The property, age and formation environment of the palaeokarst in Qinghai-Xizang Plateau

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	The property, age and formation environment of the palaeokarst in Qinghai-Xizang Plateau
	Gao Quanzhou ; Cui Zhijiu ; Liu Gengnian ; Hong Yun
刊名	Journal of Geographical Sciences
	2002
关键词	palaeokarst lateritic residuum chemical weathering Tertiary Period planation surface Qinghai-Xizang Plateau
英文摘要	The karst landforms distributed on the Qinghai-Xizang (Tibet) Plateau can be genetically classed with the Tertiary underground karst, which were gradually exhumed to the surface with the uplift of the plateau during Quaternary period. The relative deposits of the Tertiary palaeokarst processes, such as the residuum and speleothem, were discovered recently in the southern and southeastern fringe areas of the plateau, where has geological-currently been disintegrated by the headward erosion processes of the modern river systems. The major chemical components of the clay portion of the residuum consist mainly of SiO2, A12O3 and Fe2O3. The clay minerals composition of the clay portion belongs to illite-kaolinite pattern for most of the residuum samples, and kaolinite-illite pattern for a few of the samples. It can be judged from the silicic acid index and the clay minerals composition that the formation of the residuum of the Plateau was in its initial phase. However, such a lower chemical weathering index only reflected the weathering degree in the bottom or lower parts of the lateritic weathering crust. The relatively intensive chemical weathering processes of the surface layers of the lateritic weathering crust could be logically speculated. The surface feature textures of quartz grains in the residuum were formed mainly by the chemical erosion, which revealed a long-term humid-tropical environment when the residuum and the palaeokarst formed.; National Natural Science Foundation of China, No. 49901002 and No. 49371011; 中国科学引文数据库(CSCD); 2; 144-152; 12
语种	英语
内容类型	期刊论文
源URL	[http://ir.pku.edu.cn/handle/20.500.11897/427372]
专题	城市与环境学院
推荐引用方式 GB/T 7714	Gao Quanzhou,Cui Zhijiu,Liu Gengnian,et al. The property, age and formation environment of the palaeokarst in Qinghai-Xizang Plateau[J]. Journal of Geographical Sciences,2002.
APA	Gao Quanzhou,Cui Zhijiu,Liu Gengnian,&Hong Yun.(2002).The property, age and formation environment of the palaeokarst in Qinghai-Xizang Plateau.Journal of Geographical Sciences.
MLA	Gao Quanzhou,et al."The property, age and formation environment of the palaeokarst in Qinghai-Xizang Plateau".Journal of Geographical Sciences (2002).