东北地区晚二叠世岩相古地理研究

利用野外地质剖面、钻井剖面和区域地质资料,在地层划分对比和构造格局研究基础上,运用沉积相分析的方法,系统分析了东北地区晚二叠世岩相古地理特征,将晚二叠世分为吴家坪期、长兴期两个编图单元进行岩相古地理编图,恢复了东北地区晚二叠世的岩相古地理面貌。研究表明,晚二叠世经历了卡匹敦期的快速海退后,到吴家坪期晚期古亚洲洋完全闭合,随后全区进入了陆相碎屑岩沉积阶段,主要发育湖泊沉积体系和河流沉积体系,其次为扇三角洲沉积体系。长兴期延续了吴家坪期的特征,整体演化为陆相沉积,主要发育湖泊沉积体系,漠河陆及佳木斯古陆仍然存在。

Lithofacies Palaeogeography of Late Permian in Northeast China

Based on the study of field geological profile, the key data of drilling profile and regional geology, the Late Permian was divided into Wujiaping period and Changxing period for the lithofacies and paleogeography mapping, and the Late Permian lithofacies and paleogeography of Northeast China were also restored. The study shows that af ter the rapid sea withdrawal in Kapidun period,the closure of the Paleo Asian Ocean get completed in Wujiaping pe- riod,with the whole region entering continental clastic sedimentary stage. There were some brackish water deposi- tions mixed by residual seawater and freshwater in some places after the evacuation in Permian. There developed mainly lacustrine depositional system, fluvial sedimentary system followed by fan delta sedimentary system. The characteristics of Wujiaping period was inherited by Changxing period and the continental deposit mainly developed lacustrine depositional system, Mohe and Jiamusi ancient lands still existed .