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Petrology of an Irregular-Nodule Bed, Lower Carboniferous, Anglesey, North Wales

Published online by Cambridge University Press:  01 May 2009

R. A. H. Nichols
R. A. H. Nichols
Affiliation:
Department of Mineral Resources, Administration Building, Regina, Saskatchewan, Canada.
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Abstract

Some of the nodules described are similar to trace-fossils described by Donaldson and Simpson and some ichnofossils described by Seilacher, but many appear to be structures produced by sedimentary boudinage. These do not seem to be a result of organic or concretionary action. It is suggested that currents deposited thin bioclastic calcarenites with interbeds of calcite silt, and that crinoids and coral patches developed only sporadically during deposition. A few scavengers reworked the bioclastic calcarenites and calcite silt layers thus forming the trace-fossils; many of the irregular-nodules, however, were probably formed by differential compaction and segregation in the calcite silt beds, and may represent sedimentary boudins, which are relicts of former layers.

Type
Articles
Information
Geological Magazine , Volume 103 , Issue 6 , December 1966 , pp. 477 - 486
Copyright
Copyright © Cambridge University Press 1966

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