The Ordos basin and its adjacent areas were in an extensional tectonic setting in the Mesoproterozoic when the ultra-thick marine Jixian system was deposited in the study area.

• 摘要鄂尔多斯盆地及邻区中元古代整体处于地壳伸展的构造背景，沉积了巨厚的中元古界蓟县系海相地层。