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Trace-element and isotopic data and their bearing on the genesis of Precambrian spilites from the Athapuscow aulacogen, Great Slave Lake, Canada

Published online by Cambridge University Press:  01 May 2009

M. A. D. Olade
M. A. D. Olade
Affiliation:
Department of Geology, University of Ibadan, Ibadan Nigeria
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Summary

The nature and timing of ‘spilitization’, and the original composition of ‘spilitized’ Precambrian lavas fron the Athapuscow aulacogen, Great Slave Lake (Canada) are investigated, using geochemical and Rb/Sr isotopic methods. Relationships and abundances of trace elements of petrogenetic significance suggest that the spilites were not derived from alkaline basaltic magmas, but show petrogenetic affinity with tholeiitic basalts from continental or volcanic island environments. This new interpretation conforms well with the supposed tectonic and geologic environment in which the lavas and pyroclastics were erupted. Assuming an ‘open system’ behaviour for Rb and Sr during intense metasomatism, the isochron age of 1872 Ma obtained for the lavas is considered as the time of ‘spilitization’. This age, when compared with geochrono metric data obtained by other techniques, suggests that the time interval between initial volcanism and subsequent ‘spilitization’ event was brief, and probably related to diagenesis or burial metamorphism during rapid subsidence and sedimentation commonly associated with rifting within aulocogens. A relatively low initial 87Sr/86Sr ratio of 0.7018±0.0005 obtained for the lavas either reflects the low Sr isotope values characteristic of diagenetic pore fluid in Precambrian seas, or suggests that the original ‘primitive’ initial ratio was not adversely affected by the ‘spilitization’ process. .

Type
Articles
Information
Geological Magazine , Volume 112 , Issue 3 , May 1975 , pp. 283 - 293
Copyright
Copyright © Cambridge University Press 1975

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References

Amstutz, G. C. 1968. Spilites and spilitic rocks. In Hess, & Poldervaart, (Eds): Basalts, , 2, 737–53. J. Wiley, New York.Google Scholar
Amstutz, G. C. 1973. Spilites and spilitic rocks. Springer-Verlag, New York.Google Scholar
Arriens, P. A. & Lambert, I. B. 1969. On the age and strontium isotope geochemistry of granulite-facies rocks from the Fraser Range, Western Australia and the Musgrave Ranges, Central Australia. Spec. Publs geol. Soc. Aust. 2, 377–88.Google Scholar
Aumento, F. 1968. The Mid-Atlantic near 45°N: 11 Basalts from the area of Confederation Peak. Can. J. Earth Sci. 5, 1–21.Google Scholar
Baadsgaard, H., Morton, R. D. & Olade, M. A. D. 1973. Rb-Sr isotopic age for the Precambrian lavas of the Seton Formation, East Arm of Great Slave Lake, Northwest Territories. Can. J. Earth Sci. 10, 1579–82.CrossRefGoogle Scholar
Bloxam, T. W. & Lewis, A. D. 1972. Ti, Zr and Cr in some British pillow lavas and their petrogenic affinities. Nature Phys Sci. 237, 134–6.Google Scholar
Burke, K. & Dewey, J. F. 1973. Plume-generated triple junctions: key indicators in applying plate tectonics to old rocks. J. Geol. 81, 406–43.Google Scholar
Cann, J. R. 1969. Spilites from the Carlsberg Ridge, Indian Ocean. J. Petrology 10, 1–19.CrossRefGoogle Scholar
Cann, J. R. 1970. Rb, Sr. Y, Zr and Nb in some ocean floor basaltic rocks. Earth Planet Sci. Lett. 10, 7–11.CrossRefGoogle Scholar
Cox, K. G., Gass, I. G. & Mallick, D. I. J. 1970. The peralkcaline volcanic suite of Aden and Little Aden, South Arabia. J. Petrology. 11, 433–61.Google Scholar
Dasch, E. J., Hedge, C. F. & Dymond, J. 1973. Effect of sea water interaction on strontium isotope composition of deep-sea basalts. Earth Planet. Sci. Lett. 19, 177–83.CrossRefGoogle Scholar
Donnelly, T. W. 1966. Geology of St. Thomas and St. John, U.S. Virgin Islands. Mem. geol. Soc. Am. 98, 85–176.Google Scholar
Engel, A. E. J. Engel, C. G. & Havens, R. G. 1965. Chemical characteristics of oceanic basalts and the upper mantle. Bull. geol. Soc. Am. 76, 719–25.CrossRefGoogle Scholar
Faure, G. & Powell, J. L. 1972. Strontium isotope geology. Springer-Verlag, New York.CrossRefGoogle Scholar
Gass, I. G., Mallick, D. I. J. & Cox, R. G. 1973. Volcanic islands of the Red Sea. Jl geol. Soc. Lon. 129, 209–43.Google Scholar
Hart, S. R. 1970. Chemical exchange between sea water and deep ocean basalts. Earth Planet. Sci. Lett. 9, 269–79.Google Scholar
Hart, S. R. 1971. K, Rb, Cs and Ba contents and Sr isotope ratios of ocean floor basalts. Phil. Trans. R. Soc. 268, 573–81.Google Scholar
Hart, S. R. 1972. Sr isotopic composition of the oceanic crust. Carnegie Institute Washington Yearbook 71, 288–90.Google Scholar
Hermann, A. K. & Wedepohl, K. H. 1970. Trace elements and spilite genesis. Contr. Mineral. Petrol. 29, 255.Google Scholar
Hermann, G. A., Potts, M. J. & Knake, D. 1974. Geochemistry of the rare earth elements in spilites from oceanic and continental crust. Contr. Mineral. Petrol. 44, 1–16.Google Scholar
Hoffman, P. 1969. Proterozoic paleocurrents and depositional history of the East Arm Fold Belt, Great Slave Lake, Northwest Territories. Can. J. Earth Sci. 6, 441–62.Google Scholar
Hoffman, P. in press. Evolution of an early Proterzoic continental margin: the Coronation Geosyncline and associated aulacogens of the northwestern Canadian Sheild. In Symposium on evolution of the Precambrian crust: Phil. Trans.R. Soc. Lond.Google Scholar
Hoffman, P. 1973. Aphebian supracrustal rocks of the Athapuscow aulacogen, East Arm of Great Slave Lake, District of MacKenzie. In: Geol. Surv. Can. Pap. 73– 1, 151–6.Google Scholar
Hoffman, P., Fraser, J. A. & McGlynn, J. C. 1970. The Coronation Geosyncline of Aphebian age, District of MacKenzie. In Geol. Surv. Can. Pap. 70– 40, 201– 12.Google Scholar
Hughes, C. J. 1972. Spilites, keratophyres and the igneous spectrum. Geol. Mag. 109, 513–27.CrossRefGoogle Scholar
Hughes, C. J. 1973. Late Precambrian volcanic rocks of Avalon, Newfoundland-a spilite/keratophyre province: recognition and implications. Can. J. Earth Sci. 10, 272–82.CrossRefGoogle Scholar
Hughes, C. J. & Bruckner, W. D. 1971. Late Precambrian rocks of eastern Avalon Peninsula, Newfoundland-a volcanic island complex. Can. J. Earth Sci. 8, 899– 915.CrossRefGoogle Scholar
Hughes, C. J. & Malpas, J. G. 1971. Metasomatism in the late Precambrian Bull Arm Formation in southeastern Newfoundland: recognition and implications. Proc. geol. Soc. Can. 24, 85–93.Google Scholar
Jakes, P. & White, A. J. R. 1972. Major and trace element abundances in volcanic rocks of orogenic areas. Bull. geol. Soc. Am. 83, 29–40.CrossRefGoogle Scholar
Loeschke, J. 1973. Petrochemistry of Paleozoic spilites of the eastern Alps (Austria). Geol. Mag. 110, 19–28.CrossRefGoogle Scholar
Krogh, T. E. & Davis, G. L. 1973. The effect of regional metamorphism on U-Pb systems in zircon and a comparison with Rb-Sr systems in the same whole rock and its constituent minerals. Carnegie Institute Washington Yearbook 72, 601–10.Google Scholar
Mason, V. 1968. Geochemistry of basaltic rocks: major elements: In Hess, & Poldervaart, (Eds): Basalts, . 1, 215–69. J. Wiley, New York.Google Scholar
Montigny, R., Bougalt, H., Bottiga, Y. & Allegre, C. J. 1973. Trace element geochemistry and genesis of the Pindos ophiolite suite. Geochim. cosmochim. Acta 37, 2135–47.CrossRefGoogle Scholar
Moore, W. J. & Lanphere, M. A. 1971. The age of porphyry-type copper mineralization in the Bingham mining district-a redefined estimate. Econ. Geol. 66, 331–4.CrossRefGoogle Scholar
Olade, M. A. D. & Morton, R. D. 1972. Observations on the Proterozoic Seton Formation, East Arm of Great Slave Lake. Can. J. Earth Sci. 9, 1110–23.Google Scholar
Papezik, V. S. 1970. Petrochemistry of volcanic rocks of the Harbour Main Group, Avalon Peninsula, Newfoundland. Can. J. Earth Sci. 7, 1485–98.Google Scholar
Pearce, J. A. & Cann, J. R. 1973. Tectonic setting of basic volcanic rocks determined using trace element analyses. Earth Planet. Sci. Lett. 7, 293–9.Google Scholar
Phillpots, J. A., Schnetzler, C. C. & Hart, S. R. 1969. Submarine basalts: some K, Rb, Sr, Ba, rare earth, H2O, and CO2 data bearing on their alteration, modification by piagioclase and possible source materials. Earth Planet. Sci. Lett. 7, 293–9.CrossRefGoogle Scholar
Sassano, G. P. Baadsgaard, H. & Morton, R. D. 1972. Rb-Sr systematics of the Foot Bay Gneiss, Donaldson Lake Gneiss and pegmatite dikes from the Fay Mine, N.W. Saskatchewan, Can. J. Earth Sci. 9, 1368–81.CrossRefGoogle Scholar
Sinclair, A. J. & White, W. H. 1968. Age of mineralization and post-ore hydrothermal alteration at Copper Mountain, B. C. Bull. Can. Inst. Min. Metall. 61, 633–6.Google Scholar
Smith, R. E. 1968. Redistribution of major elements in the alteration of some basic lavas during burial metamorphism. J. Petrology 9, 191–219.Google Scholar
Stockwell, C. H. 1932, Great Slave Lake-Coppermine River area, Northwest Territories. Ann. Rept. Geol. Surv. Can. C, 37–63.Google Scholar
Turekian, K. K. & KuIp, J. L. 1956. The geochemistry of strontium Geochim. cosmochim. Acta. 10, 245–96Google Scholar
Vallance, T. G. 1960. Concerning spilites. Proc. Linn. Soc. N.S. W. 85, 8–52.Google Scholar
Vallance, T. G. 1969. Spillites again: some consequences of the degradation of basalts. Proc. Linn. Soc. N.S. W. 94, 8–51.Google Scholar
Wanless, R. K. & Loveridge, W. D. Rubidium-strontium isochron age studies, report 1. Pap. Geol. Surv. Can. 72– 23, 1–5.Google Scholar