湘中涟源地区下石炭统天鹅坪组-陡岭坳组沉积环境与有机质富集机理

湘中涟源地区下石炭统天鹅坪组-陡岭坳组是华南地区海相页岩气勘查新层系之一。为了探讨湘中涟源地区下石炭统天鹅坪组-陡岭坳组钙质页岩沉积环境与有机质富集机理，本文对该套页岩开展了有机碳含量、主量元素、微量元素与稀土元素等含量测试和地球化学特征分析。结果表明：V/(V+Ni)、Cu/Zn均指示天鹅坪组-陡岭坳组页岩发育于贫氧环境，生源Ba含量显示天鹅坪组-陡岭坳组沉积时期海水生产力水平较低，Al-Co-Mn反映了水体滞留程度呈现出季节性变化。对比气候、海平面变化趋势，发现古生产力、陆源碎屑物质输送、水体滞留程度受到气候波动驱使海平面变化的影响。综合对比沉积环境指标与TOC相关关系发现：陆源碎屑含量变化是天鹅坪组-陡岭坳组页岩有机质富集的主要控制因素。

Sedimentary Environment and Organic Matter Enrichment Mechanism from the Lower Carboniferous Tianeping Formation-Doulingao Formations in Lianyuan area,central Hunan Province

The Lower Carboniferous Tianeping-Doulingao Formation in Lianyuan, central Hunan Province, is one of the new shale gas exploration target beds in South China. In order to discuss the organic matter enrichment mechanism and the sedimentary environment of the calcareous shale rocks in the Tianeping-Doulingao Formation, the total carbon content, major and trace elements contents, as well as rare earth elements of calcareous shale samples have been analyzed systematically. Based on the results of the ratio of V/(V+Ni) and Cu/Zn, the Tianeping-Doulingao shale has been deposited in a poor-oxygen environment. The Babio content suggested a lower paleo-productivity level. The Al-Co-Mn data reflected that the degree of water retention showed seasonal changes. Comparing the climate and the sea level trends, it is suggested that the paleo-productivity, terrigenous detrital transport and water retention have been affected by the sea level changes driven by climate fluctuations. The correlation of TOC and sedimentary environment index also indicates that the terrigenous detrital input has been a major controlling factor for Tianeping-Doulingao shale organic matter enrichment.