摘要
北祁连—酒西地区早白垩世沉积盆地(群)充填物、古流向和沉积环境等方面的调查研究认为:早白垩世在拉张—伸展的背景下形成了南抵中祁连山,北至北山地区,东达酒东盆地,西到阿尔金断裂带以西的泛北祁连—酒西盆地。盆地充填物表现出粗—细—粗的完整沉积旋回,古地理环境经历了冲积扇—河流—湖泊—河流的演变过程,并对应着湖盆从初始扩张—加剧扩张—最大扩张—萎缩消亡的完整过程。另外,盆地南侧的昌马—旱峡—红柳峡地区在下沟—中沟沉积时期为沉积沉降中心,这可能跟阿尔金断裂带在早白垩世中—晚期的走滑活动有关,并致使泛北祁连—酒西盆地的范围和深度达到最大。
Researches on the sediments,paleocurrents and depositional environments of the Early Cretaceous in northern Qilian-Jiuxi areas show that an extensive basin（Northern Qinlian-Jiuquan Lake）,covering areas from the mid-Qinlian Mountains in the south to the Beishan in the north and from the western Altyn Fault to Jiudong in the east,existed in the Early Cretaceous.Current study indicates that the Northern Qinlian-Jiuquan Lake was involved in a sedimentary and palaeogeographical evolutionary history in succession,i.e.,from initial alluvial fan,and then fluvial,followed by lacustrine and fluvial environment finally.Depositional succession consisting of sediments in a varied grain size from coarser,fine to coarser vertically was a result of the initial,increasing and maximum extension of the Northern Qinlian-Jiuquan Lake.In addition,research suggests that Changma,Hanxia and Hongliuxia areas of the southern basin became the centers of subsidence and deposition resulting from strike-slip of Altyn Fault in the Early Cretaceous,and furthermore the basin extended to the maximum in space as a result.
出处
《地学前缘》
EI
CAS
CSCD
北大核心
2011年第4期77-87,共11页
Earth Science Frontiers
基金
国家自然科学基金项目(90914003)
中国地质调查局项目(1212011085477)
中国地质科学院地质研究所中央公益性基本业务费专项基金项目(J1106)
关键词
早白垩世
沉积特征
古地理
北祁连—酒西盆地
Early Cretaceous
sedimentary characteristics
paleogeography
northern Qilian-Jiuxi Basin
