Publication Date:
2015-04-25
Description:
Over the past decades, much research has focused on the mid-Cretaceous greenhouse climate, the formation of widespread organic-rich black shales, and cooling intervals from low- to mid-latitude sections. Data from the High Arctic, however, are limited. In this paper, we present high-resolution geochemical records for an ~1.8-km-thick sedimentary succession exposed on Axel Heiberg Island in the Canadian Arctic Archipelago at a paleolatitude of ~71°N. For the first time, we have data constraints for the timing and magnitude of most major Oceanic Anoxic Events (OAEs) in brackish-water (OAE1a) and shelf (OAE1b and OAE2) settings in the mid-Cretaceous High Arctic. These are consistent with carbon-climate perturbations reported from deep-water records of lower latitudes. Glendonite beds are observed in the upper Aptian to lower Albian, covering an interval of ~6 m.y. between 118 and 112 Ma. Although the formation of glendonites is still under discussion, these well-dated occurrences may support the existence of cool shelf waters in the High Arctic Sverdrup Basin at this time, coeval with recent geochemical data from the subtropical Atlantic indicating a drop in sea-surface temperature of nearly 4 °C.
Print ISSN:
0091-7613
Electronic ISSN:
1943-2682
Topics:
Geosciences
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