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Possible higher pressure relics within titaniferous augites in a basic sill

Published online by Cambridge University Press:  01 May 2009

F. G. F. Gibb
Affiliation:
Department of Geology, University of Sheffield, Sheffield, S1 3JD.
C. M. B. Henderson
Affiliation:
Department of Geology, University of Manchester, Manchester, M13 9PL.

Summary

An unusual type of mottled area is described from titaniferous augites in the Dippin sill, Isle of Arran. These are characterized by abundant magnetite inclusions, irregular embayed outlines and distinctive chemical compositions. The possibility that these are due to zoning, especially sector zoning, is examined and discarded. They probably represent partly resorbed relics of pyroxene which crystallized at depth prior to the emplacement of the sill. As such they could have considerable petrogenetic implications both with regard to the sill itself and to alkaline basic magmas in general.

Type
Articles
Copyright
Copyright © Cambridge University Press 1978

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References

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