中国大陆现今构造运动的GPS速度场与活动地块  

GPS VELOCITY FIELD AND ACTIVE CRUSTAL BLOCKS OF CONTEMPORARY TECTONIC DEFORMATION IN CONTINENTAL CHINA

作　　者：张培震[1] 王琪[2] 马宗晋[1] 

机构地区：[1]中国地震局地质研究所 [2]中国地震局地震研究所,湖北武汉430071

出　　处：《地学前缘》2002年第2期430-441,共12页Earth Science Frontiers

基　　金：国家重大基础研究发展规划项目 (G19980 40 7) ;国家杰出青年科学基金资助项目 ( 4 982 5 10 4) ;国家自然科学基金会重点资助项目 ( 4 98340 2 0 ) ;国家重大科学工程"中国地壳运动观测网络"资助项目

摘　　要：GPS观测结果给出了在欧亚参考框架下周边板块的运动状态 ,印度板块的运动方向约NE2 0° ,速度是 40～ 42mm/a ;北美板块的运动方向约NW 2 80°～ 2 90° ,速度是 2 1～ 2 3mm/a ;菲律宾板块的运动方向是NW 2 90°～ 310° ,速度是 37～ 45mm/a ;哈萨克—西伯利亚地盾的运动方向约NE130° ,速度是 3～ 5mm/a。GPS所揭示的中国大陆现今运动场清晰地表现出了以活动地块为单元的分块运动特征。文中给出了各主要活动地块的运动方向和速度。大部分活动地块内部结构完整 ,以整体性的运动为主 ;个别活动地块内部发生构造变形 ,地块的整体性不好。中国大陆以活动地块为单元的现今构造变形可能与大陆岩石圈的结构和性质有关 ,上地壳以脆性变形为主 ,下地壳和上地幔以粘塑性的流变为特征 ,从底部驱动着上覆脆性地块的整体运动。On the basis of velocity field constrained by GPS measurements, relative motions of lithospheric plates around continental China can be determined under a common reference framework of the fixed Eurasia. The Indian plate moves toward N20°E direction at a rate of 40～42mm/a. The Philippine plate, southeast of China, moves to about N300°W direction at a rate of 37～45mm/a. GPS stations located in North America plate show N280°～290°W motion at a rate of 21～23mm/a. Stations on the Kazakhstan and Siberian block move in a completely different fashion from that those located in continental China, suggesting that continental China may not be part of stable Eurasia, and that the boundary between these two blocks may be the active tectonic zone from Tianshan Mountains to Baikal.Widespread active faulting and folding, uplifting of mountain range, and high seismicity within the belt attest to continued crust shortening throughout the Tianshan Mountains. A velocity profile across the Tianshan between 76°E and 78°E shows about 20mm/a crustal shortening across Tianshan Mountains. Total shortening rate between longitude 83°E and 85°E is about 7 mm/a. Farther east to the longitude about lmqi City, the rate of crustal shortening across the Tianshan decreases to about 2 mm/a. The crustal shortening across the Tianshan shows a tendency of eastward decrease, which is consistent with that inferred from theoretical modeling and geological investigations. GPS measurements indicate oblique convergence across the Qilianshan Mountains region. Crustal shortening, perpendicular to the Qilian Mountains (N30°E), is (4.0±1.0)mm/a. Left\|lateral shearing, parallel to the Qilian Mountains, is (7.5±1.5)mm/a. The entire Qilian Mountain behaves as a huge left\|lateral shear zone.The North China region includes the Ordos block and northern China Plain. Despite variations in rate and direction of each individual station, GPS measurements in the North China region exhibit a relatively homogeneous strain field with most stations movin

关 键 词：地壳运动速度场 全球定位系统 中国大陆 构造运动 GPS速度场 活动地块 

分 类 号：P542[天文地球—构造地质学] P227[天文地球—地质学]