鄂尔多斯盆地北部早白垩世地层特征及对比

鄂尔多斯盆地北部早白垩世地层是一套从冲积扇到河流相、三角洲相直至湖泊相多相型空间递变的陆相地层 ,具克拉通盆地转为伸展断陷盆地特征。盆地北部早白垩世具 2个三级层序 ,分别控制了具不同动力学背景的2套沉积旋回。盆地的东部原伊金霍洛组、盆地西部的志丹群洛河组、环河组为下部沉积旋回 ,受盆地东部隆起影响 ,以北东向和近南北向断裂带控制的断块活动为主 ;盆地的东部原东胜组、盆地西部的罗汉洞组、泾川组为上部沉积旋回 ,受盆地北部隆起影响 ,以东西向断裂带控制的断块活动为主。

CHARACTERISTICS AND CORRELATION OF THE EARLY CRETACEOUS STRATA IN THE NORTHERN ORDOS BASIN

The Early Cretaceous Strata in the north of the Ordos Basin consist of the continental facies of sequence ranging from alluvial fluvial,delta to lacustrine and are characterized by the cratonic basin changing into extending fault basin.There are two third-level sequences,controlling respectively two sets of depositional cycles of varying dynamic setting. The former Yijinhuoluo Formation in the east of the basin,and the Luohe and Huanhe Formations of the Zhidan Group in the west of the basin belong to the lower depositional cycle and were influenced by the uplift of the eastern basin.The black activity was dominated by the control of the NE-and nearly NS-tredning fault zones.The former Dongsheng Formation in the east of the basin and the Luobandong and Jingchuan Formation in the east of the basin belong to the upper depositional cycle and were influenced by the uplift of the northern basin and dominated by the black activity controlled by the east-west fault zone.