc z-ar-o , The pob oLcs of quartz whi ch have boon intersooted in tho boreholes on 'welkom Gold };lin8 and the contral portion o:f Westorn Holdings Limit0d, ar8 mainly of the clear transparGnt variety, whilo pcbblus of milky quartz arc the most abundant nOar tho westorn and north-v;rcstcrn boundary of vkstQrn Holdings Limi t od . A dofinito increase in tho milky typo towards tho margin of tho basin is noticoablo~ Fubbles of tho milky type arc froquJntly fracturGd. Fracturing in tHO or thr00 directions is qui t c common? whi I.o intonse fracturing on tho s causes that t.hcsc pebbles havo a pseudo-quartzito appcaranc(.:o 7ho fractures arc somctimGs filled wi th rod iron oxide wh i ch might havo cn t crcd the cracks during tho woathering of tho source rock~ If tho fractures arc very woll d ovc Lopcd towards thC) ccn t r-c of t.ho pcbb Lo , a pinkish tinge is ObSDrvcd~ These have; prc.::viouslyb00n dGscribod aS pGbblos of ros(;-quartz~ 'I',h fracturing has aLs o b.cGU observed by steyn (1963, p. 14) in pcb bLc s of quartz pr080nt in t.h. Livingstone Roefs on tho West Rand~ Ho found that tho fracturing is only limitod to certain zones on tho pobblQ surfacos I'GvGaling a homogoneous intorioro (ii) Pobblos of Ch~rt Tho following var-Lct i.os ar o presont :: (1) V,;ry Hell r-oundcd , oval-shaped, massivo black chort , (2) Rounded to subroundod yc Ll ow=gr-cy cho r-t, (3) Badly rounded bandod chort which occurs as pobblos "i th rectangular to triangular sh apo s , - 26 - (4) Apart from tho common types, other varietios such as olivo groen and purple coloured pcobblos of chert are presont in tho conglomoratos, though in small quan- titics. From thG logging dono by previous gcologists of soveral borGhalo coro, tho author noticed that tho torm "maroon chorts" was quito ofton used tc describc tho purplo coloured pobblos of slat~ which occur noar tho margin of tho basin. Charactoristic rod pobbles of jasper aro alse deoscribod as "maroon chorts". Tho author wishos to omphasizo that this torm has no congeniality with chert nor jasper, but rofers to purple coloured slatos. (iii) Pobbles of Jaspor PGbblos of rod jaspor occur vGry seldom in tho layers of cong.l omera.t o , but an Lntcr-catLng f",aturc is tho occurrenco of the so pobbLoa in dofini t o zoncs , TYllical cxaupl cs of theso zones ara found in tho 33 Hau.l a.gcEast at No. 2 Shaft on Vïostorn Holdings Limi tod (PI. IV). Tho pebbles aro very poorly round ad with rectangular and triangular shEcpcs. (b) Non-durable Typos (i) Pebbles of Quartzito Pobbles of this typ" occur quite froquontly in tho layors of conglomera to. 'I'h r-c o t ypc s arc pr-o son t g- (1) A light gr0~n, ovon=gr-ai.ncdquartzito with a sugary texture.. This is the most common type. (2) A whitish grey, somowhat bleachod, fino-grained quartzito. (3) Dark groy, coarso-grainod pobbles of quartzito with a mottlod appearance and sago toxture do occur often. The first two typos arc oasily rocognisable amongst the dark grey matrix of tho conglomorato, whoroas tho pobbles of quartzite with a dark gray colour can only bo distinguished - 27 - with difficulty. (ii) Pebbles of Slato Pobblos of this typo occur vory seldom in the layers of oonglomerato whioh havo boon intersected in boreholos drilled on tho loaso aroa of tho Wolkom Gold Mining Company, but a definite incroaso in abundance towards the margin of tho basin is observed. Tho pobblus arc usually woII roundud with oval shapes and aro ofton elongated. Tho colour of th0 slato varies from shades of bluo to olivo groon. Pobbles of purplo slato aro afton found, but thoy incroaso in numbor towards the margin of tho basin. Tho pebblos of purplo slato also show tho tondoncy to occur in soparate zones. (iii) Pebbles of Yellow Silicified Shalo Tho pobblos of shalo oro tho most common type amongs tho non-durablo pobbles. They oro always present in the layers of conglomerate and vary in quanti ty from moderato to abundant. 'rho pebblos havo angular to subroundod odgos and irrogular or flattenod shapos. PettiJohn (1957, p. 193) postulates that pobbles of shale are deposited as soft clay galls and diagonetic rosponse dotermines tho flattenod shapo of theso particles. (iv) Pobbles of Quartz Porphyry This typo is a rara constituent and occurs usually as woll rounded pcb'nLc s, (v) Other Pebble TypGS Pobbles of granito and of somo greenish grey igneous rock wore occasionally obsorvcd~ 2. Ratios Tho rolative amount of tho various pebblo types was determined by counting tho nuraber- of each type present in tho borehole coros. Comparing tho difforent boreholes it is significant that there is a definite decroase in tho non- durable types towards tho cast (Fig. 5). This might be tho rosuIt of tho more rapid abrasion of tho loast rosistant particles in the down-current diroction. FREQUENCY - Milk Qua r t z ::: 100 o o .- o. \ , \ lOl \ , \ \ I~ \\ \ \\ \ \~ \ \ zr I~ \//, o b I oOJ.., ct> I ozr / (D tJ'I I / Cf) -4rn :!: I o ITl g OJ I j o 0Z :::t lO o-- o\ 0 »/ »CD z0 -0 / Cf) m o \.., \ m/ \ oz \/ 0-0z mI C/) CD /\ I \ C~r- CD\I / ." mo\ l> o»cj ó r- \ " ;0 ~-i t§'rJio. .' :::0 CD ::x: \ I » 00I lO' ;0 ;::ur-.~~,/ m 0~ :r:e;') I~/~,I /'V'V'v o~ r- £ I ~ (mf»)r-/~ / c o ,'" I r- '-z I --f :;:oe;') )lo z -i Om \ c »Cf) I \ N -fI / \ ~ \ m / \ Cf) -f / , \o o - - - gc - - 29 - c. PEBBLE-SIZE DISTRIBUTIon I. Size Variation One of tho most reliable and easily measured indices of palaeocurrent and disporsal in sGdimontary rocks is the scalar property of pobble size. Sovoral studios have buon dono on tho pobble-size variation in conglomerates with special reforence to the relation betwoen pobble sizes and gold distribution (Stay~, 1963; Knowles, 1966; Hodgson, 1967 and Sims, 1969). Thoso authors made usa of the maximum pobble sizes and all camo to tho conclusion that tho sizos diminishos in a down-ourrent diroction. A similar study was carriod out by tho author on tho pebblo-sizo variation in tho conglomoratos of tho Elsburg Stage as obsorvod within tho boundarios of Hostern Holdings Limited and Welkom Gold Mine. Tho object of this investigation was to detormino, (1) TIle possiblo inwash direction of tho sodiments. (2) The compotency of tho stroams during the doposition of tho conglomorates. (3) The approximate distance along which tho pebblos wore transportod. (a) Mothad Applied Tho study of tho pobblo-size variation is based on the moasuremont of pobblo sizos on tho coro of surface boroholos, because very little of tho layors of conglomerate is oxposed during underground mining operations. It is, howevor, impossiblo to measure tho sizo of overy pebble oxposod on those borehalo caras - a sampling problem common in geology. In boreholas drillod on tho loaso aroa of the Welkom Gold Mining Company, tho author has chosen a sample of about 30 cm within ovory 2 m of coro. Tho sizos of all tho pobbles which wore oxposed in the sample, wero determined. TIlomean - 30 - pcbb Lo size in tho layors of conglomorate vli thin tho Lea so aroa of tho Welkom Gold Mino is relatively snaIl and in ovary sample betweon 70 and 100 pebbles ','-'1'0 exposed. 'These samples could thus bo considored as ruprosontativo of tho intorval not moasurod. With an incroase in pebble sizo t owa r-d s tho margin of tho bas i n , a total of 1 ID within overy 5 m of core was mDasurcd" 'Thismethod of dotermining tho sizo of pobblos diffors ontiroly from the morc oonvuntional techniquos in which at least tho longest axis is diroctly mc.aaur-c,d No measurements couLd bo done on eithor of the throe apparent axes of tho pobbles found in tho borchoLc coro, thoroforo tho .~9.!:'a_raoroa of oach pcbbLe was detorminod directly on tho surface of tho borehole coro. 'The following tochnique was applied in the detormination ef tho squaro arOa of tho pebblos, A grid of 5 mm x 5 mm was ongravcd in a small shoot of transparont porspox, thus obtaining a grid pattern, each square representing 25 mm2• Every four of these littlo squares wore thon combined to give a grid pattorn of 10 mm x 10 mm - thus 100 mm2 • This shoot of porspex was then curved by means of a hot iron rod which had the same circumference as the borehole core. By sliding the curved perspex ovor tho borohoLo coro, a direct reading of tho square aroa of oach pcbblo could bo dono (Fig. 6, 1'1. V). The author is woII awaro of tho moan orror caused by tho roundod surface of tho borohole coro, but this error romains censtant throughout the measuring of all tho pebbles, and may therofore bo noglected. (In tho case of only one borohole, M'TK 3, tho author had te construct 2 curved perspex with a larger circumferenco be causo this hol") was drillod with an NX crown. In the caso of borehole MB 2, the corG was splittod, so pebble areas woro moasured with a flat piece of grid perspex.) ana disadvantago in this mothod of tho dotormination of pebble area is, howovor, whon tho sizo of tho pobblos oxcoods tho diamotor of tho bor-choLc.coro (1'1. VI). To ovorcome this - 31 - . lOre takon. A scattergram of the c-axis vorsus the pobble aroa is then cone t r'uct cd for each pcbb.l.c typc , A straight lino (regrossion lino) can then bo fitted onto t.hosc diagrams (Fig. 7, 8, 9, 10, 11 and 12). (b) Dctcrminatiorl of thG liogrcssion Linos Irho regression line for cv;_;.ryspecific type of pcbbLo can bo dct cr'nunod oi tller Glatll.cmatically or by means of a computer. By using any one of these two mct.hods , tho regrossion lino for ostimating tho pobble area for a cortain longth of tho c--ax.is of each pobblo, is thon calculated and plottod on tho scattorgram. Tho pobblo aroa can thus bo read off from the graph for a givon length of tho c=axi a, Tho X cc-ordinato r-epr-oscn t e tho length of tho c-axis, while the squaro aroa of tho pebblo is roprosontod by tho Y co-ordinato. Pebble i : ! ' i : ! : : : i I o ! i c» i~+-l~~+-~J~: l~'~+-~~ ::0 I I i f --t N C( »_x. Ul 3 3 -,'--hH-+'-hii!---i 1'-+'-hiH'--"-i+';+' ...,'[_'+-t--hi-:_jl,_l'-+'-jr~l r-,,~_t1-_-Jlj'' ,-,-J:-', ,"':.'"-,1- _l!"__~'1~.,L-f,-' , r -i'--+'--+++-hH_"-++-+-+-+-hH--+-++++-+--Hc---+-+-++-+--HH-+++-t-+-t-HI--t-+-r--r-~--'---'---'--':tt::ttI I:' I .I j__j__j_L , I:' ", " i I , ',' -+-+1 ~'---;--I-l,-r- r~r~,T'~r~~"I~';-':-~':,'~'l,'~':,--!--r--.;--.-;", -1 --;-'-;-'..,--,-t----t-+-+--'--'-H--r--t-+-LH-+,-'--+-l,;--t---tt---i!-,~--tt,r-H'-'i--_,_~'_"-",-+- 1 , Li--'Il~iJ!"+' ,- r 1 • , ,-+------jH--'--+-+-+--H-t-+-+-ri-t-t-+-+-t--- ; '-t----h-t--'-++,-+, --ri'--'-t, -',,-+,-r", 'il-t,-t" -~TI -,!---t,i--t-,,1.,,- I I 'T'~-'--r-r--: "--r--t--t, _j__J__ , ~.-;- -c--;- , -~'-~,,""~ +, -i,f--r+--'---+--rl -i;-+-i;-,-++'-t-'-i'-+++'--H-i--'-+-h--'--+-H--I-_;_-'---t-+--"-H__,_---+-+..L.ri,--+--I---'-'il-;-' -iiHl---;--+-i---H-'~ 1 l i", '! j : , , i i---r-t-i --i I :+~-~--+--'--H-- Pebble Area (sq. mm) ~ c.,_, c.,_,.v., .c::, .c_,.., (J c::, (J C) c::, c::, (J c:::, (J , , , 1 jl! , i 1 I I I , i I i I " I: I o, J_LlI_J!~ I-T,-~rlL-+'-, ++-+'-+1-+-+! --I1--->-+-+ -J+! I H!--+' -+i, +-iH--+-~+-~l~- ~-I--+-'--+-+-l-H I' ",' , 1 (') I , ! I I i I ~ , \~-+'-+--+-+-+-+--f--I!'--+'-t~-r++-+-->-+--+-! (/) ~C-1-t-+-+-+-T' -+-IIH-t--r-t-' ""I-tl-t' -+-..,'_+I'--j, 1 : I ! i 1 1 ' i , i • Cl I x» -(/)3 3 I I I I I I ! I , ,i I ' ' +-'--f--'---"--'--'--...L...J......J--I.....J....-"---'--l.......;......_._~--'-'--_L..J.--L...L~......l...J.....l.-LL i I I Pebble Area , " tt ---4-. J-+- -++ c-..::,\ i : I !i+ ==l=r () I --'-1- 1--;- _L.L x» (/)~ 3 3 <, ii -t- • -c;=1 ~,-' ~ ~~ ---'---+- - 39 - (i) Mathematical Method The regression line is given as an equation in the form: y = y + b (x - i) where y = area of the pebble xc-axis y mean pebble area N = amount of pebbles x = cfx = mean c-axisN b _ dx.Y. - Ni~ dx2 - Nx-2 (ii) Determination by means of a computer, A detailed write-up of the program used by a computer in the calculation of the regression line is given in the Addendum. The results are summarised below; DETERMINATION OF THE REGRESSION LINE FOR PEBBLES OF QUARTZ (FIG. 7). Regression line to estimate Y for a given value of X Y = -4712.59 + l83.26X Regression line to estimate X for a given value of Y x = 40.57 + O.OOY Correlation ooefficient = 0.854 DETERMINATION OF mE P.EGRESSION LIlJE FOR PEBBLES OF QUARTZITE (FIG, 8). 1. For pebbles with c-axis from 30 - 140 mm. Regression line to estimate Y for a given value of X Y -9934.47 + 255·37X Regression line to estimate X for a given value of Y X = 45.45 + O.OOY Correlation coefficient 2. For pebbles with c-axis from 140 - 240 mm. Regression line to estimate Y for a given value of X Y = -30208.08 + 422.16X Regression line to estimate X for a given value of Y X = 7.94 + 0.002Y Correlation coefficient = 0.968 - 40 - DETERMINATION OF THE IgD2_IlESSI0L1UrTE FO_!iP_EBBLES OF CHERI' (FIG. 2). Regression line te ostimate Y for a given valuo of X Y = -4851.09 + 194.36X Regrossion line to estimato X for ccgivon valuo of Y x = 40.15 + O.OOY Correlation coofficient 0.803 DETEHMIlUTION OF THE REGRESSIOn LIlTE FOli PEEBLES OF SHALE (FIG. 1_01. Hogrcssion line to estimate Y for ccgivon value of X Y -3586.03 + 165.35X Rogression linG to ostimate X for a givon value of Y X = 28.50 + O.OlY Correlation coofficient 0·917 Regression lino to estimato Y for a givon valuo of X Y -8080.95 + 235.02X Rogression lino to estimato X fo~ a given value of Y X = 37.93 + 0 OOY Correlation cocfficiunt = 0.960 DE'fERMINATION OF THE REGRESSION LIITE FOR PbllBLES OF PORPHYRY U:_I_G_~J_2J. Regrossion line to estimato Y for a given value of X Y -6495.22 + 224.l4X Regression lino to estimate X for a given value of Y X = 39.88 + OO.OOY Corrolation coofficiont = 0.904 (c) Mean Size and Its Significance To detormine tho moan pebblo size for each borohole, tho data aro calculated by moaus of a computer, which gave values for various pebblo-size paramoters and printed a report for each sample submitted. Two sots of parametors arc calculated, using the formulae of Inman (1952) and Folk and Ward (Folk, 1966, p. 81). - 41 - Those formulae are somewhat modified from their usual form, in that the size in square millimetrus is used instoad of phi sizos. Tho method of momont moasuros is usod to calculate tho moan size and mean deviation. A detailed writo-up of tho program used by tho computor is given in tho Addondum.. The formulae usod arog Inman: Moan sizo _(!l1l1l16 _+ M:M84) 2 Folk and Hard: Mean sizo whero o.g~ 11lM16= avorage mm 2 at a cumulative percentage of 16. Mothod of momcrrts e Moan According to Krumboin and Sloss (1963, p. 101), tho analysis of tho grain size of a sediment can give some idea of tho conditions undor which clastic sediments wero deposited. Mean size is proportional to the compc t oncy of the cur-r-entthat transported tho material to tho site of deposition. Tho layers of conglomerate in tho Elsburg Stago differ strikingly from one anothor regarding their moan pebble sizo. This featuro is most prominent in tho congl omcr-atos noar the maz-gá.n of tho basin. It has boon found that in tho boroholes drilled on tho loaso aroa of Hostom Holdings L'im i.tad, tho different layers of conglomerate consist of altomating horizons of big eobbles and small pebbles. Tables III and IV illustrato tho variation in mean pebble-size in the different layers of eonglomerate. Table III represents the rosults obtained from surfaee berehola ~m5, while Table IV illustrates the differences in mean pebble size as observed at Western Heldings No. 2 Shaft on tho 33 Haulage East. Observations in this haulage have boon done at intorvals of - 42 - approximatoly 75 to 150 TIl in an eastorly direction. A.'1 aver-age of approximatoly 120 pebblos woro moasured at -.lachstation. From the results in Tablos III and IV it can bo rocognised that a large variation in moan pobble size oxists. In tho Wolkom Mining Area, hewover, almost no difference in moan pobblo sizos oould be obser-ved in tho difforont layors of cOl:lslom,_;rato. TABLEIII, - f~lO difforonce in moan pebble. size in tho layers of' conglcmorate int0rs,Jctcd in boreholo MH 5. 1. 377.6 - 339.5 340.6 2. 38').5 413.3 718.0 3, 413.3 - 436.2 983·7 4· 438.9 - 444.4 1 709.4 5· 444.4 - 505·9 5 166·7 6. 505··9 - 560 il 2 871.6 7· 560.8 - 538.9 6 402.4 8. 538·9 - 603.5 605.2 9· 603·5 622·7 375·3 10. 626.1 - 651.0 874.1 IL 651.0 660.5 3 324·5 12. 662.6 748.9 898.0 13. 762.3 801.3 365.5 TABLEIV. - Tho difforoncos in mean pobblo s i ze at sevoral undorground locali tics on \fcstcrn Holdings No. 2 Shaft, 33 Haulage Bact. ----------- --- --~ Distanco to Mean pobbLc! Number- of Distanc0 to :provious station sizo , Station llJarcst peg (m 1 (mm2: '---, 1 A4676 + 22 m 3 418 2 A3999 7 m 175 4 234 3 A3574 + 5 m 166 9 063 4 A3149 + 24 m 170 2 153 5 A2603 + 9 m 128 987 6 F9117 + 3 m 110 738 7 F9778 + 21 m 77 1 843 8 H 379 + 6 m 119 12 076 9 H 744 3 m 170 1 416 - 43 - (d) Conclusions (1) Tho moan pebblo sizos in tho layers of conglomerato vary slightly from borehalo to borehole, but a gonoral decreaso in tho mean size can bo obao rvod in mai.n.Ly tv-IO di.r-cct i.ona .. ~'TQstof the Arrarat Fault ,1 dc.f ini to decreaso in a south-oastorly direction is evident, while in tho aroa cast of tho Arrarat FauLt s tho pcbbLc s i zcs show a d:_)croaso in a north- oastorly direction. rue disporsal patt0rn for tho conglomerates (Plan 3) indicates that a sudden chango in tho direction in which tho mean pcbb'lo size decroases, takes place along tho strike of tho Arrarat Fault. It is thus obvious that this fault must have an onormous structural influence after the deposition of the sedimentary layers of tho Elsburg Stage. Fig. 13 illustratos tho suggested transport directions of tho sediments during tho dopesi tien of'tho Elsburg Stage. ThG sediments are deposited on a dol taic fan sproading from Inst to oast. rue areas surrounded by detted lines represent tho lease aroas of tho differont mining proportios as they arc visu?~isod boforo tho Arrarat Fault. ruo result is that Westom Holdings Limitod was situated on tho south-wcstorn flank of the dolt a fan whilst the area, reprosenting the ,,[celkeGronld !!]ino,lay on tho north- oastern flank of the fan. Shearing stross then eaused tho down throw along tho Arrarat Fault with a vortical displaoement of 1 200 to 2 100 m to tho wost. Simultaneously, latoral displacoment took place a'long the fault-plano with the wostorn blook moving towards tho north and tho eastom one towards tho south (Fig. 13). A lateral displacement of approximately 6 000 m in a direotion north-south oould therefore bo postulated on th~ Arrarat Fault. Sims (1969) obsorvod a similar displaoement on tho Brand Fault which tronds in tho same direction as the Fault and coincides with the latter :neár tho - 44 - ~ J.4 ): oM 0 Q) .t:: . 0 J.4 » of.) ..c: IJ) "C 0 oM .0 r-i of.) of.) of.) Q) ;:$ ~ Q) Q) Q) ..c: H bOof.) IÓ Q) ..c: Q) ~ of.) ..c: J.4of.) ~ rx.. IJ) of.) r-i IÓ Il) oM J.4 of.) Q) Q) IJ) oM eo ~ 0 Q) Q) "C E of.)eo J.4 IÓ Q) ..c: IJ) . ~ oMPt ..c: ..c: ~ Q) IÓ PI J.4 ): ~ oM ~IJ) of.) ~ of.) IÓ 0 s::; J.4 Q) 0) "C ..-i IÓ IÓ r... 0 0 IÓ 'H ~ oM » r-i "C IÓ 'H Ê 'H Q) r-i r... Q) Q) of.) of.)eo IÓ 0 r-ir... 0 0 PI of.) "C IÓ 0) !i! IJ) r... ,D r-i OM r-iQ)~ ~ IÓ ;:$ IJ) r... r:r: 0 C!} 0) of.) oM ~ "C IÓ 0 Q) ~ "C IJ) 0 Cl) re r... OM Q) Q) rx.. Pt ::- r... 8 Q) of.) Q) of.) O0M of.) OM Q) r-i Il) 0 0~ oOfM.) bO r-i of.) IÓ III of.) of.) of.) ~ .Il::IJ) of.) Q) r... CS IÓ "C Q) r-i IÓ Q) IJ) r-i Q) 0 OEM CO ;:$ r... r-i Q) r-i ;:5 r... Q) ..c: Q) Q) bC Q) 0 ,D Q) of.) of.) IÓ IJ) of.) :?:: ;3: b( r... "C p.. (I) of.) .Q.c): of.) Q) IJ) r... Q) ;:$ oM Q) Q) r-i IÓ 0 .t:: 0 r... r... J:l Cl) "C CO re J::il r-i of.) Cl of.) Pt « Pt 0 r-i C\J t<'\ r-i \ \ - 45 - southern boundary of th0 Wolkom Mine. The lateral displace- ment, howovor, was loss than that along tho J..rraratFault, but thD novcrncrrt was s imiLa r-, In a doscri.p't i.on of tho pe.Laoocur-r-en t analysis of'tho Elsburg Stage on President steyn lilino,Sims (1969, p , 140) statod that "tho direction of sedimont transport during tho Elsburg StcigO was os eon t i a.lLy from west to cast" 0 From Fig~ 13 it is obvious that the President Stoyn Gold I.·.1inc must havo boen si 't ua t c.d in tho middle; of' the dol ta f'an whc z-c tho palaeocurrent directions wore essentially from west to east • .Although this research ,TaS f'ocussed on tho sedimentolo- gical aspects of thc layers of conglomerate in tho Elsburg Stage, the author is of tho opinion that, by using tho prosent results, more light might probably bo thrown on the palaeocurrent diroetions of tho Basal Roof en the Wolkom and Wostern Holdings Gold Mines. In a palaeocurront study of'tho Basal Roef' on President Steyn Mine, Sims (1969) described transport of tho sediments from south to north. A sedimentological project carried out by the Geological Department of the University of the Orange Free state on the Welkom, Free State Geduld, liestem Holdings, Presidont Brand and Pr-osLdorrt Steyn Gold !Hnos during 1966 to 1967, indicated the following palaoocurrent diroctions in tho Basal Roef: Free Stato Goduld MinGS Ltd. ,- From WGst to east. Western Holdings Ltd. ,- From north-west to south-aast. President Brand G.M. Co. Ltd.;- From south to north. President Steyn G.M. Co. Ltd. ,- From south to north. -I!c,lkoGmold Mining Co. Ltd. ,- In the south-eastern portion thO direction was from tho south, but the western and north- western part showed transport from wast to east. From the above measlremonts the major part of the Basal - 46 - Roof shows an idontical pala"ocurrent direction to that of tho Elsburg Stage. Fig. 13 CUl thus bo dividod into two zonos: tho one, south of lino RH\ can bo described as a "gold-rich zone" with a highly payab Lo Basal Reof J while tho zone north of this lino yiolds low gold val ucs, It is then obvious that Froddios Consolidatod Mines Qnd tho eastern portion of tho W~lkom Gold MinG must havo been situatod in the zono of low gold values, whilo tho rest of the minos arc situatod in tho highly payab Io zono. On t.h. ,iclkom Gold Mino lateral displaoo- ment aleng tho Arrarat Fault wou.Id. t.ho r-ef'oz-pcrobably oxplain tho area of low gold vaLuo s (110. 1 and 2 Shafts) adjacent to tho richer area on which tho No.3 Shelft is situatod. (2) From tho pubble-sizo distribution altornating zones of high and low stroam velocities Cru1 bo rocognised. Those zones arc very woII dofinod naar tho margin of tho basin~ but become less obvious oac tward and nor-thor.etwa.rd as tho pebbles docroaso in size toward.s tho centro of tho basin. (3) Analysis of the pcbb Lo ai zcs shews that tho varieus pcbb Lo typos in tho layors of conglomerate havo different moan diamoters (Tablo V). TABLE V. - Tho moan diam0tors of tho difforent types of pobblos at randomly seloctod stations. ---------_._-- ·---"'2----- -------; ! Numbor Muan pobtle size in mm ; __ J. of 'Milky 'Opa.Lo scon t ' , Station , quartz, quartz . Chert, Slate , 1 Shalo iI Qua.:rt.'ztJo.!Porphyry; f I ! ~ i --"'---- -r+ ____, ,W.H.No.l Shaft ,960.8 724.6 921·3 783.7 ' 421.3', 1274.6, 'iT.H.No.2 , Shaft 981.2 :2482.0 613.2 ; I , 9727.° 2117·3 , W.H.No-3 , Shaft :8214.6 879.0! I , 28303.8 6453.7, W.H.Ne·4 Shaft 423.0 571.0 738.2 ' 211.8 304.71 827.1 , 423.7 '387.4 241.4 283.1 i 473.9 __...:. -'I-' '-__._. ,_.l. Tho 25 largest pobbles of each type have boon measured at oach station. Comparing tho mOan pebble sizos of the different - 47 - typos (Tablo V) tho following doduotions can bo mado, Ncar tho margin of tho basin tho pobblos of chort, slato and shalc aro always much smallur than tho so of milky and opaleseont quartz, quartzite and porphyry (PI. IX and x), Tho pobbles of quartzito nrc very large in comparison to tho othor pobblc typos, whilo thos," of chort and milky quartz havo approximatoly tho same size. According to Snood and Folk (1958, p. 126) pobbles of milky quartz and chert appear to abrado at equal rates and will thoroforo romain in tho sarno sizo ratio during transpor- tation. Thus, in tho layGrs of conglomerato of tho Elsburg Stage, these two typos must havo covored the same distance during transportation. Pottijohn (1957, p. 554) found that pobblos of quartzite abrade four times f'astor than that of quartz and chert. Tho fact that tho pebblos of quartzito aro very large in comparison to thoso of qëk~rtz and chert indicates that their source area was much closor to tho basin than that of either quartz or chert. Borehors (1950, jO. 116) doscribod considerablo erosion of tho Lowor Division of tho lhtwatcrsrand System during the deposition of tho Upper Division due to a retreating shoro-lino. Accoruing to tho hypothesis of Borohors, fragmonts of quartzite wore woath;:;rod from tho expo sod formations (Lower Division) and wero thus subjoctod to a second cyclo of doposition wi thout long distance 't z-ans por-ta't i.cn, Tho author dOGS not wish to elaborate on tho rato of abrasion of pobblos in this rosoarch, but it can, howovor, bo said that tho abrasion appoars to become loss towards tho centro of tho basin, >lhoro tho difforent pobble typos have almost tho same moan sizo ('rablo V, Of. O.lil. No. 3 Shaft). 2. Sorting Tho sorting of a sodimont can bo of great importance when problems rogarding tho transportation and distribution of - 48 - tho particles have to bo solved. Pottijohn (1957, p. 36) dofined tho torm "sorting" as the spread of the particlo sizos of a sediment. Analysis of the sorting of particlo sizos may possibly indicato tho transporting agont of tho particlo. Uddcn , in his pionc0ring work on acd ámcrrta , mado uso of tho ratio bet'lioen succossivo cl2,sSUS on a n.is t ogr-am, as wall as tho total sp~Dad of tho histogram as a measur-e cf sorting (Folk:! 1966, p. 82). Trn.sk in 1930 suggcst0d a measuro, which he; dofinod as tho sorting coefficiont 9 and this r-omaincd tho most widoly usod pa.r-amot cz- for sorting of sediments until r,Jcont yoars. In 1932 ho defined tho sorting coefficient (So) as tho square root of tho ratio of tho larger quar-t iLc (tho 25 por cent va I uc - ~) to tho smaller qur.r-t iLc (tho 75 por cent va.Luc - Cl,3 ) (r:Jttijohn, 1957, n- 57). 'I'hcr-cf'o r-os So = JQ;7Q~ If tho values for thuso tva quartiles ara nearly equal, the sorting cooff'iciont approaches 1. As this formula covsr-s only 50 per cent of a cumulativ0 curve, it has a low officioncy and should theroforo bo used only in thD caso of woII sortod sediments. Griffi tho dovcLopcd 2.... nore cornpr-chcnaa.vc moasur-c, tho percontilo doviation (PD¢), covering the, central Do por cent of the sizo distribut:Lon (Folk, 1966, p. 82). Inman (1952) proposed a phi analogue to Trcsk's sorting coefficient (D¢ = ¢84 - ¢16) 2 which is baing a closor approach te tho purcentile deviation in natural sodiments of tho oV0rall p1'osence of'poorly-sorted tail fractions. Folk and Ward (Folk, 1966, p. 83) found theso measures inadequate for bimodal or skewod dlstributiens and developed tho mGasure of "Inclusive Graphic Standard Deviation". ê= Another method to calculate the sorting of asodiment is that of standard deviation. - 49 - standard deviation S where n = the number of observations xy the individual azimuths x the mean value of all the observations. Due to the many calculations involved in this method, it is thought to be impractical when the sorting of a large number of samples have to be determined. The sorting of the pebbles in the conglomerates of the Elsburg Stage was calculated by means of a computer and the formulae of Inman and that of Folk and Ward were used. As the program written for the computer was based on measurements in mm2, the calculation f'o r- sorting, skewness and kurtosis were all done by the computer on this basis. In Fig. 14 a graph for the conversion of these calculations to values for sorting as defined by Inman and Folk and Ward is given. The sorting values vary from about 1.10 to 0.55, but their distribution is strongly influenced by the Arrarat Fault. The average values to the west of the Arrarat Fault show a considerable decrease in the direction of transport (south-east) whioh is in accordance with the results obtained by the pebble-size distribution. The sorting is moderately poor (So = 0.8 :) which could possibly be representative of a transition between a fluvial and a beach environment. To the east of the Arrarat Fault the layers of conglomerate are better sorted (So = 0.6 :) ~ld probably indicate a beach environment. The sorting values also show a tendency to decrease in a north-eastern direction, indicating an increase in sorting down-stream. 3. Skewness and Kurtosis The formulae for the calculation of skewness and kurtosis were part of the program written for the computer and the values were thus calculated on the basis of square millimetres. These values were, however, not used because an interpretation for skewness and kurtosis based on them was considered not reliable. - 50 - Sorting. oo ru ru o oo ru 0 0 CD rl 0 eo 0 c ';.;~ Or-i 0 0 0 CD "0'M""'0 ~ Q(\j OU'\ Ua-, 0 0 W .".d'~ rl +' rates of the ié;lsburgStagG ar-c expo sod in und.cz-gr-oundevolopmont on \{olkom Gold lhno, is at No. '2Shaft, but this spocific Loca.Latiy is inaooossiblo.) Stations woro soloct"d .,horo pobblos aro expo sod in at loast one horizontal a~d two vortioal pla~os, thus viewing the pobblos from tho bottom (oxposuros on tho hanging._wall) as wall as from two sides almost at right anglos to ono another. Cubby broakaways and substation ofton satisfy theso oondi tions. The reason being that tho author would always bo ascertainod 124622 - 52 - of tha position of each of the three axes of the pebbles, as illustrated in Fig. 15. e CDeO og o CDe o D A. Exposure on hanga.ng-wa.Ll.(viewed from bottom) o B, Exposur-e on sidm .a.ll (sidevie:;approximately parallel todiroction of transport) D C. Exposure in cubbies, etc.(sidoview approx. at rightangles to direction of transport) Fig. 15. - Block diagram illustrating the positions of tha three axes of pebbles viewed from different ro1g1es. Fifty rod-shaped pebbles (bottom view) were salected at each of the localities. Th-.-.;;..----- 20- 15- 1.5 - 0- MEAN-NI4Z" MEAN- NI.J':" WESTERN HOLDINGS N-D4 SIIAFT 25- 2/)- 15- 15_ 0- ~ ---1.U.I.L1,J,U.:W11WJ..... A~ MEAN-NI40" MEAN-N/S7" WELKOM MINE M.lSfiAFT 25- 20- 15- ).... ~ /1}- ~ ~ ~ 5- 0- MEAN-NI27~ Fig. 16. - Histograms illustrating the ,orientation of long axes of the pebbles. - 55 - The pebblos in the conglomerates of the Elsburg Stage arc closely p~ckod with almost no matrix. This might be the reason for tho small amount of pebbles ori0ntatod perpendicular to the palaoocurrcnt diroction. 3. Pebble Clusters In a horizontal plano structures of the typo shown in Fig. 17 arc commonly found at localities where thoro arc little sorting in coarse, fluvial deposits. In these structures, cobbles or boulders on the one side givo rise to a wake or tail of coarse clements, concentratod and leaning against each other. This kind of structure resoubles a wedge or a bunch of grapes, and is there- fore termod "pebble cluster" (Dal ein, 1968, p. 233 - 241). A B ~ ~ ~ ~ G/:::/lA. .- Fig. 17. - Illustrations of pobble clusters in a horizontal plane. A. Tho wake formed by many pabbles. B. The wako consisting of only two or three elements. The arrows indicate tho direction of tho current. Large cobblos or boulders protruding from the surfaco of the river bod, hinder tho movement of smaller sized partielos, which pilo up in front of them, forming a kind of wa~e. Not all pebbles arc stopped by theso cobbles a~d boulders, as the smallor ones moved in suspension and easily by-passed the obstruction. In general, tho length is directly proportional to the height of the boulder in respect to the plane of deposition. - 56 - Viewed in cross-section, pebble clusters most commonly appear as drawn in Fig. 18. The indication of the current direction as deduced from sectional views of these structures is less reliable because the orientation of the section relative to the pebble cluster is urualOwn. Therefore only exposures of pebble clusters in a horizontal plane (hanging-wall views) were measured. (Pl. XII). o " , .. e Fig. 18. - Section through a pebble cluster. Measurements taken on 34 clearly defined structures of this type, show that the direction of the wake of coarse material, as represented by the axis which bisects the wake, is almost parallel with the palaeocurrent direction (Fig. 19). The greatest angle between the direction of the wake and that of the depositing current, in no place exceeds 350• The greatest divergence occurred mainly in the less evident structures. The presence of pebble clusters in layers of conglomerate offers evidence of unidirectional transport. In environments such as beaches, oharacterised by the baok-and-forth movement of waves, structures of this kind are 1L~likely to last. The presence of pebble clusters in the conglomerates of the Elsburg Stage probably points to deposition in a fluvial environment. - 57 It. O' ... "•.. Fig. 19,- Rose diagram showing the orientation of .... pebble clusters. - 58 - E" PEBBLE SHAPE The shape of a sedimentary particle is its geometric form and is generally described by certain parameters, viz. sphericity and roundness. Spherioity defines the general shape of the particle, while roundness describes the sharpness of tho odges and corners of a clastic fragment. Quantitative descriptions of the shape of a sedimentary particle appear to havo first been given by Wentworth in 1922 (Krumbein and Pettijohn, 1938). Eo used two parameters for this purpose, viz. a roundness ratio and a flatness ratio. Wadell differentiatod bet110en shape and r-oundrise. 1933 (Krumbein and Pettijohn, 1938). Shape was described by him in terms of sphericity.. He defined true sphericity as "the ratio of the surface area of a sphero of the sarnovolume as the particle to the actual surface area of the particle" (Krumbein and Pettijohn, 1938, p. 283 - 284). The shape ef a pcebb18 has a strong influence on its behaviour during transportation and deposition. The ease with which pebbles can be rolled or transported in suspension, their settling velocities in fluids and their packing arrangements, arG all determined by the shape of the particular pebhles. Several studies of pebbles under natural and experimental condi tions have demonstrated changes in pebble shape as a function of distance of transport (KrumbGin, 1941; Sneed and Folk, 1958). The shape of pebbles, hcwcve r , is almost entirely controlled by' L Roundno as , 2. Sphericity. 3. Souroe rook charaoteristios. 1. Roundness WadelI (Krumbein and Pettijohn, 1938) expressed the roundness of a partiole as: Roundness Average radius of cornuI' and edgesRadius of maximum inscribed circle When the corners and edges are sharp, the average radius is small and the roundness accordingly low. When the average radius of the corners approaches that of the inscribed cirole, tho roundness value approaches l.O. - 59 - Krumboin (1941) developod a chart for tho visual estimation of roun<1.'10SoSf pebbles botwoen 16 and 32 mm in diametor (Fig. 20). The siz0s cf tho pobblcs in tho Elsburg Stago on which tho rOf)(,'D"rchwas f'ocus scd , arc cz t r-cmoLy largo in com- parison 'tii th the pcbbl e sizes Krumbuin used for hi.s chart. Tho roundnoss waS doturminod thereforo by visual comparison of tho silhouetto of the pcbbLes 1,.;itll an GDlargcITlont of the set of imag'0S developed by KrumDcin. 1fhcn r:liffcr(,ut obs0rvcrr; mt;Jcc visual ;jstimatos of particlo r oundnc so , some var-Lat i on can bo cxpcc t.cd , This of'f'cc t , known as operator var i nt i on , ha.s b~;0n studied by l1.osonfcld Griffi ths (1953), who found t.lrat r.Lthough c st Lmn.tos of individual particlos may vary s i gn.i f'Lcan t Ly 9 t.h. avcl"2-go v a.Luos based on 50 or moru par-t i cLc e , tOl1d to b.....s,i rn.i.Lar , because tho orl"'ors of ostimation arc largely oorapcnaat i i.g in :::lbso!1cC of streng oporator bias. Roundness is dofin0d Dy Pettijohn (1957, :p~ 57) as~ P (rhe) = Whoro ry The .ind ividual radii of thD co.rncro.. Tho nunb cr- of corners ~ R Thu radius of thD maximum inscribod circle ~ Samos (1966) dcvc Lopcd c~r.L:.:thod according to vrhich tho roundnoss (rho) is oxpr-c s scd as the IUrC,)ntago of tho convex parts of a pobble along its periphery (Figo 21) ~ Tho following six • grades of roundness arc; di et Lngu i eh.cdby Samos (19665 p .. 127 ~ 12B) • ./l.ngular:- 0 - lO}; rho. In this caso not tho slightost rounding of an cdge or comor is visible. Subangular,- 15 - 25% rho. Sarno edges al'O slightly rounded but sooondary cornors arc still prosont. Subrounded,- 30 - 40% rho. In this caso secondary OO2'nors bogin to disappoar and tho convox parts oovor at loast ono third of the circumference" Roundod,- 45 - 60j:' rho. Socondary cornors aI'Oalmost absont, Hhilst concave parts ara smoothod. - 60 - - 61 - ;-•.. L() ~ •...: eon ;-•.. o GO ;-•.. o o N 0-- ~ o t.o ~ . r-t (\J. ..e..o. rx. - 62 - ,loll roundod ,,~ 65 - 80% rho. All parts aro smoothod and socondary corners havo disappoarod':ffi Extremoly ~Tell rounded ,- 85 - 100% rho. 'I'ihs dogroo of roundnoss can probably only bo achiovod on bcachos, This method doscribod by Sames is probably not suitable for particles smallor than 20 mm but 1'1illgive accurate results for larger particles. Prom studies of the roundness of pobblos, tho following can bo dorivodg Tho roundnoss of {l particlo is incroasod by woar and rofloets tho distance transported and tho mode of transportation. Apart from tho mode of transportation, tho reumlness incroasos in the direction of transport in the absonce of severo breakage. Large angular pobbles tend te reQ~d mere rapidly than smallonos. The rate of'roundnoss dopends, in part5 on tho hardnoss of the pobble. A study of tho roundness of tho pobbles in the Elsburg Stage gives tho felle1'1ingrosults; (a) Durable Typos (i) Quartz ~lO larger pebbles of quartz, 1'1hencompared to Krumbein's visual comparison chart, aro subroundod to roundod, yielding a value of 0.59 to 0.63. A distinctivo differonco can bo mado botwoon the rounding of tho pobblos of quartz in tho small sizo rango (200 - 500 mm2) 011 Welkom Mine and those on Wostorn Holdings Limitod. In the Wolkom Mining Aroa tho pcbbLos of quartz £11'0 all roundod to wolL roundod (0.65 to 0.73), 1'1hilstthoso in tho aarno sizo range found ncar the eastern portion of Westorn Holdings L'im i.tod and 1'1estwards, aro almost ontirely angular, yielding values of 0.3 to 0.4 according to Krumboin's chart. It would bo obvious to conclude that the rounding of tho pebblos of quartz in tho small size rango incroases oastwards, but - 63 - apart from this phonomenon, no differenco could bo observod botweon tho rounding of pebbles of quartz in tho largor size range botwoen these two areas. This Can possibly be oxplained by the fact that somo largor well-rounded pobb.Lcs br-oke up during th'3procoss of transportation. Th" majority of tho larger pClbblos show fractures filled with impurities, which uauld promote; tho abovo-mentioned process. Those angular fragmonts were roundod during further transportation into tho basin and weuld increase the number of smaller roundod p(;bblGS towards tho Oélst. (ii) Chort According to Snoed and Folk (1958, p- 126, Plum: ~J 1948), chort and milky quartz appear to abrade at "qual rates. All tho pobblos of massive: black chort arc vary woII rounded. This indicatos that tho pcbb Lc a of massivo black oho r t arc boing transportod OVGr a rolativoly Longo r- distance than tbc pobblos of quartz, which moans that tho source aroa of the chert was quito romota. In tho caso of the yellow and bandod typ3S, a vory low grado of rOlU1ding is observod. Thoso varieties of chert havo tho tendency to wuather into squ2.rc to oquant blocks, controlled by joints. Those two types of chcr-tar-e in fact hif")1lysusceptible to splitting and tend to chip or break during transport with tho result that badly rounded surfaces arc common" (b) Non-clurablo Typos (i) Quartzito Pettijohn (1957, p. 554) postulates that pebbles of quartzite abrade four timos fastor than quartz. He quotod an example whore pobblos of quartzito h2.VO attained a roundness of 0.59 after being transportod for a maximum distance of 72 km (Pottijorm, 1957, p. 553), The pebbles of quartzito found in tho conglomerate layors of tho Elsburg Stago aro well roundod to extremely woll rounded, which might indicate that those pobblos were transportod at least 72 km. rne well roundod pebbles of quartzite could also bo the rosult that many of them - 64 - have boon subjoctod to more than one cycle of sodimentation. According tc Borchers 1(50) tho Lower Division of tho Witwators- rand System was expcsed durinG tho dopGsition of tho Upper Division as tho shoreline r o t z-ua t cd in ~) 'th o basin, and could havo suffered considorablo erosion" It is, howGvcr5 doubtful whethor pebblos of quartzite derived f'rom the erosion of the Lower Division would attain such a high grado of'roundness in tho absenoe of long distance t rancpoz-t.aLton, (ii) Slate and Shdo Pebbles of slate and shalo aI'O Composod of olay, with tho rosultthat theyar,:; structurally weak and 1iill disintegrate easily whon transportation takes place in fast flowing stroams. Those partioles a.romarkedly fleettonod and somowhat rounded to sub2~gular in outlino. (iii) Porphyry All tho pobblos of quartz porphyry present in tho layors of conglomorate aro always subround0d to rOlU1dod, which indicatos that tho dogrco of ab r c.si.on arnongat tho ao pebbles was moderato .. 20 Spheriei ty Krumbein and Sloss (1963, p. 106) postulato that the rolation of tho particle intercepts to oao11 other ffie.y be oxprossed as the sphericity of'that particle. This was dof'inod by Wadoll in 1932 (Krumboin and Pettijohn, 1938) as' Truc sphorioity ; Surfacso of tho study of pobblo morphology is to bring the affect of pobblo sizos in oOlli10ctionwith pobblo shapo. This practioo, shown by Snood and Folk (1958), illustratos interesting effects within cortain particlo sizo ranges in a sedimontary rock. As Snood and Folk (1958, p. 115) point out, pobble morphology is affoctod by numerous variablos such as tho (1) initial shape when roleas,Jd from tho parent rock; (2) intornal charnctoristics of tho pobblos such as hardness, brittloncss, bedding) c18avago, Gte.; (3) original sizo; (4) transport distanco, (5) transport [,gent; and (6) othor obscuro f'a.co'rt-e, In tho study of tho shapo, rormdnoss, sphoricityand orion- tation of pobbLc s during undoz-gr-ound. obsorvations, tho author noticed that a fairly hi@l porcontago of pebbles of tho durablo typos (quartz and chort) as 11011as thoso of quart zi.to, az-o cz-ackcd or broken. Pebb.Lr.ewhicll ar-c chipped, ar-c r.Lso qui to Common. In tho borohole coro exarm.nod, brokon pcbbLos were r-r.r-o , but chipped onos wore frGquontly obsorvod. The tondoncy in pcbb Le s to break or chip is controllecl by (1) physioal proporty (hardnoss), (2) energy (stream velooity and mass of tho pebble) and (3) modo of'transport (traction, saltation and suapcns i.on }. The many pc.bbLcc of chort and quartz that WGro chipped can bo ascribod to tho hardnoss and homogoneity of the rock. Tho brokon pobblos may bG the result of processes operating during trans- portation. There are thrue modes of stream transport which have a fun- damental effect on partiolo size alld particle bohaviour. Tho first is traction, in which particles roll, slidu or tumblo along tho bottom. During saltation the paz-ti cLos bouneo along tho stream-bod in a sories of short intorrupted loaps, while in suspension the particlos ara swopt along ontiroly free from tho stroam-bod (Krwnbein and Sloss, 1963, p.203). According to Gilbort (Pittman and Ovonshino, 1968), particlos being moved -73 by traction have a oonsiderablo lower volocity than the stroam itself because of frictional loss of energy to tho str'eam-ebod, During saltati.on, the particlos moved with a voloei ty ric ar-Ly tho same ss thst of tho flowing wator, whilo partioles in susponsion havo a velocity almost oqual to that of the stream. Pittman and Ovcnshino (1968) havo found in tho Merced River, U.S.A., thc:t tho critical factor in tho broakago of pobblos is probably momontum [mass times vc Loc i.ty (f,W) ] and during the tr2l1sport2,tion of tho pcbb.Les , it can bo suggostod thnt tho saltating intormGdiato sized pob- bIos might havo éCttainod tho nuccssary volocity-mass product to break when thoy collid,) with stationéCry bouldors in tho stream-bed. Breakaeo of tllG pcbblos occur if the energy of collision oxceods tho fracture- strongth of tho pubbie. Tho enorgy of collision will be a function of tho mOffiuntum of' the pebble at the; moment of impact. Thus~ for broakago to occur, th0re must bo a cri t i.ca.Lvaf.uc of tho mass-voloci ty product. Small pobbles that cellido with a bouldcr may not possess sufficiont massj nor rnO!1l0nturn9to fracture.. A largor pobblo, although moving at essentially tho Sé:.mo veloei ty as tho smaller pobb.l.os , may fracture because of tho 12-rgur rnass which yiolds ft greater mornctnrurn, Pebblos in tho int8rmocliato sizo theroforo, will have tho groatost momentum during tho process of saltation and should bo most subjoct to brcakago , During high flood. stagc:s) tho movement of small pobblos is by suspension whuro th0s0 particlos 2.rc swopt along froG from tho stream-loud or st at á cnaz-y bouLdor-s, Tho pobblos in this size rango also havo not a sufficient mass or momontumte br-cak during collision with oach other. Thoy advanced a hypothesis to explain tho relationship botwoen pobble sizo and break2go of pebbles during transportation. To express this relationship math0rnc.tically, they assumo~ Collision energy = kmv where m = maas of thu pobble v = its volocity and le = 3. constant of proportionality. - 74 - 'I'hc so authors furthor assume tIE~:,ttho fracture strongth of tho pobblo may bo in terms uf the collision anergy required for tho fracturing of Hu...:pubbIG. ::I1:Ll1S :: Ji'rt'1C tu r ; wh,jrc (kr:1V) c ccu rs , of tho I I (kmv) V"" c I I BHOKEN - I'",--, I!=oJ "o'" I p~ I in Z r" ::,::; I IJ! f E co sion ..__--k~mv-:-----GYlC;.rgy -iC::V k \ t v . I (kmv ) 1/ HC~':l,IJTG-Sl,IliInG H (ti /-, "l'·~·',"-.li, ;L_ st SPI::;}.:rSIOTT c bct"dUUn brokon rounds size ('."~~J.,~, .es r '~nd. rJvc:rlshinu? 1968) ~ L., Distribution of colLi ci on cnul'{;-;Y (knlv) bc;twc<)n moving cLes t s and. et at i cn.u-y 'boulct.:;;rs ';.s El f'unct i on of size .. Collision anergy at whi ch rock rupture occurs, (kmv) c d(:~finD8 fiolds of broken and ur.bz-okcn pobbLcs , C, _Ii combination of plots A and B_ fJ.'h(Jdistribution of kmv v.ir-sus clast sizo at SotTIS avor,s,go stream vcLoci ty (v) 1 oxcood s (kmv) 0 only for intormediate sizo{l v ~3during sal t ot á on, Thus, int...;;;rrnGdi:ltlO lines, is also calculated. This program has boon writton with geological data specifically in mind, but may bo adaptod, with rolatively fow changes, to any application requiring regrossion lino toohniques. 2. Input to tho Program In order to uso tho program, the user must submit tho data on punched cards. This data must be punched in a specific format. Six different classes cf pebblos will be dealt with, viz. quartz, shale, quartzite, black chert, porphyry and slate. For each pobblo, the X co-ordinate is tho length of the longost - 90 - axis (in mm) perpendicular to the bedding-plane and the alc ratio is the Y co-crdinate. A large number of pebbles in each group is dealt with. Each class is processed separately. 3. ProeGssing If the above sets of points were plotted on graph paper, a scatter diagram will be obtained. The program will fit a straight line by least squares to the dots on the scatter diagram. The equations of two regression lines are calculated; firstly, to minimize the sum of tho squares of the distances parallel to the Y-axis, from the dots to the lino, and so to obtain the regression line of Y on Xl the second line will be just the opposite, that of X on Y. The user data consist of a large number of X and Y co-ordinates, which, if plotted onto squared paper, would yield a scatter diagram. Such a collection of data will be referred to as a "set" of data. As many sets of data as required may be submitted to the computer. Each set is then punchod onto cards which are fed into the computer. 4. Calculations For oach data set, tho program goos through the following steps. (a) Roads in all data cards portaining to the data set in question. (b) Counts up the total number of ordered pairs in the set, i.e. the total number of points that would be plotted on the scatter diagram. (c) Performs the following totalling operations: Total of all X oo-ordinates Total of all Y co-ordinates Total of the squares of each X co-ordinate Total of the squares of each Y eo-orCinate Total of the product of each X co-ordinate with its corresponding Yeo-ordinate. - 91 - (d) Two rogression lines equations are calculated and printed out in the form, Y = bx+a and X = bfy+at (0) b is calculated from tho formula, N N b = 1I~ xiYi ~ x . L. s,1 1 1 1 <11: 2 NN4- x (~ x. )2 1 i i 1 Whore x. tho X co-ordineto 1 y. tho Y co-ordinate 1 11 total numbor of pairs of co-ordinates. (f) (iY b x. ) .a = i lT~ 1 i i (g) Inserting those velues for a end b into Y = bx + e will yield tho oquetion ef the rogression lino of Y on X. (h) b ' is caloulatod from the formula, lT lT 11 b' = 11 L xiYi L'" x.1 Yii i ~i 2 2 11 i Yi - ( i Yi )i 1 arid }I lJ a' (2:: x. b' y. ) . IT i 1 ~ 1 1 (i) Inserting those values for a a' and b' into Y = b'x + a' will yield the oquation of the regression lino of X on Y. (j) Pearson's eorrelation coefficient is calculated te givo a moasure to the degroe of correlation betwoen tho two lines. (R = correlation coefficient) R = NL x Y Ix ~Y (10L x2 (,Z X)2Y2 (k) k = (lIL i (Iy)2)1l - 92 - 5. Output Two roports are printed out by tho computer. (a) Input Listing A list of pai.r-sof X and Y co-ordinatos, as road from tho punchod cards is printed out on this roport. Six pairs of co-ordinatos appear on each lino. Decimal points ar-opunched in thGir corroct p'Lacos, This onablos the users to chock that thG correct information has beon punched on tho cards~ and is boing used in the calculations. It is suggested t.hat tho user chock this input data thoroughly before m2~ingactual uso of tho final results. The Input Listing Report is h00ded with the description, as punched on Card 1. Tho collL'1luln1der which the X co-ordinatos arc printed, is headed "C-AXIS", and tho column under which tho Y co-ordinatos aro printed, is headed "PEB AllEL". Six pairs of co+ord i.nntos arc printod por lino, and thoro are 50 lines por page. Since Gach line corresponds to a punch card, any incorrect data can readily be corroctod, C1nd tho cards can, then be resubmitted. (b) Regrossion Rosults This report gives tho following resul te g 1. Tho rogrossion lino of Y on X. 2. Tho rogression lino of X on Y. 3. Tho cor-r-o La t i on coofficiont. The report is headed with the description as punched on Card 1. The first result is the rogression lino of Y on X, printed in tho ferm y ~ a + bx. nlOn tho regression line ef X en Y, printed in the form x ~ a' + b'y appears. Pearson's cerrelation ooefficiont, roundod to throe decimal places, is givon to moasuro tho degreo of corrolation betwoon tho two straight lino equations. The number ef peints (i.O. pairs of X and Y co-ordinates) is printod at tho end of the report. This also sorvos as a chock - 93 - on the oorrectness of the data used. 6. Intorpretation of Rosults (a) Regression LiDos ThQ first rogrossion lino oquation3 i.Ca the lino of Y on X, will bo used for o st i.mat i.ngtho valuo of Y, Givan X. Thus, with rogo.rd to this goological problom, this oquation would be usad to prodict tho eorrospcnding PEB. AREA, givon tho longth of tho C-fens. Tho second lino, thClt of X on Y, would be used for predicting tho valuo of X, given Y. With a fairly largo sample, the probability of the prodictod value boing accurate, becomes very high (approximately 95%). (b) Corrolation Coefficient The accuracy of tho predictions m~dQ from tho regression lines is bound up with tho value of tho corralation coofficiont. The quan t i ty, c a.I Lcd tho "standard error of o s't i.ma't o" may bo calculated to give tho orror to bo oxpeGtod in estimating Y for a givon valuo of X. Whon the corrol~tion coofficiont is zoro, the "orror estimato!! booomes maximuID9 and thus, knowledge of X is of no valuo in prodicting Y. As the modulus of tho c00fficiont incrGasos~ i.e. as tho coofficient a.ppz-oachc s +1 or -19 tho Horror estimato" dooroases. For completenoss, tho doviation of tho "standard error estimato" is givon bolow. This formula may be usad with tho oomputor to estimate tho errors likely to ocour from usc of the regression lines. di =(y.-~Y.) ~ From tho scattor die,gram abovo , tho following definition can be made: 94 - The average concentration of the points about the regression lino is measured by (I di 2)jN where d. is tho differenco botween 1 an obsorved Yi and a calculatod Yi frcm the regrossion line. This variance of the Y values about tho rogrossion lino can bo denotod by Soy2 Thorofare NSoy2 = L· 2d. (from dofinition)1 =L" (y _ y )21 1 Boforo continuing, tho thoory of regression lines must bo reconsidered. If a Lar-g.. number ef X values are available, tho avorage value may bo donotod by x and tho varianco of X valuas dofinod as: II S 2 - x-)2x x is morely tho arithmotic averago viz. x (L x ) j N Similarly' NS l 2= L (y - y) and y = (~y)jlT Howcver , in tho scattor ditlgTam, pairs of X and Y values arc prosont, and thereforo tho covarianco of X and Y may bo dofinod as, Jl S x Y = Z (x - i) (y - y) Multiply out = ~ (xy - xy - xy + xy) Simplify = L xy - =~XY -LX~y -~x Ly .s., L:t. lJ lJ N = ~ xy Lx L s. also lJ lJ S 2 =L x2x 2 xx +~ xx [mul tiply out (2Il = I x2 2LxL + Lx 2:: x N N = 2: x2 (I_x)2j}T - 95 - Now rofor back to tho oquations in 3(e) for b. It will bo seen that b and in section 3(f) an equation is givon for a, viz. a ( L y - b > x ) / N = - b N a y- - b x Theroforo tho equation of tho regression line boccraca s y 2- + b x = y = G -£_5[ i) + §.B: S x2 S x2 x i.o. y - -y = §.B: (x - i) S x2 Now roturn to equation (1) From tho abovo y = y- + b (x - i) 2 ." "fT > (v. _ Y. )2 '-- '" L l - -x)2 - 2 b) - i) (y - y) 1 = sy 2 2 2N = b lJ Sx - 2 b IJ S x Y from (3 ) b2 s 2 b S xy.x Furthor, it may bo provod that tho corrolation oooffioient r = §.B: Sx Sy .. 2 S 2 2r y = S x_;y__ b S xy Sx 2 i.e. b 2 S 2x = b S xy = r 2 S Y 2 Substitute in (4) s ey2 = si r 2+ si - 2 r 2 si = Sy2 - r 2 si = si (1 - r2 ) and this may bo used to oaloulato tho standard orror of estimate. - 96 - 7. Running tho Program Tho program will bo run off tho objoct deck. Tho user must supply tho data cards, sortod into corroct ardor. Tho follo",i;1gJob Control Cards will bo usod to run tho program. ~ donotes a blmik. ~ donatos a dollar sign. *~~~JOBGE01I *~~~PRTD //~JOB~GEOLI //~OPTION~LINK mCUIDE Objoct Dock r / nEXEC~LUKEDT //~EXEC Data Cards I - 97 - DETERMINATION OF PEBBLE AREAS AT UNDERGROUND LOCAI,ITIES. Locality : Western Holdings Ltd. No. 2 Shaft 33 West Haulage Peg: A.4676 Co-ordinates X + 30590.50 Y + 35249.17 ft. X + 9323.98 y + 1071+3.95 m. PEBBLE TYPE PEBBLE SHAPE SphCérical A XES PEBBLE AREA. .; .. Oval Rectangular ti Axis C Axis (mm) (mm) ~}ol1p;':ted Quartz Spherical 81.3 .~I ~ '.-5-_2, .6-----+ .. _--,_._ .._.~3,-,-3-56_._._._ .._ .~~_~rtz Spher~eal 71. 0 ,.. 48~.8.. _. . . 2,].19 .•• Shale Elongated 63.2 48.1 , ?13.8_5 Quartzite Spherical 82.8 ~.~ .-.- 1··,----- )?~~._ _.?ll:3_(.l.•. Black Chert Oval l.. . ._ .!_ 71.2 lj3.? . . . 2 ,_4!+?..•. Quartz Oval 123.6 '-_ .. 91~~ .. _} &6§ __ •. ~ll~t_zite Spherical 92.1_). _ _62.0 _ ~!.1+_8? _ ~u~.t.zit" Oval _,. __n·_6_ -; __ ~8:}_. r __ .. _ 3,_5!+~_ .. _ Quartz Oval 116.3 _')2_ ",6__ • . _8_.~'5_.3_ _ Quartzite Oval 134.4_. _,' .:- _ . .Quartzite Oval 9~.0 7_3~? •. Quartz Spherical _ 133.0 .98 ..4 . _l_O -' .3?_2 :quartzite Oval 87.3 71. 6 . ,__ . ~,_9_0§ _ Quartzite Oval 138.4 , _~6_~L...•... _ 913.5.4_. ,Black Chert Oval 117.0 64.7 '-- --'I-~--'---'- .5.,J~l _ ;Quartz Spherical 247.0 183.6 _35. ,.598 :9":lartz Spherical 87.1 61.:? _4.. ?],8 I - Quartz Spherical 97. L, 69.0.. L_. 5....?75 :Qllartzite Spherical 153.8 107.0 12 J ?5.1_ . _ :Qua:r:tz.it" Oval 148.3 111.0 12 ..921 'Quartz Spheric_al 1C:9.8 92.1 ! - .... _....-.- _' .. 7."-33. _. ,:~uartz_ite Spherical 131.0--, 58.3- 5,.n~ ;,Qu.artz Spherical 133.9 ' 138.6 ... 2(),()08...- T' ;Shale Elongated 105.0 36.3 r -'".'- ._ .. ____ ----.l .. .... 2.1921 'Porphyry Spherical ... lD3_._l.i.._.89..9 • __ ?!~67_ 1 ,-«",_,,- -"'._'_ - 'Quartz ~pher~(:a1 - ~.. .:t72~~ .: 1:31. •.1.. _ .... :t7,?~1__I ._, _._",_ :, 9:u:a!.tz. Spherical , 118.2, 112.~3 :to_,~19 ,'Qu":r.tz '.. .spllerical_ , 147_~3_~ . _,,-8.6. .... _l_lt 4_09... ,Qlia:r!zi_te S_pherica1 141:0. ~ .... 8] ..? _ ... 9!6.5_l_._ ,Quartzite Sl:'her~cal. _L 116.3; 98.7 L ••.. 9.,()l.ated 157.9 74.5 .9....,..2_3. 1__ ._ .. _.- -- .. \ " ' :B1ack C~ert~ Oval 87.5 43.4 .2,98,,0 , 4 ; Porphyry Oval 139.-2 63.8 ,. ~. -i _ t··_·_-_·_·_--_··_··_·_6·_,·_9-·7_0 i Quartz .. !_ .~_~h_er~~,~l 164.0 .,.- • -118".'''3'''''4 _._. - - 1_5...,.1._9.--1_._._._._ ••-,: ~Quartzi.~_e. ~Oval . _ ,,_l_ll.') .. , " "5_6~o_,, ~. _ ~!_(lZL .. _ . _ : ; Quartz Spher.ical_ _1)8:,8. .~.. _7_9J.; _.?t.6_132_ •• _. 1 _.. - ; Quartzite S.Pl1erical 361.8 ._.~2_5:3,,_,._ .•. _6},.9?? .... _ .. I _. ; Quartzite Oval 1_..5_8....6' _,L . __ •3. ·4-·._3----r- -,_ .•-._-_ --4_ ,.2..6.._.9._._.-_._._ .." f ._ _ ..•. ; Quartz Oval 181.2 64.9 9,094 1 ;-Qu~;tz- - - . Sph_erica_l - -:' - -153.0, 103~; -, -.·_·_·_.-: ~_"-t.3_9;~~.~ ' !_.. _ .... __'_"___ _.; \ ·-l·· \!--,B---l-ack Chert; f' Oval 59.4 41.0 • _ .... _l~9.1_1"_ .• __1 I -'-'- _.- -'r-- 'Quartzite -'r,SPller~c:a_l. __,. __ ?~~_l.,'1-' _5.2_..1-_._-~.- ..... 2,.4_3'L ......t .---.--.-.-.- ... --- I : Shale ' Oval 107.8, 38.6 3,266 t· _-, ._. .... ._.;- --_"'-'_'- ----..,-.-.-------- ...---.-- ... - !'Q.. uartzite 'SjJ~e.ri<:a,_l , 134.4; ,1.1~:4 _l- _ ••• _ .1_1_.~5.8 -_--<- ,_.. _-- .- ,_·t I I I Black Chert i Sph,:r.ical 97.2; 76.7' 5,852 • \._...-" ._,-", ...._---;.-...- . '''l--'-'-'-''"'-'-'~- -'_'_'_'-'---'_'."-"---'-'_'-'-' 'IBlack Cher_t.,;'t. ~j}_h_eI',~.c.!-~_1 -,._._.-139.6_. -' ,-.i- _._1._2._.'_f-._0.-!:._-_.'_ ..--_._-.-.-.1_'3_ ,588... __ ' .-----.' ' : qtlél.:r!~ite _:.Sl'h_erical _.387'.2 ,.. 1~~•.4.' •. _ .. 5.81?8)_. __ .• - < I I It ••_Q._.uartz ._._" _. _ -!l--_S._.p_he...r. ical . _ ._._._i. _. 18.4_..5_.'_ .....__- 11. _3. .-2----:-.• _. _._ ,_._. 161.3_9._4. --_._._.- _I i. \. I.!:??::R_l_l_~~:[._ ~- ~_:p!l.e~ic~,~....i. .~~~_. ~__.~._._.}?~?~._,~_._.._,--~ __._._9J.~~?_.-._._._.._. i: Quartzite Spherical _ T ' .103.2' 91.5, 7,411-_Q._ ~._~._.;_t.-_z._'. _.-.. _-- -s_p._~._~.- ;i-c_-~_.i_._. - ._ 79.~' , '42~6 'r- . - ...- ';,64i' - ... -.. . .;..._._. -, _. _._ ._._. -' _. _,_. -' _._._._._._._._._._._. _._._-.- ._._.- - 99 - DETERlHNATIOONF PEBBLEAREASAT UNDERGROULNODCALITIES. Locality ; Western Holdings Ltd. - No. 2 Shaft 33 west Haulage Feg: A 4676 Co-ordinates X + 30590.50 y + 35249.17 ft. X + 9323.98 Y + 10743.95 m. iPEáÏ3LE TYi'E -sHApE _._,_._._._. __ ._._._ --_ ..... ,.rEIi"BLE :SpheriCal- A XES PEBBLEAREA 'Oval :Rectangular A Axis C Axis( mm) (mm' Elo_~$~.~~~~":,.,~ ;Quartz Oval 1"" --- •• .~._- _'- -._,_,_._. '-,- - _.1- 4-3._3.-'. 'r-- - _.6_7-.1-' _.~._._._._-_.-._._._.7_,._5._4.7_ .• 'tQ.. _u•a__r. t_.z__i•te _ Oval 204.6'_"-._-_._ -f····_·_ ----_ .._-_.,_ _~~_3~~_,, 2l:?J2L _ ;Sh,:l_e 9va_l 104.5 _ _5~._3_: 4,?D_7 _ j j •••• : :Bl_a<:~C?"r_t; Oval _" 119.7 _1 )6~2__t ,, __ ~,_49J, _ :(lu,:rtz _,__ , _Srtle_ri",:l_ _ _ _ _ 1_4).:l__ '- __ ~D_8_.__T8 _l'?!22_l_: _ . __ ;Black Chert I Oval 119.0, 46.5 4,343 -'--_'_ ..- - ---','- - .-. - _._._.- ï --_ - _._._'_._~._.- -'_'---'_'_-_'-'_'_'_'_ - I',Q_u. artz, , ~ph_eri.ca_l _. __ ._.9_.-8.9 - "or' .. _ - 7-1--.·_7·_·4· I . · 5,566 .• ,Quartz I····· _._, __ . ._,_._) Syherical 7 " .... _ "j' _'_._-9.3"_'-_-_-:--._-_- ...3__8.-1;- _ ...._---._._.~ .._._2._,._3._6._4._._._ .... • :Qu"r_t_zt~e _ Oval 2-9_3._.6 - ,1' -._._._.1_.6- 1.4' .\..._., ._.. _.3_7_•,.6. _0._3._._._._._ , 271.3 ___;_ IJ~~_8__L 4_l:12_5§ _ ',9~artz _Sphe_ri(:'al. 121.6 J_ __116.0 \ l~ to_7? _.r., iShale Oval 107.0 _ _5~.__4_ 1_ _ 4,] 2~8 _ I;·S·-·l_a·_t,e·_·_ ..·_·· .. _·_·· .. Oval ._.L•. __ ._1._13_.2_ , ._._5._.6_..1:j-- •__ ._._. _._ .. _.. _._._ .... _._4._,.9_._84 ..• -_._. '-'i 'Quartzi te : Oval : 86.2. 36.7: 2,482 . I-·_·,,··_._._·_,_·· _ '" __ '_'_'_""'_'_I'_'_'_'_'_'" -'-'~---'-'-'-"-'-"-'-""'-'-'-'_'-"! !\Q_u._artz- ._._.._._ ~'S-p-.h,.e"r"ic-al-,, '''' -, -,9-.8_.-3-'. - ,._._._-7-,5.3_,'- -;_._._._._'_._5-,8__0._9._-_._-_.- ,:quar~z_ite .-.J _S_p_h"r_i_c"_l_ '- _ 15): D__ , ~2_8:J, _ ~ _l:5_~,8_5 , ;Black Chert Spherical 78.2 .- ~._.- - _4.9_..9_.,_._~_._._._._._._.3_,.0_.6_3._.- _.- t , ;,Quar:t_z Oval ~5_2_~_~ _ __ ~7_.! _ L ~O_.~?l _ ;quartz_ ' Oval 97.,5 )~._3_ _ 2_,,~~5 _ , , :S_hale_ ~_SJ'~e_r_i9,:1 .. __ 1_?2~1 !~l:~ _ i, _. _l_6J~1_4 ' 'Quartzite , ",rherical 269.3, 23 t - ... , _ ........ __ ,_, , ._ 7. _.1_ •..• L _,_._._. 4.8,13,_9._, __ " _ + •• 'Q_ ..u..-artz. Spherical\ __2~~ ._7_ .. 1_0?& __ , 19c6_5§__ . ;. I I. _ "'_"S"p_"h-e"-ri,c-.a.l"_ - _.., . __._9.8,_.2- ,,,-.----.-".--7'-9'--.0--'-'-'·\''''-'--_·_'-'--''''6'-,'-0'_8·9-'-'·'1 ' i9'H,rt~ Sl'h_e_ric_a:t_ 79._9 4~._2 ~,_58~ _ L~l1llrt~~t_e Oval ,163.1 LQ~;:~tz_ _ -, _i3p~e~~;,:~~- , - - ~ _9?~i-,~~~114.3, 14,633:6_8;0: ~-,:_-~-_~~-~-_5;!-9_;_-_-_-__ • I . -I' ---- . ;Qua!!zite., . Spherical '149.0 91.5 ... _l9_,';'0_1 _ r '-\'-".' _. .--.- --. ---''1'- _.. -"-'-'''''''-'1'- , Shale ; Oval 104.4. 63.7 5_,?20 __, _ t'· ..·_·_·_,·_ -- -- r- --.~ - ----.- ... "4-" - ---''''_'',-'_----'- _·_··-'-·r--' 'Black Chert: Spherical' 67.4. 42.9. 2,340 1"_",,,_,·· .• '_' .- .. ·_....1'-- ...._.-- - - ._-- -- "l .--- _'--,---".,---.-._._'!,",.-.---.--_._.-'--_ !'Q._.u- a-_r.t-z-.i_t.e_.- ._. - '-r'S-'p_h.-e-.r.i.c.-a.-l. _-_- .-, -':!' _.-_1..7._1-.3,_' ._...._. ._.1_2._7-_.1._' ._-r' _._._._-_1._7..,.0..9..1-._ ...._... !'Q_._u._a._r.tz__~ _._. .,'. -O_.v_a_,.l"._,_ ._-~'1..2...3. _._3.",·,_. __ ._ ~ . 94.....3_'._.I-- __ .... __ ._._._._ 9,..1.. 2"7.._._._."._". : q_ul3,z:t_z._ LO_vl3,~_ _ ' __ ~~3_·9_L_§_,;,~_2J_ 21~69 _ : _P._.o_.rp_h_.y_._ry.... _._. .•S__._p' he_r._ic..a_"l.: . . __._ ....... '1._'5_1_.._5..'... _••. _'_'_' 11_."3'_'."6; ,,.l.._. ._._ .•..1_3, ,.5...0_,_9._. _ ._. ___ ..S...l_a.t-e,_ ...... --.-""" _,'S--.p-h__e-r_-i-c__a.l-: - - _. - ._. _,. --.- ._-1-_0.4.. .-3- -.'-- ._ ..,_ - _._. _.7_9._.8-_,. - .__ ._._- ---~_..~6._.,5_.3_1. _._.~.~ ~a_r_t~:i_te__ L ~l'h_e:r~ca:l_ ___ 3~~..l: 2.1~~L.; 2~,_??L __ _l3~~c_~k_tle_r~_: _SJ'~"r_i<::l3_,.J_,_. . ~~~.6__• 5_4~_: , ~.lO"~2_._ ._ - 100 - DETERMINATIOONF PEBBLEAREASAT UNDERGROULNODCALITIES. Locality : vJes tern Holdings Ltd. No. 2 Shaft 33 \vest Haulage Peg: A 3574 Co-ordinates X + 30618.56 Y + 34188.15 ft. X + 9332.54 Y + 10420.55 m .._. -'--._._._._-~ '-'_"_"_ .. _._._-_-_-_._._._._._._._._-_. PEBBLETYPE ;PEBBLESHAPE :Spherical A XES PEBBLEAREA_. __ .__ ._._._"_._._. __ .J._. ._._._. ._._. ._._ C Axis tA x i'zC 2x .3.14(mm) (mm ) iQuartz I _.__ ._-- --- -.- :Black C_hert ' Sl'herical --191.2-'--_ ~.,--_ 151_.3--'---1----- 22'_,'7_'1_3'_'_'_'_'_'_' , :Shale ~Spheri(:'al . -T 73_.;t__,__ . )~.O__,_. ._J,..1?il. _ iBl",<:k_Cller_t c _Sph"ri_cal ..• ;t?6_.)_ __ .1:.4?'~7__~_ , .?~,_l!+~ _ " , ;gllar,tz~te_ :_:3l'llHri(!al 195.8, 156.8 'Quartzite Spherical. - ;O;~;;' ; - - - 68.3- -,- - . - - -24,100-5~;;89' - - - !'------- _.- - --_ -:--_-_-_-_-_-_-_-_-_.':--_-_-_ - --_-_''1'--'''--'''_------r-----'--- --_._._ .... _._._._._. 1'Q·_·u··a··r-tz ._" ..''-_S...p..herica.l. '_" 1 -----1-4--6-.-3--.---,_.- _1'_3'_2'._7_ ._.~._._._.-_.1_5._,2-3_9._,_ l..Q_ .u...a. ~r-t-z_it._e._-- -.. -~:-.-.S- ph...e. ri-c-_al ... _- ... _(-_ .. --1_,91...6-._--"t-" _1...6. 6_.3..:.... 25,012 ....l. __ .. _ .. _ .. ... .. , .. _...... _ .. , .. _ .. _ :B~~d_e_~d_h_e_rl! _Ov",1_:_. , -i-, _1:.2.3~: _l ?ê.~_3_ j §1.6}:L . :PorPhyr:y L _Spheri::,:l ._. __Sl_4:~_L __~8_.~_,: ?t7_9i) _ iQuartzite 1; • ···S·-p--h--e-ri_c..a..l .._... 94.3 6§~7__ ~__ ._. 5..,_()§5.._,1"'-""--"-- - .• ' ... _. L.. I 'Black Chert. Oval _, __ , ~~8_.§__..: 93.8. 13,886 ~.- ... _._ "., •• " .. -- __ .~_ .• - --_- 1 -"""-"-"-"--,--"'"-''---''-'---''''-''''' --.- _' ••.• ~:Qu_ar_t_z.i.t_e'-'_'''''_-- :''S-_p- -h-_e._r.i_c-_a._l "---"')' ,+ ..__- 9_-1_.._4._,._;_._._._._._ 58.6-:'-'ï'------_-_-_'_-_'_-"-"-4_-,_2-_0-_4 ;Q_1l~':J:.z l_S_phElri,c~~__ ~O_.§_~ }~~_9__ i ..?1~0J__. ~ iBlack Chert' Oval ,162.4. 81.7' 1 .- _ ... "'--- -'-""'--'," 0'. __ - •.. ,-- .. (- - .--.' 'ï"----"-_-_-_-"-_':'--_-_-_-_-_-_-_-_-_-_-_"_-_'_0,415 ; :911,:r_t:2tl_~e, 'Oval I __.L .• "'_" -•r-"'" .1..2..6.,-.0._,...--;'_._.- ..6..9-..3_:.- --! ..._._. _._._._6._,.8_5.3_._._._._. _._•'; i9~a,:t_z. __ ,.1. S_ph~r:ica~ _ l?~ ._9__ j._ . _.1:.2z_,~8.._1. _1Z.t.6.?L_. ._.• I "'T .~ '91l,,:r_t_2_'__ U>pheri",:l 191.6: 114.8 17,266 I t _.\- ...... _ •• _.- - "i'-'-'-'-'-'-"-'-'~'-'-'~"-'-'_'-'-'-'-"-'-'-'-' ,Slate , Spherical 122.8, 97.9! 9,437 j. -'-'-.. t·- -- - - - - - -~- ...-..- -'---'l'-'-'-'-'-'-'-'-!-'-'-'-'-'-'---'-'-'-'---'-'-'-: 'Quartzite ,Spherical • 184.3; 126.7! 18,329 ' 1-- .. - - - - -i-'-"-'~'--''''---''-''''~'-'-'-'''--'-'-'-'I-'-'-'-'_._,_._.~._._._._._._._._._._._._._.- ._~ 1'S'-'h-'-a-'-l"e ... - "--1"-i"'''- Sphe-r_.i_c- a.l... _- .. - ~',-- __ .-7._._9,_.0 -.;_i._._._._._-_._5.~.5_ .3' •. _._._,_._._._._._._3._,-,4_._2.-8 : 'Slate ' Spherical ---"9"2-'-."6--i---'i-"-'-'_'-'-4'~3'-.'8 II.._._. -_ .. _--_._. - ....,. _ .•. ,. _._ .• 1 -'-'-'-'-'-'-'-'-'_._._._._3,183 ...:. ;quax:tz, _. ,.l_S;p!leri_c."~ ... ~ ,.1~2.1 __:__ 1_35l!~_L !~,_7?? _ . - I- :~l":c_k C':_e_r_Lt i):"",1:. !_. li3_1~2_L .. ,5_],'.~_L Ll.2_8§, _ [q_u,,:,:tz_i_te : _~p_h~r:i_c."~_, ~ _ _l~3.·7_ L_ ,1_29~_4_L _l:5_.~?1 : ;qua,r!z _,: ~phe_rica_],_ L, _16?~9.L _ !~4_':3_J 2_()!/;_59 _ • I' :Sh",~e__ , _ J.. E_l?l1l>_a_t_e~+_ 110~2_+ __)?~,9 : .. _ )_. ?~l _ ;,B... l»a--c--k- _C..-h.-e-rt:.- _"'- O-. val .".__ ,_ - • - 1_3.~8.-.1;- _ ....._ ..-._._7._1._..4_·._~_._._._._._._._._._7._,.7_.4_-0_-- L~~~.z_:t_~_~_~.~l._:herical 73.1_" 3?.L._ ..... _:1_8_.7~:t._._ ,i _S"_h.ale : Oval 105.2 58.6 :, t,_.8~L _ , Qu,,:r:j;z Spherical 148.2 ... , _"_1--2'"9.4-;-1'---- _._l.?1()5). , 9~£l!'.tzite Spherical. _;_ 187.2 163.4. : 24,()11 QU5'",tzite Oval~ 3 123.9 62.0 6.0.29_ , Shale S:eher.~~~l .; '1.4.• 4 ...6.2!'Z._:_ ... 4~§i+_5_. _ . , guartzite Oval 180.4 97.8 . _l)~?~9 _ I Q:?-_~rtz Sp.herical ;-- 91.:3 .52,9" .-.r-' '__ .- '" __ )~'Z<)() .. _ , Black Chert Oval 156.2 _.-69- ._6._ -_-_._._._._._._.8_.._5._3._3._._._.- , Slate Oval 1 "L. __ . _ 2_ 8~. .2, 'C_' __ ._ .• 9_._3._..4_.I...._'._,_._. ._._9._.._3,_9._8._._._ ~..:, ; Quartzi te ,SIlherica~ 168.4 .. , _ .1?~7_OL. _. I.: ~\l?r~z 1 Sphe.r Lc a.L 15).2 127.1 ...... J?1213_4_ , Black Chert Oval 182.4 59.6 ___.. __~_.5_)2.. _-l- - - _._._._.- Oval 162.8 ... _ ....1_.1_.9_,.4 -'I'' :t_5_.?~8___. , ..~l'herical 169.2 151 ..3.. -'- .. - - J ~0,095 _ ..- , ...L, . Spherical 110.5 49,2 L_ .•• _ 4,.2§ë_ '. Black Chert'-'T Oval .1 1:35.•?_ l._._ .•• '1.1.~j ,__ . _.. _ .lJ_ •.~29 ... 1·-Q·-··u··a.r..t.·z-·i-t·-e·'----·-1··· ;:;p.h.erical, 128.1 ...._,_9, 6....8.. -;;-... _._._ .. _._.._._.9_...7_3.._4..- _._. i;' _Q._u._a._r.t_z,.i_.t._e '- .,__. .~' . Oval 1,126.4 ·t·_.-,__h._9._.8._'.-i;'-'-'- ._,_._.._8._,9.0_-9,__..- r;--'-Q'-'_u'_a'_r'_tz'_"' __ 'Oval 102.0 64.4 ' _5.•.1?o;;..L , --r"- _._- .. -1""-'-'-'-'-' : I:'_o!:'l'l1;[r.).' ; _S!'l1er_i(!al. ,_. 96._8.J- _. _~')._6.L. __ . 4t5.2.?_. : 9.,:,a_r_t~~~e_ S'p!,,,r:i.ca~ ., .9l~~.L ..... 76!!.L._.... ,5~.,:)?L _. :_Q~~t_z_itEl ' Oval .. _. _,_.. :t_29~LL_. _8§!t: L- ._.__JIJ ~'58_. __ . :_g"!.ar:.t~ .. i Oval _,_. _l0§,8__:._._~(; •.4' ._.2113_8.9._ :_J:~:t_~cCkhert: (}v"'~. _ ! 163-.3.. :__ ....7_._9...1...;--;_. - ._,_.- ._1(),1).7.. ; Quartzite S!,h.e_ri(!al .1,6'.2.1; 123.7 ;J., ..... _.- _._._" ,." - -t- i ..._.,._--.-,- Shale Spherical _'--.-' 173.8.:_ 12),4 1 ..... __. :t_6?_:z.5.. _ _ __ . Black Chert' Oval .. ~6.9.·2_~.... :1:0}.!L._ _ 1_3_.?§1_3'._. - 103 - DE'rERMINATION Oli' PEBHLE AREAS lIT UNDERGllOUND LOCALH'IES. Loc,"lity : Wes t or-n Holdings Ltd. No. 2 Shaft 33 ','/8St Haulage Peg A.3787 Co-ordine.tes X + 30,541.20 y + 34,637.17 ft. X + 9308.96 y + 10557.41 m. ~PEBBLÊ"-TYPE-'-'--"p'EBBI:i- SHAPE - _._.- - - -'-'-'-'_._.-._._.~._._.- Spherical A XES FEBT3LE AREl'c . _. -'_--' _. -.- "- ,_. _. _. -" _,_"_. _. -,_._. _. -.-._. ;"_Q' uartz- - ,_. Sj)herical 151.2 '_'_1'- 26-.8_._~'_._.- _"- - _1._5._,.C_.5_.0_._._._-_ .({ua.rtz:ite 'Oval'' 80.6 4D•.'1~, , .. _ , ,2 J ,?2_2 :Shale ,. _, ~ph,c~~c_a_l,, __ .l§~._l.__ . __12~~4, __ " .. _1.6J2_3)_. -" :Quartzite, ,,', .()val __ . 95.2, , ,5_l.6 ,3_,8.4.0 'Quartzite, "Sphe,rical 136.5 ,_ .'1_l~~.9_'i .• _ .12..'21.1_, _, :~halc, ... __ . _~p_h:,r.ic:~l. ,, __l2.9:1_~" ._5.5'::3r •. _ .•• ..516.8'5., _" 'I.S_h._a_le _S._.pherica,l ._._ ~,._._._._1. 42.6,,_._~_._._._._._.1_,2_~1_,.8 ' __ ._,_. 13'_,'5_'_5'_5" __ 0 __ , :~u..~tz. "r Sph"rical 83.7. t. ,_ .5_6~1L., _ .z,.6'!L.,_ :~~a_rtzHe. "Ov,a_l., 141.8, _..5?:2.:" " •. 6J~7.8 ; Q_ué'l1'tz,i_t" Sph"rical" '. 163.3 . l_3?~l:.~ ....• _n.'.!§~" ._ 'Black Chert 0,:,,:1_, _,. '" 1.0?~6_. _' __ ..5.'1:3_.•;. ' ••• :',12]'5 . :91lr-:x:.t,z .. ,',. O"a_l,_" .. " .l??~~ .. c._. __ 1_2§._..5_. • _1]~_ll_9._._ ~, qu.a:~z.. , _, _, .O~r-:l_., . _. _ ,l.O?:l. _. n,L. __.. ,._3_~_C)_1_'7,, ,! ~~<3!~Z Sph"x:.ic"l 1?8. 7,: . __1_:'1~9_:L. _ . ;Qu~tz S!,l~e,r.ic"l 66.1 I --- ••.•.•• _1.. Ifl.,9_: ... __ , .2}.J~~4.. __ . ~QU?...rtzi';0 OVé...:..:!. 161.3 1~' -- _." _" _' ._1. 2-' 7.1 !.. , '. _, .1.6.,1?~3_.,. ,Quartz Oval 104.8 ! -- ".. _.. - • -5--2--'.--9-1;---- ,.,,4J?Ei9_ ... Shale Ovo..l .l. 92.8 31~~~ __ '., _. ,,~7_7rL_. ,Black Chert 149.7 130 ..0.~ 15,_27'5__ ,QuiU'tz,it" _ ....SPller_i::"l_ ., _ .lc6.?:5.. _ . __ .1_2~:.8_:. ,_ .. 1.5, '5~7__ .. ' ; Shale Ovsl I _-... 117.4., _ 64~_9~. .,_~!_9~~._,_ ,, Shale" - -, ..Oval_' 102.3-,- : Quartzi te I Sllherical 149.2 121. 0; 12 ,O~7 ,; '-:'Glla_r,tz SIJh_eric.a~ ,. 15,8.1' " 122.3, 15,19.°, .. , " :! Sllar,tz Oval - 14_1... 6-'--!- ._.- _._.9_7._..3_~;_._._._._.- _._11-,.4- 3_6._._._.- :S.h~_l.':.. "" oval" 1).9:4. ••• _ _5?~D~_. §13..1___l._ , , Quartz 'Spherical 146.2: !' -._,,-"_' __'_'_-_'- -! '_'_'_' --'_ --- ...._...- _._.- - - ----""-'-'-1--1--71.'-3--'------ 13. .1.461 . , Quartz S.!'ll.e!!<:al 178.1. 132.4; 17,517 ,------_ ... " ... - -t--_·, - - -'_ --- --i----------_'-_--' .-.-.-.-.-.-.-.-- .....-- ... ----. !;.-B.l-ac--k- ...,,C--"h,-e.-..-r.t; Spherical r'- 143.2 136.5' 15,343-J.. __ ._-- .••. _ ••. _.- - --1·_· •• _•. "-"_' "_._~- _.- -.-.-.~.- ..••• --- ... _.- .. _.- :_9.u:"z:t_z;,., ':'_9,:,,1 .. ~... 1??~4. L __ _9_l:.6J ". , __1_°1'2.3__4_. i. . ' . I-Q'_. u-a._r-.t_z.. - _.- ._ .. _.L~. _._ S.-'ph_.8_r._i.ca---l; .• -. 154.3: 137.2; 16,6174' _. - _ -_. _. -' - -.'_' _. _._._._._ ....._._._- _. -._._._._. _. _ ..- i,i:::':c~·l<_~h."~~_.:_!,eric~J, , _ 151. 7 '1Q··_u..a.. rt_z.•i.• t'e ._ aval ' .._.. __... _._,.102.8 -~-._ ..-._4.-9.._1._'-_.~._._._._-_._._.3_-,_7.0_.5_._,- ;Quartz . Oval 118.4 . --' .-._. -- - - -t- _...._ ._._.- ._. _._.~.~~_6_._ ,_._._. _. _._._8.~12.4_._._._. ;Black Chert_._._ Sp'h_erical -r- _ 166.9 , l).!~~ _+_ _ _~:(,1?~ _ ,,.Blac.k.._.C_,h_e_,r._t._...,'_.O_..-v-a"l",-,_._"-'-'r''-132_.'6- ,..-_._.._._._..._..._._.8_5.-..4_,._._, ~_._._._._9._,9._0.5_._._,_.-._. .IShaLe .... ,. __._._._-l .. _O.- v..al_,--- -1-- -' 9..1_.._3._._ ...... _ .•.• _ ..4...5_.._7._,._j_._._.- _._._._3._,50..9_._._. __ ,Porphyry : Sph·e-·r_·i_c·_at'" '''_'_''''---'_ ."",_ ••. - ·l_'·_·_l_·_·_ .-.-.9--3-.-..-8. ..-.-.-.-.-.- 61..2. -,.- . .,.._._._ .. _._,. __4._,._4.6_7_ ._._ \,Q..• uar_.t_,zit_e.• - ".:_- _S_ p.""h_G_ r-._ic••a_l_ ' ._._.,J,_. _._ . 6,_3._._.._9._.'_ •• _. _1_ ,9._.._4._,_ .. _._._._._._._._._._._' 2,448 'Quartz : Spherical' 153.0 • 130.'3_'_;''-I._'_._'_'_'_'_'_._._-1_.5,61,81· ..·_····_· _. . .. :-._-_. __.... - .. - - ~""'-'_'_'_'_'_'_'''''_'_'_' _. !Quartzite ; Spherical; 172.8 • 116.1 i 1 .. ~,-.-- .... -- •• -1''" -._'_'_-- ._.~ _._ ~._._._ .. _- _ '-'_'_'\_'_'_'_'_' _._._.-l._._.~._ .... _1._5._,.7_.4_.8_._._. :l'0rp~y:rJ' .. -Óv S_pheri_cal .-' __ ~~8_:.l_ _1!~~__6_: _l..51.~t:6.._.__ : i~B'-h'_c."k-'_'C_"h."e'"rt _,.'_,_S._p.-h..o. ric.-al.' ,_._.!. _l6~•.?_ _ ., .1. _3.7....1_.'_._~._._._._._,_._._._1._8,_,2._4._1-! i :(i\l~!z.it"' L. Oval ~ J,26:~ __,__ .__9J:4_ _L_._._._. __ 912.79_._._._: !quartzite ,Oval .._ ... _L__~18_~. __ : t?6_.Z _ J _. ~1}~~. _., :S!l"J,_e._. ,_ ~phe_rj,,,al. _.L_ _1.64:8__ 1 1).?~~ _L ~7_,}~5 _ .Por-phyr-y Spherical. 149.6' 119.1' 13,986 1 . -_.-._._, ••. - _. 'j-- _.,-"" ._ .... _._._. - _ ... -' .. ,- _ ..J_-._._, -.-.-.-.~.-,-,-._ .. _.-.-.- ..• -._._.- 'ISl_a._t.e_ .•.. __ ._ .. __.~;._._.Ov__al._._._._._._. : __ ._. 137, .1:. ._._._._,6_1._.0._._.LI,_._._._._._.6_.,_2.4_.9_._._._ :guart,,:i_t_e _ i_<2v_a~ L_~_5_8_'§__' 4_l!._4_L _:;.é_4~_ :Qua!!<:._ _ _ -r __0:,,,1__ _ _ _'._.. _ _li)§ ~_4__ 1, :?_9Z_._: ,..... )J ~6§. ._._ --1 ;\Quar.tz-.--_._.-_:-.S_ph.e_ri.c_-al_,'_.._..-.!..-.-1_46.._-2''-'-'~-'-1_1'_.8"..'9-.._.._,.._._..1_._3..,.C_._li5-._.._._'_._ j.' B__ 'L._._a._._ck Ch- e-rt ' Spherical, 184.3' 112.4 16,276'-'I-'-'_'-'-'-'-'-' -'_.-:--_._ - _._._._.-.~-- _._ - - - - -,. - - _._._' ...._.-._ .. --\ iB'l.ack Ch.e._r_t l-._._._O._.v_.a" l _,I.... .1_1...9_.,7_'.: __ .- ._ .4. _7._.._3._;.~_._._._._._.,_ 4.,.4I ._ - _..1_0_._ .. __ .. :Sh"l_e_ _ :__ ~v_a;_t .. C. __ 2_06.)_ : _It:l~2._, .__2! .._9.1,2 _ '1P._._o. rp__h._,y._ ry , __ '_",'_":_'_'_' Spho_ rical, ._.:--- _ _ 9_8_._1• __ .. _ ." 64._._.4 .. __ L' ...._._''' __ ,,_._._ 5,0_1._7,_.;_._ -- ;'Bl'a-'c-'k-""_'C_'h-'-e'-rit-:'-'-'-'-'-'O_'-v"a-'l ;i_._-__1._1._4._,0._'.-!-- .. -_ ..~.6_.9_.._5,' .-..-,~.- .- - .....-....6. -,.1_4•7.. _' - . _. !9\lart~ __ ,_I.3p.h.eric"l .:. _ l~l~? .. :_ 142_~J_; g,_0_l6 _ : Shale ,Oval ,104.3 82.7 . 6,682 I ,'-'_'-'-'-'- _ ..-_._._.;_._. __ ._._._._. -~., ,- - -- ... _._.-;_ ..... _--_._._._._._-_._._._ .. \ , ~u~~z_i.t" ' Spherical ··-·Ii-·- - 1-"6.2.._3.__.._-;- _ _l.2_1C~J. .. _._ J,5_,}6_4 _t ·"1"-'-'-- _._- 'Quartzite ' Oval '_'j-' __ -,10'_1"..1, '_"1"'_ ._.5!~_7 . ._412_69 _I"_·M'_'_'_'_"."_'_'~' "'" .-._,- ,.' __ . 'Quartz . Oval 144.2 .. ~~~§_._. .. _5.1~4_~ . \"'_, ...._._._'_ .--', ... _._.- •• '_'_"_'_""!--'---" , 9\lEir.t~_ _,__ "ph_et~cal_ _ _ _ 163.2 .1_2.9.~7 ~6_'.§:2.3 _ - 105 - DETERMINATION OF PEBBLE AREAS AT UNDERGROUND LOCALITIES. Locality: Western Holdings Ltd. No.2 Shaft. 33 1,'lest Ha.ulage Peg: ,,3787 Co-ordinates x + 30541.20 y + 34637.17ft. X + 9308.96 Y + 10557.41m • L'_Po,.r__p. ,h~,y_ r•.y _ Spherical ._.,_5._.1_..8__ ',_-- _" Spherical 86.4 56.1 ;'.Q- uartz'_-- SpherLccL l_l~._7_,__ ,~O,l:_~,_' _" ,}ë2_:J9" __ ~''1uartz Spherical 143.6 . _1,_06- .-.3_._. __ ._ .. _._1._2._,._0._1._6._'_ 'Black Chert ' Oval .- -1-13.7 43.2 3,821-'-'_' - .-._.-._._._.~._._._._._._--,_._._._._-- ;Quar!~i.~e __ Oval, ....... "- '_ - _.-- .-'_'_._'119.4 59.9.'-_. -:'---------'- _ ...."_._._._._ .._._5._,._-6-11 - - - - ;Qu'3rtz .J._-- S-p'_h'-'e_'r_'ica_l_ ._.~.- _._._._9._9.1- _.~._-_.- 8_.8_._.._7.~._._._._._,_._._._7._,._0.-10 !Quartzite Oval l'- .. "'-----1- 'Quartzite Oval 1•. ·.:..._ __}3'~~2",", ,~6,'~,~, , _5,,?~3_ __ :Black Chert' Spherical 99.8 71.4 ' 5,609 .! - _._., __ ._. _••• __ ••• '_0, _'_' __ ._ ...... _._. __ ,_._._, ••• _._. __ '_ • iQ.uartzite Oval 140.0 59.6 ..., ,132',8 , ,l_2_sl~4_ .: __ , __ .]-.~,_O3~_., _ - 106 - DE'EERMINf,TIONOF PEBBLE AREASAT UNDERGROUNLDOCALITI;;S. Locality ~e3ter~ IloIdings Ltd. 33 F;ast Hemlage Peg: F 91L4 + 500' Co-icr-d i.n.ct os X + 3')1'57.11 Y + 3316?96 ft X + 3.33 Y + 10108.07 ill. :rEBBLE TYPE FEBBLE SH/IPIS Sph(:rical \ X IS S CV'll f,: (; c t oC~ngul3.r /\ Axis C Ax i s (in,: ) (mm) :QU'lrtz ~_phcricc;~l 80.6 43.8 ,Sh",le Spherical 47.1 31.0 'Quartzite ,Spherical 65.2 32. 6 1,_6?~, , 'Quartzite Sphcr'ic.al \ ' •••• _,+ - - ~_ ... - -90--..1- _._._._ - .?~',8'l' , }J~0,. __, :~l~:::_~~tz 95.3 40.7 ;Qua~~z Spherical --1-- -_ _. - _. -- e5'~,L .3_.3-.6, ..- .,...,," ,Porp,hyry, +.- Spherical Quartzite ",8_p.h0r:L_cal 88.2, 4;J~7" , _~,~)?:'?, _ ~ Quartz S_p,her'i,c,,~, . __ , ~O_2.:;J_ , _ . _~8_.2_ ~ __ . _ , '~,.5.2~ _ , iShale , Spherical 91.1 51.4 3,675 •• _._. ._ ._._,.,_._. "_._. __ ;__ •• ._."_ _' __ ... . __ e • .-._._._·~·._._·_·_·_··_·_· 72.8 - --\- _._._.5-1..9-.- -j.-- __ ._.-._ 2-,'_9.6_5._ .... _. ,;Black Chert, C, 0",,:1 _'' __ , 78.._ 1__ " _ )~.) _:__ , .. _ _l1~57 ... , 'Black Chert Oval .' _, _. _1??·_4 _'5~~)_. __ .'5c{)~ ._ Oval 79.1 32.4 2,_D_l1 J •.• uc r t.z i,te Oval lOL 1 53:8_, ... 4_,~t2~., __ 180.2 102.3 , __._._14_l~?.9. __ .. - r"'-- - t :Blac~ Cllcrt Oval 123.6 '73.1 . _, _?J~7_?_ Bl'lck Ch er t _._- __ .- l_l.i_? -.0-_._.(.-- - _9'_'1_ .1 -_.\._ ...__ _1~'.'Y?~. _ ' _ . i Sha~:o . Spherical 112.2 41.1 .).,§~l_,__-' _._-1-'· ; '~iu8.rtzi te OV-3_] - .-4_3.-.9 ····.r - ... _. 3,.6_.9_6._ - ." : Qun.rtzite Dpheric?l - _... _,- - 61_ ..0.- - 3,878.i.__ '-"1--'- '.. .- ... ..... '_._.~. _. - • -j i QU'~Clrtz OV11 . - - 95.6--;' Oval 9'7.0 Quartzite . :::;;uG.rtz ; Quartz Oval 83 L . ....1_.-"T ••. _._._42.7- .•. _.'\._-_-_ .•.•. _._-_-_2-._-,_7.,_85 - _. 'Black Chert ' Oval _L ____ c:__ , 1l/'.3•'__ ~ __ ._._._. 89.8: '_'_'_'_'_'_' 8,C57 ._._._ •• ; Shale "' _l __ ,Oval '_'_'_'_ .. _ ..• __ ._9._1. .2__ -t._-- 51.1 .J' _'_'_"_'_'_'_'_3'_,'6_'5_'8_' __ ..--. , Quartz Ov n L 1------' ... --_ .. .l. _ 107~?, _24~Li._. __ ... 2_,000 _ ! Q-uartz I Oval'_ ... - .L. 88.0 .. ~o_._o_ L., __ 2_,_?§L _\-- - - _--, : Quar_~.zite . , .Spher,i.cal 71.2', -_.~._--_._._5._1..~0_!._._._._._.-,_._.2_,-8-5_.0_-- 1'B_-lack , r' 58' 48 '._._. __ C.he-_rt•.: _~_._._._- Ova__l -_._ - _ ._.- -I_I.:'.)...,_). __._~." .•"._,_, 3.·._._l ... _._ ......... _. __ , ._.7_.9- -'--'O"-'i ; , -Por_p._hy\ ... .._r._y .. -- _.~.- Oval _' l31..C. _._.~._ ... 35.7._,._t :__ ... ""_'_'_'3_'_,'6'''48 _°.0'_'_ ,. : Sh,,~e__ ,_ _ L _ ?"aL ___ ._. _g? :3, L _ 3_6:~ _,__ , ?~.i8)_ _ :S',:,,,:r_t,, ,__ ';_p?:,::i_c:,-~_1 8_?:!_~! ..• __.6_.2.3' ••.·L._._._._._. 4,25.9_._._._._._ 1' 'B.l,a<::l<_Gh."r't,.: ,Ova_l, __ ...., _1()?:7 ~7_.~ 2JnO _ - 107 DETI:m"lIHTION OF PEBBLE AREAS AT UNDERGROUNDLUCArrrrrs . Locality: Western holdings Ltd. No. 2 :3h,qft. 33 East Haulé-.l.ge Co-ord_inDtcs X + 30457.11 y + 33162.96 It. X + 9223.33 Y + 10108 .0.7 m. ~PEBBLE 'rYPE ,spherical i\ XES PEBBLE ,3Ef., Oval Rectangular A Axis C Ax Ls 1,A x ,tc2~ 3.14( mm) \mm ) lC.LODf(a ted ·~Q.:u_._a._r._t-_z-_i._t._.e_._._--._._.- Oval_._._._._-_ .. ;... _._._ 9-6_.,9_._'_.__._._"_31.0- - -.~-._.- _._._._.2_.,_3.)_7._-_._ .. , Shale Spheric-al- - 68.5 41.7 ~,?~~ •Black Chert Ova] 112.8 __ ~~~_4__ ~ 21~9_1 _ ',B- lack Ohert Oval- .- _._._ --9-_7..._8._._\_._ .. _._.3_-2_ .3 _._._'_._._.- 2_,4.-79-'_'_ ,, ~,)uartz- Oval - _'---'--r_ - - 1_.0_.7_..2_._.~ - --_5..8_.._8'_._-"--_--- _.- _.4-,947 :Qtlart~ite ,__ ,,-p!'_er:i_c:-_~_ , 7~:~_ _ _ _5§~:2_ ~ 3_,~0'7 _ : Black Chert _._ ~. Oval _4_'10-4-. - _._._.J_+._:._,_._._._._4._1.~..-3; _._._._.- 3_,.3_._8._/.+_._-_" •Pc:ry_hyry -'-_ Sph_erica_l_ _ __6J~:3_ }~._O _lJ ?5) _ : Qlll'-r:tzi!,,, t _?p~e!~~a_l J 97 ~l ~2_.? ~ ._O~L§ _ ,_Quar:t_z~to , _S}Jherical __93_:4 _ ., 74 ~2__ ~ 3_,J?:3_ _ 'Black Chert Oval 00; .---- 80t._ , _. _.._8._.",.- __ ._._._._.36.8 ._.1__._ ..... ·._._· _2_,.3'-'_3'-3'-'_-' Quartz _Spherica_l _ ,~__ 94. 9 _5_2~~__ , ]?_~O_;; __ Oval , 121.2 __ 2_4_.? __ • ?1.34__9 _ ~ t·_ -'_'_'_'_'_'~'_" , ShEile Oval 92.7 30.2 _._.;_.._ .~..-.. _._._?._,._197.. _._._- - , Quartz CV3.1 76.0 - __ 4._8..._9._' ._ .. _.!_-_._._. __ ._._.2_.-,917.... _._._---- Quartzite Oval _1?~._3 ~2:_0__ L_ _4!~t) _ (~uartzi t e Oval Ilf8.5 31+.1 41°_7.9 _, S;~_n~~z '-1 __S_ph,,!,~c?~ 68.0 54.5 2,909-----'1""' __ -_ .... _._._--:. __ • -·---·-·-·-·1·-·---·-·---·-·-·-·-·----·-'- Black Chert Oval 97.7 29.4 2,254 - -1'-'-'- _, ,_._--._._._._._. __ ._ i _-_,_._._._-_.__.._. ._,-.- ! Quartzite Ov">l 86.9' 62.2 4,<'/+2 \'" ._, - .. - ._,." .•-l' - .. '''1- _ .. - ,--_._._"'". ._.- _'-'----r-'-'-'_'_'_'_'_'_'_'_' __ .... Quartzite Oval -.- - --~ 102.1 --_._26..-.-7- _._ ..~._'--_._._._._._._2._,._1._39 - . Shale _._- 6__9.,_5 .' _ --, .-._.-"_.-._.-.-.-._._'- .. Quartzite ,S-ph--e_ri.c_a..l.'- _.. __..-\- _._- 9-4_.6'_'_')-'_'_'5-'9_.'3--_-'-ii'-'-'-'-'-'- 1_.-,_4_-3.2_._._---- Quartz Spheri_cal'_._.- -~-- _.- 8-4--.5_·._.-_ - 1+0.'7; 2,699_- ,,, ..... .. _. .... _._._,- _ . ..,._._. __ ._._ ..--_.- .-._,--- Black Chert .~ Ova] _.- L --_._.7-9.2- --~ _ -._-4_7._.2,-'.- -I-'-'-'--- -'_2',_9'-3-4-'_'- . Q--u_a._r.t_z-_i-t_e _.- --,...- .O..V_.3- .1... - _._,_._ .1._._._,_,1_.0_.Lf.8: ,_ .- -.4_5_.9-_. 3,775'-r- _.__ .. - _,_ -.-._-_ . _Po:phyr~__ c_Oval ,_ 91.7 31_.1_;- . __2_,238 _Quart_z_ ., Spherical L 87.3_, 63.7 __" ~,365 Quartzite Oval ... _:__ ._. 126.9._;, __,.. __ •..5_9_ .5._ .•. _I ._. __._._._, 5.,.9· _2_6........ Black Chert_._._._ ...O__v.a..l _._ ._._. J __._ ... 1_.1..4.1._._\_ ...._._.3_.9.0' ._ . .l._. __ ... _._._._._3,49....2_. __ ' ___ ; It_ua:!~ite __ : _Oval : ~~~?_: 3_1~~_L ? t~6f - ~?9::.~~_i"~e;. o_v:~~._,_"_ lOl,~._?.~ __"'_~_~)•_.?_,._L._._._._. __l~!.~c~~._..._ Quartz -(I .--s--.p. he- ric- a- l- _....7-8_.._L.~'-_'[~-'_ -- ·..4·_6·_.·2.. ·---1~-·_·_·· .. _,_._.2_.,_8._4._3.-._._. ( 91la_r_t:, ~t_e ~IJ1~(_r:~c_a_l 9_2~ )~: i?_ _ ~ 21-9_8) _ - 108 -- DETERMIN.'\TlON OF PEBBLE ;'-PEAS hT UNDERGROUND LOCALI'rlE::i. Locality I!esternHoldings Ltd. No.2 Sh::ft. 3.3ii;'.st Haulage Peg: F 914'++ Co-ordin:::ttes X 3O 5?11 y" + 33162.96 ft. x « 9283.33 Y + 10108.07 m. :,_PcE_B::B~L=E"-,_T_Y_PE , FEBBLE SH.\1'E Spheric'11 h XES FEEBLE i'1PEA Oval Fi eet angul ,"lr A ·\xis C .ix Ls ; tA x -jC x ~~<.14 ted ( mm; ( :nm) (, , ""~---,. .. .,,. .. ~ '-""'."'.' ,,,, ,'"," '''' ,:,.,. .. .". .. ..", "" ,,,,,,,,& '~'~I~'''',"",""',.~""'','' _'..'".'''' """"'_. 'Black Chert' Cval 89.4 33.6 Ov"l 102.2 - 6'-.4,- _9..- _. __ ._._. ~,/.,_.1_.0/_9-_._._._-- , Sph<:jric:.1J _l??~.! 4~._3_.~ __. ._)._,_'::5 _ Quartz Oval "--- 121.9 46.7' 4,468. _. - _ -'1- - - _._,_._._._,_-_ .._.- -'---i-'-'-'-'-'-'-'- _-_._._._- :':31",CK Chert -)v,,1 ,SI'.2 38.1 2,518 _._._._-_:'-'- _.- -'_'-'---'-'-'1-'-'--- _._.- _ ,..-.,._ ._.- - ._---,"-_.___. '._'_-'-'-'.~'-'- _-~', ,BlucK ehe!,! _,__ ~V~'l_l , '~7_.). ?~~_O_-r- ?!_C_6~ _ ;Quartzite llC.7 _. _3_5.._ .3._._.~ _._._.- _-_._3-_.,066- -·1· __ __ ._-_._ .. ! quartz -Sphe-ric.al J %.4 - _._.-51-._9._---~ --_._._._-_._3._,._h._3-_8._._. ~,Sh,s,lo Ova] 97.7 ;Black Chert Ova,l _____ L _~O_l_·L_, ~.3_.?_ ~ _ __ _ _1_,i3~6 _ Quartzite Sp_h,. e__ri.cal,._ - __ ('_ 8,_9" .- 9~_._ .,. _ .... ;__ .... _ ..5_._6._.._._2.:,...._._._.-_._. 3o._,._._9o65__ ._. __ ; Quartzi te , t·_· _S_p.h- e"r._ic."-'"l- _ ..- T .76~~ __~ §~~.5. . ).!?5;!.__ ,i ~~l.FJrtztie Ova L .. _5_l ~()_ . ~ ,_1_;_3_? ,; Quartzite Sph oz-Lc aL 92.0 57.7 4_,~ti6~- : Sh"le Oval 'Black Chert Ovecl \ Forphyry Cval 109.2. _,_, _ ._ )~~}_"'. __ ,_._ .. _._.~'.~'.:22__. Quartzite Spheric:al ss. 7 62.3 _____ ~! 337 _ : 5-,!_U,?~_tz_ SphericaJ 76.3 _3_8:~_ -, ?!.;51? __ '. 1 Dla.ek Chert Oval - 195.0 3-9-._9.- -,_._._.- _._._6._,._1._0-_7._._., ;. i QUClrtz ._. 63.4._._J_._._ Quar-t-~zite Oval" _- - - - _._ T _.1_-1_.3_.7- _._;- - _._4.6_..-0-. -,-.-.-.---.-.---4.,--1--0.5 ~.Quart_~ __.Spherical 97.3 51.8__: .__4_?,5.__5 ,\ Quartzite Sphc'ric31 88.8 i, Slate ~p_h_c-r~cal _ 67.1 _.- - __ 4._6._.._7,- ~_.- _._,_. __2,._4_ 5._9._-- _ .- , ouar-t.z t t c Oval 121.0 i -;-' - , Quartzite Spheric'!l _ 89.?__ . _5~~4 ),§i2C)_ _ + • Slate Sph0rica 78.2 61.7 3,786 .. -~---,- - - l .__ .- ·'-1'-'- __ -- - -'-',-'_---- _._._._,_._._. __ Black Chert Oval 123.-9 _._ -56.9- - - - - - -'_'~'-'-'-'-'-'_'-5'-,-5- 3-3- - Black Chert Oval 17-1--.3_.._ .. __ .9__3.. _2_ ._'_._.- _-_-_.1_.2- ,5-3_2'-- .- - 1 _" Quartz Oval 79.6 _-- _.2- ,;.2.'5-5--1 - --- ..... . !.._Q~artz Oval 108.6 -, ___ ~,_6§~ _ Black Chert Oval ll4.1 ___ 4,~1.4__ 1 _Shale Oval _i__l,4_.._5_ ·!..._ .•. _._36...... _0._'• ...l,_._._._._._._-_._.2_._,387 - ,_.- , P?rp?;yr;y Oval 107.0 3q~~ .32~lL_. ! J~u_a. _r.t_zi- te- Sp~erical 79.0 64.9 ~,~!?_~_.. : _Quil'ê~_iz__t: Ov_al ll]~~ )§:". 2!~3) . - 109 - DETERHINATION CF PEBBLE MiEAS AT UNDERGROUND LOCALITIES. Locality : W8stern Holdings Ltd. No. 2 Shaft. 3.3 y;'·,st Haulage Peg: F.9117 Co-ordinates X + 301,57.17 Y + 32926.42 ft. X + 9283.31+ y 100}5.97 m , - . _.- - - - --- - PEBBLE TYPE: P}~BBLESEl.PE Sp h er-Lc a I __ ;..._.Y_l.,ESPEBELE. ._,'-. . . .A_.R_.E_A_. ._ Oval i,xis C .ix i s , Rectangular (mm ) (mm) Elongated I .~, "": -" ',';::: '" '''', =: "': =:;;:c\ "'; "'; "';"",', =:;::,;::, "". "'l" "",.,. "": "" "" ,"": =-","~,"",,,,,,,,,,,,,,_,_,,,,,". __-,,...... ,..,,.,,"... .,..-. ..,..,.~;...-,:--,;._r: C;;' , ~1 .(• ~- u"n.rt,z _ S-p- herical-'" - -- _' ... - - :Porp.h_ .y.r_y." _. -__ Oval, - " ' '9~ar!,~~~e Oval 'Quartzit0 Spherical 17_._0.-.8,_._.~._._-_._1.2-.3-.7-'~'-'-'-'-'-'-1'-6',-5f_).L_.f- - _._, :Quar~zjt() Oval _I. __ 153.0 72.6 : 8,718- _.- - -'1'-'- ---'-'-'-'-~-'-'-'-'-'- _.--- -,_.__. ;Qu~:r:t~~~_e. Spheri~~l ,~_,_ 93.3 56.6 : 4,144. - - -j- _._._ •.• _.• _._._-_._._._._._._._._._ .._. i'r, -,luar t·z 1.t.e_._0_._' .. _.O_.v_a_ l ..,. .._.__ .~._.- 1-35.5' -~-·-·-·-·-9·3-·.2-·-1,-·-·-'-·-·-·-'9-',-9·1-·2-·-·-·- - ' ;,Black Chert Srh8ric_a! 89.,9, _•. _. _51_..0_.~---_._._._.- 3,n8 _ ~Quartzite Oval ... T __ 197._2__ ~ 8§!9. .__ ._1_",1'.5___1 i ,._. ._- •.. ;Quartzite Oval n4.1 I ._._' _. __.._._.•.••. _- . -'_._._1.4-4.1 "-'i- - ~1.:t " . :Black .C_hert t, S)'_herical nO.5 83.5 , , -- T--- ,;Sh:;1e _Sp_h:r::ic_a~ __ ~ __ ??._4_ ,_. _ "?~:3_ ~, 2l-'7.?~__ i, Shale Oval 103.3 ._5.-6'-."5 1' '-'-'-'-'- ._4.,"5,.8_1-_._._._., ;Quartzite Oval 131+.2 I _..' _.. --.- 'Porphyry 0'1'11! -- __ .. ,__ ._.- 173.6_. - 1--' "' . -- ,'Shale Oval 1.1_.2-.5- - i9u~.1.rtztie Oval 219.9 n4.21 _. _l_91?1_2_ , - ( i _~{uart~ Gval 124.8 , 87.:_9_L §,_61C: _, r- ;,Po:rphyr:y. Oval 190.1 _8.3...._3,,_' ,.L.. 12,1'30 • _--1'" ,Black Chert val -r-: .... lC3:~_, __... 1~8•~.6L )12~.4 : i,Quartz erical 92.2 _1·_···· __ ".5_1_ .._2._~_:._."._. __ ._._-3_'_,7"_'0_-5'_' \ Quartzite Oval 1()?~5 _ > 5_6:~L.._._.~t5_2.9 _ ! ' .' - -.- - . ; Quartz Oval _88:L " .. __~8.?_:,_ 2J6~91- ,... _. . ~Slate Ov"l 82.8 42·}_'t._ ... ·. . ._J. ,_ :~,_l9~__ : ~:u~'1r~~_i.~e Oval 134.2 52.2; 5,.'+98.:. - -;_. i Q,!~r_tz~t2 Oval 196.5 , 41:.9.j.. §t~6_2_, i,Black Chert Oval 92: 9__ ;. .... _._ .. _3...8.. ._9'_.\._; .. _ _ _ _2! ~36. ,~._9~ar_t~ _,_ :3ph_cric_al 87.0 _.- -5'-2.-4',-1-'-'-'-'-'-'-'-3',-'57-,8_._,_,_. , Porphyry Oval 107.4 . 3,-8""..3' y- - _._._ .•.. 3_.-,228_._._ I - .._, - .u _ ••• _. "1' - t- _.9-4_..7- - ~._.- -,_.-4.3_.._8.,~._._._._._._._.-.3_.,_2-5-5 , Quartzite Oval 11-6._3._,.- _._._._.- 5_.4_..5_.!~._._'-'_._._._._4._,.9_.7_5'_. ! _._._.--_'_ • ; Slate Oval B5.8 , . 8" , .- i-- .. _...._ 5,-6,.....2_'.,_._._._._._._ ..3",_7._·.._._.- I _.'_'_'" Qua:r~zi_te. ,, _.-Ov-al_.- - _._._._"_._. ._ 7- 2- •-5 _ ~_._.. ~3.6_..6_._i,_._.- _._._._._.2_.,_0.8_.2_._._.- ' ,Shale , Oval 101.2, I Quartz , ~P?e:r::.~~al '74._7.'.,. '1' _. ,. ,_",_. -6' 0_ ..•9", _.i~_•. _. _. _. _2,_:579 __ 1.- r Black Chert Oval ____ 97 : ~ ~2_~~ )_, ?~i+_ __ . - llO - DETERMINATIOONF PEBBLEAREASAT UNDERGROUNLDOCALITIES. Locality: '''estern Holdings Ltd. No. 2 Shaft. 33 East H~ulagc Peg: F.9117 Co-cor d i.n» tes X + 304.57.17 V. ? + 3 926 • I+2 ft. Z + 9283.31, Y + 10035.97 m , Spherical A XES PF.,BIjLE AREA Oval A hxis .-t- j~x'{s~.~..',""""'ZA x l"e""""'x 31.'1"~ . E0ctangular ( mm) (mm \ ('"0:2 ) Elo ;::-";:;:';:;;,'''' :..;:::' ''':''''C'''': ',".'-.,.-.::...,.- •.• e-..:. .. ..:."' .:.-;- ':"'""'1"'"""' .;....';;..-::,_....,:,..-:::..r: ;_-. :"'-. '_-. ".:".:.:' . ._-. ':. ":. -.~, -."; ,;Bl,~~.~._~.he-rt- ,~- Oval _.~~:7.1 .. ,,2~~,4,_... _ .. 3_,??7__ ,?,!artzite 142.0 ~Black Chert OVRl I -.. - I'Ina_ck Chert Oval 114.8 .51.4 _... _ .... ~!?3.1 ... ;Shale , 0r~e~~cal 69.2 ~. _ .. _~().§_ .•.•.. _1.>6§~ _. ,~q_~a~t~te.~ ~.r.herical ._._.- 98-.0- 3_1:~ ~ .. __ .' .2122')1...r- ~Qu;{rtz Oval _,,_._1'_1--9.1+ - - _ .. ::?6.} .:_ 3. LI-02_ .••. f •• _._.I ',_. . :Qu"'\rtzi te Spherical . _. \- -' _' - -_ - - . _. _.. n._6 .... _ .~8_.? .. __ •. __ .3_,~?7. _.1'-" iPorphy,:y OV,_'11 102.9 42.2, ï' _."-._ .. )!~o.8..... 1!i•.3h, .-.. ]" e _ J Elon_gated 93.2 3?9 ' 2,6~5_ t iB Oval 43.1i ..l-'tck Chert 192.1 i;-Q- ua.r.tz Oval 102.5;.._ ,_._.- ~Qua:rtz Oval'e - -.-' 84.3. _. __ .~6.:} .. _ _ _ . !J~l;_2.I' - - . - !!-B' la-ck _.C__h'e"r.t_ Oval 172.8 48.5 6,578__ .••.. -l- _ _. _>~._."'., __ - _._._._._._ .." ~" .. '-.'~j-'" !Black Chert C:val 123.7 I ._ . ,:~_l.a~e. Cv~l _ .? ,O.l? __ ,i ';;~uartzi te ,S:p118.r. ica~_ ... __ 4_,??L.~..... t \ :'~u,'3.rtzite CVE:1 121.3 ...~_,?{~4__._ ...I_. !,.sl!:lte _, .. Oval 132 ..0 46.5 . . 4_,_8!~ .. _' 'Quartzite , . Oval ~-- - _ - 5-- 1-. _3._._._._._._._.1- ._ !QU3.rtz 93.2 59.9 1+,)3~. 1-" ,'Black Chat 112.0 41.8 ._.3_,671~. : Q~art.z_ .. Spheri.cal 02.6. 66.1 .~..,.n::)~. :B1ack _Ch:,rt Oval 102.5 32.5 ,. _2_,.?14 .., i, ~_?-a.rtz_ ovaL 176.5 _.- 3. 8.0..._(.;_._._._.- .._. 264 ,; Slate .., _ _S'p~lc:rica~_ .. 88.3 ...... 5-p~~.~.•........ _._.)!?73. ,Porphyry Oval 1c6.4 ... ??.4.:_ _ .. ~!.2q( I ,- ......,_ ,...... _ ; :luartz Spherical. _ .; 99.3 :--. 46.5.' , .. _ _:,;:;2~ ... Po,:phyrJ , Oval 11 1+.9. 4_.2-.3;. - -~-- _.- _.- _.-),-8- 15 Black Chert 93.2 5.1. .-8_. -,. --' _3.,7~9 P",:phJ:::! _ .. , .1).",,1.. . __;. _' .l_0.7.:~ r' _. _ '?:l_:~.9••_:, • _/~,)?3__ .. Quartzite Spherical 76.1' 68.0' 4,061 ___.._. ,_._ ---'-'1'"'- - _-- . ",. - _. '~''''-'- _._. __ ._._.- ...... _. ._._'i_._'_'_'_' ' '_'_'_'_" Quartz 'Spherical 89.0; 61.3 i 4,282 •.. _ -.--- -.-.- ..•. "1 -.-.-' ." _. . ",1-' ,, i _._._J_._._._._._._ _._._._._ Quartzite Oval .. c. 121.9 . _ 4?.lL _4!50.6 ..._.._._._,_._....··t·· B1!lck Chert; , Oval 109.8· 39.5 L _3_,~~~... Slate Sph"r_i~al .. 89.0 . Slate Oval 100.0; 36.3 - 111 - DETERMINATIOONF PEBBLEAREAS_ATUNDERGROULNODCALITIES. Locality : W",stern Holdings Ltd. No. 2 Shaft. 33 East naulage Peg: F .9117 Co-ordinates X + 30457.17 y + 32926.42 ft. X + 9283.34 y + 10035.97 m. ;p.EBBLi Typi· 'PEBBÏ,Ë ·SHf,PE_ .. _.- .-. _. - - ---- - - _._.- - - _. - _._._---_.- - .. : Spherical' A XES ,PEBBLE AR : 0Rvalt 1 ; .. ,; ;,~:s-·· C·.~. ~:~~- -i-'-'-;~-~"t~-;~:E;A4- ,-'i , i ec angu ar , (\ . ( \' 2' ! iEl a t o d ! mm, ~ mm , ~ (mm). ! : -::-:s-: '_-. ';:é' .. :::.:: " ~ .'_"... .. .::::-.' : ••=~.:'._-,_~,-~~...::-:.;;...:;;:-::;::;:~_'::"' '-'.,;;:_:;,::::':;',:-' :,:-.-'.r- ..';<.'.~- ,-..;:-..; ,';;_',-_" .-"';_""~:-...:.,-...; l""_' :- ......... ..,. ':'':' ... ';',01.":'" ... ";" ':'-:'':'-:':'-:':''''f:,.-::.r.l ~lack Chert ! Oval ; .- -"---.-.- _._-- .• !--- ------------------'1'----i---'---"1'--2,_3'_.4--, -2_9·._7·_:·_ .. 2,876j·_·_· ...·_·_·_·_·_·_·_·_·_·_·_·-i i ~,Quartz ... _---;-,-_ S-p-_h.-er-i'_c"a" l __ . _'_'-'- .. "_9.-8._5._._ ......_._._._.4_.5_._.2.-:-._._._._._._._._._-_._._._3._,.'5! 49 '!Q_.-u-a'r- t.z_,i_"t_e. - ._. _. - ;i-' _S._p.h_.e.-r.i-c-a.l- ._.~.- ' 141.2 : 112.1' 12,42b,'.i.o. - _.- ._. _. _ ._. -:._. _._._._._. _. _l_'_ ._.- ._._. _._._ ._._. _._. _._.-~ ;Quartzite • Ova l, : 92.5; :~l_~.~-..~..·...·.--o·~~_l_·_·.·~...'.·-·~· .9§;6~_·.~·3~6..1~; .:;9:'?~.12~,6:2~1,~~·::.~. _j~-8_;§~·~.~ 1 ' 1 iBlack Chert Spherical . 117.0 7 .. _.- __....- --..._.. _--'-'-'r'- _·..·...·...·._·_·..·...·._·_·_·_3·_.·7_·.-1-·_·_·_·_·_·-·_·_·_·_6·_,·7_.6_.8_ ... ~'Q_.u-a--r.t.z,_.- _-_._._ "r'''-'-Ov_a.l__ ._._ _ +. __ ..2_7_9.._9-_._._.-- 1--_3._7.9 -._i ._._._.-._._._._._._3._0._,299: - . :Quartzite 'Spherical _. _ .~8_.:L_.. __ .6?~O__ i. ._._4_~§.~O_.__. ;~.- -.-._._,_._._ ....I-- --_._._.- _,_._._ ..- I !' i ,Black Chert_, __~phex:~c.a~. _ 183.4 119.3, 17,175. I .•..•. _ ... -_._ -f- .. _._._-- .-._.:._ .' - ...._..•._--j_._._._-_._._._._._._ ..... _._._.: ':Q.._u.a..r._t.z._.__. ._._._'t," _O._v._a.l-._._._._'_'_'l-".'_'_ .1_'5._9. ._5. _. _.:-._. _. _5.-6.._0,._ '-' {_._._. _._. _._._.7_.,_011._. _._._._: l,B-l-a_c"k'._'-Ch..e..r..t-'-'1 , -._O._v.-al_._-_._._ -._~'1_3._0.._6._' _ ._._._.:-._.__ 8._9._.5._._.,i.._._._._._._._1._0.,_5._7.8_:.-._._.-: iS_h_a.l_e.•. _.•_ .,._. ''''1'-E'- lo_ngated:_ ... _._,~....1_8..9..._1..:_ ..•..• _._._._5._3._..5' __-4._._._._,_._._._._._._7._,.9_.4_1: ...... I ; I' f ;Q.uar~z.. _..... ,_ ()V'll .. __ .. j. _. ~2_7_._~.: __ • _7_? ~ ~ . L __. ? \,3)? _. .: Q_._uar_tzite _ . _ O_val_ --_.- "'_''-'._'_'_'_'1_'8_'3" .5 -r-'- --- 6_2._.2: _._._._._._._._._.-._.8_.,_9._5._9._. ._. Q- -.u_.a- r'-t,-zi-t_e.... _._-- -ï: _...O. _v. _a..l. -" --- -- ...... '~1.-0.4.-.7- '... _. -'- .-~._. _ ... '-'_78._.9. _:. - '1'" '_'_'_'_'_'_'_'_'_'_'_'_'_'_"; 11,847: -S_h._a.l_e._ ... _._._--(_,._._Ov...a. l_._._._._.- -~'_1.-12-.-0~'._'-'-'- .i..-.-,·_·_·_4·_4·_.0·-,·-i·_·_·_·_·_·_·_·_·_·_3·_,·8_6·-8·_:·-'i Sla.t..e_._ _ ,; _S._p--he..ri_c._a.-l, --- -'.- .. - .. 98.9'.... _;._-_._.- 5_8·-.-3-·_·_·f-·_'_·_·_·_·_·_·_·_·_·4_ ,525; _·-·-r Quartz _._._.1-. 'S_p_h.e.. r, .i•.c_a,_l. ' __ ._ 94.0 83.5'_ .•• >0. _. __ • "'l"" .__.,._ ... _._ ._,_._ • .... _.1.._._._._._._._._._._._6._,.1_.6_.1_.:; -P._o.r.•p. -hy-,_r-y_._ - _ . .,!!-- _O._ v-a, l... _, -_.... _-- ·"ri .,,- -19--5-_.1. 57.2 , 8,759:'---1 ...'_'_'- -,_._._ •..,-_._._._._._._._._._._._._._._., _B , , 6 ',,_l.a_.ck C'.h__er._t - J ... ,O, va.l ,_._._ ... _.j.-._._. 124.._6._. --•._._._._._._-_6._.3_._.._0._,._._._.~._._._._._._._ ),159, ...~ .B...l._a-c-k._.-C--h,-er_t._ ._:;-_._S._p.h_.e_r.i_c,_a.l-.. _._.-:-. _._. _9._6..._7.__,. - '1' _._. _.6-,2_..5_:._.-j'_' _._, _. - ._. _.-4.,_7._4._3.' -._._.-: Quartzite : Spherical : 112.2 -,.--- ....-.- ..-----'-'f' -.---.-.-------.- - -.--._.- .....-. ---,'--;'''----'-'-'7-''1''-.7'-1; '-._'---'---'-'-'-'- 6,317_..- _.-._..~' Sha... l_e._. - - _ .. _.- -_-toi .••• O- ._, val . - ._._._. -. -;_._:' _._._123._._.--2; .j-<_.- ._._6..9_..7_.;_ 6,740:'''f'_' - ._.- ._._._._ ._._._._._.- ", Quartzite i Oval i 114.5' 88.3' 7,936 i ._ .. -. _. - . .••• _ ._1 ... --. -. - ,-, -- .... _. - -_.-- r ._.- _.--._.- - .,_;._.__..- ._-_._.- ~_._._._._._._._._._._._._. _._-;- Shale i Spherical • 105.0 i 92.8' 7,649 i ~~~_t~·.·_·~-.·.t-.·-(_)•~.·_~.Lï.-·..··.~_2_3:-~~_r_-_~_-?:~~~_~6._~-.r~7~i2§~-.~·.~J ~O_rR?:\':r:L.. :,__ 9':t:l... __ . _ .. 1.9.?: ~ _:,.. .6..l'_~2_+ ._._9J 4X_6 ..--i' _B?:~':t:_C!_l:r.t_~._._s'p~':r_i<:,:l_._.+1_2?~8_._;_._...._8_1:.?_.~_._.__ .__ ._:c!§.~~_...._.; _9~~:r:t__z.__._.~.. ~S.!'J:er_i~~~._:_ ' ~~O_~~•.~._.•._._9?:3... -i-. __._._.__ !1_,,?,!1_._._.j_. _Q!l~~z.i:~:_.c .. O':Ill_. __ ._ 193.2 ._ .. _1:()~~_6_~ ~5.~~~3.. ~ - 112 DETER!lINATION OF PEBBLE AREASAT UNDERGROUNLDOCALI'rIES. Locality : Western Holdings Ltd. No. 2 Shaft. 33 East Haulage Peg: H. 379 Co-ordinates X + 30194.04 y + 32305.60 ft. X + 9203.14 Y + 9846.75 m. i PEBBLE TYPE PEBBLE SH.APE. '_'-'_'_'-'_'-.- _._._._._.- .. Spherical A. XES PEBBLE :Y.EA..._, - -, - - ._, _._._. - ._._. _. - -_._ -_.~. ._. . . ._._._ ._._._.I Oval Rectangular A l;X~S C Axis -tA x ~C2x 3.14 'Elongated : (mm, . (mm), (mm) : ! ""; "": ~:c::. '.-_'" "" '" ''''' "'-'""";' '=:~,'::_',"" ,-_'::,'.:";", "": "'.":-':',...",,'.'-=.'.~.'':, ,_-,..."..,,_,_,,_._,V..',:;-;.,r.',•. ..r. '-"""...".t'",:..- .....,. ...r...._..,r"... ,.._, ............. ,-=..•• -:.. ••~ .• -;:.. •. -=:.~::=,=:::r:",i : guartz : Spherical' 170.4; 125.3 i 1 - '_'_'_'_"_ --- -:-_ - ''''_ ,-.- - - _-,_ -!- _- - ... ".,- - ---- ....... - .' - ._ .••. _._j_._._ . .,.._._ 1.•6.. l,_7._60 -'_._._._.~! i : S.h,,!e... ~ .. ~]Jher'ic.al _l_3.0~L .•. ~~~J.L_.._~(~!!:?~_, : : 9t1a.r_1;~~te ~Jl~er_ic:al j 20_5.?, .l_4.CJ~~., _ .. ?2.~2~3 .. _. : .'l':1t:.p"h,Y.!"!;_(__13);ll1e_r_.i_.<~;>_~..l.__~8_~7_.1 .._...~6_~_2 .L_. ._11§~7_. ) - 114 - DETERMINATIOONF PEBBLEAREASATUNDERGROULNODCALITIES. Locality: Western Holdings Ltd. No. 2 Shaft. 33 East Haulage Peg: IL 379 Co-ordin'ltes X + 30194.04 y + 32305.60 ft. X + 9203.14 y + 9846.75 m • .,.-._.-._,. _. -. _. - " .. _'- ,_ ._._. _._._._._. - >_. _ ..... _.-._._._ .. :PEBBLETYPE PEBBLESH;"PE Spheric'll A XES _.l_ .*._._.PEB, " BL,_E,_A,_R,_E,_A. __ ._._1 OV'l1 Rec tang uLar- ii f\xi,s C t.xis tA x .1..Cz_JC 3.14 :... .: E1ong'lted ' (mm;. (mm), (mm ,) : ;:..-'~ ,:_;'..: ,_:-..: ,:..::-..,;_::-..: '-r ""_7_"_":-""":"_";';_,, '_-.'_-.:,.r. "::-.'~I::';', .. , ... 0=.'. __ ·,-....: ,-.. '-"'T';_""'p"''_''''''''': :.r.-.;r'·_'·~".¥'·""'·;"l/IUJl'':'''''''',J6'#I.::.:.:'=;;:: \=,~ !!S._la._te.-._._._..._..~..:----S--p-.h-e.-ri_c.'ll-'-'-'-':~.'-'-'- 7_2.._1-;-_·t-·_···4·..8.3' 2 733 .·_·····_·_j- _._._ .._._._._~_._._._._._._._.; 'Qu'lrtz 'Spheric'll; 143.2; 1 f---" -'-' __ ' __ 1_ •• _""""_ - - -'_'_' ,_0'o. _'.0' - .• - "'f-- _'_0'_6'.9..'. _'_ 'r"._._._._._.-,_.l.1_._2._.~0._1._6._ ....;. :;'S-1--'l't-e"-'-'-'-'-'-~'S-'p--h-e'r-i'c-''l-l-'-------'-'7'--"-'-7'0-..-3.'-.~._,_._4.4_..0_.'_._.~._._._.__ ._.2_.L4.•2,8_._._._._._.:; ; S1'lte ,Spheric'll' ; "'-'-"_.~.- _._._._.'!'- ..•.•.. _.- _._.-._.- ---'t-·- _"'._5.6_..-8. ... 39.6r :r:»: - --_._'._.j_._·_ .... _._._ ..1.. ,_7._6._5._._._._._.1 ! ; Quartzite . OV'l1 . 123.3' 92.7: 8 971 ; ! ,....-•. _-_._-_ .. _._.- j'_'_'_'-'---'_' __ . __ .t'._. __ ._._._._.~ .. _.- .. _,_._.;-._._,_ .... _._._.'_._. ._._._._.! ; Qu5trtzite Oval • 146.0: ! ,,_._ .- _._-- _·_·· ..·1-,- .- ... -'-'_ "'_'-'_'_'-._.- __ '_'_'_":-'-'-'_'_'_9'_1'-.:-0'''';'-'_'_'_'_'_'_'_'_'_'_'_'-1'-'0i ,429 : ''1U9.r_t:?.;.,.-._.-.~.... --O--V_'.l.1.._ - -·-·-·-'·--;-·-·-·-1·-5·-1·-.·0,-.·-·---·-·-·8-·7-1.3--'-··-·-·-·-·_._._._._1._0._,3._4._7 ...;.. ;tI' : '--Q--U.. 'l_rt.z.. ".- -'_'-,S-p--he_r-.i.c-'l_l.'.- - - ..- .. ·-----.1. -1·-2·-.·3-·'··I-----·1-·1--0-·.-3·-'·-, __ ·_·_·_·_·..·9_,·7-·2-·3_·_·_·_· ..·._.;1 I : ~ . . ; QU5trtz ; Sph er-LcaL ' 171.2: 127.5: 17,134 ' j' .-_._._,_ .... - .. -'-Y"_ "'_.'_._'_'_'-'-.- -'1-'--- _.-.-._._ .... _ ..... _-_._._ ......... _._._._._._._._._._ ....._._.-·_· .1. ; Porphyry Spherical 106.0: 93.2: 7,755 ' I ..._ '''-._._ ------ -'-t" .•• -'-"-'_'_'-'_'-'-'-'T'- _._._._._._._._._._._._._._ ........._._._._._._._ ....._._._._._._. ___ : Porphyry Oval . 108.5' " 38.5. 3,278 t; "~'-'-'-'-""-'-'- ._ ... _._._._._._._._ J._._. __ '-'_'-"-;'-'''''-'''''-'''''''''-I'''''''''-'-'-''''-'-'-'''''-'-'_'-'-'''1 .: Sh- a-le ... ,.. -'-'_'''',- : _._S._p .h...e. _r._L._.c_.a_.L_--:--._._' ._ 18...1..._7._,._;-_. __13._2...8...,_._.-1._._._._._._._ 18...,.9. -4._1..... _._._._.J ' : QU'lrtzite • Spher-LcaL : 123.6. 64.3 l .-' .. - - -.---- -i·_·- ....·_· ... ---'- -'-"'ï-'- _.- - ...-..-.~_._._.-._' .-- _.:-...._. ._...._._.6_,.2_3._8._._._._.-.,.- ; Quartzite 'OV'l1 ; 119.5' 59.8' 5,609 : ! .. ,_ ..• ,- ..... ----""-'f-'-'-'_'_ ....- _.- _ ..... _.;- ...._._ ....... _._ . .l.._. __ .• _ ..... _._ . .I..-._ ..... _._._._,_._ .._._._._._._._.; 'S1'lte OV'l1 137.5 89.3, 9,638 ~_.... _._._ .. "'-'-'-'I--"- -._-_.,_.- •.~--- _._' ..,_.- _.- _····-·_·_·_·_·;--_·_·_·_·_·_·_·_·_·_,_·_·_·_·_·t , QU'lrtzite Sph er LcaL 326.5; 120.6, 30,909 . ;'~"-'-'-'" .... - .. ,_._J . _._- .... __ ~ .- .. _.-. ''' .. ï .. -'-'_':-'-'-'~"-'---"-'-'''''-'-'-'-'_'-'-' 1; Sl'lte _.-- .. J.. Oval _,L; .. ,_'O.110.. .-5'--_:_ - ..56.5_'".- •. ,_. _._._._._._._._._._._._4._._,899 . ..;, ; Q_.u_.a..r._tz.__.. .- S- ph..e._.r-._L..c.a._.L-_~. ._;_' .~.."'''.9_9,_.6..'.._~.......8._9.._0._._._:_._'__.._._,_6._,.9_5.-8'-,'-'-'-'-'-j' ; Quartzite ,Oval ; 153.3: 53.2' 6,401 ; I ..:...._. . -. __ ._ ........ - .._._ ...... ---- -. _. _. __ ._._. -._'_'."_' _.- ._, _. _._- --_. - ._~_ ._._._. _ ._-_._. _. _ ._._._._._-.., \ I '. ~ .,' ,B_l.-ac"'k-'-''''C-'-hert_; .,,_._.S-.p_h._e,-r, L__ca._.L.-._ 1•'- _.-1._7-9_..0-.:_ ...,._'_1.3_1._.._9._....-.:-._._._._._._1...8._.,5._3.3...'_._._·_·_·t i:-Q._U.-'-lr-t.z-_it"e._.._._.! ....._O--V....'_l.1- -'_ - ..._.;~ .. _1..5..-8._.5'_:._,_._._ 6..9..._1._:._.-;._._.-._._._ ....8..,.5_9._7._ ....... - ..---:-. ;;.B- l_a,_c.k_._._C._h._e.r_.tJ'._._._._O._.v_a._l._._ . _.~._._._._.9_.2_-.2_.;t _._._4._2..-4._,._; ..._._'_._._'_._._3.,_0._6._8.-._._.~ , 'Quartzite , OV'l1 84.7; 59.5, 3,955 ' I"-'-"-'-'--'~' - - - -.'-"-'_" ._-_._._, __ ._I._._ •. _,~.-- -'-'-'!-'-'-'---'- -'-i-'-'---'-'-'-'-'-'-'-'-'---'-'-i ! Slate • OV'l1 10 1 __ - - -- _. - - -~_. - -- - - -- - - ~ _._.-._ .• -8._..3_.'_~_._._._.-6._4._..-6i.,_._._._._._._._._._._._._.5_.,_491 ...;. S-.h_.5_.t_l._e._.-.-.- t:·_·_·_·S_·p_h-- er i".-c-'_a'-L _._•.- ... - 1-.1-.-9.-.--8~.'~.-._.- 112.6, 10,588 ;-'-'-'-r-'-'-'_'_'_'_'_'_'_'_'_'-'_'_'-! , Quartz • '8'-'-''1' - ,O_._V.-'l_1-. '_'-'-' _._.\;' -'-' _1.-2. 3_.._9._.~.-'-. _.7.5' 850 •I _.. _._._-_ ....._. _._.- '-'!,"'_' -._._._,_._.- , .-.1_._._'_._._~ ; • Porph·yryi _·_·_· ___-_-----_·_·-t-·_;· _S_·_p·_h, er._ic-_a.l.. - -'-i-, _... 2_.7-.0_..1- : -,....._1.5_6._..0_!'-._._~-._.-.-._._._3'_3._,0._7._5._._._._'_. ; , l'_():IthJ:X_._._;_._.9.~~} .__ ._.~._.__251~~}_L._;L~6_'?_._:_._._._._._.2.~,_2}.!._,_ - -.1 : 91l,,!_l:~.i:t_e__ .L._()~aI .~__._.J8~3_ i.__ )'}:,5__ L - - Sp~:or:i.ca~ 135.3; 79.4;il---.. .. .• --.- _._ ... _._._.- T·_·_·_·_·_·_···· 8..,·4_·3_·0_·'-· .. ·_·-t :Maroon Slate; .Spheri.::al , lC9.0' 81.5; 6,973: . . I ....•. _._._ --_._._. __ ._.~ ~~j'lroonSlate. Spherical , 124.1; 93.2 ' 9,079, ."'- _ -- - j'-'_'-'---'_'_'_'_'_'_'.-'_'-'_'" _._._ \"'-''''_'- _·_·-r-' ·_·_·_·_·_·_·-·· ..·_·_·_·w··-ï ;Quartzite Spherical' 154.9 150.6' 18,317. I ...---- -.-,,- .."----- "Y"- '---_'_'" _._.- .,----.- .... - ...... --~_._....-- -'-'-'_'_'_'-'_'_'_'-'j :Black Chert;. Sp~eric"l_ _ 402.6. , . _ .l?~. 3_~ .. _. __ 25..l_2~~ : :Sll"z:t_z._ .. + _ S_ph:r_i~al _', 3.'C3.._!'_>,. _ 104.8; .. __ . _ )?,_7_5~ ., iQuartzite i Spherical 281.0 160.5 ' 35,403 1.... · ".-._,_._.-._ .. -.- _--"., .. "'''_'_ ,,;. L • - - •• _ .1-- ..... _.. _._ ..... - ....._.- .--_._._._ ..\ ;Slate I Spherical ; 171. 3: 87.2 ' 11,725! 1--"·'-' ·_·-· ·4,·· _ .....,-._-_. __, '-'_'_'\_"" _._,- _,'_ ._-._._._._.;-._._._.- _ .•_._.. _._._._._._._.~ -Q._.-u-_.a_,rtzi..t..e__ , ... -i1._.-._.S_ ph..e. ri-c_.a. _l. -... 190.5'''1''. ---.-.- _.!- ._ 9...,3. .7.;. --1,_._._._._._._._.1._1._3._._8._.7_0 .:. Q-~u_a._r._t-z-,i_t._e._.-. ;__ ._S.-.-p- he_.r_i._c._al --_--~ '....... 40,.- .-0.....2_-:_ ..... _'_._._"-- 214....3...' 67_,\ ..._,_.- .... - - _ ...,..3_2._.3_.'_._._. P_o!'~t:y_r;_r. 1..S_p_l1~r:i_ca_!, .. 1~~._•5. -', .. 9?~2 I !~!9!~ _ Quartz 'Spherical 174.5; 161. 5 - 22,122' ... -1. __ ""__"_._, ", __ .. .. .I. ..._ .... , __ ._._._' __ '_'~ __ '_-_'4'_'_'_''''_'_'_'_'_'_'_'_'_' j Quartzite ! Spherical ' 211.0:-.t·- --_·~8·_4·.-0·-;,-I-·-·-·-·_·-·-·13,913'.. ,,- _...... - -.-.--.- _.\_--_ , .. --- ... -,,-- .... _t .._ -- .....- '- .. _.. -·-'-·-·-·-·-·-·i Slate 'Spherical' 134.0; 63.9! 6,721 i .. _-- ... _.- ._. _...... _- _._~. -- .... --' ....' _._ '-._'-'''' _, .1. _. _ .... _- .. --- ... -.t ....__.-, --- .-...~_._._._._._.-._._._._._'-'-'-'! .Q..'_.u.a_r-t-z--i-_t-e._.._-.,.,...~! ._._S.p_..h,,e--r-i_c.a_l-_._.-.;_.- _._-_1.9_3._.3._- -ii __._._1.5_1._..5_'-_.~._._._,_-..-_2.2_,.9_.8..7._.!._._._..~ ..Qua<>r,.t_z.•i_t._e _ .. ~;._. __Sp....h,_e..r...ic_._a.,_l,_ .. _.+.:-,_-_._. 12_8.....2. "'.-_,i__ ._.,, 46.6 I._._.---I._ ...•. __ ._._._._._.4_.,_6._8._9._'--,! 91l~r.t:;_ ~ ._Sp~Elr_i.c1i~_;.... 310•8.,. ._7_2~~L n,_7)7 _: Maroon Sla te; Spherical ~ 268.1 I 100.8 ' 21,046: "'-"-'~'''.'-'_'-'-'-'-'_'-''.'.''-'-'- - - ..... ~- - - - - t- - _._ - - - - -t- _.- - - - - -'_'- - - _._ - , _Q._u...a. _r.tz-_t·c_·,1· .. ·O···.v. ·a_·l .. - _ - ... -,:11~0......2- _ ....._ ..... 61.3 5,302_.I"'" ... ~._._._----I._._._._._._ .... _._._._._._._._.~ 'J.P. orp._._.h_._.,y_._.ry __ ;( Ov''''a'''''l''''_'_'_'_'''1'_ ; .. _._.269.0"._'._.~ __".1..2_.6_._.2._ ..J',._._._. __ ' 2'_6'_,'w6"4_'_8'_,'_'_' 'Quartzi te i Spherical 131+.0 101. 6 ~_.w __ ._ .... _._ .... -_._.~._. -,-j. -_._._ ..- _· ..··--_·_· .. ·_·····_I·,·_·.. ·_·_·_.._·_1·_0·,_6·_8·_6·_,·_·_·-'i :Quartzite ! Oval 153.6, 52.4, 6,317' .... _. _·~__. ._·_·_·4 .._ - _._._~ __ . 'ï'-'-'- _'_'_'-:-'_'_'_'_'_'_'_'_--'_'_'_'_'_'_'! ;,"S_l_at.e_. _ ... _ ._._._.~. ' _._O...v.._a_l... _. _._._._.J '1...1. _8...-0.,.. _._._ '-"-r _._ ._.4_.9.-0'-,'-i' _._-, ._.- _._4._,5._3_.8.-' ._.-._._~ i;-Q.._.u_a..r..t..z.. it-e- -_, - -.. -ï,'-O' _v.a_l._----,_...._._.-;,-1..9.--1".7' _._._-_.~._._1.0- -0_..5_'._ 15,123,''1'' _._._._._ ._._._. _. _._._._._._; 'Black Chert , Oval . 163.0. 1-'" .. ,-- _ .... _.• ,···.. -t -.. -,-_, - ._,_, _. _. ---i--" _ ... " .... _.. - _. - .:- ._._,11_.2_.,-6,_, ..... _.- ._._._._. 1-'_4,'_4'0-'7-';-'-'-'-j !Quartz Oval '152.3: 93.2, 11,142' I _ _. .., '_""'1'''''_ .--._."._ ."- ,,"·1·· _._._._._._._._.- _·_·_·_·_·_·.-·_·_·_·_·_·_·_·_·_·_·_·_·_ -r i_Q...u. _a. r_t. z_ i--te_ --_. .:.. _.-,S-_p._.he_.r_i.c-a-_l.;_. _._._. __ ._1._7._1...0. _._.' _.- 1-"2_3. .-7._..._ -_._ ..... _._ ..... _1. 6_._,6-0_.4_.._._._,_ .. - n8 - DETERMINATION OF PEBBLE AREAS hT UNDERGROUND LOC"LITIES. Locality : Welkom G.M. Co. Ltd. No. 3 Shaft. 30 Level Connection to J.V.S. Co-ordinates x + 28329.87 Y + 22133.56 ft. X + 8634.94 Y + 6746.31 m. _'-'-'--_'_'-'---'--_--'_'_ - - - -'-'_'_'_'_'_._.-._._ .. PEBBLE TYPE PEBBLE ,slL',PE ; X '1<; c; P1i'BBL~\ _R, VA : Spherical i'- -'- '_ - ,'_._ -_::.. ~ _._, _" _. _ ----1_._ '_ .i:":__. ~f.I~_.~~_'._._._._;. Oval !\ texis C ,his . it4 x iC 3.14 : Rec tangu l.ar- (mm) (mm) (mm, ) ; Elongated " , ".-o::~.::::::::!" ,.:::t .":.' -Or.-.-:'·'·""i' :,',=', ,~,.,=::~.'.""'':,'_. ,-'_-'...c-, '_-. y-,.or. ,_. ,-'-,~.-' ,_-, :.."~,...,.~ ,-_';".-.'~.'':'.,..-..< ..- ....r.'.-_,,..._. .-._'.._....-.;........~ ..=....'..t:,::', r::;,'::: : ..... ,: ....... .11"' ........ c,.-oi Black Chert' Oval 90.1, 41.3' ! -'-""-'.-. - ._._._~'_. __.-._.- - -'_._' ,...~- '_-_-_-_-_--'-;'--_-_-_------'ï'------_-_'_-_-_-_-_'_'_._._._-~ 2,920 ' i; B-_la'.-c..k.-.,-.C_h._e-r.t-' --.-._Sp--h_'e.-ri-c_a.l_: .._.._.-:- -'_._.-3,3_..6..;_. . 32.5,'-1' - .~- _. _. _. - '-'-i' _._._._--._1._,4._0._6._._._._._.'~"~ ; Q1l_..a.tzit_8 -:_ Cl:"éll_ - . - -' ?~+~~i..». 3.. .. ", _ .. __ ~1§~6_.... ,_.... ' ! Quartzite : Oval ,74.4 48.6 2,837 , ~"-"-''''- ..- _._ I ._ .. ---- ... ;--_ . ._-.- -.- _..... - .....\-_._._._---_._._._.-._._._._.- i s~r:-l_~ .. ~_S_p_1H',:~ca..~ ~__ •. ~2:9 . ~ .. 3..4:~. _ -' ••. __ .~,_l:?.L, , : B~ac_kChert ! Oval nO.l' 55.6: 4,806 ; 1 _._._ -''''1'' .•\.. .. 1'- -'---'-'- - ..---.-._._._._._I : Shale . _ r _Oval , 73.7;- ~3_~l~, r- _ •. _~,_4§~__ .. ,_ i; C._h-e_rt__. _._._ I\..O..v_al._.-,--_._._._.-1~0_3.,.3-.-;- 47.5' 3,852 ,--'j- _•. _._._._._._."'._._._._._.-.-._._._._._._._._ i; S-h'-a.l.e _'_Oval 74 8 39 9 2 342 'I " •• _"_ .,1 •• _.,__.,. _,_ ,;,,._Q, u..a_r.t_z.- _._ J'S_phe_._r.i_c._a. l: __ ._._._;_ 118. 2._:._, .._., __ 5._0-_..3_._._- ._•.. _._._,_-_._._._._._4._,.6_._6._7 . '..J :Q1l_ar!z::it_8 ,' Oval __ ,, . ~?_2__ •. !~~...O.._' _.. _,.2,_3_?2._._ I Chert Ov eL 92.8 38.9, 2,83 1 i"'- -""-'T- ----.--t.---- .. --.-.-4.--.--.- i ::;ha_le Oval 77.4 49.0, 2,978 _ ........... ' - r- • . _._ ---'--',..-._._.,_._._,_.-.~-_._._._._._~ ; Qllcu:tzite Ova L 106.1 35.8 2,981 I "C -i---' .- -···1 _·- _,_._._._._._._-_._._._.-,- ,iShale -,_ - --_. -._. Oval _.l_. ._._1._0, 7._2·_,._1 __ ._6. 7__.3._,_._J ... _._<_._._._._._.5_.,_662 .. ._._._ ,;Sh"le Oval.,. , 113.7 61.0 _i_ •. ?,~4_4§.,__ ,__ i : Bl",ck ~]'18rt .;_ _Oval _. _ ~ .. _ .71=_5._, 4?~8. __ t., __ ,.... .?1,~07. '_' 'Black Chert Oval , 78.5 42.6, , ._.L,_ - -._ ~._.. .. _'_'-'-'-ï-'- _._._._._.2_,-5_9._0._...._._._._; ,;.Shale _...~--Oval ..- r, _. 86.4 '3..1- .4.--_ 2,130'-·-·1-'''· ._._._._,_._._ .... _.-._._! ! Black Chert: Spherical; 76.1' 54.0 _ 3,227 ' (.. _._. - ._ .•. ,_. -,-._._. _. _. _'_._. -. - ._/_. _._, - _. - '_._ ...(..•. - -_. - _._. - '-j' _. _. _._ '_. -, _. _._ ._ .• _._. - '-'- I Shale I Ovs L ; 85.3_·,_·_.·_·_·_-_4·_'·1_·._2'-t,I _._,_ 1'- ... .. - ,'_ --_._._-- -·_·_·_·_'_·_·· 3,.1. _6·_0.... ·_·_·_·_··; ; , Bl&ck Chert; Oval 72.8: 40. Lf' 2,308 , I.. ''' __ '_'_'_',_' __ ._._,_._._._._._.,..._._. .. __ . __ ." _.,_._. '_'~ __ '_._'_'_'_'_'_'_'_'_'_'_'_'.'. ~U_ar~,:~te Sp~er.i~al __ > __ .87.6 ; .~9:?_J .. .)1~9.1_. __ .: ~ I Black Cha'r-t'-'ri ..,S_p.h_e.ric.-al!._.-_,~,- 60..9_._.,C _.- 45.0' -'·_·_·_,_·_·_--_·.!·2_·_·1_·5_·1_·_·_·f ' Black Chert' Oval 102.4 -c- - 31. 4 ~• ~'-""_"_'" ._-t- .J ... _. - •. ..._,.~__._ ' "_'_'_2',_5'_2'_1'_'_'_'_'; , I __Bl._a._.ck__ C._.h_e_ rt;._.--l._ S.,,".p, herica. _l_:._. __ . __-- 8. 9__.1.'. _._~._._. _'_5'7._.._7._.,_;_._._._'_._. 4,0._3._._7._._'_._ I Black Chert! Oval 95.5' 51. 2, 1"- -.------- - -.- _... -:-- '-'--- -l'-'" -' ... _'_'_'-'_'_'-'-'---'_'-'-'_'-'_3'-,'8_'4-'8j II B_l._ac..k..... -C_h._e.rt:- ~....O....v. a..l --'-'-----ï-'-, -._ .._8_5...0. '_ ~.- ~.-4._3._..8_'._.-i'-'_.-._._._._._._._._2.,_9._2,_0.-.I ! Q_. u-.~a,._rtz..i..te_ .... __ . ~'._- _O.. _v._a. l _._ '_'_'-. _.:-.; - ._". - ....6"0'_ .8._'.. 1_, _._._3. 3._2. ,_. - 'j'" ,_._._. 1.,-5-8._4."._' ._._._.~.. ._Q._u._a.r_t_z . _. . __ ~_ ,_S, .p..h_e._r, ical; ... ._. _. _. 10..9..._8._'. _ i_._. _.5".8._5. ; . _._._. ._._ ._._5,'0_'4_4. _ ._. _._._ ..: B..l.a l! ..c,.k_._...C. -h.-e.r.t.." .i_._.S_.p_h._e.rical i I 8 6 ' - '-.- ·_·-·_·t· _,_. _.-.3_7.-."2. : _.:--- _.3_0. ".0.-. _.- tI :_._._._._...7_.,._-.""-'-"1 \i .B..l_a.c-.k--..C..h-._e.r.t.·:···l·'''·-O-.v.-a-.l'_._.-"·---·-·-i:-· ..._._._8._0.._1;'_'--;'-_' ._3.8_..6_;._..-_~_._._._._'_2.,_67._9._._._._._'._._.~ i_~_u~:t:.z_i_!:,.,.,:_,!. _O.v~,l•.:__._,_,_.i.. ,]:~~~_4_,~._._,~1_.,~ i-.- .. __ .... ?.,§§6_._.__ ,__; \ \ \, . i_I3_1_a~l<_C_h-,,:~i.0JZI:e!.~<:a_1. -,; .__?~~_9_.;,. .§~:!? .. _.~ _,_,_. __ ,_,~ .._9'J,2,_,_ ...... : 1, !. , ;j ,.S_,h_a. _le._. _._.~' -.- ..'.,O_-..v_a. l_. _. _'-' _. - ._. - ·,t·_·_._._.8_0._.8._.-ii-'~'_3.0_.8._!.-...:.-...-.._._-._1._,9.-5._3_. .-.-,_._~;.i \, ..S-h._a,_le._._..--- ._-.-~;....-O_v,_al..._."-'_'.". _' -t-i·_ ,_.-. -'_87''.''1-';-1- ._.- '4_7._.4._!...._. .;._._._._._._.3_,2._3.9_'_._._.-._.i, i _.S_._h. a_le._.£_ .. _ . __ _'.. _.1.! .. _._S. p_.h_.e_ri..c•.a_l.;... _. _, ... _. _. _. _. _.5_4, ._0._;. _. _. _._._3._0. .5:_ ..... _._ ,_. _. _. _._._. 1_,.2_.9_2._. _. _. _._._ ; - 119 - ]2ETERMINf,TIOONF PEBBLEAREASAT UNDERGROULNODCALITIES. Locality : WelkomG.M. Co. Ltd. No. 3 Shaft. 30 Level Connection to J.V.S. Co-ordin:1tes x + 28329.87 Y + 22133.56 ft. X + 8634.94 Y + 6746.31 m. _._-_._'_._._.~._._._._._._._._._._-_._._'_._- , PEBBLETYPE FEBBLESHAPE ! OSpvhaelrical A XES 'FEBBLE AREA!'. _,.' ~ - - -_'_'- ~, - _._._._._._ .... _._._._._._._._._._._._._._._.: , ! Rectangular \, ",11. /.~x,';;;lc:C" x i~ , i,J ' 'c 3 14 'Jl 1.0 ! 2 :' x;? t· i , Elon a t ed ~ (rnm ) ; (mm), (mm) , .-'_';'-:""-'--"--"--"--"":-"7-',<0: ',:::':C' ~q.:..;::":=:..=- ....::-.~~ '"C', \,,,,,:_-,:,_,-C -0-- :_"' ..:,_..,-"'"_C-":' ",--,,,,,,-"~-_. ,...._ •• ~ •• o:::. •• '::: '_'':;' ',-=-' .,;.,.::::.=- •."'....r..J":;?: '-""" •• "0_'_' ,_3. 1__.9.,_.1..'_._ .••. _._._._._.1_._,.3_._95 ..•• _._) ; ,i Quartz Spheric'll 83.7 .. 6-2,_..1-_. - .'_._ -.- -.-._. - -_. 4_,_,0-,8_.0- '._._._. _._, ,' -"'1--- "•. - i Shale Sphc,rical 37_.1I' - . ._._._. ._ - 3..0- .4·_·t·-·_·_-_·_·_·_-_·_·_·_·_8·_8·_5·-,t '1Q._. uartzite ~.~- Spherical 81.4 61.8 . 3,949 •.- 'r" .- _ ~- _.) .... _ .... -_._._._._._._,_._._._-._ .•. ! : Ch e r t Oval _._ 8-8._ ...8_ ,.. _--,._._._.-_._L.-7f. 4_.~' _._._._._._----_._3._,._.3_04 ..... _.-: :, c;hert Oval 100.6 i Quartz Sph8rical, - 9-'3_.'2__ .-.-._._._6._(.'-.0 _._._. __ ._._ .....4_-,_3. 9__0 ._._._._ .. ' ~ _._._. 'f"- _._-.--_'_'- .... i Quartzite Oval 65.3 43_._ °'_.'~ _._ ..-._._._ 2·,20i ....... _ .. ' ··_··4··_·_·_·_·--1 , ,iShale Oval 79.4 43.4 , 2,705.--- .. ..'. --- -I'W" - . - -'_""'" ._----_._._._._._._._._._._._.\--"- ! Quartzite _Spher,i",a:l ' 108.9 56.1 ; 4,796 :__~. .__ '_'_'_'4'_'_ - _. __ '-~-'-'-'-'-'-'_'-'-'-'-'-'-'-'-.p I .' -" ,i Shale : ,Spherical _.57_._:5 _._..:_ 33.0 .__._._....}J.~9?_. !., .. . , i Quartzite Sl;'herical 89~4_, .i, , 5...3-.0- -'f _.- _._. __ .3...,.7-._1._9..._._._ .•. ---: I ..._. --.- .-- _. -. - .~- , Quartzite Oval 80.4, 40.0; 2,525__\_._ •• _._. __ . " ......... . ._._ __ ___ .,_._-~ _.. __ . '_'_'_'_'_"_"_'_ ,.4 I _... , .__.__-'._ :3uartzit.': .. ,c_Oval 115.9 61.5 ""~',5_9~,, .. _,: : Qtlélrtz Spherical, '" 45.7 )): () ,', .. , , __ _l" ~84_, , ' , ; : Shale •__ ._._. _ .O_ ..v~RD l'lCNENTMEASURES MEAN SIZE 1477.69 1287.98 1258.47 SORTING -1031.03 -1048.0')" SKEWNESS -0.97 -C.56 KURTOSIS 0.70 1.19 NEAN DEV. SIZE (SQ MM.) AT CUM. PERCENT ;GES CF. 5% 3663.6 16% 2508.7 25% 1859.2 50% 908.6 75% 644 •1. 84% 446.7 95% 148.6 :leSee Fig. 14· - 141 - PEBBLE-SIZE DISTRIBUTION BOREHOLE f'1H5. SAMPLE LOCATION "ESTERN E()LDINGSLTD. COORDINATES s: 1+1480.82 x, 24494.45 Y+ 12S1t.:;.3 X+ 7465.9 DEPTH 1239 - ~h?9 feet (377.6 - 801.3 metre) ROCK TYPE ELSBURG CONGLOHER \TE SIZE IN SQ IvjH. NO. OF PEBBLES. 0//U OF l1(}T,"L. CU!1UL~TIVE% 60001 70000 1 0.01 0.01 50001 60000 0 C.O 0.01 40001 5COOO 0.02 0.03 30001 - 40000 33 0.U2 0.05 25001 30000 2 0.01 0.06 20001 25000 7 0.05 0.10 17501 20000 16 0.10 0.21 15001 - 17500 31 0.20 0.41 12501 15000 67 0.44 0.85 10001 12500 109 0.7.1 1.57 9501 10000 130 0.85 2.42 9001 9500 169 1.11 3.53 8501 9000 211 1.38 4.91 8001 8500 262 1.72 6.63 7501 8000 221 1.45 8.08 7001 7500 142 C.93 9.01 6501 7000 157 1.03 10.04 6001 6500 181 1.19 11.22 5501 6000 208 1.36 12.59 5001 5500 274 1.80 14.38 4501 5000 234 1.53 15.92 4001 4500 332 2.18 18.10 3501 4000 261 1.71 19.81 3001 3500 274 1.80 21.60 2501 3000 289 1.89 23.50 2001 2500 313 2.05 25.55 1501 2000 327 2.14 27.69 1001 1500 444 2.91 30.61 901 1000 440 2.28 33.49 801 900 563 3.69 37.18 701 800 598 3.92 41.10 601 700 543 3.56 44.66 501 - 600 961 6.30 50.96401 500 997 6.54 57.50 301 400 1430 9.38 66.88 201 300 1690 11.08 77.96 151 200 1297 8.50 86.46 101 15C 871 5.71 92.17 51 - 100 726 4.76 96.93 25 - 50 468 3.07 100.00 INHAN FOLK & ',lARD t;mlEHTHEASURSS MEAN SIZE 2464.57 1831.64 1895.25 SORTING -2267.37 -2441.07l!' SKEWNESS -1.70 -0.86 KURTOSIS 0.90 1.68 MEAN DEV. 3032.42 SIZE (SQ ~IM.)AT CUN. PERCENTAGES OF. 5% 8724.5 16% 4731.9 2596 2384.7 50% 565.8 75% 277.2 84% 197.2 95% 95.8 14· - 142 - PEBBLE-SIZE DISTRIBUTION BG8:~HOLIê FHl. SAMPLE LOCATION ',IE3TERN HOLDINGS LTD. COORDINATES y+ 34292.67 x- 2331+1. 95 Y+ 10452.4 x+ 7114.3 DEPTH 1994 - 3803 feet (6l7.7 - 1159.1 metre) ROCf; TYPE ELSBURG CCNGLCHER/,_TE. SIZE IN SQ Hh. NO. OF FEBBLE3. CUMUL.\TIVE % 60001 70000 o { . c 0.0 50001 - 60GCO o c.e C.C 40001 50000 C c.o O.C 30001 4ccoc o r ," .r-' C.O 25001 30GCC C C.O 20001 25000 o c. C' e.C 17501 2COOO o (', .(', O.C 15001 17500 (0. .,~,\ C.O 12501 15000 1 C.Cl O.Cl 10001 12500 3 c.e2 .G3 9501 10000 6 c.c4 0.C7 9001 9500 14 (',..lC 0.17 8501 9000 22 (.16 0.33 8001 8500 15 C.ll 0.43 7501 soco 2C ['.14 C.57 7e01 750(\ 28 0.77 6501 70CO 41 C.29 1.c6 60C1 6500 5C c' .35 1.42 55Cl 6ccc 67 c.48 1.89 5001 550e 126 (.89 2.79 4501 5CCC 124 (.88 3.67 4001 45\1C 233 1.65 5.32 3501 4ccc 359 2.55 7.87 3CC1 350e 564 1+.00 11.87 2501 300C 761 5.4:: 17.26 2001 2 1325 9.4, 26.66 1501 2000 1456 JC.33 36.99 lOCI 15('( 1277 9.06 46.04 901 10ce 802 5.69 51.73 801 90C 3.55 55.28 701 8(;(; 673 4.77 6C.05 6Gl 671 4.76 64.81 5C1 600 465 3.3L 68.11 401 500 511 3.62 71.73 301 4cc 435 3.('9 74.82 2C1 30C 545 3.07 78.68 151 20C 686 4.87 83.55 lel 15C 619 4.39 87.94 51 100 1092 7.74 95.68 25 5C 609 4.32 1CC.GC FCLK s 'I;WD HCIIC;NT MEASURES HEAN SIZE 1518.89 1359.85 1399.52 SORTING -1348.56 -132l •82" SKEWNESS -0.87 -0.45 KURTOSIS 0.58 0.88 MEAN DEV. 1426.00 SIZE (SQ MM.) AT CUM. PERCENTf,GES OF. 5% 4347.1 16% 2867.5 25% 2338.8 50% 1C41.8 75% 345.7 84% 170.3 95% 79.9 lESee Fig. 1'1-. - 143 - PEBBL&-SI,ZE DISTRIBUTION BOREHOLE BD1. SAMPLE LOCATION vlE3TERNHCLDINGS LTD. COORDINATES y+ 33184.93 x+ 30253.18 Y+ 10114.7 x+ 9221.1 DEPTH 2149 - 3789 feet (655.0 - 1154.8 metre) ROCK TYPE ELSBURG CONGLCMERi,TE. SIZE IN SQ Ni,. NC. CF FE:BBLES. CUHULATIYE % 60001 700CO o .0 c.o 50001 60{'00 o c.c 0.0 40001 5COOC o c. 0.0 30001 40coo c c.c 0.0 25001 30000 1 0.00 20001 25000 4 C.C2 0.02 17501 2CCCC 3 CJ)! 0.04 15001 175GO 12 c.c5 C.09 12501 150CC 17 C'. (8 0.17 1('001 1250C 28 c13 0.30 95Cl l()000 34 (:.15 0.45 9001 9500 25 c.a i 0.56 8501 9000 32 C.15 C.71 8C:Ol 850C 21 C "li', 0.80 75cl 80cc 37 ,.17 C.97 7001 7500 35 (.16 1.13 65Cl 70CO 75 C.34 1.47 6001 650C 87 0.40 1.87 5501 6coo 78 ...3.5 2.22 5001 5500 115 0.52 2.74 4501 5000 178 C.81 3.55 4COl 45CC 279 1.27 4.82 3501 4ccc 264 1.2C 6.02 3COI 35cC 38c 1.73 7.74 25cl 3CCO 578 2.62 lC.37 2001 250C 681 3.C9 13.46 15Cl 20CC 9c4 4.11 17.57 lCU 15e(: 659 2.99 2c.56 9Cl - leeG 1592 7.23 27.79 8CI 90e 2128 9.66 37.45 701 800 2cc4 9.1' 46.55 6Cl 700 1892 8.59 55.14 5Cl 6eo 1936 8.79 63.93 401 5ec 1628 7.39 71.33 301 4cc 1341 6. r;9 77.42 201 3('( 1136 5.16 82.58 151 2CC 913 4.15 86.72 101 150 863 3.92 90.64 51 100 968 4.40 95.04 25 50 1093 4.96 lCC.OO INW,N FCLK & Wi,RD Hc!jBiITHEI1SURES MEAN SIZE 1082.93 958.74 1:60-.64 SORTING -858.19 -1050.1231' SKEWNESS -1.65 -0.56 KURTOSIS 1.39 2.49 MEAN DEY. 1497.59 SIZE (SQ MN.) •;T CUN . PERCENTAGES OF. 5% 4174.6 16% 1941.1 25% 1066.2 50%, 710.4 75% 390.2 84% 224.7 95% 75.931S'oe Fig. 14· - 144 - PEBBLE-SIZE DISTRIBUTION BOREHOLE DHI. SAMPLE LOCATION 'AiELKO!G-OlLD MINING CC. COORDINATES y+ 16104.65 X+ 10861.92 Y+ 4908.63 x+ 3310.71 DEPTH 1211 - 2795 feet (369.1 - 851.9 metre) ROCK TYPE ELSBURG CONGLOMERATE. SIZE IN SQ HH. NO. OF PEBBLES. 0p' OF 'rOT j\L. CUMULATIVE % 60001 70000 0 0.0 0.0 50001 60000 0 C.O 0.0 40001 50000 0 0.0 0.0 30001 40000 0 0.0 0.0 25001 - 30000 0 G.O 0.0 20001 25000 0 C1.0 C1.0 17501 20000 0 C.O 0.0 15001 17500 0 C.O C1.0 12501 15000 0 O.C 0.0 10001 12500 0 0.0 0.0 9501 10000 0 C.C 0.0 9001 - 9500 0 0c..0o 0.08501 9000 0 0.0 8001 8500 0 0.0 0.0 7501 8000 0 0.0 0.0 7001 7500 0 Cl. (I C1.0 6501 7000 0 O.C 0.0 6001 6500 0 C.C 0.0 5501 6000 0 C.O 0.0 5001 5500 0 0.0 0.0 4501 5000 0 C.O 0.0 4001 - 4500 0 C.O 0.0 3501 4000 C C~.t'.j. 0.0 3001 3500 2 (j.03 0.03 2501 3000 1 (j.Ol 0.04 2001 25CO 0 C.O 0.04 1501 2000 0 C.O 0.04 1001 150(: 3 0.04 0.09 901 1000 0 (" . ,--,/ \..,: 0.09 8Cl 900 4 0.06 0.15 701 800 0 C.C 0.15 601 700 6 0."9 0.23 501 600 21 0.31 0.54 401 50C 76 LE 1.64 301 400 328 4.77 6.41 201 300 870 12.64 19.05 151 2CC 1073 15.59 34.64 lal 150 1545 22.45 57.08 51 100 1716 24.93 82.01 25 50 1238 17.99 100.00 INHAN FOLK & VI {,RD hChENT NEASURES MEAN SIZE 172.95 162.40 SORTING -101.65 -101.12" SKEWNESS -0.72 -0.38 KURTOSIS 0.63 1.03 !-lEANDEV. 115.16 SIZE (SQ HII.) il.CTU1<1. PERCENTAGES OF. 5% 380.0 16?c; 274.6 25% 221.9 50% 141.3 75% 89.684% 71.3 95% 48.1 3fSee Fig. 14· - 145 - PEBBLE-SIZE DISTRIBUTION BOREHOLE MB2. SAMPLE LOCATION \I/ELKOMGOLD MINING CO. COORDINATES Y+ 16247.60 X+ 26629.55 Y+ 4925.3 x+ 8116.7 DEPTH 1164 - 2433 feet <354.8 741.6 metre) ROCK TYPE ELSBURG CONGLOMERATE SIZE IN SQ MH. NO. OF PEBBLES. % OF TOTAL. CUMULATIVE % 60001 70000 0 0.0 0.0 50001 60000 0 0.0 0.0 40001 500CO 0 C.O 0.0 30001 40000 o 0.0 0.0 25001 - 30000 0 0.0 0.020001 25000 0 0.0 0.0 17501 20000 0 0.0 0.0 15001 17500 0-- e.o 0.0 12501 15000 0 0.0 0.0 10001 12500 0 0.0 0.0 9501 10000 0 0.0 0.0 9001 - 9500 0 0.0 0.0 8501 9000 0 0.0 0.0 8001 8500 0 0.0 0.0 7501 8000 0 0.0 0.0 7001 7500 0 0.0 0.0 6501 - 7000 0 0.0 0.0 6001 6500 0 0.0 0.0 5501 - 6000 0 0.0 0.0 5001 5500 0 O.C 0.0 4501 5000 1 C.Ol 0.01 4001 4500 5 0.06 0.07 3501 - 4000 7 0.08 0.15 3001 35()0 15 0.17 0.31 2501 - 3000 19 0.21 0.52 2001 2500 27 0.30 0.83 1501 2000 39 0.44 1.26 1001 1500 44 0.49 1.75 901 lOCO 101 1.13 2.88 801 900 319 3.56 6.44 701 800 393 4.38 10.82 601 700 357 3.98 14.80 501 600 628 7.01 21.81 401 500 843 9.40 31.21 301 1+00 924 10.31 41.52 201 300 1339 14.94 56.46 151 200 1276 14.23 70.69 101 150 1041 11.61 82.31 51 100 952 10.62 92.93 25 50 634 7.07 100.00 INMAN FOLK 8, WARD i',OMENTMEASURES MEAN SIZE 375.48 348.23 342.13 SORTING -257.95 -254.20'" SKEWNESS -0.71 -0.38 KURTOSIS 0.60 0.94 MEAN DEV. 351.07 SIZE (SQ MN.) AT CUM. PERCENTAGES OF. 5% 890.9 16% 633.4 25% 516.6 50% 293.7 75% 157.0 84% 117.5 955: 64.4 *See Fig. 14- - 146 - PEBBLE-SIZE DISTRIBUTION BOREHOLE ENKl_ SAMPLE LOCATION WELKO~I GOLD MINING CO. COORDINATES Y+ 24163.74 X+ 28203.97 Y+ 7365.1 x+ 8596.5 DEPTH 1751 - 3354 feet (533.7 - 1022.2 metre) ROCK TYPE ELSBURG CONGLOMERATE. SIZE IN SQ MN. NO. OF PEBBLES. % OF TOTAL. CUMULATIVE % 60001 -- 70000 0 0.0 0.0 50001 60000 0 0.0 0.0 40001 - 50000 0 0.0 0.0 30001 - 40000 0 0.0 0.025001 - 30000 0 0.0 0.0 20001 - 25000 0 0.0 0.0 17501 - 20000 0 cl.O 0.0 15001 - 17500 1 0.01 0.01 12501 - 15000 3 0.03 0.04 10001 - 12500 3 0.03 0.07 9501 - 10000 0 0.0 0.07 9001 - 9500 3 0.03 0.10 8501 - 9000 4 0.04 0.14 8001 - 8500 2 0.02 0.16 7501 - 8000 0 0.0 0.16 7001 - 7500 4 0.04 0.20 6501 - 7000 8 0.08 0.27 6001 - 6500 14 0.14 0.41 5501 - 6000 21 0.21 0.62 5001 - 5500 12 0.12 0.73 4501 - 5000 18 0.18 0.91 4001 - 4500 64 0.63 1.53 3501 - 4000 31 0.30 1.84 3001 - 3500 43 0.42 2.26 2501 - 3000 55 0.54 2.79 2001 - 2500 83 0.81 3.61 1501 - 2000 126 1.23 4.84 1001 - 1500 317 3.10 7.93 901 - 1000 581 5.68 13.61 801 - 900 51+3 5.31 18.92 701 - 800 1607 15.70 34.62 601 - 700 1023 10.00 44.62 501 - 600 893 8.73 53.34 401 - 500 671 6.56 59.90 301 - 400 837 8.18 68.08 201 - 300 1240 12.12 80.19 151 - 200 873 8.53 88.72 101 - 150 357 3.49 92.21 51 - 100 486 4.75 96.96 25 - 50 311 3.04 100.00 INMAN FOLK & \-IARD HOHENT MEASURES MEAN SIZE 561.26 570.44 647.18 SORTING -344.23 -418.78!E SKEWNESS -0.93 -0.16 KURTOSIS 1.36 1.29 MEAN DEV. SIZE (SQ MM.) AT eux. PERCENT AGES OF. 5% 1724.2 16% 905.5 25% 811.8 50% 588.8 75% 293.4 84% 217.0 95% 96.1 !ESeeFig. 14. - 147 - PEBBLE-SIZE DISTRIBUTION BOREHOLE WOl. SAMPLE LOCATION WELKOM GOLD MINING CO. COORDINATES Y+ 15399.59 x- 5765.99 Y+ 4693.8 X+ 1757.5 DEPTH 3671 - 4306 feet (118.9 - 1312.5 metre) ROCK TYPE ELSBURG CONGLOMERATE SIZE IN SQ MM. NO. OF PEBBLES. % OF TOTAL. CUMULATIVE % 60001 70000 0 0.0 0.0 50001 60000 0 0.0 0.0 40001 50000 0 0.0 0.0 30001 40000 0 0.0 0.0 25001 - 30000 0 0.0 0.0 20001 - 25000 0 0.0 0.0 17501 - 20000 0 0.0 0.0 15001 175CO 0 0.0 0.0 12501 - 15000 0 0.0 0.0 10001 12500 0 0.0 0.0 9501 10000 0 0.0 0.0 9001 9500 0 0.0 0.0 8501 9000 0 0.0 0.0 8001 8500 0 O.C 0.0 7501 8000 0 0.0 0.0 7001 7500 0 0.0 0.0 6501 7000 0 0.0 0.0 6001 - 6500 0 0.0 0.0 5501 6000 0 0.0 0.0 5001 5500 0 0.0 0.0 4501 5000 0 0.0 0.0 4001 4500 0 0.0 0.0 3501 4000 0 0.0 0.0 3001 3500 0 0.0 0.0 2501 3000 0 0.0 0.0 2001 2500 ? 0.05 0.05 1501 2000 0 0.0 0.05 1001 1500 1 0.03 0.c8 901 1000 1 0.03 0.10 801 900 0 0.0 0.10 701 800 4 0.10 0.21 601 700 3 0.08 0.28 501 600 8 0.21 0.49 401 500 48 1.24 1.73 301 400 111 2.87 4.60 201 300 341 8.81 13.41 151 - 200 526 13.59 27.00 101 150 710 18.35 45.35 51 - 100 942 24.34 69.69 25 50 1173 30.31 100.00 INHAN FOLK & WARD HONENT MEASURES MEAN SIZE 146.89 136.57 118.48 SORTING -89.33 -90.453f SKEWNESS -0.88 -0.43 KURTOSIS 0.69 1.05 MEAN DEV. 105.89 SIZE (SQ MM.) AT CUM. PERCENTAGES OF. 5% 346.0 16% 236.2 25% 186.6 50% 115.9 75% 68.8 84% 57.6 95% 43.8 3fSoe Fig. 14. - 148 - PEBBLE-·SIZE DISTRIBUTION BOREHOLE AR1. SAMpLE LOCATION 14ELKOM GOLD tUNING CO. COORDINATES Y+ 19202.81 X+ 140°3.25 Y+ 5853.02 X+ 4295.62 DEPTH ROCK TYPE ELSBURG CONGLOMERATE. SIZE IN SQ MM. NO. OF PEBBLES. 0,0/ OF TOTAL. CUHULATIVE %. 60001 70000 0 0.0 0.0 50001 - 60000 0 0.0 0.0 40001 50000 0 0.0 0.0 30001 40000 0 0.0 0.0 25001 30000 0 0.0 0.0 20001 25000 0 C.O 0.0 17501 - 20000 0 0.0 0.0 15001 17500 0 O.C 0.0 12501 15000 0 0.0 0.0 10001 12500 0 0.0 0.0 9501 10000 0 0.0 0.0 9001 9500 0 0.0 0.0 8501 9000 0 0.0 0.0 8001 8500 0 0.0 0.0 7501 8000 0 0.0 0.0 7001 7500 0 0.0 0.0 6501 7000 0 0.0 0.0 6001 6500 0 0.0 0.0 5501 6000 0 0.0 0.0 5001 5500 0 0.0 0.0 4501 5000 0 0.0 0.0 4001 4500 0 0.0 0.0 3501 4000 0 0.0 0.0 3001 3500 1 0.03 0.03 2501 3000 1 0.03 0.05 2001 2500 0 0.0 0.05 1501 2000 0 0.0 0.05 1001 1500 2 0.05 0.10 901 1000 1 0.03 0.13 801 900 1 0.03 0.15 701 800 5 0.13 0.28 601 700 19 0.49 0.77 501 600 67 1.71 2.48 401 500 291 7.43 9.91 301 400 486 12.41 22.32 201 300 722 18.44 40.77 151 200 687 17.55 58.31 101 150 568 14.51 72.82 51 - 100 623 15.91 88.74 25 50 441 11.26 100.00 INMAN FOLK & 14'loRD l'lONENTMEASURES MEAN SIZE 245.91 234.29 204.60 SORTING -155.53 _147.80"" SKEWNESS -0 •.4.8 -0.27 KURTOSIS 0.49 0.87 HEAN DEV. 150.35 SIZE (SQ MIL) AT CUH. PERCENTAGES OF. 5% 516.6 16% 401.4 25% 336.0 50% 211.0 75% 118.7 84% 90.4 95% 54.4 ""See Fig .. 14. - 149 - PEBBLE-SIZE DISTRIBUTION BOREHOLE ~ffi6. SAMPLE LOCATION \VELKOMGOLD MINING CO. COORDINATES Y+ 12163.0 X+ 23040.0 Y+ 3707.3 X+ 7022.6 DEPTH 2593 - 4370 feet (790.3 - 1331.9 metre) ROCK TYPE ELSBURG CONGLOMERATE. SIZE IN SQ MM. NO. OF PEBBLES. % OF TOTAL. CUMULATIVE % 60001 - 70000 0 0.0 0.0 50001 - 60000 0 0.0 0.0 40001 - 50000 0 0.0 0.0 30001 - 40000 0 0.0 0.0 25001 - 30000 0 0.0 0.0 20001 - 25000 0 0.0 0.0 17501 - 20000 0 0.0 0.0 15001 - 17500 0 0.0 0.0 12501 - 15000 0 0.0 0.0 10001 - 12500 0 0.0 0.0 9501 - 10000 0 0.0 0.0 9001 - 9500 0 0.0 0.0 8501 - 9000 0 0.0 0.0 8001 - 8500 0 0.0 0.0 7501 - 8000 0 0.0 0.0 7001 - 7500 0 0•0. 0.0 6501 - 7000 0 0.0 0.0 6001 - 6500 0 0.0 0.0 5501 - 6000 0 0.0 0.0 5001 - 5500 1 0.01 0.01 4501 - 5000 2 0.03 0.04 4001 - 4500 1 0.01 0.05 3501 - 4000 4 0.05 0.11 3001 - 3500 3 0.04 0.15 2501 - 3000 6 0•0.8 0.23 2001 _. 2500 6 0•0.8 0.31 1501 - 2000 9 0.12 0.44 1001 - 1500 14 0.19 0.63 901 - 1000 12 0.16 0.79 801 - 900 39 0.53 1.·33 701 - 800 84 1.15 2.47 601 - 700 139 1.90 4.37 501 - 600 308 4•.21 8.58 401 - 500 531 7.26 15.84 301 - 400 968 13.23 29.06 201 - 300 1486 20.30 49.36 151 - 200 1121 15.32 64.68 lal - 150 713 9.74 74•.42 51 - 100 827 11.30 85.72 25 - 50 1045 14.28 100.00 INMAN FOLK & WARD MOHENT liEASURES MEAN SIZE 266.19 259.92 247.74 SORTING -183.07 -180•1.4'" SKEWNESS -0.52 -0.22 KURTOSIS 0 •.60 0.93 MEAN DEV. 252.11 SIZE (SQ MM.) AT CUM. PERCENTAGES OF. 5% 635.6 169~ 449.3 25% 381.2 50% 247.4 75% 122.9 84% 83.1 95% 50.8 lEsse Fig. IJJ. '0 o o __'-o oo o o OJR.1. v o 0 v o o o »>: o00 o 0 oo o o o vo 0 0 o v o o o o / OMH .4. v o o o o o OTR. v o OMH3. o o 00 o vo o o "OTR 3 D o v o o o v " 0 o v v vv ' .. v OTR.l. vv v - -- $-v \ v v vv v v v v v OFH.2 v \ vv v v v v v v PLAN 1v OTR2. OE F.l v v I vv v v v v v v v \ A GEOLOGICAL MAP SHOWING THEv v • v v v j PRE-KARROO SURFACEv 'Iv v v \ vv v and the Subouterop of the ElsbJrg Stagev v ,v vv v v YJ&skm f/oldti;j5_ and Wa/kom void Mmdv , v v OFH I Scale /20000.v v v ID ,I' $'1,,-- V e,,",,P,?Sn..,-- V " v °OB.l. vv vv vv v Legend v v v v v v v _ Uppar ..ayav v y v v I _ c.lppt1r SC0i.77t1?tS ) )-.,,1_- lIla __ ---'" . " I • :t~_'_ ';§l.. -,.-'" .. , - , .• , 7-- I: I- ,I_--, " ~ i- 'i- / / ,J_ _'!l.' -r---.... , --~-,~ - -.- --.." '. - - -TI •- 30 - _-3-1 \ - " - 1-000- ~ \-- " "- \ \ • ~c ,'ëc .Jc " - \ 1_ eso " - • - " =i:I'" s;- ..fFL;;/h4 YvFSTE'RV ,'IOI.!:,'yti$ FiT.£E S"'~"T£Oe.:JJ.:.D., ':JLD ),I,VE óoca V/.'\I, ,JO.:._' )!'y£, CONVERSlON TABLE 10 feet 3'04 metre, 50 " , 5·24 II 100 II 30-48 u 500 " 152'4 .. 1000 .. 304-8 u PRES/DEi..,;- S-§"Y.'I' ,J.JLD ) I,VE L()CALIn DiAN SCALI; "/,:H).OOO 512 .. 128 o M H .. TR.3 • + + _---_\__ 8 o .3 SHAFT. Pl,AN 4 oEF.1. o TR. 2. 4 LITHOFACIES MAP SHOWING THE CONGLOMERATE-QUARTZITE RATIO o o oFH . SCALE: 1:20,000. N°1SHAF. + + + + oDH.1. o GED.1. .1, oMTK I - o ALo JBW. 2. - -A- . _ 2 -- -- .... oJVS. o N~J SHAFT. .. - - - - g/AL.)NC?1 Veort. Vent. - - - .. ----- - WINZE./ -- - ..-- ..-- -- -- / oMB.8./ tC)_(JtJtJ + ( o N° 1 Vert. Vent. (WINZE. + + oW.6. oMB.9. DAR. . oAR.3. \ \ N~1SHAFT. / - +-; \ oMB.3. 0 MB.1. TJ \ N? 2 SHAFj oMB.2. / . DH.1. o W.3. / --- »> /_.........-- - --- »>:- ----- ~ ~ ~ ~ <:5 °u'2. (B8 l~i ~/4ootJ =- -+ lOCALITYPi A ry SCALE I ISqt}(J(J @ @ JR 1 • o @ @ /757 &6 5'lmm • • • • o 0 o '"' @ @ @ @ • • •• • • • o 0 '"' '"' @ @ ® MH 4. • MH. • • • 14524 MI1.3 TR .50 o'"' Ol "ftnl1?sse e • • • • •• $~mrn TR.3. • o e e @ @ • • • • • TR.4. o s Ol e @ @ • • • .....--.c 0 o o o TR 1 Ol @ @ @ • • • • • • • \ \ o o G Ol ® @ © @ @ @ PLANEF.2 3 \ /791 $1 o o Ol e ® @ @ @ @ 5€m. m ® • • o o G 0 @ @ E:= 1 @ ® ® • Welkom and Western Holdings TR.2 o o @ o o 1£5$ 470 Ol e Ol @ @ @ @ @ @ sf-117m Gold Mines o o Ol e e e e Ol o @ @ @ @ @ @ @ @ @ @ o o o o e Ol ® @ @ @ @ @ @ @ @ o ISOPLETH MAP OF PEBBLE SIZE \ o o o e e e o @@@@@@G@ o o o c e o ® 0 @ @ @ © 0 \ @ \ o o o o o ® o o e e @ @ @ (5) SCALE: 1:20 000. \ u ' F N° 1SHAFT. o o o o e 1.1.9.9 52 @ @ @5; mm \ W2 SHAFT , BO.1 0 0 o o e o @ N° LA Vent SHAFï. \ 1060 é'4 0 0 o o o e e e si mm 18~~ zooa "i mm o o o o o o o o Ol 0 16tJtJ \/800 "'I. mm , o o o o o o o o o o /400 /óOO :Jf mm o o o o o o o o o o o 0 I!~O +140t) Sf. mmI o o o o o o o o _+0 o 1000 /10(J Sf .'17m o 0 eao lOOt) SIJmm o o 0 600 800 Ji, mm MTK 2 1 I JoO 350 250 30j Sr mm 65,f J3 sa mn? . • Mrl\.3 zoo - .2.5"0 ~qmm N~ 150 - ZOO ''i. mm 1 = -I o - /50 Sq mm ENK 1, MTK 1 _LD' ;~ __ _:64.£71="s~mm-. -___ -- JVS ---- VPfl. 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