Mesozoic Sedimentary-tectonic Evolution And Its Late Reformation In Ningwu-Jingle Basin

Ningwu jingle basin is located in the geographical position and special tectonic: the intraplate orogenic belt in Taihang Mountain is on the east side of the basin,the Yanshan intraplate orogenic belt is on the northeast side of the basin,the Ordos Basin is on the west side,and the Lvliang uplift zone is on the southwest side.In this paper,sandstone is the main object of study,which is used to explore the basic characteristics of sandstone skeleton particles and the parent rock combination,and to make further analysis of the source location and the origin of the tectonic background.On this basis,combined with previous research results,the author analyzed the Ningwu jingle basin-Mesozoic sedimentary and tectonic evolution and later reformation,which is of great significance for further research on the evolution history of the Mesozoic continental crust.The main conclusions are as follows:1.In the Mesozoic era,Ningwu-jingle basin deposited a set of lacustrine facies.Liujiagou and Heshanggou Fm are composed of feldspathic lithic sandstone and lithic arkose,Ermaying,Tongchuan and Yanchang Fm are composed of better roundness and sorting feldspar and lithic quartz sandstone,Yongdingzhuang and Datong Fm are composed of sandstone feldspar,and the other strata of Jurassic are composed of lithic feldspathic sandstone and feldspathic lithic sandstone.The tuffaceous sandstone is mainly developed in the Tianchi formation.2.In the Mesozoic era,in the northern part of the basin,Yinshan,Yanshan area is terrigenous denudation area which is composed of pre-intrusive granitic rocks,metamorphic rocks and sedimentary cover with mixed characteristics.In the Late Triassic period and the late Middle Jurassic,the exposed area of the ancient metamorphic rocks in the terrigenous denudation area is more extensive and has a tendency to expand gradually,and Yanshan Yinshan orogenic belt is always in the tectonic setting of the long rise.3.The early Middle Triassic strata in Ningwu-jingle Basin are inherited and developed inthe Permian sedimentary basin,and the tectonic pattern of “north high and south low” is extended;In the late three period,the inherited depression basin was formed,and after the Yanchang formation,the basin was in the state of uplift and denudation;In the early Late Jurassic,under the extensional tectonic mechanism,the basin was formed into a fault basin with a short axis and a series of faults,and the Yongding formation was deposited;During the sedimentary period of Datong group,the tectonic setting of the late Jurassic and late Jurassic was extended,and after that,the tectonic background is a compressional tectonic setting;After the formation of the Yungang formation,the humid climate quickly changed into a dry strong oxidizing climate,and the Tianchi River group was deposited.4.From the late Jurassic to early Cretaceous,the basin was affected by compression,resulting in uneven topography and the plateau was eroded in the long-term weathering process;The late Cretaceous basin,induced by the NW-SE direction extrusion,basin formed a small NE-SW synclinorium;Since the Paleogene period,the basin has entered a strong uplift stage,and in the late Miocene,there are obvious differences in uplift between the basin and the northern part of Liangshan,most of which led to the formation of today's landscape.