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An evaluation of crustal assimilation within the Late Devonian South Mountain Batholith, SW Nova Scotia

Published online by Cambridge University Press:  20 February 2012

J. GREGORY SHELLNUTT  and
JAROSLAV DOSTAL
J. GREGORY SHELLNUTT*
Affiliation:
Academia Sinica, Department of Earth Sciences, National Taiwan Normal University, 88 Section 4 Tingzhou Road, Taipei 11677, Taiwan
JAROSLAV DOSTAL
Affiliation:
Saint Mary's University, Department of Geology, 923 Robie Street, Halifax, NS, B3H 3C3, Canada
*
†Author for correspondence: jgshelln@earth.sinica.edu.tw, gshellnutt@hotmail.com
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Abstract

The Late Devonian South Mountain Batholith (SMB) of southwestern Nova Scotia is the largest batholith in the Appalachian Orogen of Eastern North America and contains economic deposits of U and Sn. The SMB comprises at least 11 individual plutons, which range in composition from granodiorite to biotite monzogranite, leucomonzogranite and leucogranite. Previous studies have suggested that a combination of fractional crystallization, assimilation of Meguma Supergroup country rocks and an influx of magmatic fluids contributed to the chemical evolution of the SMB. The amount of crustal assimilation is estimated to be as high as 33%. MELTS modelling assuming a starting composition of granodiorite with H2O = 4 wt%, pressure = 4 kbar (~12 km) and fO2 = FMQ can reproduce the chemical evolution observed in the SMB. However, some leucogranites likely require an additional component (e.g. hydrothermal fluids) to explain their alkali metal enrichment (e.g. Na, K, Rb). Zircon saturation thermometry estimates indicate the Salmontail Lake and Scrag Lake granodiorite plutons had high minimum initial temperatures of 823 ± 6°C and 832 ± 2°C, respectively, which are similar to low zircon-inheritance granitoids. The TiO2/Al2O3 and alkali-lime ratios of the surrounding country rocks and the leucogranites indicate the amount of crustal assimilation is likely to be between 10% and 20%. Our findings suggest the granodiorites of the SMB were likely produced by partial melting of the sub-Meguma Supergroup (e.g. Avalon terrane) lower crust caused by the contemporaneous injection of high temperature mafic to ultramafic magmas.

Keywords

Late DevonianMeguma SupergroupSouth Mountain BatholithgraniteAppalachian Terraneperaluminous
Type
Original Articles
Information
Geological Magazine , Volume 149 , Issue 3 , May 2012 , pp. 353 - 365
Copyright
Copyright © Cambridge University Press 2012

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References

Altherr, R., Holl, A., Hegner, E., Langer, C. & Kreuzer, H. 2000. High-potassium, calc-alkaline I-type plutonism in the European Variscides: northern Vosges (France) and northern Schwartzwald (Germany). Lithos 50, 487–533.CrossRefGoogle Scholar
Annen, C. & Sparks, R. S. J. 2002. Effects of repetitive emplacement of basaltic intrusions on thermal evolution and melt generation in the crust. Earth and Planetary Science Letters 203, 937–55.CrossRefGoogle Scholar
Barbarin, B. 1999. A review of the relationships between granitoid types, their origins and their geodynamic environments. Lithos 46, 605–26.CrossRefGoogle Scholar
Batchelor, R. A. & Bowden, P. 1985. Petrogenetic interpretation of granitoid rock series using multicationic parameters. Chemical Geology 48, 43–55.CrossRefGoogle Scholar
Cameron, B. I. & Zentilli, M. 1997. Geochemical characterization of the mineralized transition between the Goldenville and Halifax formations and the interaction with adjacent granitoid intrusions of the Liscomb complex, Nova Scotia. Atlantic Geology 33, 143–55.CrossRefGoogle Scholar
Cerny, P., Blevin, P. L., Cuney, M. & London, D. 2005. Granite-related ore deposits. Economic Geology 100, 337–70.Google Scholar
Chatterjee, A. K. & Dostal, J. 2002. Deep drill hole in Devonian South Mountain batholith, Nova Scotia: a potential for hidden mineral deposits within the batholith. Atlantic Geology 38, 1–10.Google Scholar
Chatterjee, A. K. & Ham, L. J. 1991. U-Th-Pb systematics of the South Mountain batholith, Nova Scotia. Atlantic Geology 27, 149.Google Scholar
Chatterjee, A. K. & Strong, D. F. 1984. Discriminant and factor analysis of geochemical data from granitoid rocks hosting the Millet Brook uranium mineralization, South Mountain Batholith, Nova Scotia. Uranium 1, 289–305.Google Scholar
Clarke, D. B., Fallon, R. & Heaman, L. M. 2000 . Interaction among upper crustal, lower crustal, and mantle materials in the Port Mouton pluton, Meguma Lithotectonic Zone, southwest Nova Scotia. Canadian Journal of Earth Sciences 37, 579–600.CrossRefGoogle Scholar
Clarke, D. B. & Halliday, A. N. 1980. Strontium isotope geology of the South Mountain batholith, Nova Scotia. Geochimica et Cosmochimica Acta 44, 1045–58.CrossRefGoogle Scholar
Clarke, D. B., Halliday, A. N. & Hamilton, P. J. 1988. Neodymium and strontium isotopic constraints on the origin of the peraluminous granitoids of the South Mountain batholith, Nova Scotia. Chemical Geology 73, 15–24.Google Scholar
Clarke, D. B., Henry, A. S. & White, M. A. 1998. Exploding xenoliths and the absence of “elephants’ graveyards” in granite batholiths. Journal of Structural Geology 20, 1325–43.CrossRefGoogle Scholar
Clarke, D. B., MacDonald, M. A. & Erdmann, S. 2004. Chemical variation in Al2O3-CaO-Na2O-K2O space: controls on the peraluminosity of the South Mountain batholith. Canadian Journal of Earth Sciences 41, 785–98.CrossRefGoogle Scholar
Clarke, D. B., MacDonald, M. A., Reynolds, P. H. & Longstaffe, F. J. 1993. Leucogranites from the eastern part of the South Mountain batholith, Nova Scotia. Journal of Petrology 34, 653–79.CrossRefGoogle Scholar
Clarke, D. B., MacDonald, M. A. & Tate, M. C. 1997. Late Devonian mafic-felsic magmatism in the Meguma Zone, Nova Scotia. Geological Society of America Memoir 191, 107–27.Google Scholar
Dostal, J. & Chatterjee, A. K. 1995. Origin of topaz-bearing and related peraluminous granites of late Devonian Davis Lake pluton, Nova Scotia, Canada. Chemical Geology 123, 67–88.CrossRefGoogle Scholar
Dostal, J. & Chatterjee, A. K. 2010. Lead isotope and trace element composition of K-feldspars from peraluminous granitoids of the Late Devonian South Mountain Batholith (Nova Scotia, Canada): implications for petrogenesis and tectonic reconstruction. Contributions to Mineralogy and Petrology 159, 563–78.CrossRefGoogle Scholar
Dostal, J., Chatterjee, A. K. & Kontak, D. J. 2004. Chemical and isotopic (Pb, Sr) zonation in a peraluminous granite pluton: role of fluid fractionation. Contributions to Mineralogy and Petrology 147, 74–90.CrossRefGoogle Scholar
Dostal, J., Keppie, J. D., Jutras, P., Miller, B. V. & Murphy, J. B. 2006. Evidence for the granulite-granite connection: penecontemporaneous high-grade metamorphism, granite magmatism and core complex development in the Liscomb Complex, Nova Scotia, Canada. Lithos 86, 77–90.CrossRefGoogle Scholar
Eberz, G. W., Clarke, D. B., Chatterjee, A. K. & Giles, P. S. 1991. Chemical and isotopic composition of the lower crust beneath the Meguma Lithotectonic Zone, Nova Scotia: evidence from granulite facies xenoliths. Contributions to Mineralogy and Petrology 109, 69–88.CrossRefGoogle Scholar
Erdmann, S., Jamieson, R. A. & MacDonald, M. A. 2009. Evaluating the origin of garnet, cordierite, and biotite in granitic rocks: a case study from the South Mountain Batholith, Nova Scotia. Journal of Petrology 50, 1477–503.CrossRefGoogle Scholar
Erdmann, S., London, D., Morgan, G. B. VI & Clarke, D. B. 2007. The contamination of granitic magma by metasedimentary country-rock material: an experimental study. Canadian Mineralogist 45, 43–61.CrossRefGoogle Scholar
Frost, B. R., Barnes, C. G., Collins, W. J., Arculus, R. J., Ellis, D. J. & Frost, C. D. 2001. A geochemical classification for granitic rocks. Journal of Petrology 42, 2033–48.CrossRefGoogle Scholar
Ghiorso, M. S. & Sack, R. O. 1995. Chemical mass transfer in magmatic processes IV. A revised and internally consistent thermodynamic model for the interpolation and extrapolation of liquid-solid equilibria in magmatic systems at elevated temperatures and pressures. Contributions to Mineralogy and Petrology 119, 197–212.CrossRefGoogle Scholar
Glazner, A. F. 2007. Thermal limitations on incorporation of wall rock into magma. Geology 35, 319–22.CrossRefGoogle Scholar
Halter, W. E., Williams-Jones, A. E. & Kontak, D. J. 1998. Modeling fluid–rock interaction during greisenization at the East Kemptville tin deposit: implications for mineralization. Chemical Geology 150, 1–17.CrossRefGoogle Scholar
Hanchar, J. M. & Watson, E. B. 2003. Zircon saturation thermometry. Reviews in Mineralogy and Geochemistry 53, 89–112.CrossRefGoogle Scholar
Hicks, R. J., Jamieson, R. A. & Reynolds, P. H. 1999. Detrital and metamorphic 40Ar/39Ar ages from muscovite and whole-rock samples, Meguma Supergroup, southern Nova Scotia. Canadian Journal of Earth Sciences 36, 23–32.CrossRefGoogle Scholar
Huppert, H. E. & Sparks, R. S. J. 1988. The generation of granitic magmas by intrusion of basalt into continental crust. Journal of Petrology 29, 599–624.CrossRefGoogle Scholar
Hyndman, D. W. 1984. A petrographic and chemical section through the northern Idaho batholith. Journal of Geology 92, 83–102.CrossRefGoogle Scholar
Keppie, J. D. & Dallmeyer, R. D. 1987. Dating transcurrent terrane accretion; an example from the Meguma and Avalon composition terranes in the northern Appalachians. Tectonics 6, 831–47.CrossRefGoogle Scholar
Keppie, J. D. & Dallmeyer, R. D. 1995. Late Paleozoic collision, delamination, short-lived magmatism, and rapid denudation in the Meguma Terrane (Nova Scotia, Canada): constraints from 40Ar/39Ar isotopic data. Canadian Journal of Earth Sciences 32, 644–59.CrossRefGoogle Scholar
Keppie, J. D. & Muecke, G. K. 1979. Metamorphic Map of Nova Scotia. Halifax, Nova Scotia: Nova Scotia Department of Mines and Energy.Google Scholar
Kontak, D. J. 1994. Geological and geochemical studies of alteration processes in a fluorine-rich environment: the East Kemptville Sn-(Zn-Cu-Ag) deposit, Yarmouth County, Nova Scotia, Canada. In Alteration and Alteration Processes Associated With Ore-Forming Systems (ed. Lentz, D. R.), pp. 261–314. Geological Association of Canada, Short Course Notes 11.Google Scholar
Kontak, D. J. & Corey, M. C. 1988. Metasomatic origin for spessartine-rich garnet in the South Mountain Batholith, Nova Scotia. Canadian Mineralogist 26, 315–34.Google Scholar
London, D. 1997. Estimating abundances of volatile and other mobile components in evolved silicic melts through mineral-melt equilibria. Journal of Petrology 38, 1691–706.CrossRefGoogle Scholar
Longerich, H. P., Jenner, G. A., Fryer, B. J. & Jackson, S. E. 1990. Inductively coupled plasma-mass spectrometric analysis of geological samples: a critical evaluation based on case studies. Chemical Geology 83, 105–18.CrossRefGoogle Scholar
MacDonald, M. A., Corey, M. C., Ham, L. J. & Horne, R. J. 1992. An overview of recent bedrock mapping and follow-up petrological studies of the South Mountain batholith, southwestern Nova Scotia, Canada. Atlantic Geology 28, 7–28.CrossRefGoogle Scholar
Miller, C. F., McDowell, S. M. & Mapes, R. W. 2003. Hot and cold granites? Implications of zircon saturation temperatures and preservation of inheritance. Geology 31, 529–32.2.0.CO;2>CrossRefGoogle Scholar
Murphy, J. B. 2000. Tectonic influence on sedimentation along the southern flank of the Late Paleozoic Magdalen Basin in the Canadian Appalachians: geochemical and isotopic constraints on the Horton Group in the St. Mary's Basin, Nova Scotia. Geological Society of America Bulletin 112, 997–1011.2.0.CO;2>CrossRefGoogle Scholar
Murphy, J. B., van Staal, C. R. & Keppie, J. D. 1999. Middle to late Paleozoic Acadian orogeny in the northern Appalachians: a Laramide-style plume modified orogeny? Geology 27, 653–6.2.3.CO;2>CrossRefGoogle Scholar
Nova Scotia Department of Natural Resources, Mineral Resources Branch (NSDNRMRB). 2006. DP ME 137, Regional Till and Rock Geochemical Surveys of the South Mountain Batholith by the Nova Scotia Department of Natural Resources over western Nova Scotia, Version 2, 1984–1989.Google Scholar
Petford, N., Cruden, A. R., McCaffrey, K. J. W. & Vigneresse, J.-L. 2000. Granite magma formation, transport and emplacement in the Earth's crust. Nature 408, 669–73.CrossRefGoogle ScholarPubMed
Riley, T. R., Leat, P. T., Pankhurst, R. J. & Harris, C. 2001. Origins of large volume rhyolitic volcanism in the Antarctic Peninsula and Patagonia by crustal melting. Journal of Petrology 12, 1043–65.CrossRefGoogle Scholar
Richardson, J. M., Spooner, E. T. C. & McAuslan, D. A. 1982. The East Kemptville tin deposit, Nova Scotia: an example of a large tonnage, low grade, greisen-hosted deposit in the endocontact zone of a granite batholith. Geological Survey of Canada Current Research, part B, paper 82–1B, 27–32.Google Scholar
Rudnick, R. L. & Gao, S. 2003. Composition of the continental crust. In The Crust (ed. Rudnick, R. L.), pp. 1–64. Vol. 3, Treatise on Geochemistry (eds Holland, H. D. & Turekian, K. K.). Oxford: Elsevier-Pergamon.Google Scholar
Shellnutt, J. G. & Jahn, B.-M. 2010. Formation of the Late Permian Panzhihua plutonic-hypabyssal-volcanic igneous complex: implication for the genesis of Fe-Ti oxide deposits and A-type granites of SW China. Earth and Planetary Science Letters 289, 509–19.CrossRefGoogle Scholar
Shellnutt, J. G., Jahn, B.-M. & Zhou, M.-F. 2011. Crustal-derived granites in the Panzhihua region, SW China: implications for felsic magmatism in the Emeishan large igneous province. Lithos 123, 145–57.CrossRefGoogle Scholar
Smith, P. M. & Asimow, P. D. 2005. Adiabat_1ph: a new public front-end to the MELTS, pMELTS, and pHMELTS models. Geochemistry, Geophysics Geosystems 6, Q02004, doi: 10.1029/2004GC000816, 8 pp.CrossRefGoogle Scholar
Smith, T. E., Peck, D., Huang, C. H. & Holm, P. E. 1986. A reappraisal of the alaskite/muscovite-biotite bearing granite suite of Halifax County, Nova Scotia. Maritimes Sediments and Atlantic Geology 22, 101–16.Google Scholar
Sun, S. S. & McDonough, W. F. 1989. Chemical and isotopic systematics of oceanic basalts: implications for mantle composition and processes. In Magmatism in the Ocean Basins (eds Saunders, A. D. & Norry, M. J.), pp. 313–45. Geological Society of London, Special Publication no. 42.Google Scholar
Tate, M. C. & Clarke, D. B. 1995. Petrogenesis and regional tectonic significance of Late Devonian mafic intrusions in the Meguma Zone, Nova Scotia. Canadian Journal of Earth Sciences 32, 1883–98.CrossRefGoogle Scholar
Thompson, A. B., Matile, L. & Ulmer, P. 2002. Some thermal constraints on crustal assimilation during fractionation of hydrous, mantle-derived magmas with examples from central Alpine batholiths. Journal of Petrology 43, 403–22.CrossRefGoogle Scholar
Waight, T. E., Wiebe, R. A. & Krogstad, E. J. 2007. Isotopic evidence for multiple contributions to felsic magma chambers: Gouldsboro Granite, Coastal Maine. Lithos 93, 234–47.CrossRefGoogle Scholar
Watson, E. B. & Harrison, T. M. 1983. Zircon saturation revisited: temperature and composition effects in a variety of crustal magma types. Earth and Planetary Science Letters 64, 295–304.CrossRefGoogle Scholar
Waldron, J. W. F., White, C. E., Barr, S. M., Simonetti, A. & Heaman, L. M. 2009. Provenance of the Meguma Terrane, Nova Scotia: rifted margin of early Paleozoic Gondwana. Canadian Journal of Earth Sciences 46, 1–8.CrossRefGoogle Scholar
Wenner, J. M. & Coleman, D. S. 2004. Magma mixing and Cretaceous crustal growth: geology and geochemistry of granites in the Central Sierra Nevada Batholith, California. International Geology Review 46, 880–903.CrossRefGoogle Scholar
Whalen, J. B., Currie, K. L. & Chappell, B. W. 1987. A-type granites: geochemical characteristics, discrimination and petrogenesis. Contributions to Mineralogy and Petrology 95, 407–19.CrossRefGoogle Scholar
Wilson, M. 1989. Igneous Petrogenesis. London: Unwin Hyman, 466 pp.CrossRefGoogle Scholar
Wones, D. R. 1989. Significance of the assemblage titanite + magnetite + quartz in granitic rocks. American Mineralogist 74, 744–9.Google Scholar
Xirouchakis, D. & Lindsley, D. H. 1998. Equilibria among titanite, hedenbergite, fayalite, quartz, ilmenite, and magnetite: experiments and internally consistent thermodynamic data for titanite. American Mineralogist 83, 712–25.CrossRefGoogle Scholar
Zeng, L., Saleeby, J. B. & Asimow, P. 2005. Nd isotopic disequilibrium during crustal anatexis: a record from the Goat Ranch migmatite complex, southern Sierra Nevada batholith, California. Geology 33, 53–6.CrossRefGoogle Scholar
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