四川盆地志留系龙马溪组页岩矿物组成与有机质赋存状态

选择四川盆地长宁县双河镇下志留统龙马溪组新鲜露头剖面，在野外考察的基础上，对30个页岩样品进行光、薄片鉴定、SEM、电子探针、XRD和阴极发光分析，研究龙马溪组页岩岩石学特征、矿物组成、性质和有机质赋存状态的变化特征。分析结果显示，龙马溪组页岩矿物组成为脆性（碎屑）矿物石英、长石、云母和黄铁矿；硅化和碳酸盐化作用成因的隐晶质石英（玉髓）、方解石和白云石；黏土矿物伊利石和绿泥石。划分出岩石中残留固态有机质原位的5种赋存状态，其与矿物性质具有密切关系，碎屑矿物中的解理或裂隙对页岩气的生成和运移有重要的影响，该区在成岩作用过程中可能发生过多期次的油气运移。

Mineral compositions and organic matter occurrence modes of Lower Silurian Longmaxi Formation of Sichuan Basin

In order to study the mineral properties，composition and the relationship with the organic matter characteristics in Lower Silurian Longmaxi Formation shale，30 samples from Longmaxi Formation fresh outcrop cross sections located in Shuanghe Town，Changning County in Sichuan Basin were analyzed by scanning electron microscopy(SEM)，electron probe micro analyzer，X-ray diffraction(XRD) and Cathode luminescence analysis(CL).Form the bottom up to top developed black-dark gray graptolite shale，carbonaceous shale，siliceous shale and silty shale pelitic siltstone.The analysis results show that mineral compositions are brittle(fragment) minerals：quartz，feldspars，mica，pyrite；siliciclastic and calcite minerals：Chalcedony，calcite and dolomite；and clay minerals：Illite，chlorite and montmorillonite.The organic matter occurrence modes have important relationship with the mineral character.The finer fracture in the fragment minerals have huge influence to the produce and travel of the shale gas.