Differences in karst processes between northern and southern China

The east-west trending Tsinling Mountains in central China were uplifted at the end of the Middle Jurassic [176-161 million years ago (Ma)] in Yanshanian, thus effectively and geographically defining the northern climate as cold and dry, and the southern climate as warm and humid. Influenced by paleoenvironmental variation, the karst process shows differences between northern and southern China. Using the systems approach, the authors integrated the geologic history, climate, and hydrological conditions to analyze the causes of the karst differences in northern and southern China, as well as in the Tibetan Plateau. Carbonate rock deposition began in the Meso-proterozoic Era (1,600-1,000 Ma) in north China, and in the Sinian Sub-Era (825-570 Ma) in south China. In north China, the rock formation ended in the Mid-Ordovician (466 Ma), while in South China the deposition continued to the Triassic (250-200 Ma). Tibetan Plateau was deposited in the Late Permian (257-250 Ma). The different deposi-tional environment caused different lithologies: the limestones are largely micritic in the north, but are massive and sparry in the south. The modern karst features were formed mainly in the Tertiary (53-2.6 Ma) and the Quaternary. In the Quaternary, the Tibetan Plateau arose sharply, which formed the monsoon system of East Asia, and loess started to deposit in north China, which partly delayed or prevented karstification in north China, and differentiated the karst features from those in south China. Thus, the karst process in north China is mainly hypogene, while the south is epigene in the Quaternary.