Hostname: page-component-cd9895bd7-q99xh Total loading time: 0 Render date: 2024-12-24T02:19:12.910Z Has data issue: false hasContentIssue false

B1 subdivisions in thin komatiites at Kambalda, Western Australia

Published online by Cambridge University Press:  01 May 2009

B. Thomson
Affiliation:
Upper Kennerty Mills Cottage, Kennerty Mills Road, Peterculter, Aberdeen AB1 OLR, Scotland, U.K.

Abstract

B1 subdivisions are narrow foliated zones of stubby, skeletal olivine blades, situated at the top of the granular olivine cumulates (B2) in ponded komatiite lavas. They developed at a late stage in pond crystallization as a result of compaction-related circulation of intercumulus liquids through and along the top of the cumulates. The total thickness of a B1 and its degree of blade parallelism are related to lateral position within ponded lavas. The deeper, hotter and longer-lived core regions generated a thick B1 with a high degree of blade parallelism (ordered B1), whereas the shallower, peripheral regions produced a narrow B1 with a poor degree of blade parallelism (disordered B1), or failed to develop one at all.

Type
Articles
Copyright
Copyright © Cambridge University Press 1989

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

Arndt, N. T. 1986. Differentiation of komatiite flows. Journal of Petrology 27, 279301.Google Scholar
Arndt, N. T., Naldrett, A. J. & Pyke, D. R. 1977. Komatiitic and iron rich tholeiitic lavas of Munro Township, northeast Ontario. Journal of Petrology 18, 319–69.Google Scholar
Barnes, R. G., Lewis, J. D. & Gee, R. D. 1974. Archaean ultramafic lavas from Mount Clifford. Report of Geological Survey of Western Australia, 5970.Google Scholar
Bédard, J. H. J. 1987. The development of compositional and textural layering in Archaean komatiites and Proterozoic komatiitic basalts from Cape Smith, Quebec, Canada. In Origins of Igneous Layering (ed. Parsons, I.), pp. 399418. Dordrecht: Reidel.CrossRefGoogle Scholar
Cowden, A. & Archibald, N. J. 1989. Kambalda – Kalgoorlie stratigraphy: evidence for volcanic cycles and structural repetition in Archaean greenstones, (in prep.)Google Scholar
Gresham, J. J. & Loftus-Hills, G. D. 1981. The geology of the Kambalda nickel field, Western Australia. Economic Geology 76, 1373–416.CrossRefGoogle Scholar
Irvine, T. N. 1980. Magmatic infiltration metasomatism, double diffusive fractional crystallization, and adcumulus growth in the Muskox intrusion and other layered intrusions. In Physics of Magmatic Processes (ed. Hargraves, R. B.), pp. 325–83. New Jersey: Princeton University Press.Google Scholar
Lajoie, J. & Gélinas, L. 1978. Emplacement of Archaean peridotitic komatiites in La Motte Township, Quebec. Canadian Journal of Earth Sciences 15, 672–7.Google Scholar
Petersen, J. S. 1985. Columnar-dendritic feldspars in the Lardalite Intrusion, Oslo region, Norway: I. Implications for unilateral solidification of a stagnant boundary layer. Journal of Petrology 26, 223–52.CrossRefGoogle Scholar
Pyke, D. R., Naldrett, A. J. & Eckstrand, O. R. 1973. Archaean ultramafic flows in Munro Township, Ontario. Geological Society of America Bulletin 84, 955–78.Google Scholar
Thomson, B. 1989. Petrology and stratigraphy of some texturally well preserved thin komatiites from Kambalda, Western Australia. Geological Magazine 126, 249–61.Google Scholar
Turner, J. S., Huppert, H. E. & Sparks, R. S. J. 1986. Komatiites II: Experimental and theoretical investigations of post-emplacement cooling and crystallization. Journal of Petrology 27, 397437.Google Scholar