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Algal Limestones and Associated Sediments in the Basal Purbeck of Dorset

Published online by Cambridge University Press:  01 May 2009

Philip R. Brown
Affiliation:
Exploration Research Division, Continental Oil Company, Ponca City, Oklahoma, U.S.A.

Abstract

The basal Purbeck of Dorset includes interesting “dirt-beds” or fossil soils. The limestones, previously considered freshwater, are here shown to be largely of marine algal origin containing species of Ortonella, Girvanella, and Solenopora and presumed algal stromatolites. Petrographic evidence of anhydrite, gypsum, and celestine suggests evaporitic conditions during their formation. This is supported by the presence of ostracods belonging to marine or super-saline species, and by the scarcity of other fauna.

Type
Articles
Copyright
Copyright © Cambridge University Press 1963

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