Evaluation of petrogenetic models for Lachlan Fold Belt granitoids: Implications for crustal architecture and tectonic models

The restite (one source‐component) model suggests that granitoids are derived from contrasting source rocks and that the typical linear chemical variation of Lachlan Fold Belt granitoids is produced by restite separation. However, it cannot explain the general chemical and isotopic similarity of S‐ and I‐type granitoids in the eastern Lachlan Fold Belt, the similarity of zircon inheritance patterns between the two granite types, nor their apparently simple eNd‐Sr isotopic array. A two source‐component mixing model, based on the eNd‐Sr isotopic array, suggests that linear chemical variation of the granitoids reflects variable incorporation of deeply buried Ordovician sedimentary rocks and basaltic magmas. However, isotopically defined mixes do not match the predicted chemical mixes. Also systematic and sympathetic isotopic and chemical variations are observed for both the felsic and mafic granites within suites across the Bega Batholith. For a simple two‐component model to apply, both the crustal and mantl...

[1]  D. Gray,et al.  Recognition and definition of orogenic events in the Lachlan Fold Belt , 1997 .

[2]  D. Gray,et al.  Subduction‐related deformation and the Narooma anticlinorium, Eastern Lachlan Fold Belt, Southeastern New South Wales , 1997 .

[3]  W. Collins,et al.  A three-component Sr-Nd isotopic mixing model for granitoid genesis, Lachlan fold belt, eastern Australia , 1997 .

[4]  T. Ireland,et al.  EXTENSION OF DELAMERIAN (ROSS) OROGEN INTO WESTERN NEW ZEALAND: EVIDENCE FROM ZIRCON AGES AND IMPLICATIONS FOR CRUSTAL GROWTH ALONG THE PACIFIC MARGIN OF GONDWANA , 1996 .

[5]  S. Kelley,et al.  Source of the Lachlan fold belt flysch linked to convective removal of the lithospheric mantle and rapid exhumation of the Delamerian-Ross fold belt , 1996 .

[6]  John Miller,et al.  Structural signature of sediment accretion in a Palaeozoic accretionary complex, southeastern Australia , 1996 .

[7]  B. Chappell.  Magma mixing and the production of compositional variation within granite suites: Evidence from the granites of southeastern Australia , 1996 .

[8]  G. Carr,et al.  Precise lead isotope fingerprinting of hydrothermal activity associated with Ordovician to Carboniferous metallogenic events in the Lachlan fold belt of New South Wales , 1995 .

[9]  S. Johnson,et al.  Stepping stones and pitfalls in the determination of an anticlockwise P-T-t-deformation path: the low-P, high-T Cooma Complex, Australia , 1995 .

[10]  D. L. Anderson.  Lithosphere, asthenosphere, and perisphere , 1995 .

[11]  C. M. Gray,et al.  Provenance of Palaeozoic turbidites in the Lachlan Orogenic Belt: Strontium isotopic evidence , 1995 .

[12]  E. Sawyer.  Melt segregation in the continental crust , 1994 .

[13]  W. Collins,et al.  A rift-drift-delamination model of continental evolution: Palaeozoic tectonic development of eastern Australia , 1994 .

[14]  J. Moutte,et al.  Sedimentary Fractionations between Al, Ti, and Zr and the Genesis of Strongly Peraluminous Granites , 1994, The Journal of Geology.

[15]  M. Sandiford,et al.  Sm-Nd isotopic evidence for the provenance of sediments from the Adelaide Fold Belt and southeastern Australia with implications for episodic crustal addition , 1993 .

[16]  M. McCulloch,et al.  Lead isotopic evidence for deep crustal-scale fluid transport during granite petrogenesis , 1993 .

[17]  A. Vandenberg,et al.  Ordovician terranes of the southeastern Lachlan Fold Belt: Stratigraphy, structure and palaeogeographic reconstruction , 1992 .

[18]  G. Gibson.  Medium-high-pressure metamorphic rocks of the Tuhua Orogen, western New Zealand, as lower crustal analogues of the Lachlan Fold Belt, SE Australia , 1992 .

[19]  R. Glen.  Thrust, extensional and strike-slip tectonics in an evolving Palaeozoic orogen: a structural synthesis of the Lachlan Orogen of southeastern Australia , 1992 .

[20]  D. Wyborn.  The tectonic significance of Ordovician magmatism in the eastern Lachlan Fold Belt , 1992 .

[21]  W. Collins,et al.  Palaeozoic arc growth, deformation and migration across the Lachlan Fold Belt, southeastern Australia , 1992 .

[22]  P. Coney,et al.  Implications of a Bengal Fan-type deposit in the Paleozoic Lachlan fold belt of southeastern Australia , 1992 .

[23]  D. Gray,et al.  Deformation in the Ballarat Slate Belt, central Victoria, and implications for the crustal structure across southeast Australia , 1991 .

[24]  D. Kerrick,et al.  Precise determinations of the equilibria kyanite sillimanite and kyanite andalusite and a revised triple point for Al 2 SiO 5 polymorphs , 1991 .

[25]  I. Williams,et al.  Zircon inheritance in mafic inclusions from Bega batholith granites, southeastern Australia: An ion microprobe study , 1990 .

[26]  C. M. Gray.  A strontium isotopic traverse across the granitic rocks of southeastern Australia: Petrogenetic and tectonic implications , 1990 .

[27]  A. J. White,et al.  Inclusions in Three S-Type Granites from Southeastern Australia , 1989 .

[28]  M. Barton,et al.  Magmatism and the development of low-pressure metamorphic belts: Implications from the western United States and thermal modeling , 1989 .

[29]  B. Chappell,et al.  Granite provinces and basement terranes in the Lachlan Fold Belt, southeastern Australia , 1988 .

[30]  N. Munksgaard.  Source of the Cooma Granodiorite, New South Wales — a possible role of fluid‐rock interactions , 1988 .

[31]  M. Etheridge,et al.  Shape and microstructure of microgranitoid enclaves: Indicators of magma mingling and flow , 1988 .

[32]  B. Chappell,et al.  The Importance of Residual Source Material (Restite) in Granite Petrogenesis , 1987 .

[33]  D. B. Clarke,et al.  Models for Granitoid Evolution and Source Compositions , 1987, The Journal of Geology.

[34]  L. Silver,et al.  REE Variations Across the Peninsular Ranges Batholith: Implications for Batholithic Petrogenesis and Crustal Growth in Magmatic Arcs , 1987 .

[35]  B. Chappell,et al.  The petrogenetic significance of chemically related plutonic and volcanic rock units , 1986, Geological Magazine.

[36]  V. Wall,et al.  Origin and evolution of a peraluminous silicic ignimbrite suite: The Violet Town Volcanics , 1984 .

[37]  A. Crawford,et al.  Nd-Sr isotopic and geochemical systematics in Cambrian boninites and tholeiites from Victoria, Australia , 1984 .

[38]  Alan Bruce Thompson,et al.  Pressure—Temperature—Time Paths of Regional Metamorphism I. Heat Transfer during the Evolution of Regions of Thickened Continental Crust , 1984 .

[39]  C. M. Gray.  An isotopic mixing model for the origin of granitic rocks in southeastern Australia , 1984 .

[40]  A. Crawford,et al.  The association boninite low‐ti andesite‐tholeiite in the heathcote greenstone belt, Victoria; ensimatic setting for the early lachlan fold belt , 1984 .

[41]  B. Chappell.  Source rocks of I- and S-type granites in the Lachlan Fold Belt, southeastern Australia , 1984, Philosophical Transactions of the Royal Society of London. Series A, Mathematical and Physical Sciences.

[42]  L. Wyborn,et al.  Chemistry of the Ordovician and Silurian greywackes of the Snowy Mountains, southeastern Australia: An example of chemical evolution of sediments with time , 1983 .

[43]  M. McCulloch,et al.  Nd isotopic characteristics of S- and I-type granites , 1982 .

[44]  R. Johnston,et al.  Three S type volcanic suites from the Lachlan fold belt , 1981 .

[45]  V. Wall,et al.  Petrology of the Strathbogie Batholith; a cordierite-bearing granite , 1981 .

[46]  V. Wall,et al.  Origin and crystallization of some peraluminous (S-type) granitic magmas , 1981 .

[47]  A. Crawford,et al.  Cambrian greenstone belts in Victoria: Marginal sea-crust slices in the Lachlan Fold Belt of southeastern Australia , 1978 .

[48]  T. J. Griffin,et al.  The Moruya Batholith and geochemical contrasts between the Moruya and Jindabyne suites , 1978 .

[49]  B. Chappell,et al.  Ultrametamorphism and granitoid genesis , 1977 .

[50]  B. Chappell,et al.  The Jindabyne Thrust and its Tectonic, physiographic and petrogenetic significance , 1976 .

[51]  W. Collins.  Lachlan Fold Belt granitoids: products of three-component mixing , 1996, Earth and Environmental Science Transactions of the Royal Society of Edinburgh.

[52]  B. Chappell.  Compositional variation within granite suites of the Lachlan Fold Belt: its causes and implications for the physical state of granite magma , 1996, Earth and Environmental Science Transactions of the Royal Society of Edinburgh.

[53]  J. Hogan.  Comment on "Lead Isotopic Evidence for Deep Crustal-Scale Fluid Transport During Granite Petrogenesis" by M. T. Mcculloch and J. D. Woodhead , 1995 .

[54]  B. Chappell.  (47th Clarke Memorial Lecture, 1993) Lachlan and New England: fold belts of contrasting magmatic and tectonic development. , 1994, Journal and proceedings of the Royal Society of New South Wales.

[55]  I. Williams.  Some observations on the use of zircon U-Pb geochronology in the study of granitic rocks , 1992, Earth and Environmental Science Transactions of the Royal Society of Edinburgh.

[56]  M. Obata,et al.  Migmatite and melt segregation at Cooma, New South Wales , 1992, Earth and Environmental Science Transactions of the Royal Society of Edinburgh.

[57]  B. Chappell,et al.  I- and S-type granites in the Lachlan Fold Belt , 1992, Earth and Environmental Science Transactions of the Royal Society of Edinburgh.

[58]  V. Morand.  Low‐pressure regional metamorphism in the Omeo Metamorphic Complex, Victoria, Australia , 1990 .

[59]  B. Chappell,et al.  Some supracrustal (S-type) granites of the Lachlan Fold Belt , 1988, Earth and Environmental Science Transactions of the Royal Society of Edinburgh.

[60]  E. Zen.  Thermal modelling of stepwise anatexis in a thrust-thickened sialic crust , 1988, Earth and Environmental Science Transactions of the Royal Society of Edinburgh.

[61]  W. E. Stephens,et al.  Origin of infracrustal (I-type) granite magmas , 1988, Earth and Environmental Science Transactions of the Royal Society of Edinburgh.

[62]  S. Taylor,et al.  The continental crust: Its composition and evolution , 1985 .

[63]  R. Vernon.  Restite, xenoliths and microgranitoid enclaves in granites , 1983 .

[64]  R. Price.  Geochemistry of a peraluminous granitoid suite from North-eastern Victoria, South-eastern Australia , 1983 .

[65]  B. Chappell,et al.  Granitoid types and their distribution in the Lachlan Fold Belt, southeastern Australia , 1983 .

[66]  R. Cas.  A review of the palaeogeographic and tectonic development of the Palaeozoic Lachlan Fold Belt of southeastern Australia. , 1983 .

[67]  K. Crook.  Fore-arc evolution and continental growth: a general model , 1980 .

[68]  K. Crook,et al.  Ordovician palaeogeography of the Lachlan Fold Belt: A modern analogue and tectonic constraints , 1980 .

[69]  B. Chappell,et al.  Two contrasting granite types , 1974 .

[70]  K. Crook,et al.  Ordovician and Silurian history of the southeastern part of the Lachlan Geosyncline , 1973 .

[71]  B. Chappell.  Petrogenesis of the granites at Moonbi, New South Wales , 1966 .

[72]  E. S. Hills,et al.  Turbidity currents and the graptolitic facies in Victoria , 1953 .

[73]  Germaine A. Joplin.  Petrological studies in the Ordovician of New South Wales. II. The northern extension of the Cooma complex , 1943 .