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41.
云南东川地区层状地貌面的成因 总被引:1,自引:1,他引:1
在东川地区的山地及小江河谷的两侧山麓上部,分布着不同高度和不同规模的层状地貌面,对其成因仍有不同的认识。分歧主要表现在两个方面:一是高原隆升之前的初始地貌面是否是准平原型夷平面;二是山顶面之下的梯级层状地貌面的成因。本文从以下几个方面对上述问题进行讨论:(1)层状地貌面的地貌特征及其与侵蚀河谷体系的关系;(2)层状地貌面上堆积物的性质;(3)层状地貌面与断裂构造水平展布的关系;(4)相邻层状地貌面的空间过渡关系;(5)区域构造演化背景。作者认为在云贵高原抬升过程中,东川地区以挤压穹起隆升变形为主。不同海拔高度的层状地貌面具有多成因特性。山顶面及局部高原面是高原隆升之前古夷平面的残留。并遭到后期强烈的侵蚀改造。目前,尚缺乏足够证据证明高原隆升之前的古夷平面为准平原型夷平面。小江河谷两侧的梯级层状地貌面是侵蚀或剥蚀面,它们形成于高原隆升及初始地貌面解体之后,其梯级空间分布特征与区域性的阶段隆升有关。 相似文献
42.
The thick-bedded and continuous karst crust only formed in the old stage of geomorphic development. The corresponding landscape
is the karst planation surface. The karst planation surface consists of the loose weathering crust and the base weathering
front below the crust. Its profile structure is similar to “double surface of leveling” model built by Budel. In the limestone
area, the base weathering front is the covered karst. From the Tibet Plateau to Yun-Gui (Yunnan-Guizhou) plateau and Xiang-Gui
(Hunan-Guangxi) hills, the covered karst is concomitant with the red weathering crust; all of them are the component of the
double-level surfaces of karst planation. But, they belong to the different disintegration stages of planation surface. The
different subtypes of the covered karst and the red weathering crust indicate the existence of karst planation surface. Thus,
they can be made as a reference system when the rising degree and the rising rate of the Tibet Plateau are discussed. 相似文献