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The Disappointment Hill complex: Proterozoic granulites in southwestern Newfoundland

Published online by Cambridge University Press:  03 November 2011

J. V. Owen
Affiliation:
J. V. Owen, Department of Geology, Saint Mary's University, Halifax, Nova Scotia, Canada B3H 3C3.
K. L. Currie
Affiliation:
K. L. Currie, Geological Survey of Canada, 601 Booth Street, Ottawa, Ontario, Canada K1A 0E8.

Abstract

The Steel Mountain terrane of the southern Long Range Mountains forms a fault-bounded massif of (meta)plutonic rocks including the Disappointment Hill complex (DHC), a sequence of granulite-facies lithologies containing charnockite emplaced at 1498 Ma (U-Pb, zircon). Quartzofeldspathic gneiss of the DHC contains garnet + biotite + orthopyroxene ± cordierite assemblages indicative of metamorphic P–T conditions of ca 750°C and 400 MPa. The relatively high thermal gradient (ca 70°C km−1) inferred for the DHC is attributed to a magmatic heat source.

On grounds of lithology, age and metamorphic grade, the DHC correlates to granulites of the Long Range Inlier (LRI) exposed farther north. Both complexes occur in blocks thrust westward over Taconic allochthons capped by ophiolite nappes. The block containing the DHC, however, preserves younger cover rocks, suggesting that it originated at a higher structural level than the LRI. This model is supported by lower pressure estimates for the DHC relative to the LRI (400 MPa vs 500–800 MPa). The DHC forms a link between Grenvillian rocks of the northern Long Range of Newfoundland and those of Cape Breton Island. The structural position of these massifs suggests that their emplacement was a post-Taconic event.

Type
Research Article
Copyright
Copyright © Royal Society of Edinburgh 1991

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References

Armbruster, T. & Bloss, F. D. 1980. Channel CO2 in cordierites. NATURE 286, 140–1.Google Scholar
Armbruster, T. & Bloss, F. D. 1982. Orientation and effects of channel H2O and CO2 in cordierite. AM MINERAL 67, 284–91.Google Scholar
Baadsgaard, H., Erdmer, P. & Owen, J. V. (in prep.) U-Pb geochronology of the Long Range Inlier, NewfoundlandGoogle Scholar
Barr, S. M., Raeside, R. P. & van Breemen, O. 1986. Grenvillian basement in the northern Cape Breton Highlands, Nova Scotia. CAN J EARTH SCI 24, 992–97.CrossRefGoogle Scholar
Bhattacharya, A. 1986. Some geobarometers involving cordierite in the FeO–Al2O3–SiO2 (±H2O) system: refinements, thermodynamics, calibration and applicability in granulite-facies rocks. CONTRIB MINERAL PETROL 94, 387–94.CrossRefGoogle Scholar
Bhattacharya, A., Mazumdar, A. C. & Sen, S. K. 1988. Fe–Mg mixing in cordierite: constraints from natural data and implications for cordierite-garnet geothermometry in granulites. AM MINERALOG 73, 338–44.Google Scholar
Chipera, S. J. & Perkins, D. 1988. Evaluation of biotite-garnet geothermometers: application to the English River sub-province, Ontario. Contrib; MINERAL PETROL 98, 40–8.CrossRefGoogle Scholar
Currie, K. L. 1987. A preliminary account of the geology of the Harry's River map-area, southern Long Range of Newfoundland. GEOL SURV CAN PAPER 87–1A, 653–62.Google Scholar
Currie, K. L.van Breemen, O., Hunt, P. A. & van Berkel, J. T. (in prep.). The age of granulitic gneisses south of Grand Lake, Newfoundland.Google Scholar
Dallmeyer, R. D. 1978. 40Ar/39Ar incremental release ages of hornblende and biotite from Grenvillian basement rocks within the Indian Head Range complex, southwestern Newfoundland: their bearing on Late Proterozoic-Early Paleozoic thermal history. CAN J EARTH SCI 15, 1374–9.CrossRefGoogle Scholar
Davidson, P. M. & Lindsley, D. H. 1985. Thermodynamic analysis of quadrilateral pyroxenes, part II. Model calibrations from experiments and applications to geothermometry. CONTRIB MINERAL PETROL 91, 390404.Google Scholar
Frost, B. R. & Chacko, T. 1989. The granulite uncertainty principle: limitations on thermobarometry in granulites. J GEOL 97, 435–50.CrossRefGoogle Scholar
Gower, C. F. and Rivers, T. 1988. The ca 1400 Ma Michael gabbro and Shabogamo intrusive suite—compositional constraints for Middle Proterozoic tectonic environments in Labrador. GEOL ASSOC CAN PROG ABST 13, A47.Google Scholar
Hatcher, R. D. 1983. Basement massifs in the Appalachians: their role in deformation during the Appalachian orogenies. GEOL J 18, 255–65.Google Scholar
Harley, S. L. 1988. Proterozoic granulites from the Rauer Group, east Antartica: I. Decompressional pressure-temperatures deduced from mafic and felsic gneisses. J PETROL 29, 1059–95.Google Scholar
Harley, S. L. 1984. An experimental study of the partitioning of Fe and Mg between garnet and orthopyroxene. CONTRIB MINERAL PETROL 86, 359–73.CrossRefGoogle Scholar
Hibbard, J. (compiler) 1983. Geology of the Island of Newfoundland (1: 1 000000 scale). Newfoundland Department of Mines and Energy, Mineral Development Division, Map 83106.Google Scholar
Hodges, K. V. & Royden, L. 1984. Geological thermobarometry of retrograded metamorphic rocks: an indication of the uplift trajectory of a portion of the northern Scandinavian Caledonides. J GEOPHYS RES 89, 7077–90.CrossRefGoogle Scholar
Holdaway, M. J. & Lee, S. M. 1977. Fe-Mg cordierite stability in high-grade pelitic rocks based on experimental, theoretical and natural observations. CONTRIB MINERAL PETROL 63, 175–98.Google Scholar
Indares, A. & Martignole, J. 1985. Biotite-garnet geothermometry in granulite facies: evaluation of equilibrium criteria. CAN MINERAL 23, 187–93.Google Scholar
Knapp, D., Kennedy, D. & Martineau, Y. 1979. Stratigraphy, structure and regional correlation of rocks at Grand Lake, western Newfoundland. GEOL SUR CAN PAPER 79–1A, 317–25.Google Scholar
Lee, H. Y. & Ganguly, J. 1988. Equilibrium composition of coexisting garnet and orthopyroxene: experimental determinations in the system FeO–MgO–Al2O3–SiO2, and applications. J PETROL 29, 93113.CrossRefGoogle Scholar
Leech, G. B., Lowdon, J. A., Stockwell, C. H. & Wanless, R. K. 1963. Age determinations and geological studies. GEOL SURV CAN PAPER 61–17, 140 p.Google Scholar
Mueller, R. F. 1972. Stability of biotite: a discussion. AM MINERAL 57, 7583.Google Scholar
Murthy, G. S. & Rao, V. K. 1976. Paleomagnetism of the Steel Mountain and Indian Head anorthosites from western Newfoundland. CAN J EARTH SCI 13, 7583.CrossRefGoogle Scholar
Newton, R. C. & Perkins, D. 1982. Thermodynamic calibrations of geobarometers based on the assemblage garnet–plagioclase–orthopyroxene(–clinopyroxene)–quartz. AM MINERAL 67, 203–22.Google Scholar
Newton, R. C. 1983. Geobarometry of high-grade metamorphic rocks. AM J SCI 283A, 128.Google Scholar
Owen, J. V. & Erdmer, P. 1989. Metamorphic geology and regional geothermobarometry of a Grenvillian massif: the Long Range Inlier, Newfoundland. PRECAMBRIAN RES 43, 79100.Google Scholar
Owen, J. V. & Erdmer, P. 1990. Middle Proterozoic geology of the Long Range Inlier, western Newfoundland: regional significance and tectonic implications. In Mid-Proterozoic geology of the southern margin of proto-Laurentia-Baltica. GEOL ASSOC CAN Special Paper 38 (in press).Google Scholar
Perchuk, L. L. & Lavrent'eva, I. V. 1983. Experimental investigation of exchange equilibria in the system cordieritegarnet-biotite. In Saxena, S. K. (ed.), Kinetics and Equilibrium in Mineral Reactions, pp. 199239. New York: Springer-Verlag.CrossRefGoogle Scholar
Perchuk, L. L., Aranovich, L. Y., Podlesskii, K. K., Lavrent'eva, I. V., Gerasimov, V. Y., Fed'kin, V. V., Kitsul, V. I., Karsakov, L. P. & Berdnikov, N. V. 1985. Precambrian granulites of the Aldan shield, eastern Siberia, USSR. J METAMORPH GEOL 3, 265310.CrossRefGoogle Scholar
Perkins, D. & Chipera, S. J. 1985. Garnet-orthopyroxene-plagioclase-quartz barometry: refinement and application to the English River sub-province and the Minnesota River valley. CONTRIB MINERAL PETROL 89, 6980.CrossRefGoogle Scholar
Riley, G. C. 1962. Stephenville map-area, Newfoundland. GEOL SURV CAN MEM 323, 72 p.Google Scholar
Sen, G. 1985. Experimental determination of pyroxene compositions in the system CaO–MgO–Al2O3–SiO2 at 900–1200°C using PbO and H2O fluxes. AM MINERAL 70, 678–95.Google Scholar
Sen, S. K. & Bhattacharya, A. 1984. An orthopyroxene-garnet thermometer and its application to the Madras charnockites. CONTRIB MINERAL PETROL 88, 6471.Google Scholar
Vallières, A., Hubert, C. & Brooks, C. 1978. A slice of basement in the western margin of the Appalachian orogen, Saint Malachie, Quebec. CAN J EARTH SCI 15, 1242–9.Google Scholar
van Berkel, J. T. & Currie, K. L. 1988. Geology of the Puddle Pond (12A/5) and Little Grand Lake map areas, southwestern Newfoundland. Newfoundland Department of Mines, Mineral Development Division, Report 88-1, 99107.Google Scholar
van Berkel, J. T., Johnston, H. P. & Currie, K. L. 1986. A preliminary report on the geology of the southern Long Range, southwestern Newfoundland. GEOL SURV CAN PAPER 86–1B, 157–64.Google Scholar
Waldron, J. W. F. 1988. Geometry of allochthons in west Newfoundland and the position of the Long Range inlier. GEOL ASSOC CAN PROG ABST 13, 131.Google Scholar
Waters, D. J. 1986. Metamorphic history of sapphirine-bearing and related magnesian gneisses from Namagualand, South Africa. J PETROL 27, 541–65.CrossRefGoogle Scholar
Wells, P. R. A. 1977. Pyroxene thermometry in simple and complex systems. CONTRIB MINERAL PETROL 62, 129–39.CrossRefGoogle Scholar
Williams, H. & Cawood, P. A. 1986. Relationships along the eastern margin of the Humber Arm allochthon between Georges Lake and Corner Brook, western Newfoundland. GEOL SURV CAN PAPER 86–1A, 759–65.Google Scholar
Wood, B. J. & Banno, S. 1973. Garnet-orthopyroxene and orthopyroxene-clinopyroxene in simple and complex systems. CONTRIB MINERAL PETROL 42, 109–24.Google Scholar