中国西北地区燕山期构造应力场特征与成盆作用

THE TECTONIC STRESS FEATURE AND BASINING DURING YANSHAN STAGE IN THE NORTHWEST OF CHINA

研究西北地区晚侏罗世—早白垩世、晚白垩世—早第三纪区域构造应力场发现,大致以阿尔金断裂为界,东部和西部地区应力场状态不同。东部地区晚侏罗世—早白垩世区域构造应力场主压应力为北北东向;而西部地区主压应力以近南北向为主。晚白垩世—早第三纪区域构造应力场在阿尔金断裂以东地区基本继承了前期应力场状态,阿尔金断裂以西地区主压应力方向为北西向。这种应力场特征与上述阶段形成的盆地原型、盆地反转、构造变形相匹配。

Research on the regional tectonic stress field during the Late Jurassic to the Early Cretaceous and Late Cretaceous to Early Tertiary in the northwest of China shows that the state of stress field tO the east of Aerjin Fracture is different from the that to the west of Aerjin Fracture. The principal compressive stress of the regional tectonic stress field is NNE-oriented to the east and near-meridional to ttie west of Aerjin Fracture during the Late Jurassic to the Early Cretaceous. In Late Cretaceous-Early Tertiary, the regional tectonic stress field to the east of Aerjin Fracture basically carry on the state of previous stress field and the direction of the principal compressive stress to the west of Aerjin Fracture is northwestward. This tectonic stress field feature is consistent with the basin prototype, basin reversal and tectonization forming in the relevant period.