摘要：The origin of Paleozoic oils in the cratonic Tarim Basin, China, has long been debated, with previous studies attributing most oils to the Cambrian sources. However, the geochemical characteristics and distribution of the Ordovician-sourced oils remain poorly constrained. This study integrates biomarkers, carbon isotopes, and sulfur isotopes to identify the Ordovician-derived oils in the western part of the Shuntuoguole Low Uplift. Two oils (SHB7 and SHB71X) produced from the Ordovician exhibit distinct geochemical signatures, including the absence of aryl isoprenoids, high concentrations of C30 diahopane, elevated Pr/Ph ratios, and low DBT/P ratios, indicative of a clay-rich, suboxic depositional environment. Critically, these oils display significantly lighter bulk δ34S values (4.0‰ and –1.6‰), which closely match those of the Middle-Upper Ordovician kerogen (–6.7‰ to 5.6‰) and are distinctly lower than the Cambrian-sourced oils (15.8‰ to 23.2‰). Individual n -alkanes δ13C compositions further support a different genetic origin compared to the typical Cambrian-derived oils. These findings confirm the existence of a previously unrecognized Ordovician-sourced petroleum system in the basin. The distribution of such oils is likely controlled by migration from the Ordovician source kitchens in the Awati Depression or intra-platform depressions. This study underscores the superiority of sulfur isotopes over conventional biomarkers in resolving complex oil-source correlations in multi-source basins like Tarim. ? 2025 Elsevier Ltd.

ISSN号：0146-6380

卷、期、页：卷210

发表日期：2025-12-01

影响因子：0.000000

期刊分区（SCI为中科院分区）：三区

收录情况：SCI（科学引文索引印刷版）,EI（工程索引）,SCIE（科学引文索引网络版）

发表期刊名称：Organic Geochemistry

参与作者：Wang, Daowei,Yang, Haijun,Cao, Zicheng,Wang, Qinghua,Zhang, Hao,Sun, Peng,Zhao, Weiquan,Wang, Wei,Liang, Zhengzhong,Zhang, Haoyu,Zheng, Qinghua

第一作者：蔡春芳

论文类型：期刊论文

论文概要：Wang, Daowei,蔡春芳,Yang, Haijun,Cao, Zicheng,Wang, Qinghua,Zhang, Hao,Sun, Peng,Zhao, Weiquan,Wang, Wei,Liang, Zhengzhong,Zhang, Haoyu,Zheng, Qinghua，Definitive identification of Ordovician-sourced oils in the Tarim Basin: geochemical constraints from biomarkers and sulfur isotopes，Organic Geochemistry，2025，卷210

论文题目：Definitive identification of Ordovician-sourced oils in the Tarim Basin: geochemical constraints from biomarkers and sulfur isotopes