The geology, petrography and palynology of Tertiary coals from the Eureka Sound Group at Strathcona Fiord and Bache Peninsula, Ellesmere Island, Arctic Canada

Abstract

Coal seams of substantial thicknesses and lateral continuity are developed in the Expedition and Iceberg Bay Formations at Strathcona Fiord and in the Expedition Formation at Bache Peninsula. The coals are lignite/subbituminous in rank and have low to moderate sulphur and variable ash contents. At Strathcona Fiord resources have been estimated to be in the order of 1 billion tonnes, whereas at Bache Peninsula estimated resources are 100 million tonnes. The coals at Strathcona Fiord are characterized by the dominance of wood-derived macerals of the humotelinite group, whereas at Bache Peninsula the coals have high amounts of detrital macerals (humodetrinite) and also have significant amounts of inertinite macerals. Pollen and spore assemblages in coals from the Iceberg Bay Formation at Strathcona Fiord are dominated by Taxodiaceace pollen with less and variable amounts of Pinaceae pollen, pteridophyte spores and angiosperm pollen. The pollen and spore assemblages indicate a Late Paleocene-Early Eocene age of the Iceberg Bay Formation coals. The Expedition Formation coals at Bache Peninsula have in general a somewhat less diverse pollen and spore assemblage and show a larger input of fern and Sphagnum spores. The pollen and spore assemblages in Expedition Formation coals at Bache Peninsula are indicative of (Early?) Paleocene age. The depositional environment for Iceberg Bay Formation coals at Strathcona Fiord is that of a forested swamp, which formed on a broad coastal plain. At Bache Peninsula peats formed in broad valleys, in which a fluviatile-lacustrine environment of deposition prevailed. The mires were likely less forested than at Strathcona Fiord as indicated by the abundance of ferns and sphagnum spores and the very low content of wood-derived macerals of the humotelinite group. The pollen assemblages in both Expidition and Iceberg Bay Formation coals indicate a temperate climate and moderate precipitation during peat accumulation.