Wide distribution of Cambrian salt-bearing basins is a prominent feature of older strata in Asia. The Cambrian salt-bearing sequences are mainly distributed in East Siberia of Russia, Iran, Oman, India, Pakistan, and China. The Cambrian was one of the most important epochs of potash deposition in the world. Potash salts are found in East Siberia, Iran, India, and Pakistan, and, among them, one of the largest potash deposits in the world-the Siberian Nepa Potash Basin-formed in the Early Cambrian. The Cambrian was also one of the most important epochs of rock gypsum and salt deposition in China. Gypsum deposits occur in all the three major continental blocks of China (Yangtze Block, North China Block, and Tarim Block), forming four large marine salt-bearing basins. Extensive, thick rock salt deposits have been found in the Yangtze Block and Tarim Block, where better potashbearing hydrochemical manifestations and leaching coefficient anomalies have been found for the first time. In the North China Block, a number of gypsum deposits and occurrences have been observed and Cambrian high-salinity brine and halite crystals found in oil wells. This study for the first time relatively completely analyzes the distribution and tempo-spatial evolution of Cambrian gypsum and salt-bearing basins in China, which provide an important basis for the study of the history of Cambrian paleogeographic evolution over the globe and salt and potash exploration in Cambrian salt-bearing basins of China.
China was formed by amalgamation of several small continental blocks (cratons), micro, blocks and orogenic belts in different paleoclimatic settings. It may be correlated with other continental blocks but has its own specific characteristics; therefore the tectonic environments of China's marine and continental saline basins and salt, and potash, forming environment have some specific characteristics: multiple phases of salt formation, difference in salt, forming ages, migration and concentration of salt, forming processes and diversity of component materials, as well as small sizes of marine saline basins and great changes of saline basins in the late stage and occurrence of abundant liquid mineral resources. The nature of the tectonic basement exerted a key controlling effect on the formation of potash basins. The stable tectonic region was favorable for potash concentration in a quasi, stable region, and quasi, and the quasi-stable region was favorable for salt concentration and potash formation in a local stable tectonic region. Most China's major ancient saline basins occur in "quasi, cratons (continental block)"; especially all the marine saline basins occur in continental blocks with the Precambrian basement. These regions are the key ones for potash search. Most relatively large, scale soluble salt deposits are developed in relatively stable continental nuclei. According to the characteristics of the tectonic domains where China's salt, forming basins are located, the North China, Yangtze and Tarim, Qaidam salt minerogenetic domains and the northern Qiangtang, western Yunnan salt minerogenetic belt may be distinguished. Their salt and potash prospects will be discussed separately.
ZHENG Mianping ZHANG Yongsheng YUAN Heran LIU Xifang CHEN Wenxi LI Jinsuo