摘要
目的揭示青藏高原远端隆升和增生机制。方法选取循化—贵德地区,采用高精度的数字高程模型(DEM)数据,定量分析了各种地形参数、低起伏面发育及其与岩性的关系。结果循化—贵德地区地形形态总体呈台阶状结构,在不同海拔高度存在低起伏地形;发育于盆地沉积地层(渐新统至下更新统)之上的低起伏面表现为年代越新的地层之上低起伏面高程越高,越老的地层高程越低,并且它们均低于发育于逆冲带基岩之上的夷平面;发育于盆地深切河谷两侧阶地之上的低起伏面海拔高程总体较低。结论循化—贵德地区地貌发育特征表明青藏高原东北缘自渐新世以来经历了早期(渐新世—早更新世)带状逆冲隆升与前缘盆地垂向加积和晚期(大约中晚更新世之后)区域性构造抬升与河流深切的增生过程。
Aim In order to probe into the uplifting and growing mechanism of the frontal Tibetan Plateau. nethotis Quantitatively analyzing different kinds of relief parameters, low-relief distribution and its relationship with lithology, based on high-quality digital elevation model （DEM） data. Results Xunhua-Guide area is characterized by step-shaped low-relief at different elevation. The low-relief surfaces developed above the newer strata in sedimentary basin among the Oligocene to the lower Pleistocene are in higher elevation, but above the older strata, are in lower elevation. The elevations of all above low-relief surfaces are lower than those of the planation surface above the bedrocks in the thrust belts. The low-relief surfaces of terraces, developed on both sides of the deep-cutting valleys within the basins, are lowest in elevation. Conclusion The geomorphological features in Xunhua-Guide area indicate that the northeastern Tibetan Plateau underwent a growing process of thrust uplift and the foreland basin vertical aggradation from the Oligocene to the early Pleistocene and regional tectonic uplift and fiver deep incisions after middle Pleistocene.
出处
《西北大学学报（自然科学版）》
CAS
CSCD
北大核心
2009年第3期414-424,共11页
Journal of Northwest University（Natural Science Edition）
基金
国家自然科学基金资助项目(40672135)
中国地质调查局基金资助项目(1212010660601)
