Carbonate spots: understanding the relationship to gold mineralization in Central Victoria, southeastern Australia
Tóm tắt
Historically, carbonate spots have been identified as an indicator of gold mineralization throughout central Victoria, Australia. However, the exact timing relationships between the growth of carbonates, development of deformation fabrics, and the introduction of gold has only been determined in more recent times through isolated studies on individual gold deposits. Detailed examination of the evolution of hydrothermal alteration associated with the Magdala gold deposit at Stawell recognized the fact that there were at least two generations of carbonate growth, an early rounded ankerite phase that predated gold mineralization and a later euhedral siderite phase coincident with gold mineralization. This pattern of carbonate growth is repeated in the majority of significant gold deposits, including Bendigo and Ballarat, throughout central Victoria. Timing relationships within the carbonates suggest that a fluid was introduced along bedding planes and early deformation fabrics prior to the main upright folding events that significantly modified the original sedimentary basin. It is suggested that the early rounded carbonates may have formed as a result of anaerobic oxidation of methane, derived from the sediments and advected along normal growth faults within the sedimentary basin, through interaction with downward diffusing seawater sulfate. Although the growth of the early carbonates is not related to gold mineralization, the change in the speciation of the carbonate during the later carbonate event is critical and can be tracked using a simple geochemical index that can be used not only in areas of outcrop but also in conjunction with exploration undercover.
Tài liệu tham khảo
Agar SM (1990) The interaction of fluid processes and progressive deformation during shallow level accretion: examples from the Shimanto Belt of SW Japan. J Geophys Res 95(B6):9133–9147
Annels AE, Roberts DE (1989) Turbidite-hosted gold mineralization at the Dolaucothi gold mines, Dyfed, Wales, United Kingdom. Econ Geol 84:1293–1314
Arne DC, Jijun L, Bierlein FP, Swan H (2000) Wallrock alteration surrounding Central Victorian gold deposits. Final report on Geochemistry to AMIRA for P478
Baragwanath W (1923) The Ballarat Goldfield. Geological Survey of Victoria Memoir, 14
Besanko J (1996) Characterisation of the ore fluids of Ballarat East Goldfields. B.App.Sci (Honours), University of Ballarat, unpublished
Bierlein FP, Fuller T, Stüwe K, Arne DC, Keays RR (1998) Wallrock alteration associated with turbidite-hosted gold deposits. Examples from the Palaeozoic Lachlan Fold Belt in central Victoria, Australia. Ore Geol Rev 13:345–380
Bierlein FP, Arne DC, McKnight S, Lu J, Reeves S, Besanko J, Marek J, Cooke D (2000) Wall-rock petrology and geochemistry in alteration halos associated with mesothermal gold mineralization, central Victoria, Australia. Econ Geol 95:283–312
Bierlein FP, Cartwright I, McKnight S (2001a) The role of carbonaceous “indicator” slates in the genesis of lode gold mineralization in the western Lachlan orogen, Victoria, southeastern Australia. Econ Geol 96:431–451
Bierlein FP, Arne DC, Foster DA, Reynolds P (2001b) A geochronological framework for orogenic gold mineralization in central Victoria, Australia. Miner Depos 36:741–767
Binns RA, Eames JC (1989) Geochemistry of wall rocks at the Clunes gold deposit, Victoria. Econ Geol Monogr 6:310–319
Boetitus A, Ravenschlag K, Schubert CJ, Rickert D, Widdel F, Gieseke A, Amann R, Jørgensen BB, Witte U, Pfannkuche O (2000) A marine consortium apparently mediating anaerobic oxidation of methane. Nature 407:623–626
Bucher M, Foster DA, Gray DR (1996) Timing of cleavage development in the western Lachlan Fold Belt: new constraints from 40Ar/39Ar geochronology. Geological Society of Australia Abstracts 41:66
Butler RWH, Mazzoli S (2006) Styles of continental contraction: a review and introduction. Geological Society of America, Special Paper 414:1–10
Cayley RA, Taylor DH, VandenBerg AHM, Moore DH (2002) Proterozoic–Early Proterozoic rocks and the Tyennan Orogeny in central Victoria: the Selwyn Block and its tectonic implications. Aust J Earth Sci 49:225–254
Chambers LA (1982) Sulfur isotope study of a modern intertidal environment and the interpretation of ancient sulfides. Geochim Cosmochim Acta 46:721–728
Chaussidon M, Lorand JP (1990) Sulfur isotope composition of orogenic spinel lherzolite massifs from Ariege (N.E. Pyrennes, France): an ion microprobe study. Geochim Cosmochim Acta 54:2835–2846
Christie AB, Brathwaite RL (2003) Hydrothermal alteration in metasedimentary rock-hosted orogenic gold deposits, Reefton goldfield, South Island, New Zealand. Miner Depos 38:87–107
Coleman ML (1977) Sulfur isotopes in petrology. J Geol Soc Lond 133:593–608
Cooke D (1997) The geology of the Poverty Reef, Tarnagulla goldfield, central Victoria, Australia. B.App.Sci (Honours) University of Ballarat (unpublished)
Cox SF (1987) Antitaxial crack-seal microstructures and their relationship to displacement paths. J Struct Geol 9:779–787
Cox SF (1995) Faulting processes at high fluid pressures: an example of fault valve behaviour from the Wattle Gully Fault, Victoria, Australia. J Geophys Res 100-B7:12841–12859
Cox SF, Wall VJ, Etheridge MA, Potter TF (1991) Deformation and metamorphic processes in the formation of mesothermal vein-hosted gold deposits—example from the Lachlan Fold Belt in central Victoria, Australia. Ore Geol Rev 6:391–423
Craw D (2002) Geochemistry of metamorphic hydrothermal alteration and graphitisation of host rocks, Macraes gold mine, Otago schist, New Zealand. Chem Geol 191:257–275
Cuffley BW, Evans TJ, Oussa SA (1995) History and geology of the Poverty Reef on the Tarnagulla Goldfields, central Victoria. Australian Institute of Mining and Metallurgy 8/95:69–70
Davies JF, Whitehead RE, Huang J, Nawaratne S (1990) A comparison of progressive hydrothermal carbonate alteration in Archaean metabasalts and metaperidotites. Miner Depos 25:65–72
Dugdale AL, Wilson CJL, Squire RJ (2006) Hydrothermal alteration at the Magdala gold deposit, Stawell, western Victoria. Aust J Earth Sci 53:733–758
Eichhubl HG, Greene HG, Naehr T, Maher N (2000) Structural control on fluid flow: offshore fluid seepage in the Santa Barbara Basin, California. J Geochem Explor 69–70:545–549
Flöttmann T, James P (1997) Influence of basin architecture on the style of inversion and fold-thrust belt tectonics—the southern Australian fold-thrust belt, South Australia. J Struct Geol 19:1093–1110
Forde A (1991) Late orogenic timing of mineralization in some slate belt gold deposits, Victoria, Australia. Miner Depos 26:257–266
Forde A, Bell TH (1994) Late structural control of mesothermal vein-hosted gold deposits in central Victoria, Australia: mineralization mechanisms and exploration potential. Ore Geol Rev 9:33–59
Foster DA, Gray DR, Offler R (1996) The western sub-province of the Lachlan Fold Belt: structural style, geochronology, metamorphism, and tectonics. Specialist Group in Geochemistry, Mineralogy and Petrology Field Guide 1
Foster DA, Gray DR, Bucher M (1999) Chronology of deformation within the turbidite-dominated Lachlan orogen: implications for the tectonic evolution of eastern Australia and Gondwana. Tectonics 18:452–485
Gao ZL, Kwak TAP (1997) The geochemistry of wall rock alteration in turbidite-hosted gold vein deposits, central Victoria, Australia. J Geochem Explor 59:259–274
Gray DR, Foster DA, Morand VJ, Willman CE, Cayley RA, Spaggiari CV, Taylor DH, Gray CM, VandenBerg AHM, Hendricks MA, Wilson CJL (2003) Structure, metamorphism, geochronology and tectonics of Palaeozoic rocks. In: Birch WD (ed) Geology of Victoria. Geological Society of Australia Special Publication 23:15–70
Gray DR, Foster DA, Korsch RJ, Spaggiari CV (2006) Structural style and crustal architecture of the Tasminides of eastern Australia: example of a composite accretionary orogen. Geological Society of America, Special Paper 414:119–132
Greinert J, Bollwerk SM, Derkachev A, Bohrmann G, Suess E (2002) Massive barite deposits and carbonate mineralization in the Derugin Basin, Sea of Okhotsk: precipitation processes at cold seep sites. Earth Planet Sci Lett 203:165–180
Grewar J (2004) The stratigraphic, structural, alteration and rock magnetic variations across a basalt-high, Kewell, western Victoria. B.Sc. (Honours) The University of Melbourne (unpublished)
Hinrichs K-T, Hayes JM, Sylva SP, Brewer PG, Delong EF (1999) Methane-consuming archaebacteria in marine sediments. Nature 398:802–805
Irwin H, Coleman ML, Curtis CD (1977) Isotopic evidence for source of diagenetic carbonates formed during burial of organic-rich sediments. Nature 269:209–213
Jia Y, Li X, Kerrich R (2000) A fluid inclusion study of Au-bearing quartz vein systems in the central and north Deborah deposits of the Bendigo goldfield, central Victoria, Australia. Econ Geol 95:467–494
Kerrich R, Cassidy KF (1994) Temporal relationships of lode gold mineralization to accretion, magmatism, metamorphism and deformation—Archean to present: a review. Ore Geol Rev 9:263–310
Kerrich R, Ludden J (2000) The role of fluids during formation and evolutions of the southern Superior Province lithosphere: an overview. Can J Earth Sci 37:135–164
Korsch RJ, Moore DH, Cayley RA, Costelloe RD, Nakamura A, Willman CE, Rawling TJ, Morand VJ, Skladzien PB, O’Shea PJ (2008) Crustal architecture of Central Victoria: results from 2006 deep crustal reflector seismic survey. Australian Journal of Earth Science (in press)
Krokowski De Vickerod J, Moore DH, Cayley RA (1997) St Arnaud 1:100 000 map area geological report. Geological Survey of Victoria Report 110
Kwak TAP, Roberts C (1996) Sandstone-hosted gold deposits, Victoria, Australia. A new exploration target: Recent developments in Victorian geology and mineralization. Australian Institute Geology Bulletin 20:63–69
Li X, Kwak TAP, Brown RW (1998) Wallrock alteration in the Bendigo gold ore field, Victoria, Australia: uses in exploration. Ore Geol Rev 13:381–406
Lippmann F (1973) Sedimentary carbonate minerals. Monograph series of theoretical and experimental studies 6. Springer-Verlag Berlin, Heidelberg, New York
Mapani BES, Wilson CJL (1998) Evidence for externally derived vein forming and mineralizing fluids: An example from the Magdala gold mine, Stawell, Victoria, Australia. Ore Geol Rev 13:323–343
Marek J (1997) The geology, structure and mineralization at Fiddlers Creek, Victoria. B.App.Sci (Honours) The University of Ballarat (unpublished)
Mernagh TP (2001) A fluid inclusion study of the Fosterville mine: a turbidite-hosted gold field in the western Lachlan Fold Belt, Victoria, Australia. Chem Geol 173:91–106
Miller JMcL, Wilson CJL (2002) The Magdala lode deposit, Stawell, south eastern Australia: structural style and relationships to gold mineralization across the western Lachlan fold belt. Econ Geol 97:325–349
Miller JMcL, Phillips D, Wilson CJL, Dugdale LJ (2005) Evolution of a reworked orogenic zone: the boundary between the Delamerian and Lachlan Fold Belts, southeastern Australia. Aust J Earth Sci 52:921–940
Miller JMcL, Wilson CJL, Dugdale LJ (2006) Stawell gold deposit: a key to unravelling the Cambrian to Early Devonian structural evolution of the western Victorian goldfields. Aust J Earth Sci 53:677–696
Molloy R (1994) The structural geology of the Tarnagulla area. B.App.Sci (Honours), The University of Ballarat (unpublished)
Morand VJ (1994) Calc-silicate lenses in the early Palaeozoic mud-pile of the Lachlan Fold Belt. Aust J Earth Sci 41:383–386
Morand VJ, Ramsay WRH, Hughes M, Stanley JM (1995) The southern Avoca Fault Zone: site of a newly identified ‘greenstone’ belt in western Victoria. Aust J Earth Sci 42:133–143
Motton N (1990) Low grade metamorphism and relation to mineralization of the Redband District, Avoca, Victoria. B.App.Sci (Honours), The University of Ballarat
Murphy FC, Rawling TJ, Wilson CJL, Dugdale LJ, Miller JMcL (2006) 3D structural modelling and implications for targeting gold mineralization in western Victoria. Aust J Earth Sci 53:875–889
Offler R, McKnight SW, Morand V (1998) Tectono-thermal history of the western Lachlan fold belt—insights from white mica studies. J Metamorph Geol 16:171–179
Phillips GN, Hughes MJ (1996) The geology and gold deposits of the Victorian gold province. Ore Geol Rev 11:255–302
Powell CMcA, Rickard MJ (1985) Significance of the early foliation at Bermagui, N.S.W., Australia. J Struct Geol 7:385–400
Rawling TJ, Schaubs PM, Dugdale LJ, Wilson CJL, Murphy FC (2006) Application of 3D models and numerical simulations as a predictive exploration tool in western Victoria. Aust J Earth Sci 53:825–841
Reeder RJ (1983) Crystal chemistry of the rhombohedral carbonates. Reviews in Mineralogy and Geochemistry 11:1–47
Reeder RJ (1993) Crystal chemistry of the rhombohedral carbonates. In: R.J. Reeder (ed.) Carbonates: mineralogy and chemistry. Rev Miner 11:1–47
Ryan RJ, Smith PK (1998) A review of the mesothermal gold deposits of the Meguma Group, Nova Scotia, Canada. Ore Geol Rev 13:153–183
Sandiford M, Keays RR (1986) Structural and tectonic constraints on the origin of gold deposits in the Ballarat slate belt, Victoria. In: Keppie JD, Boyle RW, Haynes SJ (eds) Turbidite-hosted gold deposits. Geological Association of Canada Special Paper 32:15–24
Schaubs PM, Wilson CJL (2002) The relative roles of folding and faulting in controlling gold mineralization along the Deborah Anticline, Bendigo, Victoria, Australia. Econ Geol 97:351–370
Sherwood Lollar B, Ballentine CJ, O’Nions RK (1997) The fate of mantle-derived carbon in a continental sedimentary basin: integration of C/He relationships and stable isotope signatures. Geochim Cosmochim Acta 61:2295–2307
Squire RJ, Miller JMcL (2003) Synchronous compression and extension in East Gondwana: tectonic controls on world-class gold deposits at 440 Ma. Geology 31:1073–1076
Squire RJ, Wilson CJL (2005) Interaction between collisional orogenesis and convergent-margin processes: evolution of the Cambrian proto-Pacific margin of East Gondwana. J Geol Soc Lond 162:749–761
Squire RJ, Campbell IH, Allen CM, Wilson CJL (2006) Did the Transgondwanan Supermountain trigger the explosive radiation of animals on Earth. Earth Planet Sci Lett 250:116–133
Stüwe K, Keays RR, Andrew A (1988) Wall rock alteration around gold quartz reefs at the Wattle Gully mine, Ballarat slate belt, central Victoria. Geological Society of Australia, Abstract Series 23:478–480
Swann H (2002) An integrated approach to wallrock alteration in the Bendigo Goldfield, Victoria, Australia. M.Sc. (thesis) The University of Ballarat (unpublished)
Taylor DH, Whitehead ML, Olshina A, Leonard JG (1996) Ballarat 1:100 000 map geological report. Geological Survey of Victoria Report 101
Taylor DH, Wohlt KE, Simons BA, Maher S, Morand VJ, Sapurmas P (2000) Creswick 1:100 000 map area geological report. Geological Survey of Victoria Report 117
VandenBerg AHM, Willman CE, Maher S, Simons BA, Cayley RA, Taylor DH, Morand VJ, Moore DH, Radojkovic A (2000) The Tasman Fold Belt system in Victoria; Geological Survey of Victoria Special Publication
Welhan JA (1988) Origin of methane in hydrothermal systems. Chem Geol 71:183–198
Whitelaw OAL (1911) The Wedderburn gold-field. Geological Survey of Victoria Memoirs 10:38p
Whiticar MJ (1999) Carbon and hydrogen isotope systematics of bacterial formation and oxidation of methane. Chem Geol 161:291–314
Willman CE (2007) Regional structural controls of gold mineralization, Bendigo and Castlemaine goldfields, Central Victoria, Australia. Mineralium Deposita 42:449–463
Willman CE, Wilkinson HE (1992) Bendigo Goldfield—Spring Gully, Golden Square, Eaglehawk 1: 10,000 maps geological report. Geological Survey of Victoria Report 93
Wilson CJL, de Hedouville P (1985) Early cleavage development in the Late Ordovician of north-east Victoria, Australia. J Struct Geol 7:401–408
Wilson CJL, Will TM, Cayley RA, Chen S (1992) Geological framework and tectonic evolution in western Victoria. Tectonophysics 214:93–127
Windh J (1995) Saddle reef and related gold mineralization, Hill End goldfield, Australia: Evolution of an auriferous vein system during progressive deformation. Econ Geol 90:1764–1775