The Geology of Some South Australian Iron Deposits
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¡5 6b1 TTM GEOLOGY OF SOME SOUTH AUSîRALTAN TRON DEPOSITS by GB.AHAM F. tIIHIllE}f Department of Mines South Austra].Ía Jantrar*¡r, J966. Ì FrontisPiece - VÙILGENA HILL Ripp1e marks ín Haematite JaspilÍte' TABLE OF CO}iIIENTS fllnfi¡fARY Page i SÎATEME}fI OF IííORK iv TNTRODUCTION I DEPOSTTS TN CORES OF TITE NJIT. LOFTY RANGES ? Mt. Jaggecl o Wenha$¡r s 10 TITE GAWLER PI,ATFORM - E]ßE PENINSTII"A 11 META-.TASPILTTES OF TIIE MIDDI,EBACK RANGES 13 IRON FORMATIONS OF CEMINAT EIN.E PENTNSIII'A L4 the t/Vamanboo Anonal-y T6 The Kopi Anomalies 29 Meta-jaspilites near KYancutta 30 MEIA.JASPTLITES OF TTIE LINCþLN UPI,AIIDS 32 Greenpatch Meta-j asPillte s 38 Koppio Meta-iasPllite 42 META-JASPTLITES OF EASTERN E1RE PE}rINSUI,A 44 Pt. Neill- (Carrow) Arronaly 46 The Cowell Anomalies 4? ÎIIE GAIVLER PLATFORM - YORKE PE{TIüSUI"A 5I THE GAVüLER PI"ATFORM - ÎITE CENTRAI PRO\IINCE 53 Haematite Jaspilites on Yüilgena Station 59 Irrlagnetite tvletá-jaspilites oñ Mtrlgathing Station 65 MEIA-.]ASPILITES OF TI{E OI,ARY PROVTNC,E 72 Billeroo 72 Koolka -14 OId ToranÍnga Da.m 7A Pltrmbago ?e CT,ASTIC DEPOSITS OF TITE ADT,AIÐE GEOSYIüCT,INE 80 Ma1colm Creek 81 Iffllia-mstown Grits 83 Yankalilla BaY 83 GI,ACIOGENE DEPOSITS OF fiIE ADU¡A.IDE GEOSY]\TCI,INE 88 Braernar Iron Formatlon etc. 88 DTAPIRIC DEPOSITS I\nRUDING ÎIIE ADELATDE GEOS)IXTSjTNE 1IO Inon King rtz Hieks (Gtadstone) 114 the Devilfs ChimneY 116 OTHER DEPOSTTS OF TI{E ADELATDE GEOS]ßTCTJTNE 118 DEPOSITS RELATED TO I.,AI{Ð ST]RFACES 119 Replacernent Deposits l-,20 Haematites - Angaston LzQ Limonites - Donnel-lYs Constock 12t Oodlawirra t22 Strperficial Deposits L22 Laterites-- Radltrn HiI1 District J22 Mt. Lofty Ranges l;24 Canga¡ Sêree Ore L25 Buck-shot Grave1 L?-6 DEPOSTTION OF SOUTH AUSTNATIAN TRON DEPOSITS L26 Jaspilltes and Meta-iasPilites L26 Veins of Títanhaematite 131 Clastic Deposits of the Adelaide Geos¡mcline. 131 Glaeiogene Deposits of the Adelaide Geosyncllne 131 Diapirîc Oeposits of the Adelaíde Geosyncline 133 Othêr DeposLts of the Adelaide Geosyncline 134 Deposits- related to land sttrfaces L34 AGES OF SOUTH AUSTRAJ,TA}Í IRON DEPOSIIS 135 JaspilÍtes and Meta-jaspilites 135 Other Ïron ÐeposÍts 136 STRUC"rUNAL Rffi,ATIONSTilPS IN SOUTH AUSÎRALTA 13? Section from Pt. Westall to the Mumay Basin )3? Section from Mt. Christie to the Radium HilI District 139 EI"ASSIFTC,A.TTON OF TRON DEPOSTTS f40 Lake SttperÍor Type, Volcanic Assocíation L40 Lake Strperior Type¡ Sedimentary Association I4I Braemar lron Formatfon 143 CONCLUSION L47 BIBLIOGRAPTflT 150 PHOTOGRAPHS APPEIVDIX PI,ANS PLan Title Scale Page 1 Sotrth Australia 1ll = 80 m. I Known Iron Deposits 2 Yorke Peninsula - Mt. Lofty Ranges lrf = 1O m. 7 3 The Gawler Platform llr = 32 m. 12 Eyre Peninslrla - Yorke Peninstrla 4 Middleback Ranges Díag. L4 Stratigraphy TìlamarrÍboo and Kopi Aeromagnetic Lll=4m. i-5 Anomalies, Meta-jaspilites near Kyancutta 6 Warramboo Dlag. I8 Frequency Ðistribtrtion of Errors in esti¡nated. iron content ?+ Vfaruamboo Aeromagnetic Anomaly ill - 20001 Pocket Srotrnd Magnetic Contours and Trend.s 8 Warramboo Aerornagnetic Anomaly Ïr = 20oor 2? Composite Geophysical and. Drilling Profil-es o lVaruamboo A,ero¡nagnetic Anomaly Graphs 28 Correlation Logs of vfD 2 l0+ E]æe Peninstrla Ir = 16 m. Pocket Geological Sketch Pla¡t I1 Lineoln Uplands Diag, 35 Stratigraphy L2 Greenpatch and Kopplo Meta-jaspilite Míneralogical Tab].e lable 40 Plan lit].e Scale Page 13 Port Neill (earrow) Anomaly Table 47 Mineralogical Table L4 îARCEOI,A Ltl= 8m. 55 PIan --ffi'fogical L5 TARCOOI,A Dlag. 57 16 -ffiatigraphyWllgena Hill 1rr = 20001 60 Geological Plart L7 Mt. Christíe 1'r = 4OOr 66 Geological Plart 18 Mt. Christie GDI Table 68 Geological and AnalYtical Log 19 Fingerpost HiIl lrr = 4OOl 69 Geological Plan 20 BÍlleroo l[ = 2O0Cl 73 District GeologY 2I Koolka Ir = SOO| 75 Geological Plan 22 OId Toraminga Dam Lrr = ZCO| 78 Geological P1.an 23 Pltrmbago 1rr = 2OOl ?9 Geotogical Pla¡t 24 Ma1co]m Creek - Vfilliamstown Grit's Ir = 1 m' 81 Geological Plan modified from Gawler 25 Malcolm Creek - Vfílliarnstown Grits Graphs 87 TiO2/Fe2O3 ratios etc ' 26+ Braemar llt=1m. Poeket Geological Sheet 27 -ilmireRazorback Ridge Diag. 92 StratigraPhic column Plan Tit].e Scale Page 28 Razorback Ridge Lll = 4orr 661 105 Stratigraphl c dÍstribution of assays 29 Razorback Rldge Diag. r06 Histograns of AssaY Valtres 30+ Iron King - fron Occurrence ilr = Loor Pocket Geologlcal PLa¡t 31 Iron Ore in Sotrth AtrstraLia Table ul6 Generalised StratigraPhic CoLumn 32 Iron Ore 1n South Atrstralla Diag. 138 Structural RelatíonshÍPs across the State PHOTOGRAPHS No Description. a ïÍarramboo Drill cuttings beÍng logged with 1 binocular microscope' Float of weathered qtrartz-magnetite 2 Kyanctrtta (mantite) gneÍss is the olly Prospect 1A òitrfa"" exþression' Looks sotrth' 3 GreenPatch 4 GreenPatch The coarse grained magnetite meta-jasPilite sanPled on, iriõ{äriürþicar Hirr- for metalltrrgícaL testing. of 5 lron Motrnt Mine Mag¡etite meta-jaspilíte leached' ilãn 1eaving white quartz sand'' Irooks sotrth- Irtlilgena Hill Sediment'ary strtrctures in Haematite 6 Jaspil"ite. Marks' 7 Wilgena Hill Fossils (?) and RiPPle jaspilite' 8 Wilgena Hilt Fossils (?) in haematite I Mt. Christie IVlartite nreta-jaspilite in otrtcrop' 6035 7 l"o TrIest lVeI]. PhotomicrograPh-rneia-iaspitite. of TS X inä"iit" A'MDEil-, Phot'o ' l1 lfest WeLI PhotomicrograPh-meia-iaspitite of !S 6036 X ? [/lä"ti{" ' AIúDEI., Prcüo' 12 IÍt. Christie PhotomicrograPh of fS 6058 X ? lnãrift" m"la-i.spilite. AIVIDEI., Ehcifo' 13 Mt. Christie PhotomicrognaPh-meia-iaspilite of !S 6056 X 7 IVIa"iiiã ' AIIDEL Hroto' L4 Billeroo Billeroo Peak looking sotrth' gilÍ""oo South 1n left backgrottnd'' No. Description. 15 Billeroo Martite meta-jasPilite at Billeroo Centre. 16 Koo]-ka Koolka North looking sotrth east. T7 Koolka Koolka North looking west showing steep north plunge. 18 Koolka Koolka Sotrth from Koolka North looklng south south west. l-9 Pl-tubago General view lookir¡g north east' 20 PJ.tmbago View along otrterop lookirg sotrth. 2L Yankalilla BaY Basal Grits. 22 Braemar Iron Razorback Ridge (Member n) viewed Formation across Member C from Títl1tic Iron Formation in Member D. Looki4g south east' 23 Braemar ïron Ironback Hil]. (tillite and Fornation qrlartzite), iron formation in the foregrotrnö and in lower hil.ls on right. Looks north east. 24 Braernar Iron fronback Range on right. Iron Formation formation on-the low hil]-s on 1,he 1eft, interglacial shales beyond'. Looks sotrth west. 25 Braemar lron Dolomitic iron formation of Levi For¡nation Range. 26 Braemar Iron PhotomicrograPh showing micro- Forruation fanlting PLzeS/58 X 46' AMDEL Photo- 27 Braemar ïron PhotomierograPh showing riqPle Forrnation marks with-concentration of round.ed. euhedra forming crests. PL286/58 X 25, AMDEL Photo. 28 Braemar fron Photomicrograph showing martitised For¡nation masnetite etrheclra ancl erratlcs. P7'ág/58 x 56. .aMDEL Photo. No. Description. 29 Braemar lron Photomicrograph showing magnetite Formation euhedra haõmatite and erratics. P?23/58 X 165. AMDEI, Photo. 30 Braemar Iron TillÍtic iron formation near Formation fronback HiI]-. 31, Braemar lron Razorback Ri4ge' Members C and B Formatlon tested bY dril1 hole RD t (collared in grrJ.If above car) a¡rd an adit. 32 Iron King General view looking north west showing the dePosit and' Poor otrtcroþ conditLons insíd'e diapirs. 33 Angaston Massive haematite resting on the karst surface of marble- 34 Donnellys Limonite replacing one bed' arotrnd' Comstock the nose of a syncline. Irooks Sotrth. 35 Oodla $lirra Limonite in shale in southerlY workings. I¡ooks north- 36 Grants High grad.e Laterite in Terminus Qtrarry. 37 Grants Low grade Laterite in East Qtrarry. t- SIJÙIXÍARY For eleven years, the authorr âs an officer of the Sotrth Atrstralia¡ Departnent of Mínes, Ínvestigated Sotrth Australian iron cleposits. FÍeld. work comprised geological mapping, geophysicsr drilling and ninirg; Iaboratory investigatíons mainly by the Australian Mineral Developnent Laboratories comprÍsecl geophyeics, chemi.cal analyses t petrological exanrir¡ations and metall¡1rgieal investigations' The data presented ill-trstrate the different techniqtres app1-ied to dÍfferent ore t.l¡Pes ' JaspíIltes are 1,he main iron formations ín sotrth Arrstralia. The haernatite jaspilite of Ttilgena Hill in the central Province contains red chert ancl shows ripple marks a¡d fossils suggestir¡g a shallow trrater envirorunent and indicating little change since deposition' iVletamo4fiism of this horizon to the north west prodtrced the magnetlte meta-iâspiliteofMt.Cnrlstie'Thisissimilartothe meta-jaspitite of Btlleroo, Koolka, etc. in 1,he olary Province. the least meta.morphosed jaspilites of the MídöIeback Rarges have red chert and resemble the jaspilíte of Vfilgena HiI}. The fnore metanonphosed varia¡rts contain magnetite, grey chert, ferrtrgÍnous silicates and non- fefftrgínotrs earbonate. Tn sotrthern Eyre Peninsula, the iron oxide 1s magnetlte and the non-ferrtrginoLls carbonates t-1 aremetalDorphosedtocalc.Silieateminerals.InCentral have Eyre Peninstrla, near Cowe1l, imptrre iron formations metamorphosedtogneissandrrgra.rtltêl|.Theironforrnations Yorke Peninsula can be traced from Eyre PenÍnsula throtrgh ]lt' Lofty Ranges' ancl St. vincentrs GLr1f to cores Ín the A,lttheaboveironformationsappeartobeeqtrivalent inage.lheyarenotlnterbeddedwithbasicvolcanicgas aretheArchaeanjaspilitesoftheWe-ctAtrstralfan Goldfield.s.Theyaresimilartotheironformationofthe Ha$ersleyRarrgesandarethtrsconsideredtobeLower Proterozoic