贵州晴隆锑矿石膏晶洞的成因及其晶体的结晶特征

A huge gypsum miarolitic cavity has been found locatedin an antimony mineralized layer. It is an interformational bleb. Four crystallization steps are recognized for mineral crystals in the miarolitic cavity. Gypsum crystals seem to have been formed through two forms of crystallization. The data on fluid inclusions and hydrogen isotopes.show that this cavity is the product of hypergenic process, the orebeariug solution is derived from meteorie water, and the compositional material comes from the oxidized ore zone. During the formation of the miarolitic cayity, the pH-value was within the range of 4--5, i.e., weakly acidic solution, and the formation temperature less than 50℃. It can be clearly seen from the crystallization behaviour of gypsum cyrstals and mineral association that there have taken place significant changes in the pH-value of mineralization solution.