The Characteristics Of Tectonic Evolution During Mesozoic And Cenozoic Era In Taiyueshan Uplift Area,Central And Southern Shanxi Province

North China Craton has been affected by the multi-directional convergence of the plate margin since the Mesozoic with structural system changed greatly.In particular,the subduction of the western Pacific plate made the eastern part of the craton lose its stability with extensive tectonic deformation and magmatic activity since the late Mesozoic.The Western Ordos Basin is basically stable,while the middle transition area is affected and transformed.Shanxi Province is located in the middle transition area where the geological conditions of Mesozoic and Cenozoic are complex.It is a natural laboratory for studying the tectonic evolution of the central part of North China Craton since Mesozoic.Based on the comprehensive collection and arrangement of previous research results,paper takes Taiyue Mountain uplift area in the western edge of Qinshui Basin in the South Central Shanxi Province as the research object.Problems such as MesoCenozoic stratigraphic distribution,characteristics of structural deformation and process of uplift-cooling of Taiyue Mountain were studied through route observation,systematic geological mapping,profile measurement and fission track analysis.The following understandings have been obtained:(1)In the study area,the Mesozoic Indosinian movement is mainly characterized by overall uplift and local slight folds.The Yanshanian movement is mainly characterized by fold uplifts and thrust faults,some of which are superimposed on the early Indosinian structures.The Cenozoic movement is mainly characterized by fault activation,intermittent and differential vertical rise and fall of the crust,and some of the faults cut off the Yanshanian structures.(2)The large-scale uplift of Taiyue Mountain mainly occurred in the Cenozoic,and it was not a overall uniform uplift,but accompanied by the large-scale compression fold shortening deformation.After the uplift,the structural inversion of Qinshui Basin caused the normal fault tilting and warping.they led to the decoupling of fission track ages and elevation together.The geological connotation reflected by the fission track ages of the samples are consistent with the geological facts.(3)The inversion results of thermal history are in good agreement with the test results.From the results of thermal history inversion,the uplift cooling in Taiyue Mountain area has the characteristics of Unidirectionality and time-space heterogeneity,early in the West and late in the East in space,and non-uniform and phased in time.It can be roughly divided into four stages: the first stage is about slow uplift from the end of Middle Jurassic to the middle of Late Cretaceous;the second stage is about rapid uplift from the middle of Late Cretaceous to the middle of Eocene;the third stage is about late Eocene to the early middle of Miocene;the fourth stage is the intense uplift since the late Miocene.On a large scale,the mountains in the middle and eastern part of northern China experienced a synchronous uplift during the late Cretaceous to the middle Eocene.(4)The tectonic evolution process of the study area can be divided into four stages: 1)during the Early Triassic to the Middle Triassic(the stable deposition stage of the craton);2)during the Late Triassic to the middle middle of the Middle Jurassic(the amalgamation stage of blocks in the north and south margin of the plate);3)during the late Middle Jurassic Cretaceous(intraplate orogenic stage);4)during the Cenozoic(extensional cracking stage).The above understandings are of great significance to the study of the Mesozoic-Cenozoic tectonic evolution of the central North China and even the whole North China Craton,as well as the practice of oil and gas exploration and production in Qinshui Basin.