Ordovician carbon isotope stratigraphy of China: A synthesis

Li, Chao; Zhang, Yuandong

Abstract

In this paper we review the published carbon isotope records (δ13Ccarb) of the Ordovician System from Chinese terranes, principally South China, North China, Tarim and Xizang (Tibet). All the δ13Ccarb values from a number of sections in each terrane and published by different authors are calibrated to integrated graptolite and conodont biostratigraphic zones, and are correlated with each other. The δ13Ccarb curves for each block or terrane are interpreted by referring to the specific geological backgrounds and are discussed with their implications. The composite curve of δ13Ccarb from Tarim agrees well with the global composite curve, but with a significantly prolonged GICE and a lack of data for the late Katian and Hirnantian. In South China, where the published δ13Ccarb values of different facies are reviewed separately, the results show that the composite curves of three facies are generally well correlated, especially for the Tremadocian and early Floian. The MDICE excursions are not convincingly confirmed in the Middle Yangtze Platform and the Jiangnan Slope, suggesting the likely presence of hiatuses within a succession of uniform facies, or that the excursions were missed due to inadequate sampling, a common problem for condensed sections. The GICE excursions have been recognized in all the facies, but show a significant prolongation relative to that in the United States. The HICE can be steadily identified in the Upper and Middle Yangtze Platform, but is distinguished by overall low values of δ13Ccarb, ca. 5‰ lower than Baltoscandia and Anticosti Island, suggesting the likelihood of missing peaks due to tectonic disturbances.

Citation

Li, C., & Zhang, Y. (2020). Ordovician carbon isotope stratigraphy of China: A synthesis. In M. Montenari (Ed.), Stratigraphy & Timescales (353-386). Elsevier. https://doi.org/10.1016/bs.sats.2020.08.010

• Online Publication Date: Oct 17, 2020
• Publication Date: 2020
• Deposit Date: Jun 6, 2023
• Publisher: Elsevier
• Pages: 353-386
• Series Title: Carbon Isotope Stratigraphy
• Series ISSN: 2468-5178
• Book Title: Stratigraphy & Timescales
• Chapter Number: 7
• ISBN: 978-0-12-820991-2
• DOI: https://doi.org/10.1016/bs.sats.2020.08.010