Geochemical evidence for a catastrophic biotic event at the Frasnian/Famennian boundary in south China

Research Article| August 01, 1991 Geochemical evidence for a catastrophic biotic event at the Frasnian/Famennian boundary in south China Kun Wang; Kun Wang 1Department of Geology, University of Alberta, Edmonton, Alberta T6G 2E3, Canada Search for other works by this author on: GSW Google Scholar Charles J. Orth; Charles J. Orth 2Los Alamos National Laboratory, Los Alamos, New Mexico 87545 Search for other works by this author on: GSW Google Scholar Moses Attrep, Jr.; Moses Attrep, Jr. 2Los Alamos National Laboratory, Los Alamos, New Mexico 87545 Search for other works by this author on: GSW Google Scholar Brian D. E. Chatterton; Brian D. E. Chatterton 1Department of Geology, University of Alberta, Edmonton, Alberta T6G 2E3, Canada Search for other works by this author on: GSW Google Scholar Hongfei Hou; Hongfei Hou 3Institute of Geology, Chinese Academy of Geological Sciences, Beijing, China Search for other works by this author on: GSW Google Scholar Helmut H.J. Geldsetzer Helmut H.J. Geldsetzer 4Geological Survey of Canada, 3303 33rd Street NW, Calgary, Alberta T2L 2A7, Canada Search for other works by this author on: GSW Google Scholar Geology (1991) 19 (8): 776–779. https://doi.org/10.1130/0091-7613(1991)019<0776:GEFACB>2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Kun Wang, Charles J. Orth, Moses Attrep, Brian D. E. Chatterton, Hongfei Hou, Helmut H.J. Geldsetzer; Geochemical evidence for a catastrophic biotic event at the Frasnian/Famennian boundary in south China. Geology 1991;; 19 (8): 776–779. doi: https://doi.org/10.1130/0091-7613(1991)019<0776:GEFACB>2.3.CO;2 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 A strong δ13C anomaly coincides with a weak Ir anomaly at the Frasnian/Famennian (F/F) boundary exposed at Xiangtian, Guangxi, south China. The maximum whole-rock Ir abundance is 0.23 ppb (0.35 ppb on a carbonate-free basis) compared with averages of 0.016 and 0.044 ppb above and below the boundary interval. The δ13C in carbonate abruptly shifts from a late Frasnian level of about +1‰ to -2.49‰in the boundary interval and then abruptly returns to pre-boundary levels, suggesting a temporary reduction of surface-water biomass. A widely distributed (over at least several hundred kilometres) limestone breccia unit of possible wave-deposit origin is present directly below the boundary in south China. Enrichments of Al, V, Cr, As, and U, and a dip in the Mn abundance in the boundary interval indicate that reducing conditions might have been associated with the element enrichment. However, an alternative hypothesis is that oceanic impact(s) at the F/F boundary near south China provided the excess Ir and caused the biotic crisis and the formation of breccia deposits observed in the Late Devonian South China Sea. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.