a1 Geology Department, Chelsea College (University of London), 552 Kings Road, London SW10 OUA, England.
a2 Laboratoire de Paleobotanique, L.A. 327 CNRS, Institut des Sciences de L'Evolution, U.S.T.L. 34060 Montpellier, France.
a3 Geology Department, Trinity College, Dublin 2, Republic of Ireland.
Twelve localities of Lower Carboniferous strata in Scotland (Loch Humphrey Burn, Glenarbuck, Pettycur, Oxroad Bay and the Berwickshire localities of Cove, Burnmouth, Gavinton, Edrom, Foulden) and in France (Esnost, Roannais, Montagne Noire) have been investigated with particular regard to their anatomically preserved floras. New data on the composition and preservation of the assemblages, their geological setting and stratigraphical age, using palynology in particular, are presented. Present data suggest that four successive groups of floras obtained from these localities can be recognised: from the Montagne Noire (mid to late Tournaisian), from the Berwickshire localities and Oxroad Bay (late Tournaisian to early Viséan), from Loch Humphrey Burn and possibly Glenarbuck (mid Viséan) and from Roannais, Esnost, and Pettycur (late Viséan). The similarities and differences between the floras are discussed with particular emphasis on stratigraphical as opposed to ecological controls. Comparisons are made with the New Albany Shale floras of the U.S.A., the Saalfeld and Glätzish-Falkenberg floras from the German Democratic Republic. The data suggest that the ferns and pteridosperms show the most striking changes through the Lower Carboniferous strata.
(Received August 12 1982)
(Accepted August 29 1984)