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In order to improve the understanding of how the high northern latitudes responded to the escalating warming which led to the middle Cretaceous super greenhouse climate, more temperature proxy records from the High Arctic are needed. One of the current obstacles in obtaining such records is poor age control on the Lower Cretaceous strata in the Boreal region. Here, we provide a biostratigraphic framework for the Rurikfjellet and Helvetiafjellet formations representing the lower part of the Lower Cretaceous succession on Spitsbergen. We also attempt to date the boundary between the Agardhfjellet and the Rurikfjellet formations. This study is based on dinoflagellate cysts (dinocysts) from three onshore cores (DH1, DH2 and DH5R) and three outcrop sections (Bohemanflya, Myklegardfjellet and Ullaberget). Relatively abundant and well-preserved dinocyst assemblages from the Rurikfjellet Formation date this unit as early Valanginian – early Barremian. The dinocyst assemblages from the Helvetiafjellet Formation are significantly impoverished and are characterized by reworking, but collectively indicate a Barremian–Aptian age for this formation. [ABSTRACT FROM AUTHOR]

New palynological analysis of samples from 13 offshore wells on the Canadian Margin and six wells on the West Greenland Margin has led to a new event biostratigraphic framework for Cretaceous-Cenozoic strata of the Labrador Sea - Davis Strait - Baffin Bay (Labrador-Baffin Seaway) region. This framework is based on about 150 dinoflagellate cyst taxa and 30 acritarch, algal, fungal and plant microfossil (mostly miospore) taxa. In the systematics we include three new genera of dinocysts (Scalenodinium, Simplicidinium and Taurodinium), 16 new species of dinocysts (Chirop - teridium gilbertii, Chytroeisphaeridia hadra, Cleistosphaeridium elegantulum, Cleistosphaeridium palmatum, Dapsilidinium pseudoinsertum, De flan drea borealis, Evittosphaerula? foraminosa, Gingi - nodinium? flexidentatum, Hystrichosphaeridium quadratum, Hystrichostrogylon digitus, Impletosphaeridium apodastum, Scalenodinium scalenum, Surculosphaeridium convocatum, Talladinium pellis, Taurodinium granulatum and Trithyrodinium? conservatum), four emendations of dinocyst genera (Alterbidinium, Chatangiella, Chiropteridium and Surculosphaeridium), six new combinations for dinocyst species (Alterbidinium biaperturum, Deflandrea majae, Kleithriasphaeridium mantellii, Simplicidinium insolitum, Spongodinium grossum, Spongodinium obscurum), one new acritarch species (Fromea quadrangularis), one new miospore species (Baculatisporites crenulatus) and one new combination for miospores (Tiliaepollenites crassipites). Most of the taxa included provide age information, almost exclusively last occurrences (range 'tops'), but some are useful mainly for environmental interpretations. Collectively, they provide a powerful tool for helping to establish the geological history of the Labrador-Baffin Seaway. [ABSTRACT FROM AUTHOR]

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. [Copyright &y& Elsevier]