DEPARTMENT OF MINES

GEOLOGICIAL SURVEY OF NEW SOUTH WALESCi. ROSE. DIRECTOR

THE MINIMAL INDUSTRY OF NEW SOUTH WALES

No. 43

URANIUM

Compiled by J. L. Willis and B. F. J. Stevens

Manuscript dated M y 1971

Issued under the authority of theHon. Wat. J0!r, M.LA,t Minister for Mines md Power

I SI ] K419340Q1-A

C O N T E N T S

Page

I N T R O D U C T I O N 5

U R A N I U M M I N E R A L S 5Primary Minerals . . . . • •. 5Secondary Minerals . . . , . . ... . . . . 6

PROSPECTING 7

T R E A T M E N T 8

USES 9

M O D E O F O C C U R R E N C E A N D W O R L D DISTRIBUTION 10

URANIUM DEPOSITS IN SANDSTONE 12

AUSTRALIAN DISTRIBUTION 13

NEW SOUTH WALES DEPOSITS 15

THE BROKEN H I L L PRECAMBRIAN PROVINCE 15

Thackaringa davidite belt 17Mundi Mundi , Brinkworth Well, and Eldee Creek areas 19Hen-and-Chickens lode . . . . 20Great Western lode 20Broken Hill line ofiode 21Copper Blow lodo . . . . . . 21Corona . . . . . . . . 22Other areas in the Broken Hill district . , . . . . 23

EARLY TO M I D D L E PALAEOZOIC G R O U P 24

Blackfellows* D^.n deposit, Condobolm-Nymagee district 24Carcoar deposits , . . . . . 28Whipstick deposits 32Miscellaneous areas . . , . . . . 35

T H E N E W ENGLAND (PERMIAN) G R O U P 38

Torrington-Emmaville area . . . . . . . . 39Inyerell area . . . . . . . . 43Watsons Creek area . . . . 44Gordonbrook area . . . . . . 44Miscellaneous areas 45

GENERAL CHARACTERISTICS AND ASSOCIATIONS OF U R / . N I U M

OCCURRENCES IN N E W SOUTH WALES 46

SELECTED BIBLIOGRAPHY 54

Key to Localities on Spot M a p 5U

THE MINERAL .INDUSTRY OF NEW SOUTH WALES

No. 43

URANIUMCompiled by J. L. Willis and B. P. J. Stevens (July 1971)

INTRODUCTION

Uranium is a radio-active, silvery-white metallic element. Thereare fourteen radio-active isotopes of uranium, principally fissionableuranium 235 (0-71 per cent of natural uranium) and non-fissionableuranium 238 (99-28 per cent of natural uranium). Uranium occurs innature as the oxide, uraninite (pitchblende), and as a constitaent of manyprimary and secondary minerals.

To date there has been no mining of uranium in New South Wales,although there are known occurrences in the Broken Hill, New England,Pambula, Carcoar, and Condoboiin-Nymagee areas.

The sections of this publication deaf ing with Australian distributionand New South Wales deposits were taken largely from Rayner (I960), butchanges have been made where more recent information is available.

URANIUM MINERALS

Primary MineralsUraninite (pitchblende), UO2 in pure form, is always partly oxidized

to U3OR. Thorium may substitute for uranium, giving a complete seriesbetween uraninite and thorianite (ThO2) in artificial preparations.Uraninite may contain from 75 to 90 per cent of uranium oxides, theremainder consisting of lead, radium, thorium, yttrium,, nitrogen, helium,and argon impurities.

Uraninite is a black, brittle mineral, with a submetallic to greasy orpitch-like lustre, brownish black, greyish, or oiive-green streak, specificgravity of 7-5-9-7, and hardness on Mohs scale of 5-5 to 6. It forms cubicor octahedral crystals, or a combination of the two.

Pitchblende is the name commonly used for non-crystalline varietiesof uraninite, often with botryoidal or reniform structure.

In New South Wales, uranisite occurs at Carcoar, Whipstick, andBroken Hill, and a mineral with the appearance of pitchblende occurs atBlackfellows Dam, near Bobadah.

Davidite. The formula of davidite is uncertain, but the mineralconsists essentially of FeTi?O7 with U8+ and rare earths substituting forFe2+ and Fe3* and V substituting for Ti. Da-ndite contains up to 8 percent uranium oxide, and is similar in appearance to ilmenite with which itis associated in the field. Davidite is dark brown to black in colour, with, asubmetailic to glassy lustre, dark brown or grey-black streak, specific

gravity of 4-5, and hardness of about 0 on Mohs scale. When crushed it isattracted by a powerful hand magnet. Bavidite was first unearthed atRadium Hill in 1906 and desc» ibed by Mawson in the same yw In NewSouth Wales it occurs in the Thackaringa area of Broken Han.

Brannerite has the probable composition (Ut Ca, Fe.Tfa, f) (Ti, Fe)aO6)is often hydrated due to alteration, and contains approximately 32 % UO3.Brannerite is brittle, yellow brown or olive greets En colour, with a resinouslustre, specific gravity of 4-2-5-4 (depending on hydration), and hardnessof 4-5 to 5-5 on Mohs scale. Absltet a thorian variety, was discovered atCrockers Well, South Australia, ia 1951 and described by Whittle (1954).In New South Wales, absite occurs in the Thaekarioga area.

Coffinite, UtSiO^^OH)^, a major mineral m the Colorado Plateausedimentary uranium deposits, has been identified from Glen Esk innorthern New South Wales.

Euxemte is a niobate and titanate of the yttrium and cerium groups,usually containing some uranium and thorium. The tnineral was reportedfrom Euriowie, Broken Hill district, by Mawson (1912%

Fergusonite is a niobate and tantalate of erbium, with minor amountsof other rare earths, uranium, thorium, calehim, iron,, titanium, etc.

Samarskite, a niobate and tantalate of yttrium and cerium chiefly,contains minor amounts of uranium.

Other minerals in which minor amounts of .uranium can also bepresent are monazite, allanite, orthite, xenotirae, tantalite-columbite,microlite, biotite, zircon, ruttie, and fluorite.

Secondary Minerals

There are a large number of secondary uranium minerals, most ofwhich consist of phosphates and arsenates sand, to a lesser extent,vanadates. These minerals have the general formula of A(UO2)2(XO«)a. n H2O, where A=Ca, Ba, Mg, Sr, Cu, Pb» Fe, Mn, Co, Ni, Al,Na, K, (NH4), or H, and X=P, As, or V. Hie value of n varies roughlyfrom 0 to 6 or 8 in the metahydrate group and from 8 to 12 in the fullyhydrated group.

Torbernite, Cu (UO2)2(PO4)a.l2 HBO, and metatoriieniite, Cu(UO2)2( ^ S H y O , are probably theinost abundant secondary uranium-bearingminerals. Metatorbernite contains 61% UO3. The minerals are flakyand bright green in colour, with a pearly lustre, a hardness of 2 to 2-5, and aspecific gravity of 3 -2. In New South Wales, torbemiteand metatorberniteoccur ar Broken Hill, Carcoar, Wbipsticks and in a number of places inthe New England district.

Autunite has the composition Ca(UQ02 (Pd^g.12EH2O, the morecommon meta variety, with 3HgO, contaiaifflg up to 63% UCV Theseminerals have a flaky appearance and are lemon yellow or apple green incolour, wilh a strong yellow fluorescence, pearly lasfcre, specific gravity of305 to 3*2, and hardness of 2 to 2-5 on Mobsuale, to New South Wales,autunite and meta-autunite occur at Broken 1KB, BlackfeUows Dam, andCarcoar.

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Csmotite,. Ks(UO^VQJ?.oH@0, contains up to 65% UO3, Themineral is lemon yellow to greenish yellow, with a dull earthy lustre, specificgravity of about 4-0 (depeadiog on ^sier content and porosity), and ayellow streak. Carnotite is very soft, the exact hardness being unknown.This mineral occurs iat&e TTiaeiaringa area, New South Wales.

Phosphuranylite, Ca(SJ0g>*(P(Xi)a(QH)4.7HaO, contains up to 79%

Uranospinite has the composition Ca(UO2)2(AsO4)2.10H2O, whilethe meia variety has kss water and contains up "to 60% UO3.

Sateeite has a composition Mg (UOa)s(PO4,AsO4)2.8-10 H2O. Themeta variety has less water and contains up to 64% UO3.

Ciirite, 2PbO.5UOs.4BLQ, has a UOS content of between 70 and 80per cent. The mineral is orange red in colour, with an orange streak,adamantine Justre*spedEc gravity of 7-3, and hardness of 4 to 5 on Mohsscale. In New South Wales it occurs at Blaekfellows Dam.

Uranophane, Ca(Ub^g(SiPs)g(OH)2.5H2O, has a UO3 content of66 per cent. The mineral is lemon, greenish, or orange yellow in colour,has a greusy lustre, specific gravity of 3-7 to 3-9, a pale-yellow streak, andhardness of about 2*5 on Mohs scale. In New South Wales, uranophanehas been tentatively identified at Woodfords No. 2 prospect at Gilgai inthe New England district.

Riitherfordine, UOs-COg, has a UO3 content of about 86 per cent.This mineral is very soft, with a yellow colour, earthy lustre, yellow sireak,and specific gravity of 5*7. R.utherfordine occurs at Corona, near BrokenHill, New South Wales.

Gwnmite (uranium ochre) Is a term which has been used to designatefine-grained* dense to gumlike, uranium minerals (usually alterationproducts of uraninite), the true identity of which is unknown. The UO3content is normally between 70 and 80 per cent. The colour ranges fromyellow through brown to black, an4 the lustre is dull or vitreous, thespecific gravity 3-9,46 6-4 (varying with hydraiion and included matter),and the hardness on Mohs scale 2-5 to 5 according to hydration. In NewSouth Wales* gummite occurs at Blackfellows Dam and at Blatherarmnear Tomngton.

A more detailed; account of the mineralogy of uranium has beenpublished; by Frondel (1958).

PROSPECTING

Most exploration for uranium is earned out by the use of a geigercounter or a scintillation detector (scintillometer), both of which, registergamma radiation emitted duringradio-active decay of uranium (for detailedinformation see Daly 1965). The scintiHometer has far greater sensitivity,but the geiger eoiinter; is considerably cheaper and easier to use andmaintain. Regional surveys are normally carried out by airbornescintillometer, and are fpllpwed tip by ground traverses over anomalouszones found in the airborne survey- Because radio-activity decreasesrapidly with distance from the source, radiometric techniques becomeineffective whent moie than a couple of me^-^ of soil cover the source ofradiation.

Geochemical methods (Page 1958, IHsley et a!. 1958) have beeuapplied with limited success to the search for uranium. The maintechniques employed are the assaying of stream water and soil samplesfor traces of uranium, and stream sediment sampling for "path-finder"elements such as copper in areas where these elements are known to occurwith the uranium.

Geological mapping remains one of the most useful aids jn uraniumexploration, firstly for determining potentially interesting areas on aregional scale and then, on a local scale, for indicating favourablestructural environments for lode-type uranium mineralization andoutlining suitable host rocks for "sedimentary" uranium deposits.

Because "sedimentary" uranium deposits are sought largely in poorlyconsolidated sediments at comparatively shallow depth, pattern drillingcan often be carried out at a reasonable cost.

Most uranium prospecting activities in Australia in past years havebeen concentrated in the Proterozoie rocks of South Australia, Queensland,and the Northern Territory because these are the areas in which all thesignificant deposits have been found. However, during 1969, 1970, and1971 some exploration activity has been directed toward? the search for"sedimentary" uranium deposits similar to those in the western UnitedStates. A considerable amount of work has been carried out in NewSouth Wales on areas where there is some likelihood of uranium beingleached from granitic environments and transported t>y grdundwater intofavourable sedimentary host rocks. This work has concentrated onDevonian sediments near Bombala; Permian and Triassic sediments mthe Sydney Basin; Jurassic sediments in the Great Artesian Basin nearDubbo, Coonabarabran, and Moree-Inverell; Jurassic to Cretaceoussediments in the Clarence-Moreton Basin; and on Cainozpic sedimentsin the Lake Oowal area. The areas investigated are mainly withindrainage networks originating in nearby Palaeozoic granite terrain.Reports dealing with this exploration work have been tabulated byWilloughby (1972).

TREATMENT(after DeCario and Shortt 1970)

Uranium ore is first crushed and ground, then somettess roasted toimprove uranium solubility and ore handling. Concenf/atiqn is carriedout by hydro-metallurgical leaching using either dilute sulphuric acidwith an oxidant for ores containing less than 12 per cen; lime, or alkalinecarbonate solutions for ores with a high lime content. The leach solutioncontaining the uranium can be purified by decantation and filtration withconventional equipment and techniques. In some cases flocculatingagents such as vegetable gums and glues ate used far settling.

The most widely used method for recovery of uranium is the solventextraction process, in which metal salts are transferred from aqueoussolution to an immiscible organic liquid. Another method is the use ofion exchange columns. Recovery of 95 per cent of the uranium by theseprocesses is common. Heap-leaching, using bacteria for acid production,is utilized in recovering uranium from low-grade ore and waste rock.Ion exchange has been developed to recover uranium from mine v/ater,drainage from dumps, and from waste solution from leaching of coppermine dumps.

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After recpyery,;ths U3Og concentrate (yellow cake) is further refinedand converted4o uranium metal or.an appropriate compound. Generallythe U3OS is fluorinated to produce uranium hexaSuoride (UF6) which isfed to a uranium enrichment plant after distillation. Enrichm t ofuranium is accomplished by gaseous diffusion. The enriched W 6 isthen converted to a suitable fuel for nuclear reactors, such as UO2 whichis used in light-water reactors. The conversion involves hydrolysis,precipitations filtration, reduction, forming, sintering, and mechanicalfinishing. The finished pellets are charged to alloy tubes which arecollected into bundles to form the finished fuel assembly.

USESUranium, because of its susceptibility to nuclear fission, is used as a

source of energy in nuclear reactors; the uranium is used alloyed tozirconium, molybdenum, etc. The nuclear reactors can be broadlydivided into four categories:

1. Electric power reactors.2. Propulsion reactors.3. Research and development, testing, and medical therapy reactors,4. Space and process heat reactors, particularly for desalination

of water.

As the oxide or carbide, uranium is used in atomic weapons. Nuclearexplosives are also being tested for peaceful purposes under the UnitedStates Atomic Energy Commission's (U.S.A.E.C.) Plowshare programme.

Eadio-fs-otopes are useful products obtained from special reactorsand from the reprocessing of partly burned nuclear fuels. More than1.000 different radio-isotopes have been identified, about 100 of thesebeing useful as substitutes for JX-rays for inspecting castings and welds;for sterilizing.drugs, isedical supplies, and foodstuffs; as a power sourcefor small quantities of electricity; for gauging control of industrialoperations; and for many, tracer or activating uses.

Uranium, in the form of various compounds, is of limited use incolouring glass and porcelain, in photography, and as a chemical agent.

To date, the greatest period of development for the uranium industrywas in ilie ' 950's when the world's major mijitary powers were stockpilingatomic weapons. ,TJ^eistpckpiles; were b ^the 1960s,; when> these countries tad man^ufactiitted sufficient weapons,the demand for uraniuiri4 tapered off. At this stage the amount of uraaiumbeing used in nuclear reactors ;was far too small to cb^peiisatef^decline in ijjanufacture?of nuclear weapons, so tKe" demandiqruraniumdropped very iapidly.f jLargef reserves |(3und in t h e ^ sensttrefl adequate; supplies fOT that cbTihtry's heed s duri^:|be:1960's;howeveivtlie situation is expected toJ^^planned construction! of nuclear power plants wifl require more uraniumfuel than the country's mining industry can supply.; The lJiS-AiE.C.estimates that--the United States will require 36 000 t of uranium oxideper yearly 1980, and i l ^ year,l^uc^ar power will become more: and more important throughput theworld a» the rates of extraction of;coa! and petroleum reach their limit.The&J rates of extraction will be governed mainly by the total quantities

available, the petroleum and coal reserves being by BO meansinexhaustible. Present limitations on the use of unclear power reactorsare the relatively low cost and availability of coal—these factors musteventually change in favour of uranium—and the problem of disposal ofradio-active wastes from nuclear power plants—this problem will increasewHh increased use of these plants.

At present there is no domestic market for uranium in Australia,but the country's first nuclear power reactor may be operating before1980. Although the reactor would provide a significam locarraarket,main potential markets for uranium up to the 1980's will be the largerindustrialized countries, such as the United States, Japan, Britain, andother European countries, whose consumption is expected to exceed theirlocal supplies,

The price of uranium has been stabilized in recent years, atSUS 6.00-7.50 per pound (453-6 g) of U3OS contained in "YeHoweake"chemical concentrate, by the U.S.A.E.C. policy of selling enriched uraniumat a price based on SUS 8.00 per pound (453*6 g) of U3Oa. This practicewill continue until 30th June, 1973, when the policy will be reviewed, andit is anticipated that there will be less government control over the price.The present prices will permit mining of ore of grade 0*05% U3Oft by opencut and of grade 0-2% U3O8 by underground mining, if tonnages arelarge and other conditions are satisfactory.

MODE OF OCCURRENCE AND WOBLD DISTRIBUTION

Uranium deposits have been discovered in many geologicalenvironments. Routhier (1963) produced a classification for uraniumdeposits, based on host rock, structure, and mineral assemblages; thefollowing classification is after Routhier (op. cit.) with slight modifications.

Deposits in Sedimentary Racks, without Visible Relation to Plutons

1. In conglomerate, with carbonaceous or hydrocarbon material andsometimes gold, e.g., Witwatersrand (South Africa), Blind River(Canada).

2. In sandstone formations, especially red sandstones or red beds, e.g.,Colorado Plateau (United States), Mounaaa (Gabon). (This categoryis discussed in more detail in the section on "Uranium Deposits inSandstone.)

3. In lacustrine deposits (sandy, clayey, peaty), eg., Vinamnfcarena(Madagascar).

4. In carbonaceous or hydrocarbon-bearing shales, lignites, bogheads,e.g., St Hippolyte (Switzerland).

5. In marine phosphates, e.g., "Phosphoria Formation" (western UnitedStates), Morocco.

6. In recent placers, especially monazite and seriotinie bearing (sourceof rare earths and principal source ofthorium); also urano-thorianiteplacers near primary deposits * a." type 19 (|>yroxenites)j e.g.,M.' iagascar (Fort Dauphin), British Columbia and Yukon, southeastMadagascar.

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?» In- dolomhlc formations as disseminations and veins and as fillings ofkarst holes, &g.» Slaw; Lake (Canada). ShinkoJobwe (Congo),Tyuya-Muyan (Ferghana, U.S.S.R.).

Deposits Associated with Granitic Phttons, Periplutonic {or Marginal)8. Pyromotasomaiic deposits, e,g.T Asegour (Morocco), Mary Kathleen

(Australia).9. Deposits with dominant sphalerite, pyrite, galena, chalcopyrite, and

little pitchblende, e.g., Coeur d'Meae (Ua»ted States), La Rabasse(Herault, francs).

10 Veins of Ni» Co, Ag, Bi, sad pitchblende. Usually periplutonic,rarely intrapJwtome. "Erzgebirge" type, e.g., Port Radium (Greatbear Lake, Canada), loaehJmsthal (Czechoslovakia), Wittichen(Germany).

Deposits witfiin Grmitic Pinions, Intraplutonic11. Vein type with, pitchblende dominant and sphalerite, pyrite, galena,

chalcr pyrite, especially iron sulphides, e.g., La Crouziile, Grury(France).

12. Type, consisting of a network of veins in fracture zones, withautunite/'gammite", "black products", e.g., Les Srugeauds, Margnac(France). (1! and 12 coastltete the "Massif Central" type.)

13. Parsonsite, pbgCUO^CPp^HsO, vein type, e.g.. Lachaux (France).14. In granitic pegmatites (eoniplex and variable mineralogy), of no

economic interest, e.g., Ambodibonara (Madagascar).

Deposits Associated with Alkaline Complexes: type 15.

Deposits Associated with Volcanic Socks16. In lavas, generally acidic (rhyolite, andesite), veins or disseminations,

e.g.,. Marysvafe (Utah,.-United States), Esterel (France).17. In volcanic chimneys, e.g.s Thomas Range (Utah).

Deposits Associated \^h Basic Racks18. Davidife vein fypp» e.g« Tete (Mozambique). Radium Hill (South

Australia)' is also ^ven as an -example but, although the majoruranium mineral is davidite. the deposit is ia pegmatitic rocksassociated mth. highly deformed gneisses.

Deposits in Metamorphic Terrains^ & t least of Ti, out of

^ h ^ ^ .20. Pyroxenite':-type With urano-tioriamts, e.g.} Southeast Madagascar.21.. la' graphitic:'b^;rcg^ Holandsfjofd (Rendalsvig, Konvay).

AltlioT3gh:*iKre Is a wide variety of |T?pes of de|?psit, major productioahas comefrom"a telatircly's^ll number of these types. Type?. 3,2,4, 5,and 12 have provided or vauld provide very large tonnages of low-gradeore, types 10 and II are generally of lower tonnage but often of highergrades (greater thjra 2% Ujjpg), types 16 and 17 are less important, andtype 14 is economTcaRy iasignificant

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In I_968, 11 188 t of U3Og, approximately 55 per cent of the non-communist world's production, came- from tthe United States, practicallyall from sandstone-type deposits in; New Mexico, Wyoming, Colorado,Utah, and Texas. South Africa accounted for 17 per cent of production(3 506 t), mainly from the Wttwatcrsrand deposits. Canada produced3 391 t, three-quarters of which came from quartz-pebble conglomeratein the Elliot Lake area or. Ontario. A smaller quantity was producedfrom a pitchblende v«in-t;pe deposit in the Beaverlodge area ofSaskatchewan. France produced 1 j l ! t representing just over 6 per centof non-communist world production. Gabon, Australia, Spain, andSweden were minor producers.

URANIUM DEPOSITS IN SANDSTONE

In recent years a large amount of exploration has been directedtowards finding uranium deposits in relatively undeformed sandstoneformations. This exploration has been induced by the very largequantities of uranium found in these "sedimentary uranium" deposits inthe v/estern United States of America. A short description of thesedeposits is included below.

In the western United States, uranium deposits in sandstoneenvironments have been classified as the Wyoming roll type and theColorado Plateau peneconcordant type (Fischer 1970).

The Wyoming roll-type deposits consist of uraninite and coffinitemainly in pore spaces of unlithified Eocene arkosic sandstone andconglomerate. The ore bodies also contain up to several per eeot ofpyrite, abnormal amounts of selenium, molybdenum (in some deposits),sparse copper mineralization, and only small amounts of vanadium.Fragments of carbonized fossil wood and sparse, thin, shaly layers arepresent in the lenticular sandstones and conglomerates, which are up to100 m or so in ihickness and are interbedded with siitstone and mudstone.The sedimentary sequence was deposited by streams into intermontanebasins, and was subsequently covered by sediments rich in volcanicmaterial. Mos'c of the oxidized ore occurs in crescent-shaped bodiesthat extend vertically through part or whole of a sandstone unit and areconspicuously discordant to the bedding. Within a sandstone unit, rollore bodies are scattered along a crescent«shaped interface severalkilometres long, between unaltered and altered sandstone. An individualere body on a large roll may be 10 m or so in width and extend a coupleof hundred metres aloag the roll axis. .

According to the most widely accepted theory, uranium has beenintroduced by oxygen-bearing groundwater moving down dip along thehost beds and altering the sandstone, with the free oxygen being consumedat the altered/unaltered rock interface. As this interface migrated downdip, newly introduced uranium would be precipitated by reduction ashort distance beyond the interface, and earlier deposited uraniumexposed to oxidation at the interface would go into solution and move ashort distance downward, again precipitating by reduction. The sourceof uranium could have been solution from granite in uplands, solutionfrom arkosic material in the host beds, or solution from overlying volcanicash.

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The peaeconcqrdant uranium deposits of the Colorado Plateau regionconsist of uranjnite, coffinite, vanadium minerals (montroseite andvanadium-bearing mica, chlorite, and clay), and the common sulphides ofcopper, Pyrite and marcasite are common, and traces of sphalerite arewidespread. Molybdenum, selenium, chromium, nickel, cobalt, and silverminerals are present but very minor. The minerals occupy pore spacesand replace carbonized fossil wood and occasional sand grains insandstone units within Trlassic and Jurassic interbedded sandstone andmudstone formations, the sandstone occurring as lenses 15 to 30 ra thickand .up to a few kilometres wide. These rocks were deposited in broadbasins or foreland areas, the material being derived from remote highlands.Subsequently these arfcosie sandstones and m«ist©?,es were overlain by acouple of thousand metres of marine and continental sediments and somevolcanic,rocks in places. The deposits are discrete tabular bodies,nearly parallel to bedding, averaging about a metre in thickness and up toa few .-hundred metres-in width. There is no "front" or "bask" to thedeposits aod their boundaries are sharply defined. Some alteration ispresent in the host sandstones.

Present theory is that the ore metals were introduced by groundwatermoving along the host beds. It has been suggested that the water wasweakly alkaline and moderately reducing, and that precipitation of theore minerals occurred in a stronger reducing environment localized inmasses of sandstone rich in carbonaceous material, H ^ or even H2.This concept and the features of the ore bodies favour astatic system ofconcentration. The same three sources of ore metals have been suggestedas were suggested for the Wyoming roll-type deposits.

AUSTRALIAN DISTRIBUTION

Rayner (1^60) stated that the most significant uranium depositsknown in Australia occur within an acurate belt through east-centralAustralia and include the uranium-bearing Precambrian fields of SouthAustralia (e.g., Radium Hill, Crackers Well, and Mount Painter), NewSouth Wales (Broken Hill), Queensland (Cloncurry-Mount Isa), and theNorthern Territory (e.g., the Rum Jungle and South Alligator Valleyareas). Recent significant finds at Pandahus Creek, Westmoreland,Nabarleky Ranger~ and Koongara since 1960 also occur within thisarcuate belt. Broadly, the belt corresponds with the eastern rim of theancient Precambriatv shields of western and central-northern Australiaand with the western fringes or Mnge lines of the main shelf zone througheast-central Australia, as illustrated in figure 1. The Broken Hill regionis contiguous with and very similar to the Frecambrian setting of thebetter finbwn South Australian uranium occurrences, and also Ms manysimilarities with the Precambrian Cloncurry-Mount Isa districtAccording to Rayner (op. cit), there is strong evidence to suggest that theBroken Hill (Wiliyama) and Cloncurry blocks are comparable andperhaps co-extensive, forming a north-south Precambrian unit partlyembracing the main shelf zone tu£ partly succeeding it to the east. TheBroken Hill and Cloncurry Precambriaa fields are comparable in manyrock and mineral assemblages, and between the two outcropping areasthere are some basement highs or ridges buried beneath later sediments

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•Broad Tectonic Units

Phenerozoic strata,mainly pisiform cover.

erogenic zone

Proterozoic (2300-500 m.y.)mobile zones

^ ^ i (aider than 2300 m.y.) and• • i probable Archaean cratonlc blocks.

Major Uranium Deposits

1. Rum Jungle

S. South Alligator Valley

3. Na&arlek - Ranger

4. Pandanus Creek — Westmoreland

5. Mary Kathleen

6. Mount Painter

7. Crockers Well

8. Radium Hill

N.S.W. Uranium Occurrences

A. Broken Hill

B. New England

C. Blackfellows D$m

D. Carcoat

E. Whipstick

6309

Figure J. Major araniom deposits of Australia, and New South Wales uraniumoccurrences. (Geology modified from Brown, Camplbsll, anil Crook 1$>68)

It would appear thus that the most significant of the uranium deposits(and some large base-metal deposits) occur in relatively unstable and moremobile belts which lie off the shield and which have suffered aconsiderable degree of folding and faulting. These zones aiso haveabnormally high thermal gradients which Rayner suggested may representzones of relative crustal thinness. Within the stable craionie-"zones,which form a large proportion of the western part of Australia, there isless indication of maior uranium mineralization (see Corbett acdMcLeqd 1965).

-Because the only deposits which have so far been economicallyexploited occur in the younger Preeambrian fields (mainly MiddleProterozoie or Carpentarian), exploralion has previously beenconcentrated in these areas. However, it is of some significance thatprimary uranium mineralization has now been shown to occur in NewSouth Wales in rocks of several younger geological ages. Uraniumdeposits are ass'ocia'ted,: with various stages of growth of the TasmanGeosynclin?, These deposits are in Lower to Middle Palaeozoic rocksin the Carcoar, Whipstieki Blaekfellows Dam, and other areas, in Permianrocks ofthe New England district of New South Wales, arid inPalaeozoic granites and shales in the Avoca, Storeys Greek, Blue Tier,and Heemsicirk districts of Tasmania. The Tasman GeosyneKne is .cor iplex-.'mobile belt of sedimentation which has suffered a number o»periods of orogenic movement, igneous activity, and ore deposition.Uranium deposition in this region appears to have been related in mostcases to granitic injections or granitizing action, the term granite includingpegmatites, aplites, and greisens.

NEW SOUTH WALES DEPOSITSDescriptions of the Nesy South Wales uranium deposits and the

following discussion on the;r general characteristics and associationshave been taken from Rayner's (1960) report with some alterations andadditions based pn more recent information.

There has been "no production of uranium in New South W- ies, butthe recorded occurrences of uranium minerals have wide geographicaldistribution and-a range of geological environments from Precainbrianto Permian.

The uranium deposits may be placed in three broad stratigraphicand geographic groups:

1. Precambriau—Broken Hill dVrict, far western New SouthWales.

2. Early to Middle Palaeozoic—central and southern New South/ . W a l e s . •• .•• ;•;.- / . /

3. Late Palaeozoic—New England district, northeastern NewSouth Wales.

The Brokea Hill Preeambriaa PjOTince

The spatial distribution of radio-active deposits in the Broken Hilldistrict is shown in iigure 2...which, outlines the relationship of theuranium localities to the Protero2oic "Willyaroa Complex, to a numberof major tectonic features, and to outcrops of the Mundi Mundi type of

15

RF.FERKSCtrjr--; Granifes of the

' • i i ^tifysma Complex

- .-__ Fautt. sh&a/ & cmsti zones

$ Uranium occwtonces

x Cfher radioactive localities.Definite uranium mineralsnot proved, or niwie radio-activity cltio chiefly tothorium

r o k e n l l i l l ' • ' " ' .mUsm Hill line of lade

Figure 2, Uranium occurrences and radio-acfiye localities of ihe Broken Hill district.(Merged from Raynef 1960)

16

granite and its associates. It can be seen from the figure that all but om;of 'me known uranium occurrences in the district occur within IhuWillyama Complex. The Mundi Mundi-type granites are small bosses,sills,Md dykss consisting generally of even-grained. alkaH-Tich,la?cocrEitk;granite^ j ^ i £ 6 0 ^ ^that the ^^dl iMundi Granite fes an important relationship to theuraniurn m r i i ^ J i t i

Di the BroSsa Hill mam lode, the Great Western mine, and lifee-andChlckeas lainej uranium is associated with. silvef4ead*zinc

mineralization. tfreiBrokett 1M and Gteat 'Western are ^Broken Hilltype:' deposits, and; the :Hen-and-Chickeas is a; "Thackaringa type"deposit, At Copper Blow; Bonanza, and Lakes Nob and} to a less«rextent, in the Miwli Mundi-Eldee zone, the uranium association is withcopper,

THACKARINGA DAVIDHE BELT (extending approximately from GR 42003Sto GR 427042, Menindee 1:250,00C)

Tbs Thackaringa davidite belt is situated from 19 to 29 towest-southwest of Broken Hill, adjoining the northern side of the BrokenHill-Adelaide road. The area is only 64 km northeast of the davidite lodesof Radium Hill in South Australia.The dep-ssits were discovered byH/H. andGhX. Baker in February 1913, after an airborne scintillontetersearch had revealed no major anomajy, This, and tne fact that thedavidite deposits are adjacent to a main road, led Rayner to the btsliefthat the district had not been exnaustively prr spec! ed for xiranium.

Tfip dayidjte and other radio-acdve minerals of the Thackaringa teltoccur fh" riegmatites, aplitic granites, quartz Veins, and shear zones witliinthe Willyamaj Complex; The iMUyama Complex cbmiste chiefly of aseries of metasedimerits in the form of sillimanite- and mica-schists andgranitic gneiss Which haye beenpartiy granitizM Bandsof amphibolite are present tfirowghout the area and ap^ar to beinterbedded ^fth the Willyaraa sediments. These probably representmetemorphosed, basic sills, flows, or tuffs, but some may Jaave beenderived from calcareous sediments.

The belt to which the known davidite occurrences are confined is9*6 km in length and about i-2 km in width. The greater part of thisbelt has low relief and is devoid of rock outcrops.

Pegmatization in the area is widespread and probably related to morethan one period of formation. The uranium-bearing pegmatites are oflate introduction into the Willyama sequence, and postdate otherpegmatitic developments in the area. They are commonly coarse grainedand are, in places, transgrcssive to the gneissic sediments and amphibolitesbut are chiefly aligned within or parallel to certain fault or shear zones.Associated with these pegmatites are small segregated masses of white andbluish translucent quartz. Also within the davidite belt are severaldevelopments of aplite and red aplitic granite, probably genetically relatedto the abovementioned pegmatites. These rocks contain disseminationsand pods of davidite.

The davidite belt has a structural complexity common to Wiilymaregions and intensified by the influence of the major transgressive fault orcrush zone referred to by Andrews (1922) as the Thackaringa-KnnaclesFault. .. . . . - . -=-* - ; . . . . . . . . ; •" ' . " ' '

3486I-B I /

Following early folding and raetamorphisnvwUh some granitizationof the original sediments, there was cross-folding,'faulting, crushing,.andattenuation. Serpentinite was introduced at this or a later stage.Subsequently; there would appear to have been further tectoaic movement,with faulting and shearing and the introduction of the Miindi Mundi'typegranite and associated pegmatites and aplites. The later intrusives, raturn, show some effects of tectonic strain (such as occasional developmentof cleavage) but, Bniike the earlier granitic gneisses, could not be describedas gneissie. The uranium mineralization was probably introduced latein, or at the end of, this sequence of events.

The Thaekaringa davidite belt is situated immediately north of themain expression of the Thaekaringa-Pinnacfes Fault zone one of thedominant structural features of the Broken Hill area. North of the mainfault zone and traversing the daviditv bearing area, there is a curved shearstructure or crash zone, the Albert Shear Zone, considered by Raynerto have an important relationship to the uranium mineralization.Within the Albert Shear Zone, which is up to a couple of hundred metresin width, the rocks are schistose and laminated, with the production ofmuch sericite and the development of sheeted and grooved quartz with®fractures. Another shear zone, containing sheeted quartz and linkingthe Thackaringa and Albert zones, trends northwestwards through thev estern end of Bakers block (Rayner 1958} and adjacent to the serpentinitebody. No davidite mineralization is known southwest of this structure.

At the northeastern end of the davidite felt, a group of smalltraasverse shears is present, with strikes ranging from northwest to north.These minor structures cut across the Albert zone and tend: to containthorium rather than uranium minerals. The northwest system is parallelto the Pine Creek Shear Zone and another fault further to the northeast,and to the Thackaringa section of the Mundi Mundi scarp.

Davidite has been found in veins and irregular lenses of pegmatite,in quartz veins of quartz-rich sections of pegmatite, in aplites or apliticphases of the pegmatites, in red aplitic granite or microgranite,in laminated quartz-feldspar rock, in sericitized and biotitic schistoserock, and in nodular biotite rock as kernels, all within the Albert shear,and in detrital form as surface fragments and as grains in creek sands.

The davidite is associated with rutile, haematite, ilmenite, magnetite,biotite, quartz, feldspar, muscovite, and some pyrite, A small amountof the yellow decomposition product, carnptite, is present on the davidite.At one locality, a few detrital fragments resemblttT Uraonerite were found,and the thorium minerals thorite asd monazite occur in the belt.

Within the uranium lodes, the davidite occurs as grains, "eyes",small lenticular pods and veinlets, and irregular "nests" and bunches.These occurrences are sporadic and the davidite is rarely continuous formuch more than lt> cm. Commonly it is intergrown with rutile, ilraenite,haematite, or magne tite. The bulk of the gangue of the host rock consistsof quartz and feldspir with a lesser amount of mica, Biotite is commonly •concentrated with the davidite-bearing sections, The pockets of daviditeand its associates tend to occur in quartz-rid 1 phases of the pegmatMcand aplitic hosts, or with quartz of later entry, and in particular where the

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quartz is blue or blue /grey and translucent xa^ksr than wher; a is whiteand opaque. The same feature is evident in the shear zones. Thefeldspars near the davidlte may show more -°d colouration than in thebarajn sections of the pegmatites; thh ,-jdGuratf.on may be caused partlyby radio-active emanations, t - . ;a dae largely to staining from the ironoxides. Some pyrif? V.ii been observed hi the lode formation and inliinonitic boxw .-ii:, aiati ca ities after pyrite are apparent on a small scale.

Rayiser (1960) gave detailed descriptions of individual prospectingar«as, including Bakers* Ke&sys, Fyfes and Bostons areas.

MUMDl MUND!, BRINKWORTH WlZUL, AND ELDEE CREEK AREAS

The Mundi Mundi radio-active prospect (GR 4250G724, Broken Hill1:250,Q0G) is 30 km &ortfcyest of Broken Hiii. The radio-activity occursin undetermined nilHeral Form in grey mica-quartz schist and biotite-siliimanite schist; SIMI, in particular, in iron oxide-rich bands. Theschistosei band is ..up to 30 ni wide and for a length of several hundredmetres gives radidmetric readinp of tv/o to four times normal background.Higher counts (to 15 x N) are restricted to a belt 10-6 m wide and 180 mlong, and particularly at the nose of a small fold where the schist isironstained. Traces of malachite and some white fluorescent incrustationsare r%cn present. The uranium oxide content of the schist is between001 »fld004%U<V

This 180-in long uraniferous schist belt is associated with Willyamagneisses and with pegmatites and granite. A large granite boss cropsout less than 3 km to the east, and there are several small sills of similargranite in proximity to the prospect. These granites are of the MundiMundi type to which the uranium mineralization may be geneticallyrelated.

The Brmkwoith Well deposit (GR 42680759, Broken Hill 1:250,000)is 3 km northeast of the Mundi Mundi prospect, on an arm of MundiMundi Creek. This deposit also lies within a schistose belt, and in theregional sense is on a northerly continuation of the Mundi Mundi belt.Radiometric anomalies were obtained in an area of over 45 min lengthand 6 m in width. Autunite, associated with small greisenoas veins,occurs in limonittc bands at several locations within the schist. Gtanitebodies of Mundi Mundi type occur less than 3 km-to the east. In theiron oxide patches, the wrasiura content is of the ord«*r of 0-14% CJ/>S.

The Eldee Creek prospect (GR's 43110791 and 43270805, Broken Hill1:250,0Q0) is 6 to 10 km north-northeast of Brinkworth Well. Radio-activity is confined to the narrow Eldee Creek Shear Zone which, isseveral kilometres Jong, trends northeasterly, and is of variable widthfrom several centimetres to 6 1 ^ averaging 1-5 niv The zone is occupiedby schist of.distinctive appearance, and is transgressH'e in part, cuttingother schistose sediments, amphibolites, quartz-tourmaline rock, andpegmatites at the southern end and passing through nifissive pegmatitehills at the northern end. Quartz veins are common throughout this2one, particularly along the walls, and at one location several surfacefragments of quartz with limonite and malachite exhibited slightradio-activity.

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Commonly, along the surface of the sheared zone, ra> 'o-Etctivity ofthe schist was found to be equivalent to 0-05% U3O8, or less. Nearthe northern end, where the schist forms u definite band a couple ofmetres wide between w«l!s of massive pegmatite, autunite and non-fluorescing yellow and orange secondary uranium minerals are found inrhc outcrop. Assays of the aufcanite-bearing schist are in the order of0-2% U3O«. The autunite occurs a'toug ironstatfted cracks oblique tothe schistosity.

HEN-AND-CHICKENS LODE (GR 43610650, Broken Hill 1:25O»OOO)

The Hen-and-Chickens mine, 19 km northwest of Broken Hiii andforming part of the Daydream lode system, is an old silver-lead mine ofthe Thackaringa ore type. The lode formation dips to the southeast at30° and is overlain by a sill-like body of leucociatic granite of fine andeven grainsize. A similar granitic sill occurs beneath the lode. Schists,pegmatites, and amphiboSites of the Willyama Complex form the othercountry rocks. The granites are regarded as infmsives of the MundiMundi type and may have a bearing on the mineralization (see figure 2).

The radio-activity occurs in a lode formation containing cerussite,cerargyrite, a little galena, biadheiroite, azurite, and a coarsely crystallinesiderite gangue. In the oxidized zone the gossan contains abundant"limonite" (goethite) pseudomorphous after siderite.

The radio-activity results from uranium minerals of unknowncomposition, is commonly less than 0*1% U3Oa, and is highest in thesurface section of the oxidized zone, declining in intensity but persistingin some degree in the deeper workings. It was noticed that the mostintense radio-activity is in bands of dark-brown limonitic products,particularly near the roof of the lode, and with some glassy quartz inassociation. In part the limqnitic boxwork shows relict rhombohedralstructure of the replaced siderite.

This association of uranium mineralization with iron (and in somecases manganese) oxides is noteworthy in a number of New South Walesexamples.

GREAT WESTERN LODE (GR 44240553, Broken Hill 1:250,000)

The Great Western is an old silver-lead-zinc mine, 9-5 kmnorthwest of Broken Hill, displaying some radio-activity in similar formto that at the Hen-and-Chickeriss••.•but differing in that the primarymineralization at the Great Western is of the Broken Hill type.

A lode formation 1 to 4 '5m in width strikes northeasterly ia foldedschists and pegmatites of the Willyama Complex. Greatest degree ofradio-activity is in the upper portion of ati iflclined adit where the lode isoxidized and has a hanging pall of pegmatite and a footwall of siHimasiteschist. The oxidized lode material contains cerussite, carbonates ofcopper, quartz, fluorite, garnet, gahriite, and iron oxides, c*ffie surfacedumps show by their nature that the deepest workings reai,*. ae sulphidezone, and radio-activity is in the order of 0*05% U3O8 in the decomposinggalena fines.

20

The strongest radio-activity is in ferruginous bands, as in theHen-and-Chickens lode, The intensity declines as the workings arefollowed down, implying that traces of primary uraniam mineralizationexist in the sulphides, and are the source of secondary concentrations,

BROKEN HILL LINE OF LODE (GR 447045, Broken Hill 1:250,000)

The great silvcr-Iead-zinc ore bodies of the main line of lode atBroken Hill received early attention in the search for sources of uraniumsince, by virtue of the very considerable tonnages of ore mined andtreated* any appreciable trace of uranium throughout the ore might meanthat it could be economically concentrated and produced as a significantby-product. However, taken as a whole the ore bodies are singularlylacking in radio-activity. Radiometrie surveys at surface and under-ground, and of mill products, commonly have yielded negative results.However, two occurrences of minerakmical interest are worthy ofreference.

1. In a specimen of radio-act ;ve pegmatized gneiss occurring aswall rock on the eastern side of the lead lode on the No. 18level of The Zinc Corporation Lttl's mine, uraninite wasdetermined accompanying a hydrocarbon, as described byEdwards and McAndrew (1953). The gneiss is described ascontaining layers of biotite, with grains of a carbon-bearingmineral, in which were set particles of uraninite, and a fewparticles of pyrite and marcasite in association.

2. Traces of ujaninite have been ;dentified in some concentratesamples from the Broken Hill South mine.

COPPER BLOW LODE (GR 453027, Menindee 1:250,000)

Radio-activity from the presence of uranium minerals has beeninvestigated in the Copper Blow copper and iron lodes (also known as theBalaclava Copper Blow), 19 km south-southeast of Broken Hill.Radio-activity from this locality was first noted by Daly and White (1952)and subsequently examined by geologists of The Zinc Corporation Ltd.Metatorbernite was found by E. O. Rayner and R. E. Rslph in excavatinga radiometric "high" in the Warren open cut section of the lodes.

The individual lodes are narrow but form a strongly linear groupabout 1-5 km in length and are contained within a shear or retrogradezone which is up to 45 m in width towards the southern end. For themost part this shear zone is parallel to the strike of the enclosing countryrocks. The latter are part of the Willyama Complex and include biotite-silKmanite-garnet schist, granitic gneiss, amphibolite, and pegmatite.The host rock for the lode is in part a quartz-biotite-serieite schist withgrains of magnetite.

These rocks, and the lodes, have a prevalent strike of 040° and dipnorthwest at about 70°, but there are local variations. In particular,there is some buckling or foreshortening by folding in the vicinity ofstrongest radio-activity. The major Thackaringa-Pinnacles Fault zoneis only 0-8 km to the south of the lode outcrops.

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In the northern section of the lode zone, narrow lodes of haematitewith some magnetite were formerly worked as a source of flux forsmelters at Broken HH*. In the southern section, copper mineralizationaecornpanko that of iron, and narrow lodes were worked for copperdown into the sulphide zone (deepest working about 90 m) av the Warren,Stenhouse, and Balaclava shafts.

Though slight radio-activity has been observed throughout the lodesystem, significant radio-activity is confined to the copper-bearing sectionsat the southern end. Maximum intensity is in the Warrenroncti cut.Uranium values are present over a width of 6 m, of which 2 m in; oneface assayed from 0-1 % to 0*3 % U2Q8. In the oxidized zone, haematite,limonite, magnetite, malachite, azurite, and chrysocdlla were observed.Metatorbemue was located at the base of the face referred to above,chiefly on joint faces in biolite schist, with limoaite, malachite, andquartz. Sulphide dumps near the W a r ^ shaft showradio-activityequivalent to 0-05% U3O8, in association with ch^cp^yrite, pyrite, andmagnetite, and this suggests that some uranium minerallzatJon is presentin the sulphide zone.

Penetration of the primary zone by The Zinc Corporation Ltddrill holes near the Warren workings revealedvery little uranium contentin the sulphides. However, the primary magn§tite-r>yriterchalcopyritelode encountered by the drill showed slight radio-activity (higher thanthat of the wall and country rock), and Edwards and Baler (1953, quotedin Rayner 1960, p. 80) commented on the sulphide as examined in aspecimen as follows:

"The ore consists predominantly of fine-giained magnetite intersected by fineveinlets cf ebaleopyrite and pyrite. The chaicopyrite has corroded the pyritc andenclosed residuals of it. In addition it contains a small number of ex-solutionbodies of sphalerite and valleriite, and of pyrrhotite.

"A polished section of the specimen was left in contact with a nuclear researchplate for three days. The resulting autoradiographshowed approximately 20 smallscattered radial aggregates of alpha-particle tractes, indicating the presence/"of aradioactive mineral occurring as minute particles dispersed through the specimen.Some of the aggregate contained 5, some 15 and some ! 5 to 60 alpha-particletracks. Some of the radioactive centres lay within areas of chalcopyrite and couldpossibly be attributed to? minute inclusions in the chalcopyritejjbut it was notpossible to locate"the radioactive mineral with certainty."

It seems reasonable to conclude that in the Copper Blow deposit theuranium mineralization is essentially associated with that of copperin the primary zone, with secondary deposition and enrichment (includingthe copper-uranium phosphate, torbernite) in the oxidized zone.

CORONA (approximately GR 445130, Broken Hill 1:250,000)

It was stated earlier that all the toowniiranram-beanng deposits inthe Broken Hill district were emplaced in the Willyama^Complex, withone possible exception; The exception is the pre^nce at Cor qna of thesecondary uranium carbonate, ruAeribrdine, ^ dolp^Torrowangee Group (LateProterozoic). , : ;;

:

This occurrence is 3 km northwest of Corona nomestead and 14 kmin a direct line nortfe of Broken Hill (see figure Thetde^sit is dn^A^western flank of a tongue of the Corona Dolomite (Tb^owangee Group)v/hich enwraps the northern nose of thei Euriowie Im^er (WillyamaComplex). Incrustations of the greenish-yellow ruth^rfordine occur on

22

nodules of iippure,ironstained dolomite, which is associated with asheared zone about 3-5 m wide containing some slaty bands and dippingeastwards at about 45^. This zone is overlain on the east by moremassive dolomite3 and is Tinderlaiii on the west by a mass of ironstonewhich caps aline of hills trending nqrth-northwesterly. The rutherfbrdinecrusts are localized where a subhorizootal displacement (with some drag-folding) in the limonitic underwall intersects the sheared dolomite andslate.

The limonitic exposure of the footwali of the rjtherfordine depositis part of a narrow zone of ironstone which continues southeasterly forsome 19 km towards Torrowangee. A number of small and oldworkings, evidently placed in the search for silver and lead, are locatedalong this zone, and the ferruginous material is in places slightly radio-active. The ironstone belt approximates to the line of the Coronaoverthrust fault, along which, between Corona and Torrowangee, theolder Willyama beds of the Emowie InHer have been thrust over theTorrowangee rocks from the east.

This localized occurrence of rutherfordine suggests fixation at afavourable point under twofold control—chemical and structural. Themigratory character of uranium salts is well known, and distance travelledfrom a primary source may have been considerable before deposition inthe neutralizing dolomitic environment Whilst the secondarymineralization appears to be within rocks of Torrowangee &gz, thesource material may have been in the neighbouring Wiliyama rocks of theEuriowie Inlier or in buried basement rocks, and conceivably migrationwas by way of the fault system which separates the tv, j rock groups.It is probable that movements have been recurrent along the fault zoneup to comparatively recent geological times.

OTHER AREAS IN THE BROKEN HILL DISTRICT

A number of other radio-active localities are known throughout thearea occupied by the Wiliyama Complex in the Broken Hill district.These occurrences may be briefly listed as follows:

1. At the old Bonanza mine, Thackaringa (GR 41490385, Menindee1:250,0OO), a few flakes of (meta) torbernite have been foundin heavily ironstained mica schist with quartz on dumps wheresilver-lead and copper minerals occur.

2. At Arnolds prospect, Thackaringa (GR 41800376, Menindee1:25O,0OO), radio-activity is present in a long pegmatite vein,but is restricted to patches which are rich in biotite.f

3. I \ the Lakes Nob area (GR 430067, Broken Hill 1:25O,GO0),24 km northwest of Broken Hill, some radio-activity isassociated with copper carbonates, being strongest m Jimonitiecrusts on joint planes. ;

4. At Mount Franks prospects (GR's 43120746 and 43100760,Broken Hill 1:250,000), 30 km northwest of Broken Hill, weakradio-activity has been tested by shallow pits. :

5. Slight radio-activity has been detected at the Southern Cross(GR 443061, Broken Hill 1:250,000) and Wolseley(GR 436055,Broken Hill .1:250,000) silver-lead mines of the Broken Hilltype, respectively 13 km north and 9-5 km northwest of BrokenHill.

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6. In the Sentinel area (GR 423015, Menindee 1 ilSO.QGO), 43 kmsouthwest of Broken Hill, fairly strong radio-activity isassociated with a gneissic biotite-quarlz rock (ihft qiiarte isbluish in part) within areas of granitic gneiss and amphiboliteat a locality 6*5 km southwest of the quartz-magnetiteprominence known as the Sentinel. Microscopic examinationand chemical, electromagnetic, and mechanical concentratingtesis have confirmed that most of the radio-activity results ftcmthe presence of monazite, and establish this area as a potentialsource of thorium. Chemieat assay shows tliat someuranium is also present. Radio-active pegmatites and creeksands occur near the Sentinel.

7. Five kilometres north of Copper Blow, low radio-activity,substantially due to uranium, occurs in pegmatite adjacent loamphiboHte. The pegmatite consists of pink feldspar, quartz,and muscovite with some ilmenite or Hmenite-magnetitcintergrowths.

8. One and a half kilometres east of the above prospect, lowradio-activity has been detected in a pegraatitic rock composedessentially of feldspar, faiiotite, and quartz (some blue),associated with gneissic sediments and ampfaibolite.

9. Haifa kilometre northeast of Mulculca homestead (GR 468026,Menindee 1:250,000), 29 km so» r^ast of Broken Hill, a small,weakly radio-active pegmatite body with pink feldspar, qurrtz,and ilmenite-magnetite occurs within-'the Redan Gneiss.

10. At Redan station (GR 471018, Menindee 1:25O,O0O), 35 kmsoutheast of Broken Hill, radio-activity has been detected inquartz-biotite sections of several pegmatitic bodies within theRedan Gneiss.

11. Several bodies of pegmatitic rock containing monazite occur16 km west of Broken Hill: near the Adelaide road.

12. Mcnazite occurs in biotite-quartz with pegmatite 13 kmsoutheast of Broken Hill,

13. The Triple Chance feldspar-beryl mine near Egefaek (GR 414024,Menindee 1:250,000), 35 km southwest of Broken Hill, containstraces of monazite.

14. Euxeaite has been reported (Mawson 1912) at Euriowie, 64 kmnorth of Broken Hill.

15. Slightly abnormal radio-activity i; present in mica schists inseveral parts of She field, e.g., *ir the Broken Hill racecourseand the Thackaringa silver-lead lodes.

Early to Middle Palaeozoic Group

BLACKFELLOWS DAM DEPOSIT, CONDOBOLIN-NYMAGEE DISTRICT

The Blackfellows Dam uranium deposit (GR 46439856, Nymagee1:250,000) is situated 18 km south of Bobadah and 52 km southeast ofNymagee (see figure 3). The uranium mineralization is-associated withcopper and silver-lead-zinc minerals in a fissure lode within granite(Rayner 1957, 1959).

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Cainozolc?Late Silurian toLate Devonian

Silurian & Siluro-Dsvonlan.

Silurian

Ordovician

REFERENCE

Alluvia! deposits

Sediments

Acidic volcanics

Middle ]*•-* + i Granite

Early

vv v

TN

mm,. Sediments

Sediments

SCALE

? Miles10 0 10 „. ,. Kilometres

© Radio-active locality

vv_ Geological boundary

Fault

6309

Figure 3 . "Geological setting''of, BlackfelloBS Dam prospect. (Geology after titstacMan 1:500,000 Geological Sheet 1969, provisional edn)

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General Geology and Structure

The lode is within, but towards the northeastern margin of, a largearea of outcropping granite which has been called the Erimeran Granite(Lloyd 1936). This granite has intruded Late Ordovician sediments tothe south at Tallebung, probable Ordovician sediments to the east, andSilurian sediments to the west and south. The granite is overlain byEarly Devonian sediments and minor volcanic*on the northern extremity,towards Nymagee. Siluro-Devonian, other Early Devonian, and LateDevonian rocks in the region appear to post-date the Krimeran Graniteand other related granitic bodies.

The Erimeran Granite is typically a porphyritie two-mica type withphenocrysts of piagioclase feldspar up to 10 cm in. length, The graniteis porphyritic even is aplitic phases. Shearing of the granite Is commonnear the margins in contact with the sediments. Near the Blackfellowsline of mineralization, in places the feldspar phenocrysts in the enclosingErimeran Granite have preferred orientation in a northwesterly direction,subparalle! to the mineralized zones. This same northwesterly directionis also the strike of numerous linear late to post-magmilte variants andchloritic veins, viz., siliceous, aplitic, greisenous, and chloritic veins,some of which are radio-active.

The Ordovician and Silurian strata were folded about northwestaxes, dominaEtly in the Late Silurian to Early Devonian (Bowning)orogeny. The £rimeran Granite and its associates were probablyintroduced at the time of this diastrbphism and shjiwthe effects of forcesstill acting in the same direction. The primary mineralization (includingany primary uranium) of the Blackfellows Dam deposit was considered byRayner (1960) to have been introduced shortly after, perhaps as anend-phase of the Erimeran granitic injections.

The Uranium Mineralization and Its Associates

Significant radiometric counts in this region were first noted on themain shaft dump of the old Blackfellows Dam mine, by H. O. and T* Pearcein 1954. The lode was worKed on a s i ^ ^ w f e w t h e period 1880-1888,apparently for copper and silver-lead-zinc, but there is no record of anyproduction.

Secondary uranium minerals identified on the dump are torbernite(or metatorbemite), autunite, curite (the comparatively rare hydrateduranate of lead, identified by H. F. Whitworth l« Ftayner 195T), f»idyellow to orange uranium ochres, These minerals are partly in st granulargranitic gangije and partly in a soft, dark, chloritic ij^ngue, A trace ofblack mineral surrounded by a halo of bright-orange ahd^ellow powder,embedded in a siliceous specimen on the dump, was strongly radio-activeand may be cftchblenae. Associated ininerals on the dump aresphalerite, chaicopyrite, pyrite, malachite, aconite, jgalena, cerussite,quartz, feldspar, dark-purple fluorite, and oxides <>f iroin iu^ mahganese.A siliceous outcrop, consisting chiefly of iron §nd manganese oxides,denotes the capping of the lode formation in the vicisity &[ the workiiigs.There is some evidence of leaching but the outcrop is not sdohglygossanous. Several potholes into the capping withm 50 m;©f the mainshaft have revealed a few flakes of torbernite.

26

As examination oftheMndj?rground workings shows that the lodeformation is a tabularbody with well-defined hanging and footwalls,enclosed within wall rocle of Erimeran Granite. The strike of the lodeis northwest and the dip is to the southwest at an average of 70s withvariations resulting from rolls and bulges in the footwail. The length ofthe lode proved underground is 12 m and surface indications suggest thatit is longer; the deepest development is n winze the base of which is21 m below surface, and the width T^^B from 0-5 to i-5 m. In a driveat the 8-S-m level, soft clay formation oil a smooth footwall is suggestiveof movement along this direction, and the lode, with its predominantlychloritic gangue, may be classified as a fissure type. Evidence at thenorthwestern end of the drive and in the winze favours a steep north-westerly pitch to the ore formation.

The uranium mineralization is irregularly distributed, but the highesturanium oxide content is in the base of the winze—that iSj in the deepestand most northwesterly point of proving. This po,nt is still well withinthe oxidized zone, which probably has a degree of leaching. The loadmaterial in the lower part of the winze averages approximately 0-13%U3Og across approximately 1 m, with higher grade ore bands (0-75 to20%) within the formation at the northwestern base of the winze.Localization of ore shoots appears to be governed by steeply pitchingroils in the footwall.

Torbcrnite^^ jradmitej and yellow ochres are the most readilyrecognizable uranium minerals in the lode, but do not seem to be insufficient 4 quantify to account for all the uranium oxide contentTorbernite is present both in chloritic gangue and on small jointfaces in thegranitic wall rock; It is probable that the torbernjte io this zone^ as wellas thei mother occurrences described from New South Wales, is morecorrectly termed m^itofbefmte, which kthe temperature conditions prevailing at and hear ihe surface of thedeposits in question. Sfe^arly, the mineral r^rrcd tp by the field nameof Mtunite is probably more correctly described mineMogicaHy asmeta-autunite? ,

Near thetop of'the winze in Blackfcllows E>am mine, small nqdules,up to 1 cm across, of a black substance in a clay matrix occur ia thefootwall section of the lode. The nodules were found to be extremelyradio-active when tested by geiger or scintillation counter. Polishedsections cut across several nodules revealed that the bulk of the specimensconsist of pyrolusite, but show also in places around the rim of thenodules a coUofonn crust and veining of a lighter coloured-mineral ormixture. Autoradiographs of the specimens, taken over 14 hours, showedstrong radioj^acnve images confined to these crustal layers; the pyrolusiteconstituting the internal -part of the nodules showed no radiographiceffect at all in the period of test Similarly, polished sections of thenormal radio-active ore from the bottom of the winze, subjected toautoradiography over similar periods, gave only weak emanation imagesin no way comparabk in intensity to the rim phenomenon of the nodulesreferred to abc&i,

Rayner (1,960) concluded that the high radio-activity of this nodularmaterial from BlackfeUows Dam mine is confined to an outer alterationlayer around pyrolusite, and emanates from the presence of one or moreof the daughter elements of uranium, probably radium and/or itsdaughter products, probably deposited frcm acid sulphate waters.

27

Only the oxidized portion of the Blackfcllows Dam lode is known sofar, and no definite primary uranium mineral has been isolated. Thewater table is probably about 60 m from the surface. The nature of thelode formation, the secondary uranium minerals as described, and theassociation with zinc, lead, and copper minerals are such that it is believedthat hypogene uranium mineralization in the forra of pitchblende oruraniaite may well occur in the primary zone.

Despite a paucity of rock outcrops in the neighbourhood of theBlackfeliows Dam mine, detailed mapping of a small area revealed anumber oflinear features (described as en echelon shearing in, a report byMarathon Petroleum Australia Ltd 1970) traversing the Erimeran Graaitein trends approximately parallel to the Blackfellows ry.mm, Thesefeatures include altered siliceous granitic bands and narrow ^ones whichare ehioritic or clay filled or stained with oxides of iron and manganeseand tend to be niore radio-active than the normal Erimeraa Granite;the granite in turn is twice as radlomerrie as the nearby Invaded sediments.Geophysical testing by electrical methods indicates a line of anomalythrough the Blackfeilows Dam lode and traceable from at 'east 60 msoutheast to 180 m northwest of the mine, as well as showing severalsimilar parallel lines in areas of soil cover.

At a site 490 m bearing 325° from the Biackfellows Dam shaft thereis a prominent outcrop (the Honeysuckle prospect) having minimumdimensions 35 by 10 m and consisting of greisen rock with chlorite anddisseminated chalcopyrite, sphalerite, and galena. Radio-active countsup to eight times normal background may be obtained over this outcrop,and flakes of torbernite are present.

Low-order radiometric anomalies have been obtained from severalother localities in the district* particularly in a zone representing extensionsof strike northwest and southeast of the Biackfellows Dam occurrence.Flakes of autunite and uranium ochres occur in coarse biotite rgranite3 km southeast of Blackfellows Dam. Slight radio-activity has alsobeen recorded from a ferruginous section cf the 27 m level in theMouramba (Nymagee) copper mine, 51 km to the northwest.

CARCOAR DEPOSITS (GR 21208432, Bathurst 1:250,000)

At Carcc-ar, esntral New Snath Wales. 209 km west of Sydney,primary and secondary uranium minerals are present in association withcobalt, molybdenum, and copper deposits. The deposits consist of smalllenses within a zone 1*2 km south of Carcoar township.

General Geology and StructureThe regional environment of the uraniuni-beariHg deposits at Carcoar

is illustrated in figure 4. The uranium-bearing lodes occur on the soii>L-eastern flank of a body of hornblende diorite, being localized in shear.*within slates and andesites and at the contact between these rocks and theintrusive diorite. The diorlte is in turn intruded by granite of ths Carcoarbatholith, of which the main mass crops out 1 -2 km north of the mineraldeposits.

28

IP h"* + .*

Tertiary

REFERENCE

Boseff (Tb)

Grdov!cian<

Corcoor

Angu//eng

Secfs

Mfnor intratlvuf. disrltc (c'iJ,

T N

!

fflonienife (m), fe Vspor porphyry (fp),gcbbro fjo), syeniie (sy)Anchsitic vofccfiici ens? detiv&dtatiimtntf {©cf.JS>io/e ofirf ji/f*fortu mainly (&mO

Anxfetli* ons?fuff (Snip) .

Sfffsfone, sfofe, ondes/'fic vo/con/cs

Sfdfit onrf (juSirfS greyweefce (SaW

Ccreocr urenfum presoecfs(else Co, C", «o, Wi)

Oi/ier jnefd(f/c rfspf ffs

SCALE

0 iMiles

a Kilometre

6309

4, Geolo^cal setting of the Carejar ursnium prospects. (Gealcsg? silerBsfharst* 2 £9,0*00 Geologissl SSsst 1968)

29

Ordovician slates and arkoses, andcsttes, and andesitic taffs in the"icinity of the deposit have been extensively sheared and crushed an4have had their original textures destroyed. Alteration and recrystallfcatjonhave produced chloritii; slates and amphiboliiic schists, and in the andesiiesthe augite has been replaced by amphibofe.

Hornblende diojdte crops sat as a large mass in the vicinity-ofCarcoar, be ween the "'aitovemeittloaed m;m and the Carcosr Granite,and has several dy-k/s-Hke offsfcoots into lie sediments in the vicinity ofthe ore bodies. Th« diorite consists essentially of altered rjlagioclase andamphibole, with biqtite which has been efilpritized. The diorite has beenintruded by the granite .and partially assimilated or gtanitized, and showsmaiked banding and epidotization,

The Careoar Granite is a pfomine'/ftt regional feature, transgressivain nature, occupying most of the area between £arc,oar and BJayiiey. Itranges in composition from a normal granite with dominant potashfeldspars to a -quartz diorite. Veins of 'apiife, fine-grained quartfefeldsparporphyry, pegrratite, and quartz, as well as veinlets bf epjdote, occur aslate-phase expressions of the graniti/i activity, both within "the.-graniteand in the invaded sediments and volcanics. The granitic rocks showsome tendency to gaeissjc structurej md in particular are strongly sheare/Jalong the western margin of the bat?aDlith north of Larcoar. ! & age ofthe granite (which, as referred to 1/ater, |s considefed to have a beatyii gon the age of niineralization) cannfit fee fixed within narrow lunits $ t t &stage, but is fc/eiween late Siluriara (BeWning Orogeny) and late E?nrlyCarboniferous (Kanimblan Orogeriy)»

Sedimentary beds and interbedded volciinics near the lodes strikenortheast and dip to the southeast at 20° to 70°. Shearing and jomtingin a north-south system is prominent, with other sets of linear structuresin northeasterly and northwesterly directions.

Cobah-Molybdenum-Uraniitrn DepositsUranium mineralization lit Carcoar is associated with abandoned

cobalt workings on Portions I, 2, 3, 7, and 25 in Parish Shaw, CountyBathurst. Secondary uraniujn minerals occur on the dumps of oldworkings which are now mainly infilled, and mineragraphic examinationhas shown that primary_ u/rajtiinite is present both in cobaltite andmolybdenite. Radpmetric grid surveys (Raynet; yand, Relph 1957) haverevealed that the radio-activity is essentially limited to the old workings,except fcr s^eral adjacent virgin anomalous areas where subsequenttesting has uncovered secondary uranium minerals. Copper mineraliz-ation is also present near these anomalies (as well as-jjyjdte, pyrrhotite,and arsenojpyrite), but the association of uranium with\c6pper in thisinstance is not nearly as-well marked as is the association with cobaltand molybdenum.

The cobalt deposits were worked in the period 1888-1895, Deepestworking was probably about 30 m. Mingaye and David (188$) reportedths cobalt ore to be present in small lenses or bunches within slates ordiorite, or at the contact between the two. It is probable that the lensesdiscovered have all been worked out. Available surface evidence fromthe workings and the configuration of is^rads indicates that the strike ofthe ore lenses ranges fr6m north to nortneast. The former direction is

30

that of small shear zones in which the lenses are emplaced. Thenortheasterly direction corresponds to another .net of shears and to thestrike of the enclosing sedimentary and volcanic rocks. It is also the strikeof one or two persistent felsitie fears paraiiet to the zone of ore kssss.The members of this interbedded suite dip to tfie southeast at angles of20° to 70°. Wall rock and gangue material of the lodes, as judged fromdumps and surface workings, include slates (partly chloritic and silicified),dioriie, ^niphibole schist, aritl serperitinite.

Secondary uranium minerals on the dumps of the old cobaltworkings include torbernite and autunite (or their meta-varieties) and anori-fluorescent yellow radio-active mineral. Associated minerals areerythrite. coMltitej glaucodot, molybdenite, molybdite, annabergite,'malachite, azurire/ chaicopyrite, pyrite, and arsenopyrite. Quartz,feldspar, chlorite, and amphibote are present also.

Scintillation counter rudiometric grid surveys by Rayner and Relph(1957) revealed several anomalies. At anomaly No. 15 in imworked andsoil-covered ground between cobalt and copper workings, shallow testingrevealed nodules of auiunite, w'th brilliant green fluorescence. Thenodules were up to 5 to 8 cm across and assayed 12% U3O4. Thisdevelopment is in unconsolidated subsoil, but deeper testing snowedthat aumnite in association with quartz veins persists in situ withinslaies and sheared amphiboliiized sediments, and pitches to the southeast.The strike of this zone is approximately north, subparallel to that ofthe nearby cobalt workings and to the strike of joints'and shearing m theadjacent copper workings.

Primary uranium rnineralizatiQn in the form of uraninite was firstdetected inmincragraphic ^armnatipn by StiUweU (1952), w reportedthe: tiranmite; associated with cobaWte and ats^iopyrite. In polishedsection examination and autpradiography: by Rayrier oh specimiens of theprimary cobalt^molybdenite ore, uraninite'was confirmed in associationwith the cbbaltite and also shown to be present In the molybdenite.

Under the ore micrpscopej, small crystals of uraninite were detectedcommonly less than 1 nirn* across. Autoradibgraphs at 24 hours showedstrong 4m^na^onsi from>j>c>siti6ns in the specimens corresponding tocrystgg sabsequentty determined as uraninite. Usually the crystals arepartly rounded or corroded and cracked, and are rimmed by a greenishsecondary alteration product. The vraninite crystals are present incobaltite and molybdenite, and in a gangue ef quartz and serpentinousmaterial, and appear to be later in the paragenesis than the othersulphides. Stringers of tiny uraninite crystals may be seen associatedwith microstructures which transgress and affect, for example, the textureof the molybdenite.

Molybdenite is present in curved lamellae showing the effect of strain.Small disseminated crystals of cobaltite are associated with larger crystalsof arsenopyrite and with another white, isotropic mineral which is thoughtto be glaucodot. Analytical results by Mingaye from this locality accordwith the composition of glaucodot (Mingaye and David 1889).

The cobalt-molybdenum-uranium lenses are considered to beepigenetic, and to be connected with the closing stages of the activitywhich brought m the Carcoar Granite. It is not altogether clear whetherthis granitic activity introduced the uranium minerals into levels nearer

3L

the surface for the fyf$i time, or whether the granitization acted as aconcentrating agency which gathered trace metallic elements from theexisting more basic rocks (dloi-ite, aridesitc, etc.).

Feldspar and quartz in the ganguc, quartz veins in the lodeenvironment together with bands of apparently intrusive fclstte andfine-grained porphyry parallel to the lode zones, provide some supportfor the view that the lodes arc associated with late igneous activity.

Uranium mineralization is believed to be of a similar age to theCarcoar Granite (viz., in the range late Silurian to late EarlyCarboniiiMrous).

WHIF5TXCK. DEPOSITS (149° 42-5' E 36° 5?' S, Bega 1:25O,QO0)

Primary uraninite has been detected in the molybdenum-bismuth orepipes at Whipstiek in the far South Coast district of New South Wales.The Wfaipstiek deposits are situated near the village of Wyndh'am, 24 faninland from the coastal town of Parabola.

General Geology

Uranium-bearing molybdenum-bismuth ore bodies occur as pipeswithin the Bega Granite, being localized near the upper margin of thegranite at or near intrusive contact with overlying sediments. The orepipes have been described, .especially with reference to molybdenum andbismuth mineralization, in several reports (Andrews 1916, Rayner andHail 1956, PJiiner 1968). Figure 5, based on field work by L. R, Hall,shows the regional geological setting for the deposits.

The Bega Granite is a coarse siliceous type consisting of quartz,orthoclasej biotite, and muscovite. Near the contact there is a markedincrease in the amount of muscovite, with developments of greisen. Thegranite is well jointed, and ia addition to containing the ore pipes it istraversed by narrow dykes of felsite, porphyry^ and pegmatite and byseveral quartz veins. Variations in the texture aftd composition of thegranitic host occur in and around the pipes as a result of marginalchMngjlate-magfflatic. and metasomatic processes.

Sediments of tOrdovician and Late TJevoniaa age are .'.present,,separated by an unconformity, only the Ordoyiciiii rocks being intrudedby ths Bega Granite, these OrdpVician rocks consist of st|pngiy jfbldedand cleaved skies* qtiartziiteSj and hornfelfi Ko fbislls haye'beien Jteuadin the vicinity of the minesj but iithologifalJy these rocks resemble jenownLate Ordovician beds which crop but some 80 km to the north and west.

Overlying the Bega Granite and the ?Ordovician sediments, gentlyfolded beds of Late Devoniaia age are found at no great distance from theWhipstick ..^posits. These Devonian strata are latef Mage than the BegaGranite, and include arkosic grits and sandstones" which rest uponweathered granite surfaces.

32

SCALE0

Tertiary

LateDevonian

Early loi

Devonian

Ordovlcian

Marrimbula' Group

LocbielFormation

Rhyotiie

Sega

*• •• "«*'. . . .

*

*u>\V

V¥ '1

REFERENCEGrwuis, etc.

Shaltt sandstoncongfomerof e (dotted)

I Basalt with interbedded

1H

Granifm. apnte,andpegmatite

Quartiitctsands1onc,h l l i s/ofe

' # Mines one? prospects

After Rayner (I960); geology by L.R. Hall 6309

Figure 5. Geological setting of the Whipstick laolyMennm-blsmHth deposits.• '• (Mainly after Rayner I960, geologj-- by L, R. Kali)

33

Thus, the age of the Bega Granite, and probably of the mineraldeposits, though not precisely known* must be within the range lateOrdovician (Benambran) to late Middle Devonian (Tabberabberan).The body is shown on the Bega 1:250}000 Geological Sh«et (Hall et at1967) as Early to Middle Devonian.

The Molybdenutn-Bismuth-Umtmim PipesUraninite occurs as minute crystals disseminated in the ore pipes,

which have beea worked for their molybdenum and bismuth content.Production at intervals in the period 1891-1943 totalled at least 17 MO tof ore, which yielded about 200 t of bismuth concentrates and 100 t ofmolybd?"ite concentrates. The grade in bulk was in the order I to 2per cent bismrth and 1 per cent molybdenum. The principal group ofpipes, responsible for most of this output, were exploited at the Whipstickmines; other pipes mined, all within I km of the Whipstick, include thoseof Mount Metallic, Pheasants Nest, Turbets, aod Wyndfiam No. 2,

The pipes are of small oval to circular horizontal cross section, butare of considerable, though tortuous, vertical extent In this respect,as well as in their characteristics of mineralization and zoning, theyresemble productive molybdenite-bismuth pipes in the New Englanddistrict and in North Queensland. The Whipstick pipes are up to 7-5 macross and 150 m in length. They occur in or near the chilled marginsof the granite and show a tendency to branch in the upper limits. Thepipes were formed by introduction of the mineralizing fluids alongintersecting cracks and joints followed by alteration or replacement ofthe granite around these intersections.

The gangue of the ore pipes consists of granitic rock composed ofvarious amounts of microcline, albite, quartz, muscoyite, and spessartitegarnet, with fluorite, chlorite, magnetite, and biotite as accessoryminerals. One pipe is composed almost entirely of garnet while inanother the mica is accompanied by garnet and brittle white quartz.The spessartite (Stillwell 1943) is confined to the ore zones and does notappear in the normal granite, which forms the country rock.

In 1949, radio-activity was detected (Daly 155S) in molybdenite-bismuthmite specimens from Whipstick held in the Geological andMining Museum and the Australian Museum, Sydney. Radio-activitywas confirmed in the field, and a molybdenite concentrate prepared byflotation showed a uranium content consistent with 0*1 % U3O8. In thecourse of an examination of the molybdenite and bismuth occurrencesof Whipstick, Rayner and Hall (1956) measured definite but weakradio-activity over remnant ore dumps and underground exposures.Strongest reaction was obtained from molybdenite-bismuth andmolybdenite-garnet ore from the main Whipstick mine. Selected samplesfrom the upper adit and from molybdenite-garnet ore from the loweradit workings gave •'respectively 0-029% and 0-33% U3O8. It appearsin general that radio-activity is confined to the ore pipes, is withmolybdenite rather than with the bismuth minerals, and is higher wherethe molybdenite is with garnet gangue (as in part of the old Whipstickmine) rather than with a granitic gangue. A few blocks of lode capping,with iron and manganese oxides and exhibiting some leaching, alsoproved radio-active. Subsequently, a few flakes of torbemite, in"granitic" ore with rosettes of molybdenite, were found on a dump at thePheasants Nest mine (Hall 1956).

34

The presence of uraninite crystals in the primary ore was firstestablished by A. Montgomery (pers. comm, to E. O. Rayner), later byRayner (1960), and subsequently by Pinner (1968). Rayner, bymijieragraphie and autoradiographic examinations, fotad uraninite inmolybdenite specimens and in molybdenite-garnet ore dumped from thelower adit workings of the old Whipstick mine. The uraninite crystalsare mostly less than J mm across. They are commonly rounded orirregular but are fresft «nd some show crystal outlines.

In primary ors from these pipes, PHmer (op. cit) identifiedmtiiyvhmms s«u bfentathinile with minor amounts of uraninite, pyrite,gold, bismuth, joseite A and joseite B (both Bi4 (Te, S)3), tetradymite(BLCTe, S)3), chalcopyrite, arsenopyrite, and skmteradite ((Co, Ni)Ass_s).

Under the microscope it can be seen, that the molybdenite showssbrain effects, and the hard crj'stals of uraniiite and spessartite garnetshow cracking, in many cases these cracks being oriented parallel to""^restructures in the molybdenite. At least some of these effects may be

ied to post-ore movements, when both the granite and the ore pipeswere cut by felsitic dykes. These dykes, in some instances exploiting orez:ones for their entry, probably used the same planes of weakness asearlier furnished access to the ore-forming fluids.

MISCELLANEOUS AREAS

Radio-activity has been observed in several other areas in centraland southern New South Wales, but recognizable uranium minerals are-not commonly present, and in several cases the radio-activity emanates-from thorium and potassium minerals,

BurrinjuckTwo and a half kilometres north-northwest of the Black Andrew

wolfram mine, which is located at 148° 34' 30" E, 35° 02' 20" S,.Canberra l:25O#OO sKeet, near the boundary of Parishes Chiidowla andWest Goodradigbee, County Buccleuch, specimens of decomposedgranite show a fBw small flakes of a yellow fluorescent mineral whichhas the appearance of autunite.

Albury (Adamson 1954) •At Eastern Hill, between Portions 75 and 863 Parish-Albury, County

Goulbura (2-5 km due east of Albury Railway Station) slightly abnonmiradio-activity is recorded in sheared granite and pegmatite stained whh;scorodite.

BuddigowerRadio-activity is associated wub qaartz in a specimen from a vein;

within granite of the Buddigower tin field, Wyalong district.

East; AntiqgongLow radio-activity is associated with arsenopyrite, pyrite, and;

galena in a grey quartzose rock from an old mine at East Armagong(Young-GrenTeM district). The beta/gamma ratio suggests the presence-of uranium, but no definite mineral could be recognized.

35

QUEENSLAND

».+ + * * + V. (W^-4,* + +}

Figure & Uranium occurrences of the New England region. (Geology after theGeological Map of Nsw South Wales 1973)

36

4. * f

REFERENCE

Cainazoic basalts & minor sediments,Mcsozoic sediments

Carboniferous, Permian & minor Tria^^^granite plutons

Folded Palaeozoic sediments &volcanics

1 Uranium occurrences (listed below)••""» Stale bolder

SCALE

0 |S Miles

20 0 SO Kilometres

URANIUM OCCURRENCES123456789

1011121314

is16

MeKenzies prospectML21, Ph Flagstone Co. GoughGarths lodeHeisers lodeFielders Hill lodeBismuth lodeNine Mile lodeSmiths mica lodeBlatherarm lodePulganbar depositSilverValley• JodeWoodfords No. 1 prospectWoodfords No.2 prospectKingsgate mine.Giants Den localityGlen Esk deposit

6309

37

Toongi(GR 153988, Dubbo 1:250,000)One and a half kilometres north of Toongt Station (Dubbo district),

in Portions 39 and 19, Parish Oxley, County Gordon, an outcrop oftrachyte or quartz-felsite, 1 km in diameter, exhibits abnormal radio-activity, in the order of eight times background as measured on theground as a mass effect. A similar radio-active deposit occurs 6*5 kmfurther south, and each deposit gave an anomaly by airborne scintillationcounter (Daly 1953). The degree of radio-activity is considered to te inexcess of that which could be imparted by the potassium isotope K40 alone,and must be partly due to traces of uranium or thorium throughout thefine-grained, acid igneous rock.

Essington (GR 268834, Bathurst 1:2S0,00O)

A radio-active spberulitic felsite near Essington (Oberon district)was examined by Whitworth (HI Rayner 1960), who reported as follows(p. 90):

"Uncorrected measurement of radioactivity gave a value equivalent to thatproduced by 0*12 per cent, of uranium oxide, but the beta-gamma ratio suggestedthat a large part of the radioactivity was due to some dement other than uranium,A careful microscopic examination failed to show any recognisable uranium orthorium minerals. Chemical assay failed to detect any uranium or thorium.Possibly one-tenth of the radioactivity could be ascribed to the potassium content ofthe rock, but it is suggested that most of the radioactivity is due to the presence >jfsome of the daughter elements of uranium or thorium."

Rockley Area

J. Taylor (written comm. to E. O. Rayner) reported that geochemicalsampling of stream waters in the Rockley area revealed higher thannormal uranium content at the junction of the north branch of CaloolaCreek with the Newbridge^Reektey road, at the junction of the southbranch of Caloola Creek with the same road, and at the junction of BackCreek with the Roekley-Burraga road.

Collarena Hall (GR 50830365, Narromine 1:250,000)

Daly (1955) recorded radio-activity in a specimen of malachite in theGeological and Mining Museum, said to have come from the West Bogancopper mine.

Duckmalo'' (GR 296836, Bathurst 1:250,000)'

Daly (1955) als-,. recorded radio-activity in a museum specimen fromRiddles mine (bismuth) at Duckmaloi.

Rock Flat

Fourteen kilometres south of Cooma, at Rock Flat, Paine (1959)recorded radio-activity in travertine around a mineral spring.

Hie New Englaoa (Permian) Group

In the New England region—an elevated orogen occupying a largepart of northeastern New South Wales—uranium minerals have beenfound in a number of localities within a belt 45 km long from north tosouth by 160 km wide irom east to west (see figure 6).

38

This belt is composed largely of a composite suite of granitic rockswith increasing acidky in the younger members. Rayner (1960) showedtliM, without exception, the many uranium-bearing deposits, thoughlocally influenced in emplacement by favourable structures, have beenintroduced into the upper and marginal zones of the younger acidgranites and their late-phase associations, or at the contact of theseirttrusives with invaded sediments.

The known depositions consist mainly of secondary uranium minerals,Jhe commonest of which is torbernite, and to date have proved to be ofmineralogieal rather than economic interest.

Greatest orogenic influence on the disposition and structure of therocks of the New England highlands was the Hunter-Bowen diastrophismat the close of the Palaeozoic Era, during which strong meridional foldingand large-scale overthrusting and faulting occurred.

From the Permian to early Triassic, vast composite granitic batfaolithswere injected into the core of the New England orcgen, the upper limitsof the granite now being exposed over considerable areas by erosion.These bathoiiihs have invaded and altered Ordovician, ?SiIurian,Devonian, Carboniferous, and Permian folded sediments alike. Asignifkartt raeiallogenetic province was formed in the New Englandregion during late phases of the Hunter-Bowen Orogeny, by theintroduction of a variety of ores which appear in the main to begenetically connected with the granitic intrusives. These include ores oftin, tungsten, molybdenum, bismuth, gold, antimony, mercury, cobalt,and some silver-lead-zinc, and copper ores. The loci of deposition arecommonly such structural traps as fissures, joints, pipes, contacts, andbrecciated zones in the granites and adjaceat overlying sediments.

Andrews (1909) and Andrews and Mingaye (1909) distinguished theseveral types and relative ages of the granites and porphyries of the NewEngland region and, of particular interest to the present discussion,recognized a late, coarse-grained, acid biotite granite (the so-called "tin"granite) with which the tin and tungsten deposits are associated.Investigations by L. J. Lawrence, J. C. Lloyd, and E. O. Rayner haveshown that the uranium mineralization is also mainly connected with thisparticular granite, and especially with a range of late- and post-magmaticdifferentiates near the granite margins or projected into adjacentsediments, lavas, and pyroclastics. These late variants include pegmatites,aplites, fine-grained granites, greisens, quartz veins, and quartz-topazbodies.

TORRINGTON-EMMAVILLE 4EEA

In the Torriflgton-Emmaville-Gulf-Binghi sector of the New Englandprovince, the late Permian acid biotite granite intrudes a suite of slates,limestones, tuffs, conglomerates, and lavas. These intruded andmetamorphosed rocks, on'Hthological comparison with fossiliferousmarine beds within and adjacent to the area, are regaided as being ofPermian age.

39

Within the peripheral areas of the granite, in marginal zones of thesediments adjoining the granites, and at the granite/sediment contacts,there are developed a number of specialized acid intrusive bodies andmineralized veins. These include simple and complex pegmatites, aplites,red microgranites, greisens, quartz-topaz (silexite) bodies, and quartz-chlorite veins. Most or ail of these formations are very late phases ofthe granitic intrusion, or are post granite in the sense that the maingranite mass was solidified or immobile before their iRtfodyction intodefined structural channels which are commonly of the fissure type,

The ore bodies that include uranium mineraiization may be classedas partly late pegmatitic and partly hydrothermal (fesure fillings, withsome rrietasomatic replacements), and the primary mineratfetion istentatively regarded as being of Late Permian (HttBter-nsweit} age.

The secondary uranium minerals so far known—and of these byfar the most common is torbemite, Cu (UG^gCPCys. !2H2O, ormetatorbernite, Cu {UD^aCPO^. SHUO, and perhaps zeuperite,Cu (UOgJaCAsOj)!!. 10-16H«O~-are associated in the iibovementionedlode hosts with the Miowing tnnterais: ftrfoeHts, easstierite, sfssnepyrite,pyrite, pyrrhotite, chalcopyrite, bornitei spnalefite, gafena, smaitlte,cobaltite, bisrnuthinite, molybdenite, quartz, feldspar, stilbite, niuscovite»biotite, zinnwaidite, beryl, bromd&e, Suorlte, tourmaline,, topaz,chlorite, rutile, Ilmenite, and monazite.

The lodes in which these associations occur have been worked fortheir tin and/or tungsten content, the minerals of the other elements aslisted above being present only in minor amount. The tin and wolframmineralization has been previously described by a number of authors(e.g,, David 1887, Came 1911, 1912, MuIhoUand 1953, Lawrence 1955).The wolfram mineralization has been considered to be mainly in the formof ferberite rather than wmrainite4 and much of the biotite is the lithium-bearing variety zinnwaidite (Smith. 192^).

The uranium minerals tend to occur with the tungsten and mixedtungsten-tin deposits, rather than with the main tin lodes of the area.This association also reflects the fact that the uranium and tungstenmineralization is chiefly at the nriargius or roof of the granite batholiihwhereas many of the major tin TeT»-sts-TrlthTO fe-fesdy ^f 4hs-gFaRitey g gwhereas many of the major tin TeT»-sts-TrlthTO fe-fesdy ^ gat some distance from the sediments. It is considered that the secondaryuranium minerals represent concentrations from traces of uraninite orpitchblende disseminated in the primary lodes.

From 3 to 9*5 km northwest of Torringtcn (also spelt TormgtoH), anisolated pendant or foundered block of Permian sediments (slate andconglomerate) crops out within the biotite enmite* hs4m bsasiag minoruramum at Fielders Hill and Black Swamp are associated with this block(figure 6). The Fielders Hill deposit .is within a sill-like body of quartz-topaz rock intruding the sediments. Another group of minoruranium-bearing lodes occurs at and near the granite/sediment contactm the Emmaville-The Gulf area, 13 to 34 kis ssrthwest oi EmmaYilte,A third group of deposits is presem near the margia of granite and at agranite/sediment contact in the Binghi and Silent Grov? localities.1 -5 to22-5 km northwest of Torrington.

40

Several of th*m deposits may be described mdividu.iHy and briefly asfollows,

Garths Lode (ML 4 Parish Flagstone, County Gough; GR 45833709,Grafion 1:250,000)

This is a fissure-lode mthm^smw about50 m from { s i p n t a r yy.--''TheJocte-.war-foriiSerly:-worked-:for.f|a along a length "of

2!ft m ; a n 4 : # 4$£t?>$"of.' JS':"rn¥-:.aM ha$-tecftr>dnJI$d.;ta about *^5;;m.

Totfeefnlte iifissoetaiea wiUi.-casatcdtfej-'biOtitei ana;feHloriiei";.aisO'presentare Jefbewe^hajcopyritc, arsenopyriie, - tourmaline,• monazite, ...topaz,dear and smoky qoi&^;asd"|i«ca'.aiid:pBfpWfluorlte.- ,1'hejorwmiieflakes arid crystals-coinnio'hiy" occur on^smairjoint facis in-pegoiatltic or

:..- *.:.'r : ' : . . . i . .S .. . . . c . • ..T j ^ ^ _ ^ _ ^3 ^ E f T ^-X 1 J . j ' . . • . _ ...?., _ E . J ^ J ^ * ^ ; a f c ; J l t a

purple flttoflLe.

Heisirs Lmie (ML .68. Pciirish FiansioBe. Couaty Gou^h, adfaeent toGarths Sodc; Gil 45883698, Gniftoa I ;2503000)

A, greiscppiis loge is developed within sfficeoits granite at thegraniie/sedlmea! contact and has been worked on a small scale for tin.tbfbeniife fla^s am present la cklbrltic gangiis ami on small ftacmrsfaces*: .Associatea' rmffietais arc"• rassrteiiitej••;" ftrbefiw, pyrite, -q-aartz,chlorite,•' chryspcolSa, sliiblte, oiositc, (Tzinnwaldite), magnetite,tounfialirtfi, ana i l d l f

Nine Mile (McVowons) Lode (Portion 17, Parish Paradise North,County Gough; GR. 46463650, Grafton 1:250.000)

A quantose pegmatitic vein follows the gnmite/spdimeni contact.A few flakes of torberriile are associated wilh fcrberite, arsenopyrite,cbalcopyrife, tourmaline, biotite, fluorite, quartz, and topaz.

Fielders Hill Lode (ML 325, Parish Rock Vale, County Clive;GR 46803744, Grafion 1:2505000)

At fieyers Will a quartz-topa?, rock, probably a differentiate froma gratiHic inagma (Lawrence and Marknanx 1963), occsrs %vithin theTorrington i^diihetttary ^ndant . The deposit has been- worked fort ^ t i S A ' 1 % i i ^ : ^ ^ £ 5 n i Hfete? and 45 B h d K p j in? and 45 BhdKpj in

h9 J 5 9 1 p # c 5Q0Q0 t qf ore were produced with a ferberiteconte|it of approxiraately 0*5 per cent Seine tol^tieraiti flakes andcrystals have been found^n fracture surfaces and In cavities, particularlyinanarrdWi^twplydippingshear2OQe. AsmallaMountofchaicopyrife,purple fluorite, and tdurmaline is also present.

Bismuth Lode (near Fielders Hill; GR 46823723, Grafton 1:2S0..(K)0)

At the Si5^5th=lodg slightly afenurmm^a^lo-actiyity was detected byRayner (1960), who iiqted the presence of xnonazite. Lawrence andMarichaa 4t%3) ictenliib^ ^^slsllg^ :ssosaaiterg«frsircoa Is blotMe inpolished sections of saffiorite (CoAsoV-native bismuth-biotite rock from

41

the mine dump. The mica contains significant quantities of lithium(Smith 1926). Lawrence and Markham (op. cit., p. 358) gave thefollowing description:"The uraninite crystals average 005 mm. in width and are embedded in the biotiteflakes, imparting very marked pleochroic haloes to the mica. The uraninite isalways euhedral and exhibits sharp (100) faces occasionally modified by (111).Individual crystals are normally surrounded by a circular zone of pyrite togetherwith a little marcasite. The crystals also exhibit pronounced radio-active "blasting"which usually extends into the surrounding pyrite rim. . . . Marcasite appears tohave migrated into the radial fractures imparted by the blasting. The concentrationof uianinite appears to be too low to be of economic importance."

Blatherarm (Bollingers) Lode (Portion 15, Parish Bates, County Clive;GR 47653730, Grafton 1:25O,OOO)

In the Blatherarm lode intersecting pegmatite and greiseti lodes,occurring within granite, were formerly worked for wolfram and recentlyhave been examined for beryllium and uranium. Radio-activity hasbeen noted on the dumps, being caused partly by the presence ofmonazite crystals. However, chemical assays show that some of theradio-activity is also due to uranium; selected material has yielded up to1 -5 % U,O8, but the bulk of the ore would be only a tenth or less of thisfigure. No definite uranium mineral has been isolated, but yellow,powdery urarJ'.im ochres are present, and perhaps carnotite since aqualitative test shows the presence of vanadium. The most radio-activepart of the deposit is rich in biotite and has a high beryllium contentIn addition to crystals of beryl, the beryllium oxide bromellite isalso present. Accessory minerals include smoky quartz and tourmaline.

Smiths Mica Lode, Black Swamp Creek (ML 65, Parish Rock Vale,County dive; GR 47143760, Grafton 1:250,000)

Smiths mica lode consists essentially of massive bictite at the contactbetween aplite and sediments. Fine scales of torbernite are sparselydistributed through the biotite. Associated minerals are ferberite,cassiterite, tourmaline, and small crystals of beryl and smoky quartz.

Other LodesTraces of torbernite have also been found at the following localities.

1. Fords Hill, 1-5 km east of Smiths mica lode, in a wolfram-bearing pegmatite vein in granite.

2. Silent Grove (McDowells) lode, consisting of aplite, quartz,and greisen at the junction of coarse ^vmite and slate, andcontaining cassiterite, tourmaline, bismuth, galena, chalcopyrite,and molybdenite. :: :

3. McKeozies prospect, Portion 81, Parish Flagstone, CountyGough (GR 45653704, Grafton 1:250,00O, in a greisen vein ingranite near a sedimentary contact, with traces of ferberite,galena, and arsenopyrite. V

4. ML 21, Parish Flagstone, County Gough (GR 45793717,Grafton 1:250,000), at The Gulf, in a greisen vein in granite,with some cassiterite.

5. Hannahs prospect, The Gulf, in a quartz-tourmaline vein ingranite, with traces of ferberite, molybdenite, chalcopyrite, andcopper carbonates.

42

In many other localitiesM ihis area the radio-activity in lode andalluvial deposits is caused chiefly by the thorium content of. monazite,and in other cases disseminated accessory minerals v4th slight radio-activity impart to granitic rocks a radiometrie count several times inexcess of that given- by neighbtjuring sediiiteniary rocks.

Of pafticuiar interest is, .the; presence of radio-actiyc soil in severalparts of tfe- Mid. & a r HigRlanH jprnc Creek, on The Gulf roadbetween jhe Nine; Mile and Beisers lodes, strong Tadic^aeiiviiy has beennoted in soil overlying granite, the count .fate btin| highest at- tlie grassroots and declining as each inch of soil was removed. Though somemonazlte Is present in this..neighbourhood, the beta/gamms ratios suggestthe presence of some uranium not In equilibrium in the soiL Similarly,radio-active soil.above granite occurs 0-8 km from Torrington PostOffice, and in the Bingbi area a black radio-active soil of carbonaceousanfiS3raoce is present. These occurrences suggest a fixation of membersof tha uranium series by deposition from groundwaiers under favourablegCQchemica! conditions"

IJSVERELL AREA

Several urasium-faeaiing lodes occur in the Inverell area, a localitiesnear Gilgai sad Howell (figure 6). As with the deposits of theEmrnaYiiJe-Torrington iirea} the lodes in these localities occur respectivelyin the marginal portions of coarse acid granite and at the csntact of thistype of granite with reittaajats of oyerlyiiig Permian sediments.

Wood]"arils No, I Prospect, Gilgai (Portion 370, Parish Clive, CountyGough; GR 41563040, Inverell 1:250,000)

At Woodfords No, 1 prospect, GiJgai, torbernite occurs as flakes andcrystals in a group of irregular greisen formations within the granite.Gumnxite occurs in association \vith arsenppyrite in the bottom of a smallcut (Wyriti 1961). The greisen bodies may be roughly elliptical in shapeor form narrow Intersecting stockworks, and are less regular than thenormal tin-bearing fissure veins of the region. The greisen is normallyfine grained and grey in colour, is slightly leached near the surface, andcontains disseminations of arsenopyrite, pyrite, and chaleopyrite. Thetorbemite is present in this slightly gossanous material, and moreparticularly is concentrated in reddened ferruginous bands and alongironstained joint faces with sonie smoky quartz in association. Selectedtbrb^rlfte^iferi^ ^ bulk of thegreisen is well below 0-1 %.

Woodfords No. 2 Prospect, Gilgai

Woodfords No. 2 prospect, Gilgai, is several kilometres northeastof No, 1 prospect A narrow quartz vein within granite occupies a fissurestriking 254° and traceable for 5 km, but^ radio-activity is cojifined to abrown ferruginous quarto-breccia vein 90 m in IengOi adjoining thesouthern wall of the barren quartz vein, The \ddth of the breccia veinis from 20 to 90 cm. A yellow to orange secondary uranium mineralencrusts haematitej limonite5 and quartz, or is present as linings andfillings of small vughs. The mineral has been tentatively identified asuranophane or beta-uranotil, and could derive from pitchblende oruraninite at depth.

43

Silver Valley Lode, Howell (GR 40412942, InVerell 1:25O,000)

•f

radio-activity has been measured in a narrow fissure lodeformerly worked for sjlvcr-lead-zinc, in FML 10, Parish Mayo, CountyHardinge, near the village of Howell, 29 km soutli of Inverelt Thefissure occurs in a coarse acid granite a; ;ts junction with overlying slatesand quartzites which are probably of Permian age and crop otit as asmall pendant in granite country. The fissure contains several ssj$i# oreshoots of galena and sphalerite with chalcopyrlte and pyritej Siightradio-activity due to uranium was observed on the damp, but is Negligiblealong most of the workings and apparently confined to very localizedpatches in the sulphide body.

WATSONS CREEK AREA

Ninety-seven kilometres further souths in the Watsons Creek orGiants Den locality (GR 403193, Manilla 1:250,QG0), 18 km northwest ofBendemeer (figure 6), traces of torbernite are to be fopnd in anenvironment very similar to that of the InyerelL and Tbrrington-Emmayille areas described above. The torbernite is associated with tinia bodies of greisen in acid granite, at no great distance from tfie intrusivecontact of the latter with the Early Palaeozoic WoolonlM $ek$.

Lloyd (1954d, p. 1) has given a summarized descnption of thegreisen in the following terns:"The summit of the Giant's Den Mountain consists for tlie jgreMer part of aquartzose greisen, in which, abundant small flakes of muscovite are/developed. Thegreisen mass is about 600 yards long by 300 to 350 yards wW/e- Numerousirregularly-shaped masses of unaltered granite and several large masses of mica rock,are scattered through the greisen.

"Numerous quartz veinlcts and siliceous lenticular rnasses are present in thegreisen and mica-rock, all being narrow and rather irregular iiiibeinayiour. TfteSBhave been prospected for tin to depths of 50 to 70 feet. ... . Associated with thtecassiterite are quartz, tourmaline, chalcopyrlte and traces of bismuth andmolybdenite."

The flakes of torbernite present occur mainly invflie quartz-tourmalinerock.

GORDONBROOK AREA

isiasralization sear GordoflbkOok station jn the upjperClarence River Valley, on the eastern flanjcjof the Northern fSfewEngland) Highlands, has an interesting association -with cobalt, copper,and mercury minerals. The deposits are in rfletamo:rphoseci Palaeozoicsediments near the contact >f the latter w f h p t r u s ^and granodiorite of prpbable late PermiEin age. Tile; iwner|i]ization jsregarded as being; of Hunter^bweji age. A belt-^t. serpentinite cropsout several kilometres to the north. Ejklf a Idlpmetre east of thedeposits^ the metalliferous belt passes beiieath a cover of post-graniteJurassic sediments (figure 6).

Flakes of torbernite have beea found spai'sely distributed inbrecciated slate and with quartz vemlets in small crush zones, lliesetorbernite indications occur at the surface in several locations onPortions 24, 20, and 70, Parish Pulgaixbar, County Brake (GR 577$3483,Grafton 1:250.000). Traces of copper, cobalt, and arsenic mineralization

44

may be observed accompanying the torbernite. The area is adjacent to,and ntey'-beona structural zone represehting a soutlitastem extension of,a lode group formerly worked JFor copper and mercury, The mineralassemblage in this general zone includes arsenTcai cobalt sulphide anderythrite, chaleopyrite and secondary copper minerals, pyrite andhaematite, cinnabar and mercurial tetrahedrite (schwazite), calcite, andq u a r t z . .: . .-._..•.;;,.., "•.•.....__.;_ _'....... _ . . . . . _ _ . ' . „ . . ;

A specimen containing arsenical cdBalt sulpW^ disseminated inblack chert yas; noted to fdntSm Spme-small flakesyof tqrternite alongcracks -andiuh "slight^ jc|>bj^ inrperalhad $eeijt leached, Ra^iometriep?aypf^sjiiJeriilMeKeedlctlhat to beexpjeted ftoptKe smll^amountjpf t^b^raife^iSble, a^;|hebeta|gammaratiE hQwed yraniuni not greatly out oT^qOilibriiiin. It was cdnclydedthat traces of a primary uranium mineral, possibly uranimte andproB3bly associated with the cobalt ore, roay be present.

MISCELLANEOUS AREAS

WtmgleBuijg

- JLadid-activity from the Wunglebung area (40 km southeast ofTenterfield) v/as first noted in a museum specimen of itiolybdenite-bisrnuth oreW(Daly j?55). Subsequently, an airborne scintillographsurvey tyhejjico^t^1953). Slightly ;abnbrrnalrsaio-activ^ oil the groundwhere molybdenite; pipe deposits; had been, /worked at the contact ofgranite and porphyry. No deft^ite uranium minerals have yet beenfound," TheTnature o l tfe^irbprn^ahomalies suggests a mass effept fromtrace mineralization over a large area rather than from concentrations inthe small molybdenite pipes.

Kingsgate (GR 503306, Grafton 1:25OsOOO)

Radio-activity has been recorded from specimens of molybdenitefrom pipes within granite at Kingsgate, in the Glen Innes area (Daly1955) (»g«re 6). Subsequent ground examination failed to reveal anyappreciable radio-activity associated with the old dumps and workings,other than some due to the thorium content of monazite.

Atttmga

Daly (1955) recorded radio-activity in a museum specimen ofmolybdenite-bismuth ore,' from Attynga^ northwest of Tamworth.However, this locality could not be confirmed.

Glen Esk{GR 56341351,, Hastings 1:2503000)

Coffinite has been jicntiSed In a tin prospect at Glen Esk (figure 6).

45

General Characteristics antl Assocations of Uranium Qcc«rrcii«es in NewSouth Wales

(Modified from Rayner I960)

In preceding sections the individual uranium occurrences in NewSouth Wales have been described. Although in most cases the depositsare not of immediate economic significance, each provides geologicaland mincralogical data towards a generalization on favourableenvironments and modes of formation. <-

In this section, salient points of deposition, structural controls andcommonly recurring rock and mineral associations are reviewed andcorrelated. It is hoped thai an outline of these features will be not onlyof general scientific interest but will also furnish in some degree apractical guide to uranium exploration.

From a general consideration of the deposits, several features becomeapparent—for example, the close relationship in moss instances v/ith acidintrusives, the localization of mineralization in structural- features fromregional lineaments down to microplanes, ant! the bias towards associationwith certain minerals.

ROCK ASSOCIATES

Acid IgneousThere can be little doubt that many of the uranium deposits in New

South Wales are connected with acid igneous intrusives, and In particularwith late or end-phase activities.

The uranium-bearing mineral deposits of the New England regionare in lode formations and structures in peripheral zones of acid-granitebathoHths or at the contact with intruded sediments. The hostformations are either late-phase variants of granitic activity, such aspegmatites, aplites, microgranites, greisens, and quartz-topaz rocks, orepigenetic hydrotherma! veins svhich are believed to be geneticallyconnected with the granites. The Gordonbfook occurrence is insediments, but close to their contact with intrusive granite.

At Whipsticky uraninite is in pipe deposits within the marginalzones of granite and at the contact with intruded sediments. AtBlackfellows Dam in the Condobolm-Nymagce district, the uraniumminerals are in a fissure lode within granite but at no great distance fromthe sedimentary contact. Granites accompany the traces of uraniummineralization in the Burrinjuck, Buddigower* and Oberon districts.Uraninite and secondary uranium minerals at Carcoar occur at thecontact of diorite and a suite of sedimentary and vblcanic.rpcks,- but agranite batholith crops out within 1*2 km and may plunge beneath thedeposits.

In the Precambrian region of Broken Hill, the relationship of uraniummineralization to granites is in some cases very obscure. TheThackaringa davidite belt is associated with pegmatites, aplites, andmicrogranites which may be related to end-phase granitic activity butmay also have been produced during metasiorphism. Other minordeposits in the district are in pegmatites. In the Mundi Mundi,

46

Bdakwortli Weil, Efdee Greek, and Hen-and.-Chickens areas there is adose spatial relationship of the deposits to piutons and small oiTshootsof ihe Mundi Mundi type of granite. .El&whertV&s at Copper Blow andGresi-Western,'there is no obvious association with granite.

The various granites which have teen referred xo in association withuranium <lept>si?« in different parts of New Soutfi Wales are usually veryacid •ieucoeraiietypes wlthii dearth or 'absence bf .mafic minerals and a lowCaO IIIWJ Mgffln^ooicat Copmonlj1: these granites display higher thanawra^raditt-actMty; lor example^ Hie j-rimemn gramie in fteBla.ckfcl.tows D^ni locality, the 'Hlrr' granite of New England, and ihegranites .at WMpsiIck;.'and Carcoar are -usually- two to three limes asradio-active as neighboiiring sediments and other rock types.

Tins Wait fadso-aciMiy of add Igneous rocks is, of course, afed feature c-n world scale, atief w attributable to radio-active

Biinetals conteining ssnali amounts of uranium, thorium,f i (isotope Kw). Mtseh of Ae dispersed uranium content is

iii a readily icacha&!e Sbnn.

There appears to bs s similar dispersion of activity io some felslriean3 traehife :ro«lsf as at Toongi, the Warrurofaungle Moastains^ andEssington. I t was nosed, however, that there were ao known uraniumdeposits, nor any significantly abnormal level of radio-activity, associatedwith the many porphyries which occur throughout the State.

In addition to the association of uranium with aplites and pegmatitesas mentioned earlier, special reference may be made to the association ofuranium minerals with greisens, particularly in the Palaeozoic groups.Torbernitc-bearing grey chlontic greisen of the Hone'-suckle prospect atBlackfellows Dam in the central vvest, with disseminated specks ofchalcopyme, sphalerite» and galena* closely resembles the torbernite-bearing greisen at Woodfords No, I prospect at Gilgai (New England),which has disseminated specks of chalcopyrite, arsenopyrite. and pjTile.Somewhat similac greisen also occurs at Garths lode and elsewhere in iheNew England district, and is also present at Whipstick. At the uraniumoccurrence af Storeys Creek in Tasmania, a greisen rock of similar typecontains disseminated chaleopyrite arid sphalerite, and it is significantthat Tninute crystals of uraninite have been observed there in thisenviroament. This type of deposit therefore^ may be characteristic ofthe Palaeozoic granite belts of eastern Australia- It may be that in suchexamples as Blackfellows Dam there arc several successive stages ofliraJiium deposition: JfiLrst, a dissemiiiaftion in granitic and greisenoustypes^ and secondly a lateri inore concentrated accumulation in veinformations,

It may bje appropriate to tHese observations to quote Larsea and Phair(1954.quotMinmynst I960,p. 95):•

"(a) During isost of the magmatic cycle both uranium and thorium form inhost accessory minerals.

(b) As differentiation proceeds \o the highly hydrous pegmatite stage, moreand mote uranium forms discrete minerals and less and less eaters thecommon accessory minerals.

(c) Commonly a t a very late magmatic stage, a change takes place whichbrings ihe uranium and thorium to the parting of the way5;, the uraniumgoing with the hydrqthcnnal solutions and leaving the thorium tocr}'s*aI3ise with the final silicate-rich fraction.

47

(d) This change is believed brought on by a shift towards more oxidisingconditions. It may result from a relief of pressure caused by intrusionof the magma inlo higher hearths. Evidence for this shift in osidaiion-rediieticm"equilibria is found in the replacement of early-formed ferrousmagnesium silicates by magnetite."

Basic Igneousin general, the uranium deposits do not favour an association with

basic or intermediate igneous rocks. These types are absent from theimmediate environment of mineralization in such fields as Condobolin-Nymagee, Whipstick, and New England. Almost invariably such rocksas gabbros, serpentinites, and basic lavas have a very low radiometriclevel, usually below that of the sedimentary rocks.

At Carcoar, dioriie (aad perhaps earlier andesitic rocks) may havesome connection with the uraninite-bcariBg cobalt lodes, but it is thoughtmore likely that the nearby Carcoar Granite was the activating agency.

in the Broken Hill field, amphiboistes are commonly found.near mostof the uranium deposits, and serpentioite occurs close to theTJiaekaringaand Copper Blow areas but there is no proof in either case that there is agenetic connection, and amphibolites are very common throughout theWillyama sequence in places where no uranium mineralization is known.

SedimentaryLittle can be said about the association of uranium with sedimentary

rocks in New South Wales occurrences because not many deposits arepresent in sediments other than in structural and epigenetic lodes. Nobedded-type deposits have yet been found containing uranium oreminerals, in either syngenetic or disseminated epigenetic form, in sufficientconcentration to approach any economic significance, although, as statedin the earlier section on prospecting, potentially favourable areas ofsedimentary rocks have recently been investigated.

MetamorphicOf the metamorphic host rocks, such fissile and foliated types as

slates and schists are the most common and favourable (e.g., CopperBlow, Mundi Mundi, Eldee, Carcoar, and Gordonbrook, and thecontact metamorphosed sediments at Whipstick and New England).This association may be a function of their structural behaviour, thoughit is known in some cases outside New South Wales to be due to chemicalfavourability, as in carbonaceous slates.

In the Broken Hill field, a few grains of davidite are found in sericiteand biotite schists in the Albert Shear Zone, together with an abundanceof quartz reefs, so that the daviaite is of metarnorphic or hydrothernmlorigin. Higher than normal mass radio-activity occurs in micaceousschists in many parts of the Broken Hill district, but its nature has notyet been determined.

STRUCTURAL CONTROLS

It is clear that structural features have been important in thelocalization of uranium-bearing deposits in New South Wales. Thesefavourable structures (which range from large-scale regional faults,fissures, and shears, which may be several kilometres in length, down tominor joints, micro-fractures, bedding planes, and interstitial openings)

48

have tieen referred to in the descriptions of the individual fields. Thesestructural "traps" have played an important rcle, not only in. primaryemplacements, but also in secondary depositions from'groundwatersolutions.

In the Broken Hill, district, prominent shear and fault zones are lociof deposition for uraniurn-bear*£tg deposits in the Thackarfnga daviditebelt and at Copper Blow and Eldee Creek. In the Cpndobolm-Nyiriageedistrict, a fissure zone is host to the Blackfellows Dam lode, arid parallelstructures are radio-active. At Carcoar, the uranium-bearing cobalt-molybdenum lodes are lenses within small shear zones. At Whipstickand'in the New England district, fissures and joint intersections in granite,and the contacts between granite and intruded sediments, determine thepaths and points of emplacement for lode deposits. In all fields, minorjoints, fracture planes, vughs, and interstices provide the site for secondaryuranium minerals.

MINERAL ASSOCIATIONS

Examinations of the various deposits throughout New South Waleshave shown that there are certain metallic and non-metallic minerals withwhich the uranium tends to be associated, and which therefore may actas guides or indicators in the search for further deposits.

MetallicUranium in New South. Wales may be associated with the minerals of

cobalt, copper, molybdenum, bismuth, silver-lead-zinc, tungsten, tin,iron, and manganese. It does not appear to favour an association withthe gold, antimony-gold, and major copper-gold deposits of the State.Several of the metallic associates are worthy of separate mention.

CobaltThe association of uranium with cobalt is a notable one, despite the

paucity of cobalt deposits in New South Vales. Uraninite occurs withsulpharsenides of cobalt at Carcoar, and uranium minerals occur withsimilar primary cobalt minerals at Gordonbrook and Bismuth (NewEngland). Cobalt is jpiesentih tie main Broken Hill lead-zinc lodes andthe Consuls 16de, and in large pyritic lodes at Aplite Hill and Big Hill,.9*5km southeast of Thackannga homestead. Outside the State, cobaltis a fe?*ure of the Rum Jungle area, is present at Crocker Well, and iscommon in the Cloncucry-Mount Isa field, while overseas it is a prominentmetai in iMsmferous deposits m the C6ngo3 Joachimstahl, Cornwall,CaMdA. and Colorado. :

MolybdenumThe association of uranium with molybdenite appears to be a feature

of minor deposition.along eastern Australia. At Whipstick, uraniniteoccurs iiv molybdenite in the molybdenum-bismuth pipes, and similarpipes ia New England (e.g,,.. at Kingsgate) and noithern Queensland areradio-active. Uraniniie also occurs in molybdenite in the cobaltiferouslodes at Carcoar.

49

CopperCopper is an associate of uranium in several of the Broken Mil!

deposits (e.g., Copper Blow), at Btackfcliows Dam and Cartoar,, and intraces in many of the New England deposits. Copper is well known ae auranium associate at Rum Jungle and in many deposits abroad;however, uranium mineralization has not been noted in the larger copperdeposits of this State.

Son-MetallicSeveral non-metallic and gnngue associates may be specially

mentioned.

FluoriteFiuorite, especially of dark-purpie colour, is frequently found with

the uranium deposits. Purple fluorite occurs in ihe Blackfcliows Damlode, and in New England in the Garths, Heisers, and Fielders Hill lodes.Fluorite. including the purple variety, is present in the Mount Elite andMount Robe localities, at no great distance from the Efdea Creek depositat Broken Hill, and occurs in the Alter! Shear Zone of Thackaringi andin the Great Western lode in the same field. A small amount of fiuoriteis also present in the Whipstick 3odes. Dark-purple fluorite veins arcreported by Rayner (I960) in the Crocker Well area of South Australia.Green, with minor purple, fluorite Is present in the Bismuth mine nearTorrington, where there is minor uranium mineralization.

It has been reported that the dark-purple colour of fiuorite may beof diagnostic significance since ii is mostly due to-minute'inclusions ofuranium in the crystal structure. This concept appears reasonable inview of the findings of Bill, Sierro, and Lacroix (1967) that red and greencolourations in some fiuorifes are caused by rare-earift impurities.

Quart:Quartz is a common, almost ubiquitous associate, but it is desired

to draw attention only to special varieties, namely, blue and smokyquartz.

Smoky quartz, almost black ia masy instances, is characteristic ofsuch New England deposits as the Woodfords Nos I and 2, Garths,Smiths mica, and Blatherarin lodes. The smokiness of quartz has beenattributed to the radiation of colourless quartz by radio-active substancesin solutions from which it formed (Holder 1925).:

Blue quartz (actually a tmge from clear totranslucent grey and bluequartz) is characteristic of the Thackariiiga cJavidite belt at Broken Hill,and also occurs in the Radium.Hill and! Crocker Well fields across theborder in South Australia. In the Thaekaringa zone the blue quartz isregarded as an intimate associate of the uranium mineralization, and isthought to be hydrothermal in origin and distinct from other generationsof abundant white quartz. The blue and grey colourations of quartzmay in some instances be due to ultra-microscopic inclusions of futile.It must be pointed out that the blue quartz is a feature of many silver-lead-zinc lodes of the Broken Hill type throughout the Broken Hilt field, andis not necessarily indicative of uranium mineralization.

50

Bi&titeThe presence of black and bronze biotite, often in coarse and massive

developments, is a common .feature in many New South Wales uraniumlocalities. In the Broken Hifl field, bioutc is abundant in the Thackaringaarcar concentrated ,mih the bunches ofc dayidite, rutile, ilmenite,hae^'a'titc, and tnapeilte. Is the Albert ^ Shear Zone of this belt, somegreea nifcas with the biotite probably contain vanadram or chr^niuim.Efsewficrcjn ihe Broken Hill field, fadro-aclMty in a number of pegmatitesis-restricted to biotite.flch sections, Biotita is abundant at the CopperBlow lode and In the Eldce Creek and Sentinel areas.

In the New England district, abnormal developments of biotitecharacterize portions of the uranium-beariag Garths; Smiths mica,Heisers, and Bismuth lodes, At least some ofthe biotite in this regionlias been determined as the lithia variety ziniiwaldite, and the lithiummineral lepidotits has also been reported (David 1887) from this field.Lawrence and 'Markham (1963) reported uraninite in lithium mica atBismuth.

Other ngn-metallic associates

These include berji, topaz, tourmaline, monazite, and chlorite inNew England; chlorite at Carcoar. Biaekfellows Dam, and Whipstick;garnet* zircon, and feldspar. The feldspars may be reddened byradio-activity at such localities as Tfaackaringa and Woodfords No. i(Gil^ai). but at both localities the colouration is also in part due to ironstaining.

The radio-activity of thorium, and the distribution of its minerals,have not been specially considered in this pubh'cation, which is restrictedto discussion of the uraiiium deposits. It may be stated that primaryand detrital deposits of moaazite occur in several fields, more particularlyin the Broken Hi}! and New England regions, and that monazite in thedetrftal heavy-mineral beach-sand deposits of the North Coast constitutesan imporlast source of thorium.

ABSORPTION OF URAKIUM SERIES BY IRON AND MANGANESE OXIDES

In the course of myestigating uranium deposits in New South. Wales.it was noted that in many instances the highest radio-activity in oxidizedzones was associated witli iron oxides and in some cases also withmanganese bxides. Tie association with "iimomtes" was noted in lodegossans, in outctops of transported iron, and in bands and crusts on jointarid bedding pjanes. ;

In the Broken HiH district, radio-activity and U3O8 content at theHen-and-Chickens silver-lead mine are greatest in g'v.thite pseudo-morphous after siderite, aud pronounced radio-activity is shown bylimpnitic bands in the Great Western, Copper Blowy Lalus Nob, Bonanza,Mundi Muiidi, Brinkwortb Well,r Eldee Creek, and Coronal deposits.In the New England district, radio-activity was noted in ferruginous bands -and joints in a number of deposits, and at Blackfeliows Dam andWhipstick iron-manganese cappings are radio-active.

H was established in most of these instances that the radio-activityarises from the uranium scries in disequilibrium, but mostly no definiteuranium minerals couid be recognized in the brown to red iron oxide.The occurrences appear to represent deposition from uranium-hearingsolutions and fixation by absorption.

The process is no doubt similar to that outlined by Lovering (1955)and his associates, who concluded that uranium minerals in an oxidizingsulphide environment go into solution in acid sulphate waters as uranyisulphate in the presence of ferric sulphate. When these acid waters areneutralized, ferric sulphate hydrolizcs io form colloidal ferric oxidehydrate. This absorbs the uranyl ion and removes roost of the uraniumfrom solution. As the colloidal ferric oxide hydrate ages, it crystallizesto form goethite, and in this process most of the uranium is expelled toform particles of secondary uranium minerals in the resulting limonite.

In the Blackfellows Data deposit, nodules of pyrolusite in a claymatrix have a high radio-activity which has been resolved as probablydue to an absorbed outer layer of radium and its daughter products.The deposition appears to be an unusual one, and such occurrences arenot greatly featufed in the literature. The deposition may be of similarnature to that described by Petterson (1945), of layers of radium and itsdaughters around manganese nodules from deep-sea deposits. It may benoted that manganese, like uranium, is a lithophile element.

With further reference to the Blaekfellows Dam deposit, it is probablethat there has been some leaching of uranium from the upper zone.Here only part of the oxidized zone has been penetrated, and such mineworkings as exist are 60 to 70 years old, having been developed in thesearch for copper and silver-lead-zinc before there was any interest inthe uranium content. The nature of the lode and of the secondaryuranium minerals and associated oxidizing sulphides is such as to suggestthe possibility of pitchblende at depth. The deposit may in some respectshave some analogy with the'Wood, mine, Colorado, investigated by Phairand Levine (1953). There, in surface dumps,'.high radio-activity, at firstthought to be due to pitchblende, was proved to be caused largely byradium. The highly radio-active samples studied were from a lode withingranite walls, and consisted mostly of clay with some chalcopyrite, pyrite,and sphalerite present. The significant point in this example is thatthis mine, between 1872 and 1917, was a notable United Statespitchblende producer, yet today iio pitchblende is io be found on dumpsor in the walls of old mine openings. The authors conclude that thepitchblende has been leached from these supergene zones by highly ncid-solutions-(rich in H2SO4 in such sulphide-rich lodes), and that the radiummay be residual and not a Te-deposition. Pitchblende is encounteredwhen new slopes are opened up or holes drilled, and this points the needin such examples for exploration beyond the old workings^particularlyat depth. The Bleckfellows Dam prospect, perhaps on a smaller scale,may well furnish an analogous example.

NATURE AND CLASSIFICATION OF MINERALIZATION

A rigid classification of the uranium deposits of Mew South Walescannot be satisfactorily set down at present," because of the number oflocalities in which./Mily' secondary minerals are known, and because in

-these instances it is not always clear whether the uranium minerals are

52

derived in the oxidized zone from subjacent primary minerals or havebeen deposited from solutions migrated from some remote source.

The davidite deposits at Thackaringa are regarded as late pegmatiticto hydrothernial primary lodes. Their form and mineral associationssuggest rather the hydrothermai stage, and that they were deposited athigh temperatures and may he classed as hypothermal ^though perhapsof lower temperature, environment .than true pegmatites). The uraninite-bearing f o ^ a! Carcoar and Whipstick, the Blackfellows Dam deposit,acd those of the New England region, probably represent depositions atsomewhat lower temperatures.

In addition to these depositions from ascending hot fluids, some ofthe secondary' minerals, e.g., some torbernhe, autimite, rutherfordine, andfixations with iron and manganese oxides, have been formed byprecipitation or absorption from cold groundwater solutions.

I53

SELECTED BIBLIOGRAPHY

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.t |9 |6. The Molybdenum Industry in New South Wales. Miner. Rcsoiir./.w/. Surv. N.S.U.,24.

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•~- and MISGAVE, J. C. A., 1909. The geology of the New England Piateauwith special reference to the granites of northern New England. Part 4.Petrology. Rec. geol. Sun: N.S.IV.. 8 (3), 196-251, S figs, ! pi.

BILL, H.. SIERRO. J.. and LACROIX, R-. 1967. Origin of colouration in somefluorites. Am. Miner.. 51 (7-8), 1003-1008.

BROWN, D. A., CAMPBELL, K. S. '., and CROOK, K. A. W., 1968. THE GEOLOGICALEVOLUTION OF AUSTRALIA AND NEW ZEALAND. 409 pp. Pergamoa Press,London.

Bauer, J. and LANOLEY, J. M., 1949. General geology of the Mandurarna district.B. Sc. Hans. Thesis, Univ. Sydney, Sydney (unpubl.).

CARNE, J. E.. 1911. The Tin-Mining Industry and the Distribution of Tin Ores inNew South Wales. Miner, ilesour. geol. Surv. N.S. IV., 14.

1912. The Tungsten-Mining Industry in New South Wales. Miner.Resour. geol. Surv. N.S. I'/., 15.

CORBETT, D. W. P. and MCLEOD, I. R., 1965. Uranium, in Aust-nlian MineralIndustry: The MiiMtsi Dspesiu. Midi. Bar, Miser. Eemy, GeoL Ggaphys,Aust., 72, 651-659, I fig.

DALY, J., 1953. Radioactive surveying from a helicopter. Rec. Bur. Miner.Resour. Geol. Geophys. Aust., 1953/106, 17 pp., 11 pis (unpubl.).

-, 1955. Examination of museum specimens for radioactivity. Rec. Bur.Miner. Resour. Geol. Geophys. Aust., 1955/18, 7 pp., 1 pL (unpubl.}..

, 1965. Radiometric methods, in Exploration and Mining Geology.Publs %th Commonw. min. metall. Congr. Aust. N.Z., 2, 136-143.

and WHITE, D. A., 1952. Radioactive investigations in the Broken Hilldistrict. Rec. Bur. Miner. Resour. Geol. Geophys. Aust., 1952/58,19 pp (unptibl.).

DAVID, T. W. E., 1887. Geology of the Vegetable Creek Tin-Mining Field, NewEngland District, N.S.W. Mem. geol. Surv. N.S.W., Gcol, I.

DEC/.RU>, J. A. and SHORTT, C. E., 1970. Uranium, in Mineral Facts and Problems.Bull. U.S. Bur. Mines, 650, 219-242.

EDWARDS, A. B. and BAKER, G., 1953. Copper Blow diamond drill core specimens,Broken HiJJ district, N.S.W. Mineragr. Invest. Rep. Commonw.-'set. ind. res.Org. Aust., 550 (unpubl.).

Red MCANCSEW, J., 1953. Uraninke from Broken Hill, N.S.W.Mineragr. Invest. Rep. Commonw. sd. ind. res. Org. Aust., 541 (unpubf.).

FISCHER, R. P., 1970. Similarities, differences, and some ^r.etic problems of theWyoming and Colorado Plateau types of uranium utiposits in sandstone.Econ. Geol., 65 (7), 778-784, 1 fig., i tabl.

FRONDEL, C , 1958. Systematic Mineralogy of Uranium and Thorium. U.S. geol.Surv., Bull. 1064, 400 pp., 24 figs, 8 tabl.

HALL, L. R., 1956. Radioactivity at Whipsttck molybdenum-bismuth mine. Tech.Rep. Dep. Mines N.S.W., 2, for 1954, 28.

54

— — — , ROSE, G,, and POGSON, D. J., 1967. fiega 1:250,000 Geological Sheet.Gcot. Surv. N.S.W., Sydney.

HARRISON, iL J. and LLOVD, 5. C , 1954, Radioactive deposits. New discoveriesami areas -worthy of further investigation, liep.geol. Surv. N.S.H1'., GS1954-012lunpuhl.).

Hoi.&hs., E., 192S. The cause of colour in smoky quartz and amelhvst AmMiner.. 10 (9).

HOWARD, L. E., 1957. Carbqrne radiottietric survey at Blackfeiiows Dam prospect,near CondoboUn, N.S.W. for. Bur. Miner. Resour, QeoS. Geophys- Aust1957/57, 2 pp., J Riajv (anpabJ.j.

ILISLEY, C. T., BILIS.-C W.t and POLLOCK, J. W., 1958. Some gsochemical methodsof uranium exploration, in Survey of Raw Materials. Proc. 2nd U.N.International Conference on the Peaceful Uses of Atomic Energy, 2, 126-130.

NECKS, O,, J9S9. Geophysical survey at B!as±fciiGW5 Dam uraniunj prospect,Condobolin district. N.SAV. Ree. Bur. Miner. Resour. Ceo!. Geoohrs, Ati-a1959/44, 4 pp., 3 pis (unpubi.).

LASSEK, E- S. 33d PHSSR, G., 1954. The Diatribuiion of Uranium and Ttioriam ini^isam Rscks, :z NJJCLJEAS GSOLOOY. John Wiley, New York.

LAWRENCE, L. J.. 1955. The nature and genesis of the ore deposits of the MoleTabioSand with special reference to tin and tungsten. Ph.D. Thesis. Univ.N.S.IK, Sydney (unpubi,).

and MARKHAM, N. L., 1963. The petrology and niincralocy of thepegmatite complex of Bismuth. Torringion. N.S.W. J. geol. Sac. Ami 10 (2)343-364,7 figs, 3 pis. " - .

LLOYD, A. C , 1936. Geoiwgical survey of the Cobar district. Progress report.A. Rep. Dep. Mines N.SJV. for 1935, 87-89, 1 fig.

LLOYD, 3. C , 1951. Radio-active rocks at Toongi, near Dubbo. A. Rep. Dep.Mines N.S.iV. for 1951, 88.

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——-—, 1954b, C. S. Hannah's uranium prospect, The Gulf. Rep. wo/. Surv.N.S.W.t GS 1954/057 (uapubl.).

, 1954c. W. Mickey's uranium prospect, Binghi. Reward particulars.Rep. gcoi. Snrv. N.S.W., GS 1954/062 (unpubi.).

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—•—-—-. 1954L-Prelisiinary note on the occurrence of torbernite nearCopmanfiiirst, Rep.geoL Surv. N.SJV., GS 1954/068 (unpubi.}.

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N.S.W., GS 1954/075 (i^QabL).— , i954j. M. Grunberg's uranium prospect, Silver Valley. Rep. geol.

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particulars. Rep. geol. Surv, N.SJV.. GS 1954/083 {unpubi.).LoVERfNG, T. G., 1955. Progress in radioactive iron OKides investigations. Ecati.

GeoL, 50 (2), 186-195, 2 tabl.

55

MARATHON' PETROLEUM AUSTRALIA, LTD, 1970. Final report, E» L. 146. N.S.W,Gevi. Surv. N.S.IV. File, GS 1970/162 (unpufa!.).

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PHAIR, G. and LEVINE, H., 1953. Notes on the differentia! teaching of uranium,radium, and lead from pitchblende in H.SO* solutions. Econ.t GeoL, 48 (5),359-369, 7 tab!.

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RAGGATT. H. G.. 1937. Geological survey of the Condobolin-Trundle district.Progress report. A. Rep. Dep. Mines N.S.W, for 1936, 92-95.

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RAYNER, E. O.. 1957. Pcarces' uranium prospect, Biackfellow's dam, Condobolindistrict. Tech. Rep. Dep, Mines N.S.IV., 2, for 1954, 26-28. 2 figs.

, 1958. Davidite and other radioactive occurrences in the Tha^kartngaarea. Broken Hill district. Tech. Rep. Dep. Mines N.SJV., 3, for 1955,62-72, 5 figs.

1 1959. Second report on the Blackfellows Dam uranium prospect,Condobolin district. Tech. Rep. Dep. Mines N.S.W., 4, for 1956, 61-64,2 figs.

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and Hall, L. R., 1956. The Whipstick molybdenite-bismuth deposits,Pambula district. Tech, Rep. Dep. Mines N.S.IV., I, for 1953, 53-60, 2 figs,2 pis.

and RELPH, R. E., 1957. Uranium-cobah deposits at Carcoar, NewSouth Wales. Tech. Rep. Dep. Mines N.S. W., 2, for 1954, 21-26, 1 fig., 2 pis.

ROUTHIER, P., 1963. JLES GlSEMENTS METALLIFERES: GEOLOGIE ET FaiNCrpES litRECHERCHE. 2 vols. Masson, Paris.

SMITH, G., 1926. A Contribution to the Mineralogy of New South Wales. Miner.Resour. geol. Surv. N.S. W., 34.

STILLWELL, F. L., 1943. Molybdenite ores from Whipstick, New South Wales.Mineragr. Invest. Rep. Commonw. sci. ind. res. Org. Aust., 274 (unpubl.).

56

~~—, 1952. Uraniferous cobalt ore from Carcoar, N.S.W. Mineragr. Invest.Rep. Commanw. sci. ind, res. Qrg. Aust., 507 (unpubl.).

WHITTLE, A, W. G,, 1954. Absiie—a new miners! related to brannerite.Rev., Aiktaide, 91, 99-106, 5 figs, 3 tab).

Min.

, D. JM 1972, Exploration for "sedimentary uranium" mineralizationin New South Wales. Summary of work done 1969-71. Rep.geol. Sun: N.S.W.,GS 1972/057 (unpubl).

WYNN, D. W., 1961a. Radioactivity at Rock Flat, near Cooma, N.S.W.Rep. itep. Mini's N.S.IK, 7, for 1959, i47.

Tech.

, 1961b. Recent developments at Woodford's uranium prospect, GiSgai.N.S.W. Tech. Rep. Dep. Mines N.S.IV., 7, for 1959, 149-153, 2 figs.

57

KEY TO LOCALITIES ON SPOT MAP

1. Thackaringa group

2. Mundi Mundi, Brinkworth Weli, Eidee prospects

3. Hen-and-Chick^ns mine

4. Great Western mine

5. Broken Hill line of lode

6. Copper Blow mine

7. Corona prospect

8. Blackfcllows Dam prospect

9. Carcoar deposit

10. Whipstick deposits

11. Giants Den locality

12. Glen Esk prospect

13. Inverell group

14. Kingsgatc mine

15. Torrington-EmmaviUe group

16. Pulganbar deposit

NOTES

0 V 1

^PHd^SE/hf

:d Tsy the l>eyartEQeu.t of Mines, K.S.W.

MINERAL INDUSTRY OF NSW SOUl'H WALES

Siir-iasary Report ScriesIt is proposed that the followiog reports will be published set .,,

net necessarily in the order listed, and collectively will represent a revisedequivalent of Th-j Mineral Tmwstry of New South Wales (1928) now out

I. Aluminium (Bauxite)*2. Antimony"3. Arsenic*4. Asbestos5, Barium (

n6. Eerylliuui7. Bisxnutji

*8. Chromium9. Clays

10. Coal•11. Cobalt

1.2. Constructional Materials13. JCoppcr

*14. Diatomitc (Diatomareous Earth)*i5. Feldspar*16. Fluoritc (FltiorsT>ar)

17. Fullers Earth and Beatonite*1S. Gemstoaes (Opal. DiamoDd, Sapphire, Emeraid, etc.)

19. Gold*20. Gypsum*21. Lron22. Lead-ziDv-silyer

t23- Limestone and Dolomite (and Lime and Cement)*24. Magnesium (Magacsita)*25. MaSgaticsa26. Mineral Figments27. Minor Metals..28. Miscellaneous Minerals ""••"29. Molybdenum30. Oil Shale

•31. Perlite32. Petroleum and Natural Gas

-'33. Platinum34. Silica35. Sflllmanite36. Sulphur (including Pyrits)

*37. Talc, Steatite and Pyrophyllits38. Thoriuin39. Tin40. Titaaium (Rutile and UiGenite)

Ml. Tungsten (V/Oiframitc anc Scheelsto)42. Underground'Watcr .

"43, Uranium44, Zirconium

*45. Nickel "*46. Rhenium'::47. Fly Ash

° Published t Part 2, Dolomite, published