LATE CARBONIFEROUS PLANT ECOLOGY ACROSS AN ALLUVIAL PLAIN TO COASTAL PLAIN TRANSECT, JOGGINS, NOVA SCOTIA

The fossil cliffs of Joggins, Nova Scotia contain one of the best three-dimensional exposures of Upper Carboniferous (Langsettian-Duckmantian) rocks anywhere in the world. Quantitative and qualitative analysis of fossil plant distribution within a revised sedimentary facies framework has recently been undertaken for the section. Facies association 1 is interpreted as a well-drained alluvial plain dissected by flashy anastomosing channels. Channel margins were sparsely covered in Calamites, inter-channel areas supported fire-prone medullosan pteridosperms, whilst upland sites were cloaked by fire-prone cordaitalean forests. Facies association 2 is interpreted as transition between well-drained alluvial plain and poorly-drained coastal plain environments. In this setting, Calamites sparsely covered channel margins whilst fire-prone sigillarian-medullosan forests dominated inter-channels areas. Facies association 3 is interpreted as a poorly coastal plain with large meandering distributary channels. Coal-forming mires containing lepidodendrids and pteridosperms were prevalent in this environment, whilst dense stands of Calamites grew on channel margins. Facies association 4 is interpreted as being deposited during periods of marine highstand. This contains a sparse flora including cordaitaleans, progymnosperms and pteridosperms, representing a coastal or upland flora. These data provide important new insight into Late Carboniferous vegetation ecology along an alluvial plain to coastal plain transect.