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Blocks of Plutonic Aspect in a Basaltic Lava from Faial, Azores

Published online by Cambridge University Press:  01 May 2009

M. Jane Baker
M. Jane Baker
Affiliation:
Dept. of Geology and Mineralogy, University Museum, Oxford.
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Abstract

A number of coarse-grained blocks, consisting of forsteritic olivine, chrome-diopside, calcic plagioclase, and chromite in varying proportions, were found in an ankaramitic basalt on Faial. With one exception, the blocks show remarkably little alteration. There is no evidence of zoning in any of the minerals. Indications of strain are frequent. Dark scoriaceous material is often present along intercrystal boundaries and fractures. The textures and gradations in composition suggest that these blocks were formed by crystal accumulation.

Type
Articles
Information
Geological Magazine , Volume 103 , Issue 1 , February 1966 , pp. 51 - 60
Copyright
Copyright © Cambridge University Press 1966

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References

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