摘要：The formation and enrichment mechanisms of organic-rich shales under different marine environments remain unclear. Recently, Cambrian Qiongzhusi (QZS) shales with greater thickness and total organic carbon (TOC) content were found in a deep-water shelf (DWS) than in the adjacent shallow-water shelf (SWS) of the central Sichuan Basin, and these locations provide ideal conditions for determining the mechanisms underlying differ-ences in organic matter (OM) enrichment. In this study, we investigated the TOC, pyrolysis, organic carbon isotopes (delta 13Corg), biomarkers, and elemental geochemistry of the QZS shales. Based on a detailed comparison between shales from the DWS to the SWS, an OM enrichment model of different shelf conditions was established and the reasons for the higher TOC content in the DWS were clarified. The deposition of QZS shales was accompanied by a large-scale regional transgression. Against the background of an overall humid climate, the water mass at the bottom of the DWS was more restricted, resulting in limited external material exchange and supply. The water mass of the DWS represented by the bottom of the QZS was anoxic and showed the devel-opment of euxinic conditions. The biogenic Ba (Babio) content of the samples in the DWS under deep basinal conditions was significantly greater than that in the SWS region, which reflects higher primary productivity and is associated with a large accommodating space and upwelling flows caused by the hydrothermal activities in the DWS. Under conditions in which OM enrichment is dominated by productivity, the DWS is a more favorable location for the formation of high-quality shales.

关键字：Primary productivity; Shales; Hydrothermal activity; Cambrian; Deep-water shelf; Sichuan Basin

ISSN号：1367-9120

卷、期、页：卷: 239

发表日期：2022-11-01

影响因子：3.449400

期刊分区（SCI为中科院分区）：三区

收录情况：SCIE（科学引文索引网络版）,地学领域高质量科技期刊分级目录（国外T2）

发表期刊名称：JOURNAL OF ASIAN EARTH SCIENCES

参与作者：张本健,杨岱林,王云龙

通讯作者：李强,朱联强,朱联强,曹玉顺

第一作者：柳广弟,宋泽章,孙明亮

论文类型：期刊论文

论文概要：李强,柳广弟,宋泽章,张本健,孙明亮,朱联强,杨岱林,王云龙,朱联强,曹玉顺，Organic matter enrichment due to high primary productivity in the deep-water shelf: Insights from the lower Cambrian Qiongzhusi shales of the central Sichuan Basin, SW China，JOURNAL OF ASIAN EARTH SCIENCES，2022，卷: 239

论文题目：Organic matter enrichment due to high primary productivity in the deep-water shelf: Insights from the lower Cambrian Qiongzhusi shales of the central Sichuan Basin, SW China