聂拉木县幅地质调查新成果及主要进展

New results and main progress in geologial survey of the Nyalam County Sheet

发现中—晚三叠世鱼龙化石、三叠系和侏罗系珊瑚-海绵生物礁灰岩,识别出白垩系与侏罗系层序不整合界面,查证并获取若干二叠系大陆裂谷型火山岩和早白垩世岛弧型火山岩新的资料。在综合研究地层古生物、层序地层与沉积相、磁性地层、岩浆岩、变质岩、区域构造等资料的基础上,将测区地质发展演化分为:前奥陶纪基底形成、奥陶纪—泥盆纪稳定陆表海、石炭纪—侏罗纪离散型被动大陆边缘、白垩纪—古近纪汇聚型前陆盆地、新近纪—第四纪后造山隆升5个阶段。

During the 1:250000 geological survey of the Nyalam County Sheet, the authors found Mid-Late Triassic ichthyosaurus fossils, Triassic and Jurassic coral-sponge reef limestone, recognized the unconformity between the Cretaceous and Jurassic sequences and checked and obtained new data of Permian continental rift volcanic rocks and Early Cretaceous island-arc volcanic rocks. On the basis of the data of stratigraphy and paleontology, sequence stratigraphy and sedimentary facies, magneto-stratigraphy, magmatic rocks, metamorphic rocks and regional tectonics, the geological evolution in the survey area is divided into five stages: the formation of pre-Ordovician metamorphic basement, Ordovician-Devonian stable epicontinental sea, Carboniferous-Jurassic divergent passive continental margin, Cretaceous-Paleogene convergent foreland basin and Neogene-Quaternary post-orogenic uplift.