【摘要】 利用中国境内外天山地区1992～2005年382个GPS测站的原始观测资料计算了天山地区现今地壳运动速率,分区域定量分析了天山地壳缩短速率变化的方式和特征。天山的汇聚速率由西向东逐步减小,具有分段变化的特征:西天山(72°E～77°E)的汇聚速率为20±1mm/a,中天山(77°E～82°E)的汇聚速率为12±1mm/a,东天山(82°E～92°E)的汇聚速率只有5mm/a左右,整个天山现今汇聚变形速率平均为12mm/a。天山南北向挤压缩短并不能笼统地概括为均匀分布:82°E以东的天山地区,汇聚变形基本表现为连续线性变形,天山南北山前断层调节的变形量并不明显高于山体内部;82°E以西的天山地区,其南北山前断层调节的变形量明显高于山体内部,天山地壳的挤压缩短形变主要发生在南北两侧盆地山体过渡地带,在这些形变吸收带上,北向的挤压速率迅速大幅减小,山体内部区域北向的挤压速率变化则相对缓慢得多,其变形强度与地震活动具有很好的一致性。岩石圈和软流圈的差异运动导致了天山新生代构造变形。从天山南北山前断层缩短速率的东西差异分析,造成天山东西变形差异显著的原因是帕米尔北向推挤和塔里木顺时针旋转的共同作用:在天山西端(75°E以西),其挤压缩短(17mm/a)是由于帕米尔高原北北西向的推挤作用;而75°E以东的地区,其差异构造变形的原因则主要是塔里木顺时针旋转的结果。更多还原

【Abstract】 Using the GPS data which is collected from 382 observation stations of inner and outer Tianshan area during 1992~2005,the velocity field of contemporary crustal deformation in Tianshan area is calculated and the characteristics and means of crustal movement in Tianshan area are analyzed quantitatively.The deformation of this area is controlled by boundary faults.From west to east,the velocity of convergence decreases,the velocity of west Tianshan(72°~77°E)is(20±1)mm/a,the middle Tianshan(77°~82°E)(12±1)mm/a,and the east Tianshan(82°~92°E)only(4±1)mm/a.The average velocity of convergence of whole Tianshan is 12mm/a.However the shortening of the crust in Tianshan area is not uniform:The main deformation takes place at the reverse fault and fold zone along both side of Tianshan Mountain.At the inner of Tianshan,the velocity of convergence is nearly zero,i.e.it looks like a rigid body.At the same time,the deformation intensity of the whole Tianshan has a good consistency with the seismic activity.The differential movement of lithosphere and asthenosphere causes the Neozoic deformation of Tianshan.The difference between the crust shortening rates in west and east direction of Tianshan,is resulted from the pushing action by Pamir and the clockwise rotation of Tarim.In the west Tianshan(west to 75°E),the convergence is caused by the push of Pamir in NNW direction,and in the east to 75°E,the difference of tectonic deformation is caused by the clockwise rotation of Tarim.更多还原