摘要: |
湖北京山大隆组出露甚好,根据沉积特征,该组为一套海退序列的沉积,其下部沉积环境为外陆棚沉积,上部沉积环境为内陆棚沉积。由于外陆棚紧靠大陆坡,极易发育上升洋流。处于这样的海退时期,带来了生物群的更新,由早期的放射虫变为大量藻孢子,无疑为高有机质、高生产力来源打下了良好的基础,极有利于京山大隆组广阔范围内优质、优良质烃源岩的发育。 |
关键词: 微体生物群 沉积特征 海退 烃源岩 大隆组 湖北京山 |
DOI: |
附件 |
投稿时间:2015-05-05修订日期:2015-07-10 |
基金项目:国家自然科学基金(40839903)资助 |
|
Sedimentary characteristics and their bearings to the source rocks in the Dalong Formation, Jingshan region, Hubei |
CHEN Bin, XIAO Ming-yuan, WU Li-yun, CAI Xiong-fei |
(1. Faculty of Earth Sciences, China University of Geosciences, Wuhan 430074, Hubei, China; 2. Institute of Geophysics and Geomatics, China University of Geosciences, Wuhan 430074, Hubei, China; 3. Key Laboratory of Biogeology and Environmental Geology under the Ministry of Education, China University of Geosciences, Wuhan 430074, Hubei, China) |
Abstract: |
The Dalong Formation crops out very well as a succession of regressive deposits in the Jingshan region, Hubei. The Formation may be divided, according to sedimentary characteristics, into the outer shelf deposits in the lower part and inner shelf deposits in the upper part. Due to slow regression, the shallow-water organisms especially algae appear massively in the upper part of the Dalong Formation, where the organic matter contents are much higher in the upper part than in the lower part. The frequently upwelling oceanic currents close to the continental slope brought about not only abundant algal spores, a source of high organic matter contents and high productivity, but also more nutrients from the bottom to the surficial waters for the variability of the organisms. The factors cited above are interpreted to be favourable for the formation of the excellent source rocks in the Dalong Formation. |
Key words: microbiota sedimentary characteristics regression source rock Dalong Formation Jingshan in Hubei |