阜新盆地盆缘断裂与构造演化

本文从阜新盆地盆缘断裂研究入手,应用地质力学的观点对盆地的构造演化进行讨论。阜新盆地发育有6组盆缘断裂,即东西向、北东向、北西向、南北向、北北东向和北东东向断裂,其中以前4种断裂为主。所有盆缘断裂除具明显的压性、压扭性特征外,还具有其它的力学性质,其运功方式也是多变的。盆缘断裂大致可以划分出3个期次:第1期力学性质表现为压性、扭性、张性;第2期力学性质为压性、压扭性、张性为主兼扭性;第3期为压扭性、扭张性、张扭性。它们具有统一的应力场,是一定方向、一定方式地壳运动的产物。燕山运动第四幕导致盆地强烈回返上升,燕山运动第五幕和喜山运动形成了现今阜新盆地的构造格局。

BASIN-MARGIN FAULTS AND TECTONIC EVOLUTION OF FUXIN BASIN

This paper discussed the tectonic evolution of Fuxin basin in the light of studied basin-margin faults,applying the standpoints of geomechanics.There were six sets of faults:EW,NE,NW,SN,NNE,and NEE faults,the first four sets were of the main faults.These basin-margin faults clearly presented compress,compresso-shear and other mechanics natures,the movement manners were varied.There were three stages showing different mechanics natures,the first shew compress,shear and tensile;the second shew compress,compresso-shear,tensile and shear;the third shew compresso- shear,shear-tensile and tenso-shear.They were product of crustal movement with particular direction and specified manner in the same stress field.The existing struc- tural framework of Fuxin basin came into being after Himalayan orogeny,the fifth phase of Yanshanian movement,and strong inversion during the fourth phase of Yan- shanian movement.