caa a22 4500 386401705 CHVBK 20180307112201.0 cr unu---uuuuu 161130e198911 xx s 000 0 eng 10.1017/S0016756800007019 doi S0016756800007019 pii (NATIONALLICENCE)cambridge-10.1017/S0016756800007019 Acritarch dating of latest Tremadoc - earliest Arenig (early Ordovician) sediments in the Carmarthen district, south Wales [Elektronische Daten] 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. Copyright © Cambridge University Press 1989 Molyneux S. G. British Geological Survey, Keyworth, Nottingham NG12 5GG, U.K. Dorning K. J. Pallab Research, 58 Robertson Road, Sheffield S6 5DX, U.K. Geological Magazine Cambridge University Press 126/6(1989-11), 707-714 0016-7568 126:6<707 1989 126 GEO https://doi.org/10.1017/S0016756800007019 text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1017/S0016756800007019 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Molyneux S. G. British Geological Survey, Keyworth, Nottingham NG12 5GG, U.K NATIONALLICENCE 700 1- Dorning K. J. Pallab Research, 58 Robertson Road, Sheffield S6 5DX, U.K NATIONALLICENCE 773 0- Geological Magazine Cambridge University Press 126/6(1989-11), 707-714 0016-7568 126:6<707 1989 126 GEO CC0 http://creativecommons.org/publicdomain/zero/1.0 nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-cambridge