Comprehensive Study Of The Chuxiong Basin Structure Changes With Post-transformation

Formed during Mesozoic-Cenozoic period, the larger reformed Chuxiong Basin in south of China has good petroleum geological condition. Whether in exploitation or in scientific study, it is necessary for us to study on tectonic evolvement and late reformation of the Basin in Mesozoic and Cenozoic period.On the basis of widely looking up, learning and rescanning preceding research and first-hand exploitation data, applying the thinking of "whole , dynamic and integration", this paper makes a study on the tectonic evolvement and late reformation of Chuxiong Basin in Mesozoic and Cenozoic period.It's over half century in exploitation and geologic study, it was until 2000 that two deep test well were successfully drill in Chuxiong Basin (Wulong 1 and Yancan 1), which provide first-hand exploitation data and important information to show geologic character and oil-gas conservation in basin. The paper analyses geologic tectonic and condition of oil-gas conservation on the basis of data of the two well,.By the analysis of thermal reformation in Wulong 1, we think that anticline in Wulongkou belong to the thermal tectonic, the thermal reformation in Wulong 1 and the regional high thermal background are its immediate evidence. The action of magma and thermal liquids under tectonic change is its essential cause.By the analysis of the grievous loss of liquid in Yuncan 1, we think that it has immediate relation with the act and change of unclose liquid on the great scale because of fracture incision, different carina and strong erosion by tectonic change.After finding the cause of thermal reformation in Wulong 1 and the loss of well liquid in Yuncan 1 and on the basis of discussing their cause from point to surface, we discuss the effect on oil-gas preservation condition combining the study on magma act in Mesozoic and Cenozoic in basin and it's around.Tectonic change (movement) is the main factor restricting and affecting each reformed action. In the paper, studying on unconformity surfaces, referring, collecting and cleaning up relative research and data, gathering 154 unconformity surfaces(points) by the numbers and combining with the data of tectonic, sediment and physical geography, we disscuse tectonic change in Mesozoic and Cenozoic, divide stage and character of tectonic and confirm property, distribution, formingcausing and basic character, then we find nine unconformity surfaces which show that there are nine obvious tectonic action in Mesozoic and Cenozoic in Chuxiong basin. The parallel unconformity surfaces by five obvious tectonic actions show the whole rise and sedimentation in basin. The four obvious angle unconformity surfaces in basin and it's around tectonic action show the strong tectonic distortion and magma action.On the basis of the stage of tectonic change and character, we think Chuxiong Basin is a larger reformed basin formed from late Triassic and underwent strong tectonic change in Mesozoic and Cenozoic. Tectonic evolvement underwent two stages of basin growth and late-reformation, and the property and character of each stage are different.