VIMP Report 10 The geology and prospectivity of the Tallangatta 1:250 000 sheet I.D. Oppy, R.A. Cayley & J. Caluzzi November 1995 Bibliographic reference: OPPY, I.D., CAYLEY R.A. & CALUZZI, J., 1995. The Geology and prospectivity of the Tallangatta 1:250 000 sheet Victorian Initiative for Minerals and Petroleum Report 10. Department of Agriculture, Energy and Minerals. © Crown (State of Victoria) Copyright 1995 Geological Survey of Victoria ISSN 1323 4536 ISBN 0 7306 7980 2 This report may be purchased from: Business Centre, Department of Agriculture, Energy & Minerals, Ground Floor, 115 Victoria Parade, Fitzroy, Victoria 3065 For further technical information contact: General Manager, Geological Survey of Victoria, Department of Agriculture, Energy & Minerals, P O Box 2145, MDC Fitzroy, Victoria 3065 Acknowledgments: The authors wish to acknowledge G. Ellis for formatting the document, R. Buckley, P.J. O'Shea and D.H. Taylor for editing and S. Heeps for cartography I. Oppy wrote chapters 3 and 5, R. Cayley wrote chapter 2 and J. Caluzzi wrote chapter 4. GEOLOGY AND PROSPECTIVITY - TALLANGATTA 1 Contents Abstract 4 1 Introduction 5 2 Geology 7 2.1 Geological history 7 Pre-Ordovician to Early Silurian 7 Early Silurian Benambran deformation and widespread granite intrusion 8 Middle to Late Silurian 9 Late Silurian Bindian deformation 9 Early Devonian rifting and volcanism 10 Middle Devonian Tabberabberan deformation 11 Late Devonian sedimentation and volcanism 11 Early Carboniferous Kanimblan deformation to Present day 11 2.2 Stratigraphy - sedimentary and volcanic rocks 11 Ordovician 11 Silurian 13 Devonian 15 Triassic 17 Tertiary 17 Quaternary 17 2.3 Intrusive rocks 17 Dyke rocks 17 Cambrian? 18 Silurian 18 Devonian 20 3 Economic Geology 22 3.1 Gold 22 Alluvial goldfields 25 Primary gold 35 3.2 Base Metals 79 Base metal mineralisation 80 3.3 Tin 87 Alluvial Tinfields 88 Primary Tinfields 89 3.4 Other Metals 92 3.5 Non-metallic minerals 94 4 Summary of Exploration 97 4.1 History of exploration 97 Gold 97 Base metals 97 Tin 97 Other minerals 97 4.2 Major exploration programmes 98 5 Economic potential and prospectivity 109 Gold 109 Base metals 109 Tin 110 Other Metals 110 Non Metallic minerals 110 References 111 Appendix 1 128 Location of expired Exploration Licences TALLANGATTA 1:250 000 Mapsheet Appendix 2 138 2 GEOLOGY AND PROSPECTIVITY - TALLANGATTA Summary of exploration targets within the Tallangatta 1:250 000 Mapsheet. Appendix 3 148 Exploration Licence Summary - Tallangatta 1:250 000 mapsheet Victorian Initiative for Minerals and Petroleum (VIMP) report series 156 List of Figures 1 Tallangatta locality map 6 2 Tallangatta main structural features (back pocket) 3 Geology, mineral prospects and tenure, Tallangatta 1:250 000 mapsheet (back pocket) 4 Major mineralised areas within TALLANGATTA 23 5 Victorian gold production 25 6 Tabberabbera and Benambra Zone gold production 25 7 Primary gold production for the major goldfields, TALLANGATTA. 36 8 Orientation of gold bearing quartz reefs from the Harrietville goldfield 42 9 Longitudinal cross section of the Sambas mine, Harrietville. 45 10 Orientation of gold bearing quartz reefs from the Bright-Wandiligong goldfield 46 11 Orientation of gold bearing quartz reefs from the Freeburgh goldfield 47 12 Orientation of gold bearing reefs from the Bethanga goldfield 59 13 Orientation of gold bearing quartz reefs from the Corryong goldfield 60 14 Orientation of gold bearing reefs for the Dart River goldfield 64 15 Orientation of gold and copper bearing reefs from the Granite Flat goldfield 67 16 Orientation of gold and copper bearing reefs from the Granya goldfield 68 17 Orientation of gold bearing reefs from the Mitta Mitta goldfield 71 18 Orientation of tin bearing reefs and dykes from the Mitta Mitta goldfield and tinfield 71 19 Orientation of gold bearing reefs from the Mt. Wills goldfield 74 20 Orientation of tin bearing reefs and dykes from the Mt. Wills goldfield 75 21 Orientation of gold bearing reefs and dykes from the Sandy Creek goldfield 76 List of Tables 1 TALLANGATTA gold production 25 2 Gold production estimates for various TALLANGATTA goldfields 26 3 Major alluvial gold production - Tabberabbera Zone 27 4 Major alluvial gold production - Benambra Zone 31 5 Major primary gold production - Tabberabbera Zone 40 6 Major gold mines - Tabberabbera Zone 41 7 Major primary gold production - Benambra Zone 54 8 Major gold mines - Benambra Zone 56 9 Major mines on the Bethanga lodes 59 10 Limestone Creek Graben base metal occurrences 81 11 Wombat Creek Graben base metal occurrences 82 12 Benambra Zone base metal occurrences 84 13 Copper production for the major gold mines - Bethanga goldfield 87 14 Alluvial tin production - TALLANGATTA 88 15 Primary tin production - TALLANGATTA 89 16 Major primary tinfields - TALLANGATTA 90 17 Summary of drilling at Wilga and Currawong prospects 100 18 Preliminary exploration results from EL 653 103 19 Pan concentrate results for EL 653 103 20 Summary of drilling at Reedy Creek 104 21 Summary of exploration results in EL 656 105 22 Summary of drilling in ELs 1223 and 1462 108 GEOLOGY AND PROSPECTIVITY - TALLANGATTA 3 Digital Data Sets TALMINE.xls Mines databasae, Excel version TALMINE.txt Mines database, ASCII version TALCODES.doc Legend of codes used in mines database, Word version TALCODES.txt Legend of codes used in mines database, ASCII version TALREFS.doc References cited in mines database, Word version TALREFS.txt References cited in mines database, ASCII version 4 GEOLOGY AND PROSPECTIVITY - TALLANGATTA Abstract This report is a summary of geology and prospectivity of the Tallangatta 1:250 000 sheet and is intended to provide information to explorers making application for exploration licences in parts of the Eastern Highlands Initiative area where the exemption from mining and exploration licences will be lifted in the near future. Broad areas with potential to host a variety of styles of mineralisation have been outlined as a result of this study. These areas have been identified based on the results of prior exploration, known geology and an appraisal of the new geophysical data. Disseminated copper-gold and tin deposits, together with vein gold, tin and tungsten and volcanic hosted base metal mineralisation all represent potential exploration targets within the area. GEOLOGY AND PROSPECTIVITY - TALLANGATTA 5 1 Introduction This report represents part of a data package that has been prepared to provide information to explorers in the Tallangatta 1:250 000 sheet areas, which is located in northeast Victoria (Fig. 1). The data package has been prepared to provide information to explorers in a part of the Eastern Highlands Initiative area where the exemption from mining and exploration licences will be lifted in the near future. This package includes the results of airborne magnetic/ radiometric surveys flown over this area, between November 1994 and March 1995, as a component of the VIMP Eastern Highlands Initiative program. A summary of the geology, mineralisation and exploration history are presented in this report, together with recommendations for areas worthy of further exploration for a variety of commodities. It details for the first time the range and styles of primary gold, tin, tungsten and base metal mineralisation in the sheet area, together with comments on their mode of formation. A comprehensive reference list directs the reader to more detailed descriptions of the geology and mineralisation of the area. The digital data set accompanying this report details the location, geology and production from over 1500 individual mines and prospects on the Tallangatta 1:250 000 sheet area. A digital data set covering the Tallangatta 1:250 000 sheet area in MapInfo and Arcview format is available for purchase from the Business Centre, Department of Agriculture, Energy and Minerals, Ground Floor, 115 Victoria Parade, Fitzroy. Themes in the data package include topographic data, geological boundaries, geophysical surveys and images, mines and prospects, geochemical samples, drill holes, and historical and current exploration tenements. GEOLOGY AND PROSPECTIVITY - TALLANGATTA 7 2 Geology conjugate faulting across eastern Victoria also occurred during the Early Carboniferous Kanimblan deformation (Morand & Gray, The geological history of north eastern Victoria, 1991). During the Triassic, a suite of alkaline covered by the Tallangatta 1:250 000 map igneous and volcanic rocks intruded in the (TALLANGATTA) spans Cambrian to Recent Benambra region. times. This geological summary includes an overview and literature review of the current The geological history of TALLANGATTA since understanding of the geological evolution of the the Early Mesozoic has been one of uplift and Tallangatta region, and a brief summary of the erosion, with sporadic minor outpourings of main rock types occurring in TALLANGATTA. alkali basalt lavas in the Tertiary and Quaternary. TALLANGATTA covers much of the Omeo Zone (Gray et al., 1988) of Victoria, and also parts of the Kosciusko Batholith and Kiandra Group of 2.1 Geological history New South Wales (NSW). The Palaeozoic history of the Omeo Zone is complex. A poorly Pre-Ordovician to Early Silurian understood episode of sedimentation, volcanism and intrusion may have occurred as early as the The known rock record in TALLANGATTA Cambrian (The Bethanga Granite Gneiss, and probably starts in the Cambrian. A series of other polydeformed gneisses of the Gundowring high grade gneisses and migmatites displaying Terrane). Submarine sedimentation (the a complex history of polydeformation occurs in Hotham Group) and minor volcanism (the the northwest of TALLANGATTA, around Lake Kiandra Group and Blueys Creek Formation) in Hume. The Bethanga and Bellbridge Gneisses the Ordovician, was followed by regional are considered to be melted S-type granite metamorphism ranging from low to very high migmatite (P. Fleming, pers comm.). These grades (involving partial melting in places) and rocks are separated from the Bethgarno Gneiss regional folding and faulting during the Early and the Rubyview Gneiss by the Talgarno Fault Silurian Benambran deformation.