Lower Cretaceous cold snaps led to widespread glendonite occurrences in the Sverdrup Basin, Canadian High Arctic

Field: Earth and Planetary Sciences (Physical Sciences)

Research Article| July 01, 2017 Lower Cretaceous cold snaps led to widespread glendonite occurrences in the Sverdrup Basin, Canadian High Arctic Stephen E. Grasby; Stephen E. Grasby † 1Department of Geoscience, University of Calgary, 2500 University Drive N.W., Calgary, Alberta T2N 1N4, Canada2Geological Survey of Canada, Natural Resources Canada, 3303 33rd St N.W., Calgary, Alberta T2L 2A7, Canada †steve.grasby@canada.ca Search for other works by this author on: GSW Google Scholar Gennyne E. McCune; Gennyne E. McCune 1Department of Geoscience, University of Calgary, 2500 University Drive N.W., Calgary, Alberta T2N 1N4, Canada Search for other works by this author on: GSW Google Scholar Benoit Beauchamp; Benoit Beauchamp 1Department of Geoscience, University of Calgary, 2500 University Drive N.W., Calgary, Alberta T2N 1N4, Canada Search for other works by this author on: GSW Google Scholar Jennifer M. Galloway Jennifer M. Galloway 2Geological Survey of Canada, Natural Resources Canada, 3303 33rd St N.W., Calgary, Alberta T2L 2A7, Canada Search for other works by this author on: GSW Google Scholar Author and Article Information Stephen E. Grasby † 1Department of Geoscience, University of Calgary, 2500 University Drive N.W., Calgary, Alberta T2N 1N4, Canada2Geological Survey of Canada, Natural Resources Canada, 3303 33rd St N.W., Calgary, Alberta T2L 2A7, Canada Gennyne E. McCune 1Department of Geoscience, University of Calgary, 2500 University Drive N.W., Calgary, Alberta T2N 1N4, Canada Benoit Beauchamp 1Department of Geoscience, University of Calgary, 2500 University Drive N.W., Calgary, Alberta T2N 1N4, Canada Jennifer M. Galloway 2Geological Survey of Canada, Natural Resources Canada, 3303 33rd St N.W., Calgary, Alberta T2L 2A7, Canada †steve.grasby@canada.ca Publisher: Geological Society of America Received: 27 Jun 2016 Revision Received: 07 Nov 2016 Accepted: 22 Dec 2016 First Online: 06 Jul 2017 Online Issn: 1943-2674 Print Issn: 0016-7606 © 2017 Geological Society of America GSA Bulletin (2017) 129 (7-8): 771–787. https://doi.org/10.1130/B31600.1 Article history Received: 27 Jun 2016 Revision Received: 07 Nov 2016 Accepted: 22 Dec 2016 First Online: 06 Jul 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Stephen E. Grasby, Gennyne E. McCune, Benoit Beauchamp, Jennifer M. Galloway; Lower Cretaceous cold snaps led to widespread glendonite occurrences in the Sverdrup Basin, Canadian High Arctic. GSA Bulletin 2017;; 129 (7-8): 771–787. doi: https://doi.org/10.1130/B31600.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGSA Bulletin Search Advanced Search Abstract Dramatic global climate change in the Early Cretaceous suggests that numerous boreal cool events perturbed otherwise warm conditions. Abundant glendonites in Valanginian and Aptian strata are thought to be key markers of cold conditions; however, their use as climate indicators has been questioned. Therefore, a detailed study of glendonites in the context of host-rock geochemistry was conducted on Cretaceous strata exposed on Ellef Ringnes Island, Sverdrup Basin, Canadian High Arctic, to elucidate paleoenvironment controls on periodic glendonite occurrence throughout the Early Cretaceous. Two prominent glendonite zones were identified in Valanginian and Aptian strata. Data for carbon stable isotopes show δ13Ccarb values of –29.5‰ to –10.5‰, consistent with a carbon source from organic matter within the surrounding shale. Trace metal data suggest deposition occurred under an overall oxidizing water column in a setting with higher than average phosphorus and highly degraded organic matter. There is no variation in the geochemical parameters of the mudstones with or without glendonites. Glendonite-bearing zones are coincident, however, with regional evidence for brief periods of colder climate conditions within the otherwise warm Early Cretaceous. We conclude that while the overall conditions for glendonite formation were prevalent throughout the Cretaceous, it was the brief cold periods that provided the final range of stability for their preservation in discrete zones of Valanginian and Aptian strata. These results support the model of an overall warm Early Cretaceous climate being punctuate by several “cold snaps” of as-yet uncertain origin. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.