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Petrology and geochemistry of Cambrian boninites and low-Ti andesites from Heathcote, Victoria

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Abstract

In the Heathcote Greenstone Belt of central Victoria, a sequence of boninites and low-Ti andesites is overlain and intruded by tholeiitic basalts with affinities to backarc basin basalts. Two suites of boninites have been identified: one (Type A) with Ti/Zr ratios of 63±4, (La/Yb)N of 2–3 and HREE 5 times chondritic levels. The other suite (Type B) overlies Type A boninites and has Ti/Zr ratios of 23±3 and lower TiO2 and HREE contents (2–3 × chondrite), but shows significantly greater LREE enrichment, with (La/Yb)N greater than 5. Fractionation within both suites was largely controlled by the low-Ca pyroxenes protoenstatite and enstatite. Plagioclase-phyric low-Ti, high-Mg andesites occur in fault contact with the boninites, and have Ti/Zr and (La/Yb)N ratios very close to those of Type B boninites, but at higher absolute abundances of TiO2 and HREE. They are not related to either boninite suite by any realistic fractionation scheme, but originated from the same source as Type B boninites by approximately half the degree of partial melting that generated the boninites.

Type A boninites could have been generated when LILE-enriched hydrous fluids derived from a subducted slab invaded depleted, clinopyroxene-poor lherzolite at depths less than 30 km, and initiated H2O-undersaturated partial melting. In a later partial melting event at similar depths, continued influx of metasomatic fluids into by now highly-depleted peridotite could have generated Type B boninites and low-Ti andesites. The presence of boninites and low-Ti andesites in the Cambrian Heathcote and Mount Wellington Greenstone Belts in southeastern Australia suggests that the early history of the Lachlan Foldbelt took place in a subduction-related, intraoceanic setting.

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References

  • Arculus RJ, Wills KJA (1980) The petrology of igneous blocks and inclusions from the Lesser Antilles island arc. J Petrol 21:143–199

    Google Scholar 

  • Bougault H, Maury RC, Elazzouzi M, Joron JL, Treuil M (1981) Tholeiites, basaltic andesites and andesites from Leg 60 sites; geochemistry, mineralogy and low partition coefficient elements. Init Rept DSDP 60:657–677

    Google Scholar 

  • Cameron WE, Nisbet EG, Dietrich VJ (1979) Boninites, komatiites and ophiolitic basalts. Nature 280:550–553

    Google Scholar 

  • Cameron WE, McCulloch MT, Walker DA (1983) Boninite petrogenesis: chemical and Nd-Sr isotopic constraints. Earth Planet Sci Lett 65:75–89

    Google Scholar 

  • Cawthorn RG, Davies G (1983) Experimental data at 3 kbars pressure on parental magma to the Bushveld complex. Contrib Mineral Petrol 83:128–135

    Google Scholar 

  • Coish RA (1977) Ocean floor metamorphism in the Betts Cove ophioite, Newfoundland. Contrib Mineral Petrol 60:255–270

    Google Scholar 

  • Crawford AJ (1980) A clinoenstatite-bearing cumulate olivine pyroxenite from Howqua, Victoria. Contrib Mineral Petrol 75:353–367

    Google Scholar 

  • Crawford AJ, Keays RR (1978) Cambrian greenstone belts in Victoria: marginal sea crust slices in the Lachlan Foldbelt of south-eastern Australia. Earth Planet Sci Lett 41:197–208

    Google Scholar 

  • Crawford AJ, Beccaluva L, Serri G (1981) Tectono-magmatic evolution of the West Philippine-Mariana region and the origin of boninites. Earth Planet Sci Lett 54:346–356

    Google Scholar 

  • Crawford AJ, Cameron WE, Keays RR (1984) The association boninite-low Ti andesite-tholeiite in the Heathcote Greenstone Belt, Aust J Earth Sci 31:161–175

    Google Scholar 

  • Crawford AJ (1985) The geology and petrogenesis of a low-Ti, high-Mg andesite suite from Mount Dryden, Victoria (in prep.)

  • Dietrich VJ, Emmerman R, Oberhansli R, Puchelt H (1978) Geochemistry of basaltic and gabbroic rocks from the West Mariana Basin and the Mariana trench. Earth Planet Sci Lett 39:127–144

    Google Scholar 

  • Dietrich VJ, Gansser A, Sommerauer J, Cameron WE (1981) Palaeogene komatiites from Gorgona island, east Pacific — a primary magma for ocean floor basalts. Geochem J 15:141–161

    Google Scholar 

  • Dick HJB, Bullen TE (1984) Chromian spinel as a petrogenetic indicator in abyssal and alpine-type peridotites and spatially associated lavas. Contrib Mineral Petrol 86:54–76

    Google Scholar 

  • Gamble RP, Taylor LA (1980) Crystal/liquid partitioning in augite; effects of cooling rate. Earth Planet Sci Lett 47:21–33

    Google Scholar 

  • Green DH (1984) Genesis of MORB, ophiolitic basalts and boninites. (Abstr) Workshop on Expt Petrol, Monash Univ

  • Grove TL, Bence AE (1977) Experimental study of pyroxene-liquid interaction in quartz-normative basalt 15997. Proc 8th Lunar Sci Conf: 1549–1580

  • Hellman PL, Smith RE, Henderson P (1979) The mobility of the rare earth elements: evidence and implications from selected terrains affected by burial metamorphism. Contrib Mineral Petrol 71:23–44

    Google Scholar 

  • Hickey RL, Frey FA (1981) Rare earth element geochemistry of Mariana forearc volcanics, DSDP Hole 458 and Hole 459B. Init Rept DSDP 60:735–742

    Google Scholar 

  • Humphris SE, Thompson G (1978) Hydrothermal alteration of oceanic basalts by seawater. Geochim Cosmochim Acta 42:107–125

    Google Scholar 

  • Humphris SE, Morrison MA, Thompson RN (1978) Influence of rock crystallization history on subsequent lanthanide mobility during hydrothermal alteration of basalts. Chem Geol 23:125–138

    Google Scholar 

  • Jenner GA (1981) Geochemistry of high-Mg andesites from Cape Vogel, Papua New Guinea. Chem Geol 33:307–332

    Google Scholar 

  • Lofgren GE (1977) Dynamic crystallization experiments bearing on the origin of textures in impact-generated liquid. Proc. 8th Lunar Sci Conf: 2079–2095

  • Marsh BD (1976) Some Aleutian andesites — their nature and source. J Geol 84:27–45

    Google Scholar 

  • Natland JH (1981) Crystal morphologies and pyroxene compositions in boninites and tholeiitic basalts from DSDP Holes 458 and 459B in the Mariana forearc region. Init Rept DSDP 60:681–707

    Google Scholar 

  • Nelson DR, Crawford AJ, McCulloch MT (1984) Nd-Sr systematics in Cambrian boninites and tholeiites from Victoria, Australia. Contrib Mineral Petrol 88:169–177

    Google Scholar 

  • Nesbitt RW, Sun SS (1976) Geochemistry of Archaean spinifextextured peridotites and magnesian and low-magnesian basalts. Earth Planet Sci Lett 31:433–450

    Google Scholar 

  • Pearce JA (1975) Basalt geochemistry used to investigate past tectonic environments on Cyprus. Tectonophys 26:41–67

    Google Scholar 

  • Pearce JA (1978) Petrogenetic studies of metabasalts using immobile trace element ratios. J Geol Soc Lond 135:192–215

    Google Scholar 

  • Pearce JA, Cann JR (1973) Tectonic setting of basic volcanic rocks determined using trace element analysis. Earth Planet Sci Lett 19:290–305

    Google Scholar 

  • Reid DL (1979) Petrogenesis of calc-alkaline metalavas in the mid-Proterozoic Haib volcanic subgroup, Lower Orange River region. Trans Geol Soc S Afr 82:109–131

    Google Scholar 

  • Rhodes JM, Dungan MA (1979) The evolution of ocean floor basaltic magmas. In Deep Drilling Results in the Atlantic Ocean (Eds) Talwani M, Harrison GC, Hayes DE; Amer Geophys Union M Ewing Series 2:262–272

  • Roeder PL, Campbell IH, Jamieson HE (1979) A re-evaluation of the olivine — chromite geothermometer. Contrib Mineral Petrol 68:325–334

    Google Scholar 

  • Saunders AD, Tarney J, Marsh NG, Wood DA (1980) Ophiolites as ocean crust or marginal basin crust: a geochemical approach. Proc Int Ophiolite Symp, Cyprus, 193–204

  • Sharaskin AY, Dobretsov NL, Sobolev NV (1980) Marianites; the clinoenstatite-bearing pillow lavas associated with the ophiolite assemblage of the Mariana Trench. Proc Int Ophiolite Symp, Cyprus, 473–479

  • Sun SS, Nesbitt RW (1977) Chemical heterogeneity of the Archaen mantle: composition of the earth and mantle evolution. Earth Planet Sci Lett 35:429–448

    Google Scholar 

  • Sun SS, Nesbitt RW (1978) Chemical regularities and genetic significance of ophiolitic basalts. Geology 6:689–693

    Google Scholar 

  • Sun SS, Nesbitt RW, Sharaskin AY (1979) Geochemical characteristics of mid-ocean ridge basalts. Earth Planet Sci Lett 44:119–138

    Google Scholar 

  • Tatsumi Y, Ishizaka K (1982) Origin of high-Mg andesites in the Setouchi volcanic belt, southwest Japan; II. Melting phase relations at high pressures. Earth Planet Sci Lett 60:293–304

    Google Scholar 

  • Varne R, Brown AV (1978) The geology and petrology of the Adamsfield Ultramafic Complex, Tasmania. Contrib Mineral Petrol 67:195–207

    Google Scholar 

  • Walker DA, Cameron WE (1983) Boninite primary magmas: evidence from the Cape Vogel peninsula, PNG. Contrib Mineral Petrol 83:150–158

    Google Scholar 

  • Wood DA, Gibson I, Thompson RN (1976) Element mobility during zeolite facies metamorphism of the Tertiary basalts of eastern Iceland. Contrib Mineral Petrol 55:241–254

    Google Scholar 

  • Wood DA, Marsh NG, Tarney J, Joron JL, Fryer P, Treuil M (1981) Geochemistry of igneous rocks recovered from a transect across the Mariana Trough, arc, forarc and trench, Sites 453-461, DSDF Leg 60. Init Rept DSDP 60:611–645

    Google Scholar 

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Authors and Affiliations

  1. Department of Geology, University of Tasmania, Sandy Bay, 7005, Hobart, Tasmania, Australia

    Anthony J. Crawford

  2. Department of Geology, Australian National University, P.O. Box 4, 2600, Canberra, A.C.T., Australia

    W. E. Cameron

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  1. Anthony J. Crawford
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  2. W. E. Cameron
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Crawford, A.J., Cameron, W.E. Petrology and geochemistry of Cambrian boninites and low-Ti andesites from Heathcote, Victoria. Contrib Mineral Petrol 91, 93–104 (1985). https://doi.org/10.1007/BF00429431

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