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Acritarch dating of latest Tremadoc – earliest Arenig (early Ordovician) sediments in the Carmarthen district, south Wales

Published online by Cambridge University Press:  01 May 2009

S. G. Molyneux  and
K. J. Dorning
S. G. Molyneux
Affiliation:
British Geological Survey, Keyworth, Nottingham NG12 5GG, U.K.
K. J. Dorning
Affiliation:
Pallab Research, 58 Robertson Road, Sheffield S6 5DX, U.K.
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Abstract

An acritarch assemblage from beds beneath the Ogof Hên Formation near Carmarthen (the ‘Login beds’) resembles assemblages from the Watch Hill Grits and underlying sediments of latest Tremadoc or earliest Arenig age in the Skiddaw Group of the English Lake District. We conclude that the Login acritarch assemblage is younger than at least some part of the late Tremadoc Angelina sedgwickii Biozone, but older than the early Arenig Didymograptus deflexus Biozone. Its occurrence may therefore coincide with that of the graptolite Tetragraptus approximatus. This is of particular significance in any attempt to define an internationally correlatable base for the Arenig Series in Britain.

Type
Articles
Information
Geological Magazine , Volume 126 , Issue 6 , November 1989 , pp. 707 - 714
Copyright
Copyright © Cambridge University Press 1989

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