Paper No. 7
Presentation Time: 2:30 PM

CHEMOSTRATIGRAPHY OF THE FURONGIAN (UPPER CAMBRIAN) DEPOSITS OF THE SINO-KOREAN CRATON: INSIGHTS ON GLOBAL CORRELATION AND TRILOBITE EXTINCTIONS


MCKENZIE, N. Ryan1, GILL, Benjamin C.2, CHEN, Jitao3, PARK, Tae-yoon4, MYROW, Paul M.5, WOO, Jusun4, HUGHES, Nigel C.6 and CHOI, Duck K.7, (1)Department of Geological Sciences, University of Texas at Austin, Austin, TX 78752, (2)Department of Geosciences, Virginia Polytechnic Institute & State University, Blacksburg, VA 24061, (3)Nanjing Institute of Geology and Paleontology, Chinese Academy of Sciences, 39 E Beijing Road, Nanjing, 210008, China, (4)Division of Polar Earth-System Sciences, Korea Polar Research Institute, Incheon, 406-840, South Korea, (5)Department of Geology, Colorado College, Colorado Springs, CO 80903, (6)Department of Earth Sciences, University of California, Riverside, CA 92521, (7)School of Earth and Environmental Sciences, Seoul National University, San 56-1, Sillim-dong, Gwanak-gu, Seoul, 151-742, South Korea, rmckenzie@jsg.utexas.edu

We report a compilation of biostratigraphic data paired with new high-resolution carbonate carbon isotope data from middle to upper Cambrian strata of the Sino-Korean Craton. Within the compilation of trilobite biostratigraphy three Furongian extinction events are recognized, in stratigraphic order, between the Neodrepanura and Chuangia biozones, the Chuangia and Changsahnia/Irvingella biozones, and the Kaolishania and Asioptychaspis/Tsinania biozones. These extinctions appear to be correlative to three extinction events recorded on the Laurentia paleocontinent. The Neodrepanura extinction has been previously correlated with the global end-Marjumid extinction that occurs at the Cambrian Series 3–Furongian boundary at the onset of the Stepteoan Positive Carbon Isotope Excursion (SPICE). The Chuangia extinction is broadly correlative with the end-Steptoean extinction. The Kaolishania extinction is broadly correlative with the end-Sunwaptan extinction and occurs at the onset of a +2‰ δ13C excursion, which is also present in Laurentia. Until now the Steptoean and Sunwaptan extinctions have only been identified in Laurentia and the presence of correlative extinction events on the Sino-Korean Craton suggests they were global in magnitude. Furthermore, the onset of positive δ13C excursions at the Neodrepanura and Kaolishania extinctions suggest a common driver for these events, and the isotope data are consistent with models that postulate episodes of increased oceanic anoxia may have served as the ‘kill-mechanisms’ for these extinctions.