【摘要】 为了探讨盐源盆地富有机质页岩形成原因,促进区域页岩气的勘探开发,本文主要通过元素地球化学特征研究了龙马溪组页岩硅质成因及沉积环境。结果表明,研究区龙马溪组黑色岩系富含有机质且硅质含量较高,Al₂O₃与TiO₂呈正相关与SiO2/Al₂O₃呈负相关说明硅质成分具有较多陆源碎屑成因。高含量的过量硅（Si过量）,较低的Mg O含量,Ba、As、Sb、Sc等元素的高度富集、轻稀土富集、正Eu异常、矿物中的放射虫等微生物化石以及斑脱岩的存在说明硅质主要为生物成因,同时受到热水沉积及火山作用的影响。氧化还原敏感性元素V、Ni、U较富集,铈负异常、铕正异常以及草莓状黄铁矿等特征及相关图解一致表明其形成于被动大陆边缘深水陆棚缺氧的还原水体环境,同时受到一定程度的上升洋流或者热水影响,沉积了深海沉积物。生物成因及热水成因（火山成因）的页岩常富含有机质,还原的水体环境有利于有机质的保存,在此沉积环境下,形成的研究区龙马溪组黑色页岩有机质丰度高,类型较好,厚度较大,初步认为具有较好的资源潜力。更多还原

【Abstract】 Objectives: Detailed element geochemical analysis are carried out on black shale of the Longmaxi Formation in the Yanyuan Basin,southwest Sichuan province In order to investigate the formation of enrichment organic matter shale and expand the scope of shale gas around the Sichuan Basin.Methods: Basde on the field work,thruogh the microscope observation, the chemical analysis of main elements,trace elements and rare earth elements of rocks,the organic geochemical analysis such as TOC,Ro of Longmaxi Formation black shale.Results: The study shows that the black shale is rich in organic matter and higher siliceous contents,positive correlation of Al₂O₃ and TiO₂ contents and negative correlated of SiO₂/Al₂O₃ ratios and Al₂O₃ contents show that the siliceous rocks with higher proportion of terrigenous argillaceous deposits. The high contents of Siexc,low contents of Mg O,The elements Ba,As,Sb,and light rare earth enrichment,positive Eu anomaly and microbial fossils in mineral and the presence of bentonite shows that siliceous rocks main causes for biogenic, affected by the hydrothermal sediment and volcanic deposit at the same time. Redox-sensitive elements V,Ni,U are enriched,NASC normalized REE contents of Ce negative anomalies,Eu positive anomalies and strawberry pyrite and some structural background discrimination diagrams show that they are formed in the reduced sedimentary water environment of the passive continental margin,and are affected by a certain degree of rising ocean currents or hot water and deposited the deep-sea sediments at the same time.Conclusions: The biogenic and hydrothermal genesis（ volcanic genesis） silicates are often rich in organic matter,and the reduced water environment is conducive to the preservation of organic matter. Therefore,the study area forming a widely distributed organic matter source rock of Longmaxi Formation and is the favorable development area of shale gas source rock.更多还原