Whirl Structure and Constraint on the Mineralization in Ge’erke Gold Orefield, Maqu, Northern Qinghai-Tibetan Plateau
详细信息
- 责任者：Yuan Wanming (State Key Laboratory of Geological Processes and Mineral Resources ; China University of Geosciences ; Beijing 100083 ; China) ; Li Hongyang
- 刊名：Acta Petrologica Sinica
- 出版年：2010
- 卷期：26(6)
- 关键词：金矿 ; gold ores ; 旋卷构造 ; vortex structure ; 甘肃 ; Gansu Province
- 页码：p.1785-1792
- 图表：5 illus., 21 refs.
- 分类号：1001
- issnNo：ISSN1000-0569
- isbnNo：CN11-1922/P
摘要
This work identified a whirl structure, about 4 500 m in diameter, that was closely related to the mineralization in the orefield, and both of them have coincident scale and distribution. The nuclear column of the whirl structure is consisted of marbleized dolomite and concealed rock body. There are 6 radial arc cyclothems in the whirl structure, of which the vertical surfaces (arc fracture) of 4 cyclothems at south are convex to W-NW and belong to tensional structural planes, and the vertical surfaces of 2 cyclothems at north are convex to NE and belong to compressional planes. They are two rotation-shear structures with different features that compose the whirl structure. The whirl structure is clearly visible in the ETM remote sensing image and terrain maps, orange positive-landform cyclothem surfaces alternate with dark blue negative-landform zone; apex of the vertical column area is about 4 000 m, relative elevation difference is 500 m. A lot of quartz diorite veins occurred in the vertical surfaces. Gongbei district, Dashui district and Ge’ertuo district are respectively located at No. 1, 4 and 6 cyclothems, i.e. at NW, NE and SE trend cyclothems that have larger scales. It is the tensional structure planes of the cyclothems that became ore-host structures. Therefore, the rotation-shear planes are main host structures in southern tensional cyclothems and the ore-host structures intersect with rotation-shear planes in northern compressional cyclothems.