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研究了广西来宾铁桥剖面栖霞组的黏土矿物组合和地球化学特征的纵向变化特征。黏土矿物分析结果表明,栖霞组上部和下部地层中,黏土矿物含量较高,以伊利石、绿泥石为主,含少量的高岭石和蒙脱石;中部地层中黏土矿物含量较少。在电子显微镜下,有些黏土矿物,如伊利石,发育在草莓状黄铁矿晶体之间,形成于早期成岩作用阶段。整体上黏土矿物成因与陆源碎屑物质输入有关。配套的地球化学分析表明,Al、Fe和Ti质量分数等反映陆源物质的指标,在栖霞组下部和上部质量分数较高,中部明显较低。上述黏土矿物分析和地球化学测试结果意味着该地区二叠纪栖霞期呈现一个明显的陆源碎屑物质输入旋回变化,早期和晚期陆源物质供应较明显,而中期较贫乏,可为该区进一步古地理研究提供重要参考。
The vertical variations of clay mineral assemblages and geochemical characteristics of Qixia Formation in TieBiao, Guangxi Province, are studied. Clay mineral analysis results show that the clay minerals in the upper and lower formations of Qixia Formation are higher, mainly illite and chlorite, with a small amount of kaolinite and montmorillonite; clay minerals in the middle strata are less. Under the electron microscope, some clay minerals, such as illites, develop between the strawberry-like pyrite crystals and form during the early diagenesis. The overall causes of clay minerals are related to the input of terrigenous clastic matter. Supporting geochemical analysis shows that Al, Fe and Ti mass fraction reflect the terrestrial material indicators, the Qixia group lower and upper part of the higher mass fraction, the central part was significantly lower. The above clay mineral analysis and geochemical test results indicate that the Permian Permian Qixia shows a significant cyclonic input change of terrigenous clastic materials. The early and late terrigenous material supplies are more obvious, while the mid-term is poorer, which may be further ancient Geographical research provides an important reference.