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A paleoclimatic and paleoatmospheric record from peatlands accumulating during the Cretaceous-Paleogene boundary event, Western Interior Basin, Canada

2015; Geological Society of America; Volume: 127; Issue: 11-12 Linguagem: Inglês

10.1130/b31166.1

1943-2674

Rhodri Jerrett, Gregory D. Price, Stephen T. Grimes, Alex T. Dawson,

Coastal wetland ecosystem dynamics

Research Article| November 01, 2015 A paleoclimatic and paleoatmospheric record from peatlands accumulating during the Cretaceous-Paleogene boundary event, Western Interior Basin, Canada Rhodri M. Jerrett; Rhodri M. Jerrett † 1School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK †E-mail: rhodri.jerrett@manchester.ac.uk Search for other works by this author on: GSW Google Scholar Gregory D. Price; Gregory D. Price 2Centre for Research in Earth Sciences, School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK Search for other works by this author on: GSW Google Scholar Stephen T. Grimes; Stephen T. Grimes 2Centre for Research in Earth Sciences, School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK Search for other works by this author on: GSW Google Scholar Alex T. Dawson Alex T. Dawson 2Centre for Research in Earth Sciences, School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK Search for other works by this author on: GSW Google Scholar Author and Article Information Rhodri M. Jerrett † 1School of Earth, Atmospheric and Environmental Sciences, University of Manchester, Oxford Road, Manchester M13 9PL, UK Gregory D. Price 2Centre for Research in Earth Sciences, School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK Stephen T. Grimes 2Centre for Research in Earth Sciences, School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK Alex T. Dawson 2Centre for Research in Earth Sciences, School of Geography, Earth and Environmental Sciences, Plymouth University, Drake Circus, Plymouth, PL4 8AA, UK †E-mail: rhodri.jerrett@manchester.ac.uk Publisher: Geological Society of America Received: 17 Jul 2014 Revision Received: 20 Feb 2015 Accepted: 30 Mar 2015 First Online: 08 Mar 2017 Online ISSN: 1943-2674 Print ISSN: 0016-7606 © 2015 Geological Society of America GSA Bulletin (2015) 127 (11-12): 1564–1582. https://doi.org/10.1130/B31166.1 Article history Received: 17 Jul 2014 Revision Received: 20 Feb 2015 Accepted: 30 Mar 2015 First Online: 08 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Rhodri M. Jerrett, Gregory D. Price, Stephen T. Grimes, Alex T. Dawson; A paleoclimatic and paleoatmospheric record from peatlands accumulating during the Cretaceous-Paleogene boundary event, Western Interior Basin, Canada. GSA Bulletin 2015;; 127 (11-12): 1564–1582. doi: https://doi.org/10.1130/B31166.1 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 Petrological and δ13C analyses were undertaken on contiguous specimens of coal and intercalated minor organic-rich clastic sediments collected from coal seams spanning the Cretaceous-Paleogene boundary in the Alberta and Saskatchewan portions of the Western Interior Basin. The generally high smectite content of the coal suggests that the original mires were largely small, disconnected, and rheotrophic, readily receiving abundant waterborne detrital clastic material of largely volcanic origin. Nevertheless, using the distinctive claystone that marks the Cretaceous-Paleogene boundary as a regional datum, it is possible to correlate cycles in the vitrinite and inertinite composition of the coals over >500 km. Estimates of peat accumulation rates suggest that the cycles in vitrinite and inertinite composition represent regional, cyclic fluctuations in wildfire and oxidation of the peatlands and overlying canopy at a frequency of hundreds to thousands of years. The likely causes of these fluctuations were cyclic, regional-scale changes in temperature. The Cretaceous-Paleogene boundary event occurred early during a phase of gradually increasing temperature and/or decreasing rainfall, but peak wildfire and desiccation of peat occurred up to 14,000 yr later than the Cretaceous-Paleogene boundary, and the mires did not experience significant water stress in the immediate aftermath of the extinction event. A persistent, 1.5‰–3.0‰ negative δ13C excursion occurs across the Cretaceous-Paleogene boundary, but it cannot be readily separated from four, further negative excursions later in the earliest Danian. The negative carbon isotope excursion linked to the Cretaceous-Paleogene boundary began a few hundred years before the event itself, and recovery occurred within 21 k.y., and possibly in as little as just a few thousand years, consistent with recently calibrated shallow-marine δ13C records. Hence, the atmospheric and surface ocean carbon pools were coupled at this time. The absence of evidence for catastrophic change in the climatic regime at the time of the Cretaceous-Paleogene extinction in these mires supports the notion that the negative shift in atmospheric δ13C was brought about by changes in the δ13C composition of the surface ocean. This is consistent with the greater magnitude of extinction experienced by marine fauna relative to the terrestrial realm. 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