Ediacaran delta C-13 chemostratigraphy of South China

• Published in: Chemical Geology
• Main Authors: Zhou, Chuanming, Mao, Shuhai
• Format: Report
• Language: English
• Published: ELSEVIER SCIENCE BV 2007
• Subjects: carbon isotopes; chemostratigraphy; Neoproterozoic; Ediacaran; South China; PRECAMBRIAN-CAMBRIAN BOUNDARY; NEOPROTEROZOIC DOUSHANTUO FORMATION; SNOWBALL EARTH HYPOTHESIS; EARLY ANIMAL EVOLUTION; YANGTZE PLATFORM; CARBON-ISOTOPE; NORTHWESTERN CANADA; MACKENZIE MOUNTAINS; PROTEROZOIC STRATIGRAPHY; MARINOAN GLACIATION; Geochemistry & Geophysics; Canada; Mackenzie mountains
• Online Access: http://ir.nigpas.ac.cn/handle/332004/19254; https://doi.org/10.1016/j.chemgeo.2006.06.021

We report new delta C-13 chemostratigraphic data of the Ediacaran System in South China. Using litho- and biostratigraphic markers as independent calibrators, we combine new and previously published delta C-13 data to construct a composite delta C-13 profile for the Ediacaran System in South China. The composite curve shows, in chronostratigraphic order, 1) a negative 613 C excursion (EN 1) in the Doushantuo cap carbonate that overlies the Ghaub-age Nantuo diamictite; 2) a pronounced positive delta C-13 excursion (EP 1) in the lower Doushantuo Formation where Doushantuo-type acanthomorphic acritarchs, red algae, and animal embryos first appear; 3) a mild negative delta C-13 excursion (EN2) in the middle Doushantuo Formation; 4) a positive delta C-13 excursion (EP2) in the upper Doushantuo Formation where Doushantuo-type acanthomorphic acritarchs, micrometazoans, and stem group florideophyte red algae become abundant and diverse; 5) a pronounced negative delta C-13 excursion (EN3) near the uppermost Doushantuo Formation; 6) a strongly positive delta C-13 excursion (up to +6.3(parts per thousand) PDB; EP3) in the lower Dengying Formation; 7) a stable delta C-13 plateau (ca. + 2.5 parts per thousand PDB; EI) in the middle and upper Dengying Formation where abundant vendotaenid algae, macroscopic Ediacamn fossils, biomineralized animal tubes, and mostly horizontal animal traces occur; and 8) a -10 parts per thousand negative delta C-13 excursion (EN4) immediately below the Ediacaran-Cambrian boundary. The general pattern of this composite delta C-13 curve is robust, despite a considerable amount of variation among the 613C profiles of different sections. This composite delta C-13 curve provides a first-order chemostratigraphic framework for the subdivision and correlation of the Ediacaran System in South China. (c) 2006 Elsevier B.V. All rights reserved.