陕西蟒岭地区宽坪群的构造演化

本文将宽坪群的构造演化序列分为两大阶段,即海西一印支运动及其以前的以褶皱为主的变形;燕山运动以来的以断裂为主的变形。两个阶段所形成的构造均沿着北西西和北东两个方向延伸,显然它们是北西西和北东两个方向的构造波系在蟒岭地区活动的表现,并由此形成了该区的斜向构造格局。

THE STRUCTURAL EVOLUTION OF THE KUANPING GROUP IN MANGLING AREA, SHAANXI PROVINCE

According to a lot of field observations and statistical analyses, the primitive structural patterns of the Kuanping Group in Mangling area are restored and analysed in this paper,and the polycycle structural deformation is also traced back and discussed in detail. Two major stages can be found through the structural evolutional history. One is dominated by the folding during tbe periods from the Zhongtiao to India-China-Hercynian movement, and the other by the faulting from the Yanshan to Xishan movement.It is clear that the strikes of the most developed structures in Mangling area are always in NE or NW directions in many kinds of deformation or in many periods. The result of the writer's research shows that the deformation results from two great tectonic wave systems that acted and intersected during different geological times to from various oblique structural patterns in this area.