华北主要构造单元及边界带现今水平形变与运动机制  

CURRENT HORIZONTAL DEFORMATION AND KINEMATIC MECHANISM OF MAJOR TECTONIC UNITS AND BOUNDARY ZONES IN NORTH CHINA

作　　者：杨国华[1] 谢觉民[1] 韩月萍[1] 

机构地区：[1]中国地震局第一地形变监测中心,天津300180

出　　处：《地球物理学报》2001年第5期645-653,共9页Chinese Journal of Geophysics

基　　金：国家重点基础研究项目 (G1 9980 40 70 3 )

摘　　要：根据华北地区 1 992 ,1 995 ,1 996 ,1 999年高精度GPS观测结果 ,给出了华北地区各主要构造单元间两个时段 (1 992— 1 996年和 1 996— 1 999年 )的相对水平运动 .其结果为 :①相对于鄂尔多斯单元 ,阴山单元的运动为 (0— 2 3 )± 1 .6mm/a ,方向约 0°—W1 3°N ,属于相对较弱左旋走滑运动 .②相对于鄂尔多斯单元 ,晋冀鲁豫单元的运动为 (4 4± 1 0 )— (2 5± 1 5 )mm/a,方向约为S5 0°— 3 0°E ,属于右旋型拉张运动 ;相对于燕山单元 ,则为 (4 7± 1 4)— (4 3± 1 4)mm/a ,方向约为E3 7°— 9°S ,属拉张型左旋走滑运动 .③相对于晋冀鲁豫单元 ,胶辽鲁苏单元 1 992— 1 996年的运动显示了顺扭的运动特征 ;1 996— 1 999年的运动为 (2 6± 1 5 )mm/a ,保持顺扭趋势 ,方向约为W1 1°S ,总体上属于北张南压的右旋走滑运动 .分析表明 :现今地壳构造活动与现代地壳构造运动性质基本一致 ,但量值有所差别 ;地壳运动存在着数年尺度的较明显的波动性 ,这可能是大陆地壳运动的一个主要特征 ;1 996— 1 999年的运动不同于1 992— 1 996年 ,主要表现为鄂尔多斯单元北移态势增强 ,山西断陷带和燕山构造带两侧拉张性有所减弱 ,可能是张北地震后应力调整与华北地区边界力耦合共同作用的结果 .WTHT Based on the data of high-precision GPS for 1992,1995,1996 and 1999 in North China,this paper presents the relative horizontal movements occurred in two periods (1992_1996 and 1996_1999) among the major tectonic units in North China area. The results are (1) relative to Erdos unit,Yinshan unit moves in direction of 0°-W13°N with an amplitude of (0_2.3)± 1.6?mm/a in the form of left-lateral strike slip;(2) relative to Erdos unit,the movement of Jin-Ji-Lu-Yu unit is of right-lateral extension with an amplitude of (4.4±1.0)_(2.5±1.5)mm/a in the direction of about S50°_30°E;while relative to Yanshan unit,it is of left-lateral extensional strike slip with an amplitude of (4.7±1.4)_(4.3±1.4)mm/a in direction of E37°_9°S;(3) relative to Jin-Ji-Lu-Yu unit,the movement of Jiao-Liao-Lu-Su unit is characterized by clockwise torsion in the period of 1992_1996. The trend of clockwise torsion is kept with the amplitude of 2.6± 1.5mm/a in the direction of about W11°S in the period from 1996_1999,showing a right-lateral strike-slip movement of extension in the north and compression in the south on the whole. The analysis indicates that the current crustal tectonic movement is basically consistent with the current crustal tectonic kinematic property with a little bit difference in the amplitude;Significant fluctuation with a time-scale of several years exist in the crustal movement, which might be a principal feature for the continental crustal movement;The movement in the period of 1996_1999 is different from that of 1992_1996,which is characterized by the strengthening of Ntrending shift to Erdos unit and the weakening of extensional movement along both sides of Shanxi rift zone and Yanshan tectonic zone. It might be resulted from the joint coupling effect of stress accommodation after Zhangbei earthquake and the boundary force in North China area. WTHZHTH

关 键 词：华北地区 构造单元 边界带 水平运动 水形形变 运动机制 GPS监测网 数据处理 

分 类 号：P542[天文地球—构造地质学]