Palynostratigraphy of the Cretaceous–lower Palaeogene sedimentary succession in the Kangerlussuaq Basin, southern East Greenland

Abstract

A new palynological event biostratigraphy for the Cretaceous–lower Palaeogene succession in the Kangerlussuaq Basin, onshore southern East Greenland is presented. Sixty-three biostratigraphical marker events are recognised, based on the first and last occurrences of dinoflagellate cysts and pollen from eleven key outcrop sections through the Sorgenfri, Christian IV, Sediment Bjerge and Vandfaldsdalen Formations of the Kangerdlugssuaq and Blosseville Groups. The palynological events are correlated with published event stratigraphies and with palynological zonations from North–East Greenland, West Greenland, North America, the North Sea and the Faroe–Shetland Basin. The palynological records date the Sorgenfri Formation as middle Albian to Coniacian or ?early Santonian, the Christian IV Formation as ?late Campanian to late Maastrichtian and the Sediment Bjerge Formation as late Danian to late Selandian. The biostratigraphic ranges of dinoflagellate cysts, pollen and macrofossils around the lower to upper Maastrichtian boundary are discussed and correlated.The palynological records and recent isotopic dating results (40Ar/39Ar) of volcanic rocks indicate that the youngest sediments of the Vandfaldsdalen Formation are of Thanetian or early Ypresian age. The study documents two major hiatuses in the area: the boundary between the Sorgenfri and Christian IV Formations spans the ?upper Coniacian–Santonian and Campanian, whilst the unconformity between the Christian IV and Sediment Bjerge Formations possibly spans the uppermost Maastrichtian and the lower Danian, indicating that the Cretaceous–Palaeogene boundary is represented by a major unconformity, as recognised widely around the northern North Atlantic.