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The petrochemistry of the basic volcanic rocks of the South Connemara Group (Ordovician), western Ireland

Published online by Cambridge University Press:  01 May 2009

P. D. Ryan ,
M. D. Max  and
T. Kelly
P. D. Ryan
Affiliation:
Department of Geology, University College, Galway, Ireland
M. D. Max
Affiliation:
Geological Survey of Ireland, 14 Hume Street, Dublin 2
T. Kelly
Affiliation:
C/O Shell Int. Pet. Exploration, Carel van Bylandtlaan, Den Haag, The Netherlands
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Summary

16 samples of Ordovician basic volcanic rocks of the South Connemara Group, which abut the southern side of the metamorphic rocks of the Connemara massif in western Ireland, have been analysed for both major and trace elements. Although subject to low grade regional metamorphism and subsequently hornfelsed by the Galway Granite (400 Ma), their immobile element contents do not appear to be significantly disturbed. These elements characterise the metabasites of the South Connemara Group as ocean floor basalts having their origins in a marginal basin. The Skird Rocks Fault, separating the South Connemara Group from high grade metamorphic rocks of the Connemara massif, is consequently regarded as the northern margin of the vestiges of the lapetus Ocean which can be traced into, and along, the Southern Uplands Fault.

Type
Articles
Information
Geological Magazine , Volume 120 , Issue 2 , March 1983 , pp. 141 - 152
Copyright
Copyright © Cambridge University Press 1983

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