Research Article| September 01, 2009 Major perturbation in sulfur cycling at the Triassic-Jurassic boundary Kenneth H. Williford; Kenneth H. Williford 1University of Washington, Seattle, Washington 98195, USA *Current address: Curtin University of Technology, Perth, Australia; E-mail: k.williford@curtin.edu.au. Search for other works by this author on: GSW Google Scholar Julien Foriel; Julien Foriel 1University of Washington, Seattle, Washington 98195, USA Search for other works by this author on: GSW Google Scholar Peter D. Ward; Peter D. Ward 1University of Washington, Seattle, Washington 98195, USA Search for other works by this author on: GSW Google Scholar Eric J. Steig Eric J. Steig 1University of Washington, Seattle, Washington 98195, USA Search for other works by this author on: GSW Google Scholar Geology (2009) 37 (9): 835–838. https://doi.org/10.1130/G30054A.1 Article history received: 21 Jan 2009 rev-recd: 09 Apr 2009 accepted: 28 Apr 2009 first online: 02 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 Kenneth H. Williford, Julien Foriel, Peter D. Ward, Eric J. Steig; Major perturbation in sulfur cycling at the Triassic-Jurassic boundary. Geology 2009;; 37 (9): 835–838. doi: https://doi.org/10.1130/G30054A.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 SocietyGeology Search Advanced Search Abstract Stable sulfur isotopes from the reduced sulfur fraction of Late Triassic–Early Jurassic marine sediments at Kennecott Point in British Columbia, Canada, show evidence for a major perturbation in sulfur cycling coincident with a major carbon cycle perturbation in the wake of a mass extinction event at the Triassic-Jurassic boundary. The δ34S of reduced sulfur shifts from values consistent with open system bacterial sulfate reduction (−30‰) to values higher than any previously reported for Early Jurassic sulfates (20‰) and consistent with complete utilization of sulfate and Rayleigh fractionation in a closed system. We suggest that this isotopic shift was initiated by declining seawater sulfate concentration due to evaporite deposition in nascent Atlantic rift zones and enhanced by a local mechanism, such as a decoupling of the zone of sulfate reduction from the sulfate supply due to a catastrophic increase in the flux of land-derived sediments reaching the sea in the wake of massive terrestrial plant die-off during the Triassic–Jurassic mass extinction. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.