An integrated chemostratigraphic (delta C-13-delta O-18_(87)sr/(86)sr_delta N-15) study of the Doushantuo Formation in western Hubei Province, South China
High-resolution isotopic analyses were conducted on core samples from the Ediacaran Doushantuo Formation at the Wangjiapeng section, western Hubei Province in South China, whereby two laterally traceable, negative delta C-13(carb) excursions (EN1 and EN3) were recognized. The magnitude and duration of these excursions permit intra-basinal and inter-basinal correlation, which indicates that they probably represent a global change in seawater composition. The occurrence of decoupled delta C-13(carb)-delta C-13(org) with almost invariable delta C-13(org) values at Wangjiapeng, Zhongling, Yangjiaping sections is consistent with remineralization of a dissolved organic carbon (DOC) pool by means of sulfate reduction, as recorded in EN3. The synchronous presence of EN3, a shift to higher Sr-87/Sr-86 and decrease of Mn and Fe contents and delta N-15 values together points to a glacial influence whereby oxygenation and remineralization of reduced carbon produced C-13-depleted DIC. Glaciations cause a drop in sea level, which itself leads to increased continental shelf area to be exposed to surface weathering, and ultimately to enhanced delivery of radiogenic Sr-87. The increase of Sr-87/Sr-86 ratios, sulfate and phosphate are consequences of surface runoff into oceanic environments and such perturbations induce biogeochemical changes.
1.Chinese Acad Sci, Inst Geol & Geophys, State Key Lab Lithospher Evolut, Beijing 100029, Peoples R China 2.Univ Tokyo, Atmosphere & Ocean Res Inst, Chiba 2778564, Japan 3.UCL, London Ctr Nanotechnol, London WC1E 6BT, England 4.UCL, Dept Earth Sci, London WC1E 6BT, England 5.UCL, Ctr Planetary Sci, London WC1E 6BT, England 6.Univ Tokyo, Dept Earth Sci & Astron, Meguro Ku, 3-8-1 Komaba, Tokyo 1538902, Japan 7.Gakushuin Univ, Fac Sci, Dept Chem, Toshima Ku, Mejiro 1-5, Tokyo 1718588, Japan 8.Japan Agcy Marine Earth Sci & Technol JAMSTEC, Dept Subsurface Geobiol Anal & Res D SUGAR, 2-15 Natsushima Cho, Yokosuka, Kanagawa 2370061, Japan 9.Cent South Inst Met Geol, Yichang 443003, Peoples R China
Recommended Citation:
Lan, Zhongwu,Sano, Yuji,Yahagi, Takuya,et al. An integrated chemostratigraphic (delta C-13-delta O-18_(87)sr/(86)sr_delta N-15) study of the Doushantuo Formation in western Hubei Province, South China[J]. PRECAMBRIAN RESEARCH,2019-01-01,320:232-252