神木—双山地区太原组桥头砂岩沉积特征及演化

在对砂岩的岩石学、粒度分析、地球化学、沉积构造、垂向层序、测井曲线及沉积体系展布等资料分析的基础上,研究了鄂尔多斯盆地神木-双山地区太原组桥头砂岩沉积特征,探讨了砂体沉积演化过程,建立了桥头砂岩沉积模式。桥头砂岩形成于相对海平面下降时期的辫状河-浅水三角洲沉积体系,陆源碎屑物质被河流不断向南搬运充填入盆地中,形成辫状河、浅水三角洲、障壁砂坝-潟湖-潮坪、陆表浅海在空间上共存的岩相古地理格局。

Sedimentary Characteristics and Evolution of Qiaotou Sandstone,Taiyuan Formation in Shenmu-Shuangshan Area,Ordos Basin

Based on the analyses of sandstone petrology,grain size,geochemistry sedimentary structure,vertical sequence,well logging traces and distribution of sedimentary systems,the sedimentary characters of the Qiaotou Sandstone in Taiyuan Formation in the Shenmu-Shuangshan area are systematically studied,and the sedimentary model is established,the evolutionary process of sand sediments is discussed.The Qiaotou Sandstone is a deposit of braided river-shallow water delta depositional system during a relatively lowstand period.Continental-source clastic is persistently carried to the south basin by river.The lithofacies and palaeogeographic pattern is combined river,shallow water delta,barrier bar-lagoon-tidal flat and epicontinental sea.