TASMANIA Mineral resource potential assessments of selected areas Arthur River to Pieman River DECEMBER 1990 TASMANIA DEPARTMENT OF MINES QS.K 6930 MINERAL RESOURCE POTENTIAL ASSESSMENT OF SELECTED AREAS ARTHUR RIVER TO PIEMAN RIVER DEPARTMENT OF RESOURCES AND ENERGY DIVISION OF MINES AND MINERAL RESOURCES DECEMBER 1990 Scm /- ./ AREAS OF MINERAL RESOURCE ASSESSMENT ARTHUR RIVER TO PIEMAN RIVER o 10 20 30 40 km L-_______L- ______~ ______~ ______~' 500,000 5440000mN I .............•.......•..•• .. i················ ..... ....... ....... .1- ............ i 1 5420000mN 5400000mN .. -.-.------------------, - .... -_ .. __ . ---- ! 5380000mN 332000mE 334000mE 336000mE F & FIS CATEGORIES mI Recommended area for proleclion (RAP) ~ Deferred foresl use 1. Thornlon River; 2. Donaldson-Meredllh; 3. Savage River RAP; 4. Ramsay and Yellow Ck RAP; 5. Parsons Hood RAP; 6. Wild Wave RAP; 7. Pedder RAP. Figure 1 1 CONTENTS Page INTRODUCTION 3 DEFINITIONS 3 CONCLUSIONS 4 DATA 6 (a) Geological Maps 6 (b) Geological Summary 8 Older Rocks 8 Palaeozoic and younger rocks 12 Granite 13 References 13 (c) Geophysical Coverage 15 (d) Mineralisation 15 (e) Previous Exploration 16 1) Thornton River DFU area 16 Wild Wave RAP Pedder RAP 2) Donaldson-Meredith DFV area 18 Savage River RAP Ramsay and Yellow Creek RAP Parsons Hood RAP ASSESSMENT 25 (a) Quality of Data 25 (b) Preliminary listing of possible resource models 25 (c) Current mineral resource potential 28 (d) Future mineral resource potential 29 2 Page APPENDIX 1 Maps showing EL, SPL, and ETA 30 coverage 1971-1975, 1976- 1980, 1981-1985, 1986- 1990. APPENDIX 2 Exploration company reports on open file. 31 LIST OF FIGURES Figure 1: Areas of mineral resource assessment Arthur River to Pieman River showing F and FIS categories. Figure 2: Preliminary mineral resource potential map. Figure 3: Maps of geological atlas standard. Figure 4: Regional geology. Figure 5: Supplementary regibnal geology. Figure 6: Depth to granite contours around the Meredith Granite. Figure 7: Airborne magnetic map - total intensity contours. Figure 8: Gravity station coverage (existing and required). Figure 9: Metallic and industrial minerals. Figure 10: Construction material workings. 3 INTRODUCTION This document is one of a series about mineral resource potential in parts of Tasmania. It deals with the mineral potential of a number of areas between the Arthur River and the Pieman River. In the Forests and Forest Industry Strategy each of these areas has been classified either as a 'Recommended Area for Protection (RAP)' or as a 'Deferred Forest Use' area. The assessments presented here are regarded as preliminary. There has been no synthesis or reinterpretation of the results of programmes carried out by mineral exploration companies and others in and around the various areas, nor have all the relevant data from company reports yet been examined . Presentation of material follows the format established in previous volumes in the series with a segment on the available data and a segment on the assessment of that data. Company reports are more fully referenced in this document (see Appx . 1, Appx. 2) than in previous documents. DEFINITIONS ESSENTIAL QUALIFICATION : a mineral resource potential assessment is a product of the circumstances that apply at the time the assessment is made . As the available data, theoretical concepts, exploration techniques, commodity prices and industrial usages which influence mineral resource potential change, so will the assessments . A HIGH MINERAL RESOURCE POTENTIAL exists where the geological characteristics favourable for resource accumulation are known to be present, or where enough of these features are present to support the relevant genetic model and where there is evidence that mineralisation, not necessarily of economic size or grade, has taken place. 4 A MODERATE MINERAL RESOURCE POTENTIAL exists where the geological data suggest that the factors favourable for formation of a class of deposit are present or can be reasonably inferred, or where the geological features of the area show a reasonable degree of fit with those of the deposit class considered. There need not be evidence of mineralisation in the area. A LOW MINERAL RESOURCE POTENTIAL exists where the geological conditions suggest that mineral concentrations are unlikely and that the relevant genetic model cannot be supported. As noted by Taylor and Steven (1983), this requires an element of positive knowledge. A category of UNKNOWN MINERAL RESOURCE POTENTIAL is used in situations where either the geoscientific data base is inadequate to assess the likelihood of the resource accumulation, or the relevant deposit models are so poorly understood that a reasonable assessment cannot be made. This definition is not to be equated with low mineral resource potential, but takes into account a high degree of uncertainty or incompleteness in the available information. CONCLUSIONS There is a range of geological features in th~ Donaldson-Meredith DFU area which have good resource potential. The Timbs Group, especially the Bowry Formation, has high potential for ochre, magnesite, repetitions of the IAlpine anomaly' pyrite-magnetite-copper mineralisation and small repetitions of the Savage River pyrite­ magnetite mineralisation. There is high potential for silica flour where the areas of interest are underlain by the dolomite formations of the Ahrberg Group. These formations also have high potential for dolomite as a resource in its own right since metallic impurities appear to be relatively low. In the mafic-ultramafic complexes there is moderate to high potential for platinum group elements. 5 Carbonate rocks around the Meredith Granite have high potential for skarn and more distal replacement deposits containing tin and tungsten. Vein systems containing tin, tungsten, silver, lead and zinc are known to be associated with the Meredith Granite and there is moderate to high potential for further discoveries. There is also potential for vein and other systems, related to the Pieman Heads Granite and Sandy Cape Granite, to be present in the Rocky Cape association in the western part of the Donaldson-Meredith DFU area and in the Thornton, Wild Wave and Pedder areas. This potential would be substantially enhanced if the granites extend E and NE at relatively shallow depth as recent, unpublished geophysical interpretations indicate . In addition to the resources of high or moderate to high potential, there are resources of low to moderate or moderate potential. These include base metals in sediments, copper associated with tholeiitic basalts and gold in various styles as well as several other resource models. For the resource models identified at this stage the potential of the Thornton, Wild Wave and Pedder areas is low or low to moderate. The apparent absence of carbonate rocks is a majo~ contributing factor to this status. 6 DATA (a) Geological Haps Blissett, A.H. and Gulline, A.B. 1962. Geological Atlas 1 Mile Series, Sheet 50 (7914S), Zeehan. Dep. Mines Tasm. Brown, A.V. 1983. Regional Geology of the Dundas -Mt Lindsay-Mt Ramsay area. Geol.Surv.Tasm. (see also Geol.Surv.Tasm.Bull. 62). Brown, A.V. 1984. Regional geology of the Mt Youngbuck-Magnet area. 1: 25 000. Geol. Surv. Tasm. (see also Geol. Surv. Tasm. Bull. 62) . Gee, R.D .. Gul1ine, A.B., Bravo, A.P., Legge, P.J., Groves, D.l. 1969. Pieman Heads Sheet. Geol.Surv. Tasm. 1 Mile Geol.Map Ser. (Zone 7, No . 42). Groves, D. !. 1973. A century of tin mining at Mt Bischoff, 1871- 1971. Bull.Geo1.Surv.Tasm. 54. Jack, R., Groves D.!. 1965. Geology of the Mt Meredith-Ye11owband Creek area. Tech.Rep.Dep.Mines Tasm . 9. Longman, M.J. and Matthews, W.L. 1962. Geology of the Bluff Point and Trowutta Quadrangles. Tech .Rep.Dep.Mines Tasm. 6. McNeil, R.D. 1961. Geological reconnaissance of the Arthur River Area . Tech.Rep.Dep.Mines Tasm. 5. Reid, A.M . 1923. The Mt Bischoff tin field. Bull.geol.Surv.Tasm. 34. Rio Tinto Australian Exploration Company. 1957. Reconnaissance of northwest Tasmania. 7 Spry, A.H., Ford, R.J. 1957. Reconnaissance of the Corinna-Pieman Heads Area. Proc.Roy . Soc.Tasm. 91. Taylor, B. L . 1955. Asbestos in Tasmania. Geol.Surv.Min.Res. 9. Turner, N.J . , Brown, A.V . , McClenaghan, M.P., Suetrisno, in press . Geological Atlas 1:50 000 Series, Sheet 79l4N, Corinna. Division of Mines and Mineral Resources, Tasmanian Department of Resources and Energy. Urquhart, G. 1966. Magnetite deposits of the Savage River-Rocky River region . Bull.Geol . Surv.Tasm. 48. Ward, L.K. 1911. The Mount Balfour mining field. Bull.Geol.Surv.Tasm. 10. Waterhouse, L.L. 1914 . The Stanley River tinfield. Bull.Geol.Surv.Tasm. 15. Williams, E., Turner, N. J. 1973 . Geological Atlas 1:250 000 , Series, Sheet SK55-3, Burnie. Dep.Mines Tasm. Williams, V. A. 1983. EL43/70 Arthur River, Tasmania. Report on exploration for the year ending 15th October, 1983. CRA Exploration Pty Ltd Dep.Mines Tasm . TCR 83-2036. The 'Burnie' 1:250 000 geological compilation map (Williams and Turner, 1973) from which Fig. 4 is ultimately derived is relatively old and is based on maps of mainly reconnaissance standard and of very uneven quality. The compilation includes the 'Pieman Heads' 1 inch to 1 mile sheet (Gee et al . , 1969) which is a standard geological atlas sheet but it predates the 1:25 000 maps 'Dundas-Mt Lindsay-Mt Ramsay' (Brown 1983) and the 'Mt Youngbuck-Magnet' compilation (Brown, 1984). The 'Burnie' 1:250 000 compilation a l so predates the 'Corinna' 1:50 000 map (Turner et al., in press) which covers much of the southern part of the area of interest. 8 North of AMG 5 404 000 m N and west of AMG 374 000 m E there are no standard geological atlas maps in the area of interest (Fig. 3) . The geology in parts of this region is the poores t known in Tasmania, particularly between Savage River, Mt Frankland and the Arthur River.