VIMP Report 5 Mineral exploration history of the North West VIMP area by S. Rooney March 1995 Bibliographic reference: ROONEY S., 1995. Mineral exploration history of the North West VIMP area. Geological Survey of Victoria VIMP Report 5. © Crown (State of Victoria) Copyright 1995 Geological Survey of Victoria ISSN 1323 4536 ISBN 0 7306 7413 4 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, P O Box 2145, MDC Fitzroy Victoria 3065 Acknowledgments The author wishes to acknowledge G.Ellis for formatting the document. R.Buckley for editing the document. A.Eaton and L.Allwood for assistance with tables and information stored on the GEDIS database. A.Maggart for assistance with exploration expenditure and the drafting of licence location diagrams along with B.Pettigrove. And finally, K.Weston, D.Faul and B.Guerin of the Exploration Unit for help in obtaining information pertaining to the various licences. MINERAL EXPLORATION HISTORY - NORTH WEST VIMP AREA 1 Contents Abstract 2 1Introduction 2 2History of exploration 3 2.1Gold 3 2.2Heavy mineral sands 3 2.3Base metals 4 2.4Brown coal 4 2.5Diamonds 4 2.6Uranium 4 2.7Gypsum 4 3Major exploration programmes 5 References 71 Appendices 1 Location of Expired Exploration Licences 98 2 Summary of exploration targets within the North West VIMP area 109 3 Exploration Licence summary: North West VIMP area 116 Victorian Initiative for Minerals and Petroleum (VIMP) report series 121 Tables 1 Drill hole summary 18 2 MINERAL EXPLORATION HISTORY - NORTH WEST VIMP AREA Abstract 1 Introduction This report summarises the mineral exploration Since the introduction of the Exploration activity undertaken within the North West Licensing (EL) system in 1965, a total of 292 VIMP area since the introduction of the licences have been granted within the North Exploration Licensing (EL) system in 1965, West VIMP area and their locations are providing a comprehensive synthesis of the presented in Appendix 1. The exploration exploration that has been conducted in the area. programmes are summarized in Appendices 2 and 3. A complete outline of the available work Historically, gold has been the main target of programmes conducted over the EL's within the exploration in outcropping rocks of the Lachlan North West VIMP area is presented in Section Fold Belt around the southern margin of the 3. A description of the geology and Murray Basin. Modern mineral exploration prospectivity of the southern margin of the activity in the Initiative area has concentrated Murray Basin, which lies within the North West on hard rock and alluvial sources of gold as well VIMP area, is presented in Bush et al. (1995 as directed towards heavy mineral sands. There [21386]). has been a lesser concentration of exploration applied to other targets including molybdenum, The appropriate bibliographic reference brown coal, base metals, uranium, gypsum and number(s) are given for each EL and are listed diamonds. in the Reference section in numerical order. MINERAL EXPLORATION HISTORY - NORTH WEST VIMP AREA 3 2 History of exploration Bulk tonnage low grade disseminated ore bodies (e.g. in slate beds) or higher grade quartz stockworks became the target of exploration Modern exploration within the North West into the 1980's with exploration concentrated in VIMP area has mainly been directed towards the St Arnaud-Pyrenees Ranges region. Results gold and heavy mineral sands which have been of exploration in general showed a highly the subject of extensive regional programmes. erratic spatial distribution of gold. WMC A lesser concentration of exploration has been identified a broad zone of brecciated, altered applied to other targets including molybdenum, and mineralised sediments in the vicinity of the brown coal, base metals, uranium, gypsum and Kingston mine (EL's 1449, 1613, 2164, 2292). diamonds. Due to advances in metallurgical processing and the increasing gold price throughout the 2.1 Gold 1980's, open pittable gold mineralisation became the main emphasis for exploration Historically gold has been the mainstay of companies. exploration conducted around the North West VIMP area. Gold was first discovered at Into the 1990's possible meso-epithermal Wedderburn in 1852. This was followed by disseminated gold deposits in I-type granites, discoveries at Wehla, Landsborough and intermediate to mafic intrusives and sediments Stawell in 1853. The discoveries of gold spread in contact metamorphic aureoles have become with alluvial goldfields opened up at Carapooee the focus of exploration for gold mineralisation. in 1854, Stuart Mill in 1856, Emu in 1857, Geophysics has shown possible extensions to Fentons Creek, Burkes Flat, Rostrons and greenstone belts which have the potential for Navarre in 1858 and Redbank in 1860. Vein large scale quartz gold veining. Palaeozoic gold was first discovered at St Arnaud with the placer deposits near the Roses Gap historical main quartz reefs discovered in the subsequent workings (EL 2445) and Witwatersrand type rushes to the area in 1855. Reefs were gold mineralisation within sediments of the progressively opened in many of the other ancestral Murray Delta (EL 3220) have also goldfields with Emu, Wehla and Redbank been explored. becoming busy reefing centres (Flett, 1979 [1743]). Gold mining in the region continued up Alluvial gold of sufficient volume to support a until the 1920's when it rapidly declined. mining operation has been investigated throughout the period of modern exploration. Western Mining Corporation Ltd (WMC) has Targets have included shallow and deep leads been exploring in the Stawell area since 1945 (St Arnaud and Avoca River lead systems), testing the continuity of previously mined ore perched Tertiary gravels and Recent alluvials. bodies (Clappison, 1974a&b [3182, 6201]). Small inferred resources were delineated at Throughout the 1960's the principal target for Landsborough (EL's 833, 1221, 1538, 3255), gold was unworked extensions to previously Kooreh (EL 938), Burkes Flat (EL 1173), mined deposits. Planet Resources (EL's 25-28) Inglewood (EL 1308), Carapooee (EL's 1365 & conducted a regional programme from 1965 to 1646), Emu (EL 1640) and Bealiba (EL 3225). 1970 over the western goldfields concentrating on the Nelson, New Chum and Bristol Lines of 2.2Heavy mineral sands reef at St Arnaud. A series of extensive regional programmes were "Indicators" according to historical literature conducted throughout the North West VIMP played an important role in the concentration of area searching for heavy mineral sands. gold. The emphasis of exploration shifted Following the initial discovery of heavy mineral towards indicator belts and disseminated gold deposits near Kerang in the Parilla Sand, outside vein deposits from the late 1960's into exploration has been conducted by Reef Oil, the 1970's throughout the Wedderburn- Westralian Sands (Tioxide & Austiex), CRAE, St Arnaud-Pyrenee Ranges area. This achieved RGC, BHP, Aberfoyle (Sandhurst & Balmoral) some success in the late 1970's when areas of and Fidunu (T.C.Pacific, Euraust Minerals, low grade disseminated mineralisation were Burmine & Denison Australia). Exploration for identified on the Nelson line in St Arnaud by heavy mineral accumulations has dominated Planet Mining (EL 541). activities in the Murray Basin during the 1980's. The principal exploration tool has been 4 MINERAL EXPLORATION HISTORY - NORTH WEST VIMP AREA delineated from air photo interpretation. A 2.6Uranium layer of clay has prevented geophysical methods from being an effective means of locating heavy Prior to the Nuclear Activities (prohibition) Act mineral concentrations. Two types of deposit 1983, sedimentary uranium had been the target have been delineated within the North West of exploration programmes. Exploration VIMP area; coarse grained, linear strand-type models postulated the sedimentary uranium mineralisation (e.g. Tyrrell Ridge) and fine was in a redox position within Tertiary grained, laterally extensive WIM-type sediments with the source being nearby granitic mineralisation (e.g. WIM 150). Strand-type bodies and the transport mechanism aquifers deposits have been delineated at Hopetoun, (EL's 633, 634, 1247). Karkarooc, Watchem, Wycheproof, Nyah West, Horsham and Birchip. WIM-type deposits have been identified in the Horsham area, northeast 2.7Gypsum and southwest of Drung South. Gypsum mining within the North West VIMP area has taken place since the 1940's at 2.3Base metals Nowingi. Limited exploration has been conducted for the mineral with the aim of Limited exploration has taken place for base extending deposits currently being worked. metals within the North West VIMP area. Anomalously high base metal geochemistry near Wedderburn led to the exploration for Pb- Zn hosted shale mineralisation (EL 919). In the 1990's models for base metal mineralisation have included structurally controlled, intrusive related copper mineralisation and volcanogenic massive sulphide mineralisation. Airborne geophysical surveys have been used to select prospective areas. Molybdenum disseminated in intrusives or porphyries was the target of exploration around Mafeking and Zumstein (EL's 117, 118). 2.4Brown coal Tertiary brown coal was the original target of the regional exploration conducted by CRAE over the Murray Basin. Sub-economic resources were identified in the Wycheproof, Torrumbarry-Tandarra