Is the Stable Ordos Block Migrating as an Entire Block？

详细信息   

• 责任者：Chen Xiaobin (Institute of Geology ; China Earthquake Administration ; Beijing lOOO29 ; China) ; Zang Shaoxian
• 刊名：Chinese Journal of Geophysics
• 出版年：2011
• 卷期：54(7)
• 关键词：岩石圈 ; lithosphere ; 水平运动 ; horizontal movement ; 鄂尔多斯地台 ; Ordos Platform
• 页码：p.1750-1757
• 图表：3 illus., 2 tables 29 refs.
• 分类号：0300
• 出版序号：15
• issnNo：ISSN0001-5733
• isbnNo：CN11-2074/P

摘要

Under the constraint of GPS velocity field, a 3D viscoelastic modeling was realized for studying the lithosphere dynamics of North China and its adjacent area based on the comprehensive geological and geophysical data, such as 3D rheological structure, the active blocks of China, velocity structure, thermal structure, et al. The reliability of modeling results was proved high by means of a detailed comparison of the fitting of GPS velocity field and the Euler Poles. It is confirmed that in the horizontal direction the Ordos block is moving as a whole. Based on the results, the Euler Poles of Ordos block along the depth were calculated, which presents an obvious difference between the upper-middle crust and the lithosphere mantle. A gradient zone of the horizontal velocity is located in the lower crust. We can get the anti- clockwise twist of the lithosphere mantle relative to upper-middle crust through furtherinvestigation of the velocity variation along the depth at 4 sites. So by this study, although the horizontal movement of Ordos block is moving as a whole in lateral direction, a gradient velocity zone exists in the lower crust. Those results imply a ductile shear belt in the lower crust of the Ordos block.