兰天武地区现今大地垂直形变场演化与地壳运动特征

CHARACTERISTICS OF THE EVOLUTION OF RECENT VERTICAL DEFORMATION FIELD AND THE CRUSTAL MOVEMET IN LANZHOU-TIANSHUI-WDUU AREA

用分段线性速率整体动态平差法处理了兰天武地区２０多年来的多期水准资料，分析了该区现今大地垂直形变场演化与地壳运动特征。研究结果表明：该区垂直形变七十年代曾表现出山间盆地大幅度上升的强烈逆继承性运动；八十年代华家岭等两北部山地上升、东南部盆地下沉的继承性运动增强；而目前基本恢复了正常的继承性运动状态。进一步分析认为：强烈逆继承性运动和继承性运动增强是区域应力场趋于强化的标志；正常继承性运动的恢复可能是应力场调整的结果。

By use of integral dynamic adjustment of the piecewise linear velocity the leveling data for more than 20 years in the Langhou-Tianshui-Wudu area are proceed and the characteristics of the evolution of recent vertical deformation field and crustal movement are analyzed in this paper. The results indicate that in this area the large scale elevation of basin as strong inverse inherited tectonic movement appeared in 1970s, the mountain rising in west of the Huajialing region and basin subsiding in south east as inherited tectonic movement intensified in 1980s and at present the inherited movement returns to normal. From the further study it is concluded that the strong inverse inherited tectonics movement and the intensification of inherited tectonic movement is a mark of increasing stress field and the return to normal inherited movement probably is the effect of stress field adjustment.