PALYNOLOGY OF THE LOWER CRETACEOUS CHASWOOD FORMATION, ELMSVALE BASIN AND SHUBENACADIE OUTLIER, NOVA SCOTIA

Abstract

The unconsolidated sand and clay deposits of the Shubenacadie and Musquodoboit basins have been documented in detailed studies since the 1950's. General mapping projects from as early as the 1900's have postulated that the deposits are of Cretaceous age. More recently they have been found to be of late Early Cretaceous (Aptian-Albain) age. Previous workers have hypothesized a non-marine depositional environment, but marine foraminifera have also been reported, suggesting the possibility of marine pulses. The present study has found freshwater protists such as the dinoflagellates Nyktericysta sp. and Peridinium sp., zygnematacean (algal) cysts Lecaniella foveata, Lecaniella irregularis, Tetroporina sp., Ovoidites grandis, Ovoidites parvus and Ovoidites spriggii and other protists such as Schizocystia rugosa, Schizospora reticulatus and rareBotryococcus sp. A variety of trilete spores, gymnosperm pollen grains and angiosperm pollen grains have also been found giving an age of Barremian to early Lower Albian. The palynomorphs tend to occur in assemblages dominated by one or more fossil types. For example, assemblages dominated by freshwater protists represent an environment of shallow, slow moving fresh water, while the assemblages dominated by trilete spores and pollen represent terrestrial deposits where little or no standing water was present. All of the assemblages found in the present study support a non-marine depositional environment

Pages: 149 Supervisors: Rob Fensome