中国钾盐区域分布与找钾远景

Regional Distribution and Prospects of Potash in China

中国大陆是由不同古气候环境下的若干小陆块(克拉通)、微陆块和造山带拼合而成,既可与其他大陆块对比,又有其特殊性,因而导致中国海、陆相盐盆地构造环境和成盐成钾的某些特殊性,表现为:具有成盐多期性;成盐时代的差异性;成盐作用迁聚性;物质成分多样性;海相盐盆地规模较小;盐盆地后期变动大和液态矿产等特点。构造基底性质对钾盐盆地形成的具有关键性控制作用:稳定构造区在准稳定区有利聚钾;准稳定在局部稳定构造区利于聚盐成钾。中国主要的古代盐盆地多产于"准克拉通(陆块)"、特别是海相盐盆地均发育于前寒武纪为基底的陆块中,该区是找钾的关键地区。且规模较大的叠合结构可溶盐沉积多发育于较稳定的陆核中。按中国成盐盆地所在构造域特点,划分为华北盐类成矿域、扬子盐类成矿域、塔(里木)—柴(达木)盐类成矿域以及羌北—滇西盐类成矿带,并分别讨论其成盐找钾远景。

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 liquid mineral deposits.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-stability 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 with a superposed structure 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.