鄂尔多斯盆地西南部及邻区沉积了一套以黄旗口组为代表的巨厚的中元古界碎屑岩系,该套地层具有重要的油气勘探潜力,但目前人们对该套地层的勘探认识尚不够深入,利用碎屑组分、主微量、稀土元素等地球化学手段,结合区域及深部背景特征,探讨了该套地层形成时期的沉积环境和构造背景.结果显示,黄旗口组整体形成于气候干燥的淡水氧化或富氧的过渡环境,沉积期古海水温度较高(平均为32℃);黄旗口组碎屑组分及其主微量元素特征与东非裂谷区相似,加之其沉积于淡水环境,并具有自下段至上段石英砂岩含量逐渐增加的特征,表明研究区黄旗口组应处于陆内裂谷构造背景,自早至晚构造沉积环境日趋稳定,其中早期应为陆内裂谷环境,晚期可能变为坳陷环境,该构造背景的形成可能与华北克拉通逆时针旋转有关. In the southwestern part of Ordos Basin and its adjacent area, a huge Paleoproterozoic clastic rock series represented by Huangqikou Formation was deposited, which has important potential for oil and gas exploration. At present, however, But not deep enough, the sedimentary environment and tectonic setting of this set of strata were discussed by means of geochemical means such as detrital component, main trace and rare earth element, combined with the regional and deep background characteristics.The results show that Huangqikou Formation Paleoclimate, dry climate of freshwater oxidation or oxygen-rich transitional period, ancient seawater temperature during depositional period is relatively high (average is 32 ℃); the features of clastic components and their major and trace elements in Huangqikou Formation are similar to those in the East African Rift Valley, Fresh water environment and the gradual increase of the content of quartz sandstone from the lower section to the upper section, indicating that the Huangqikou Formation in the study area should be in the intracontinental rift tectonic setting. The tectonic-depositional environment has been steadily stabilized from early to late, of which the early intracontinental rift Environment and later may become a depression environment. The formation of this tectonic setting may be related to the anticlockwise rotation of North China craton.