PP41A-1335:
Furongian Stable Carbon Isotope Excursions (SPICE and HERB) in the Mixed Carbonate-Siliclastics on an Epeiric Platform of the Taebaeksan Basin, Korea
Thursday, 18 December 2014
Gong S Chung1, Jong N Lim1, Tae-Yoon Park2, Kwang-Sik Lee3, Byung-Su Lee4 and Kwang-Soo Seo5, (1)Chungnam National University, Geology and Earth Environmental Sciences, Daejeon, South Korea, (2)KOPRI Korea Polar Research Institute, Earth-System Sciences, Incheon, South Korea, (3)Korea Basic Science Inst, Cheongwon, South Korea, (4)Chonbuk National University, Earth Science Education, Jeonju, South Korea, (5)Kongju National University, Geoenvironmental Science, Gongju, South Korea
Abstract:
Stable carbon isotope stratigraphy of the Late Cambrian mixed carbonate-siliciclastics from an epeiric platform allows a good stratigraphic marker and interpretation of paleoenvironmental conditions. The SPICE (Steptoean positive carbon excursion) and HERB (Hellnmaria-Red Tops Boundary) events are distinctly developed in the Furongian (Late Cambrian) of mixed carbonate-siliciclastics (Sesong and Hwajeol Formations) deposited on an epeiric platform of the Taebaeksan Basin, Korea, part of the North China Platform. The SPICE event occurs in the Prochuangia mansuyi zone and in the lower part of Chuangia zone of trilobite in the Sesong Formation with the δ13C values ranging from 1.1 to 1.8‰; it occurs in the stratigraphic interval mostly composed of nodular shale, massive to laminated fine sandstone with intercalation of limestone conglomerate beds which is interpreted to have been deposited in the inner to middle ramp. The HERB event begins at about the Eoconodontus notchpeakensis FAD of conodont and ends in the lower part of the range of E. notchpeakensis in the Hwajeol Formation. The HERB event shows negative δ13C values up to -5.5‰ forming a conspicuous and distinctive peak. The HERB event occurs in the stratigraphic interval mostly composed of nodular shale, limestone-shale couplet, and limestone conglomerate which is interpreted to have been deposited in the middle ramp. The onset of HERB event at the E. notchpeakensis FAD in the Taebaeksan basin, Korea suggests that the HERB event may be an excellent tool for intercontinental correlation defining the base of the terminal Cambrian (Stage 10). The paleoenvironmental conditions of the SPICE and HERB events seem to be contrary to each other; the SPICE event may be caused by the high rate of primary production and the high rate burial of organic matter with probable association of the high rate of input of terrigenous sediments. In contrast, the HERB event may be caused by the low rate of primary productivity, the reduced burial of organic matter, and the high rate of oxidation of organic matter.
