ARCUS | Arctic Research Consortium of the United States

7th Annual ARCUS Award for Arctic Research Excellence


Submitted by   Peter C. Lippert
Authors   Peter Lippert and J. A. Tarduno
Category   Physical Science
Title   Early Cretaceous Climate Perturbations: A View from the Arctic
Affiliation   Earth and Environmental Sciences, University of Rochester, Rochester, NY, USA

Abstract

The Sverdrup Basin of the high Canadian Arctic contains a record of climatically-sensitive Early Cretaceous sediments. In particular, these sediments contain glendonites, calcite pseudomorphs of the metastable mineral ikaite, which are thought to signify cold climate conditions. The duration of cooling, however, has been unknown. The temporal relationship of the glendonites to other Early Cretaceous global events has also been unconstrained. We report biostratigraphic and magnetostratigraphic data from Ellesmere Island that suggest the glendonites represent relatively short (100-400 kyr) events during the Valanginian (~134 Ma). Moreover, these cooling events appear to be contemporaneous with the onset of the ∂13C carbon isotope excursion that marks the Valanginian oceanic anoxic event. Thus, there appear to be short-term reversals (cooling) of climate in what is otherwise recognized as the start of Cretaceous greenhouse conditions.