The Petrology of Mesozoic Alkaline Intrusives of Central Newfoundland

Lamprophyre dikes occur as northeast-striking swarms and in radiating patterns around alkaline stocks. They range in age from Jurassic to Cretaceous and are interpreted as the result of the rifting associated with formation of the North Atlantic Ocean. They show strong evidence of coexisting immisci...

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Bibliographic Details
Published in:Canadian Journal of Earth Sciences
Main Authors: Strong, D. F., Harris, A.
Format: Article in Journal/Newspaper
Language:English
Published: Canadian Science Publishing 1974
Subjects:
Online Access:http://dx.doi.org/10.1139/e74-114
http://www.nrcresearchpress.com/doi/pdf/10.1139/e74-114
Description
Summary:Lamprophyre dikes occur as northeast-striking swarms and in radiating patterns around alkaline stocks. They range in age from Jurassic to Cretaceous and are interpreted as the result of the rifting associated with formation of the North Atlantic Ocean. They show strong evidence of coexisting immiscible silicate liquids, with leucocratic globules in a darker host matrix. The globules are richer in CO 2 and Na 2 O than the host and these liquids are not similar in composition to those of other immiscible liquid pairs. The whole suite is interpreted to have resulted from high pressure eclogite fractionation followed by volatile build-up due to lower pressure fractionation of olivine, titanaugite, plagioclase, biotite, and/or kaersutite.