陕西蓝田红门寺地区丹凤群构造变形特征

THE CHARACTERISTICS OF THE STRUCTURAI DEFORMATION OF DANFENG GROUP IN THE HONGMENSI AREA,LANTIAN COUNTY, SHAANXI PROVINCE

本文对蓝田红门寺地区丹凤群的变形特征,提出至少经历过三期主要构造变形及混合岩化作用。

As a narrow and long bell, the Danfeng Group is distributed alone the southern part of the Northern Qinling Orogeiuc Belt. It is a series of meta-morposed volcanic-sedimentary rocks formed during the early Palaeozoic Era. In this paper, the arthors mainly discuss the structural deformation of the Danfeng Croup in the Hongmensi area of Lantian County, Shaanxi Province. By means of the method of structure-stratigraphy analysis, the authors determined the stratigraphic sequence of the Danfeng Group in this area. Furthermore, they have discriminated the superposed folds of the three main structural deformational episodes, as well as the correspondant metamorphism and migmatization.Their research results show that there are three major directions of the main stress action on the Danfeng Group, near S-N; NE-SW; and near E-W. According to their views, the major deformation of folding took place during the Caledonian, the Hercynian-Indo China and the Yanshan Orogenies. The major nappe structure and ductile shear zones, however, were, possibly formed during the Yanshan Orogeny.