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- 2018
离石北部北川河阶地特征及其新构造指示
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Abstract:
详细研究了离石北部一带阶地的地层地貌特征，并尝试对吕梁山山体的隆升进行分析探讨。结果表明，晚更新世以来该区有过三次间歇性隆升，并且三级阶地形成以来即晚更新世早期山体隆升相对快速强烈，二级阶地形成以来即晚更新世晚期至全新世时期山体隆升处于相对缓慢的过程。
The Lvliang Mountain uplift area is located in the west of Shanxi Fault Belt. The extent and the period of the mountain uplift and the river terraces on the mountain have been rarely studied, in particular, after the late Quaternary. In this study, the stratigraphic and geomorphological features of the terraces in the north of Lishi are studied in detail, and the uplift of Lvliang Mountain is also discussed. The river valley of the study area is wide, and the Beichuan River develops on the eastern side of the valley. In addition, the east side is narrower and the west side is wider, which is the main human activity area. The width of the valley is about 0.9~1.6 km, and the elevation difference of the valley is small and the surface is flat. The floodplain and the first and second terraces are also widely distributed in the Beichuan River valley. The third terrace is rarely developed in the area. The first-order terrace and river floodplain formed during the Holocene period, the second-order terrace formed in the Late Pleistocene period, and the third-order terrace formed in the Early-Late Pleistocene period. Meanwhile, the third-order terrace is incomplete, and it has larger height difference than the height difference in the second terrace. The second-order terrace is narrow and the first-order terrace is relatively wide, and the height difference of the two steps is not remarkable. The first-order terrace is relatively wide and the river floodplain is relatively narrow, and the height difference between the two is not significantly big. The results show that the mountain has been uplifted three times intermittently since Late Pleistocene; in addition, the uplift of the mountain is relatively rapid and intense, and the uplift proceeds in a relatively slow process from the Later-Late Pleistocene to the Holocene periods.
