Current Vertical Motion Analysis of Northwestern Margin of Ordos Based on Precise Leveling
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摘要: 鄂尔多斯块体受青藏块体和华北块体的挤压，在其周缘形成一系列褶皱和压性断层，构造较为复杂。本文利用1980、1990和2014这3期精密水准资料计算了鄂尔多斯块体西北缘的垂直运动速率，分析结果表明：① 位于阴山断块隆起与鄂尔多斯断块隆起之间的河套盆地相对下沉，其中临河盆地最为明显，下沉速率为2-4mm/a，位于鄂尔多斯块体西缘的吉兰泰-银川断陷带沉降速率有所减缓，目前沉降速率约为2mm/a；② 整个测区表现为明显的山区上升、盆地下沉的继承性运动；③ 穿过乌拉山北缘断裂和磴口-本井断裂的2条水准剖面显示断裂两侧的垂直运动速率差异小于0.5mm/a。Abstract: Ordos block was squeezed by the Qinghai-Tibet an block and North China block, and the tectonic activity was intense. In the periphery of Ordos block, there was a series of wrinkles and compressive faults with complex constructure. This paper used three-phase data of 1980, 1990 and 2014 to calculate vertical velocity of northwestern margin of Ordos and the analytical results indicated that ① the Hetao basin between the rise of Yinshan fault block and Ordos fault block relatively sank, in which Linhe basin was the most evident and the sink rate was about 2-4mm/a. The sink rate of Jartai-Yinchuan rift zone on the western margin of Ordos block slowed and the sink rate was about 2mm/a; ② the whole testing zone exhibited the evident inherited movement characterized by mountain rise and basin sinking; ③ the two leveling section through the northern margin fault and Dengkou-Benjing fault showed that the difference between vertical velocities flanking fault was less than 0.5mm/a.
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Key words:
- Precise leveling /
- Ordos /
- Fault /
- Vertical velocity
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图 2 1980—1990区域垂直形变矢量图和等值线图
Figure 2. The vector and contour diagram of 1980—1990 vertical deformation
图 3 1990—2014区域垂直形变矢量图和等值线图
Figure 3. The vector and contour diagram of 1990—2014 vertical deformation
图 4 乌拉山北缘、乌拉山山前断裂水准剖面观测值曲线
Figure 4. The level profile of Ural north rim fracture, Ural before fracture
表 1 平差统计
Table 1. The statistics of adjustment
时间跨度 公共点数 单位权中误差 参考基准 1980—1990 538 0.88mm 棋东49基 1990—2013 343 0.72mm 棋东49基 
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