Sedimentary successions and palynoevent stratigraphy from the non-marine Lower Cretaceous to the marine Upper Cretaceous of the Nuussuaq Basin, West Greenland

Abstract

Abstract The Nuussuaq Basin, West Greenland, comprises the only exposures of Mesozoic sedimentary strata on the west coast of Greenland. The Nuussuaq Basin exposes Cretaceous and Paleocene siliciclastic strata, referred to as the Nuussuaq Group, overlain by volcanic rocks, mainly of Paleocene age, referred to as the West Greenland Basalt Group. Regional seismic studies indicate that the Cretaceous strata of the Nuussuaq Basin may be correlated to the Appat and Kangeq seismic sequences in the offshore basins. The present paper re-investigates five profiles, trending roughly east-west, from northern Disko to southern Svartenhuk Halvo, which exemplify the litho- and biostratigraphy, with a focus on the pre-Campanian deposits. The oldest exposed strata belong to the non-marine Kome Formation of possible Albian age. Dinoflagellate cysts that indicate brackish water conditions characterize the Albian and early Cenomanian, whereas marine dinoflagellate cysts occur in the latest Cenomanian, and in younger deposits. The dating of the Nuussuaq Group is based mostly on palynology, supported by scarce ammonites. A new, refined palynoevent stratigraphy is established, based on the study of many new and older sections. The new palynoevent stratigraphy allows a better correlation between widely spaced onshore sections and offshore successions, and provides an improved basis for paleogeographical interpretations.