建昌—喀左盆地中生代构造演化

根据地层接触关系和构造特征,建昌—喀左盆地中生代地层可划分为早三叠世构造层、侏罗纪构造层和早白垩世构造层;早三叠世—侏罗纪末发育收缩构造样式、白垩纪发育伸展构造样式。从各构造样式的特点得出建昌—喀左盆地中生代构造演化:早三叠世—侏罗纪末,地球半径减小、岩石圈板块自转加快且向两极漂移,由于太平洋板块相对欧亚板块向北漂移,在盆地所在区形成收缩构造样式;进入白垩纪,地球半径增加、岩石圈板块自转减慢且向赤道漂移,由于太平洋板块相对欧亚板块向南漂移,在盆地所在区形成伸展构造样式。

Jianchang-Kazuo basin tectonic evolution in Mesozoic era

Based on the study of strata contact relations and structural features,the Mesozoic strata in Jianchang—Kazuo basin can be divided into lower Triassic structural layer;Jorassic layer and lower Cretaceous layer.The tectonic style during early Triassic to the end of Jurassic belongs to contracting;and in Cretaceous belongs to extending tectonic style.According to the characteristic of each tectonic style,the evolutional laws in Jianchang—Kazuo basin during Mesozoic era are obtained as follows: during early Triassic to the end of Jurassic,the radius of the earth decreased,and the rotation of the lithospheric plates became quicker and drifted to both poles,as Europe and Asia plate drift relatively to the north opposite to Pacific Ocean plate,this area which the basin located in forming a contracting tectonic style;in Cretaceous era,the radius increased and the rotation of the lithospheric plates became slower and drifted to equator,as Europe and Asia plate drift relatively to the south opposite to Pacific Ocean plate,forming a extending tectonic style.