矿物中包裹体气体成分的物理化学参数图解

DIAGRAMS OF PHYSICO-CHEMICAL PARAMETERS FOR GAS COMPOSITIONS OF INCLUSIONS IN MINERALS

已知流体包裹体的挥发性成分,主要为H_2O、CO_2、CO、CH_4、H_2和O_2,假设它们之间存在下列三种基本化学反应:H_2+1/2O_2=H_2O;CO+1/2 O_2=CO_2和CH_4_+2O_2=CO_2+2H_2O,并已达到平衡。作者等对超临界状态的成岩成矿作用,作出了几种压力下的1gfo_2-T、1gfco_2-T和Eh-T图解。利用这些图解,不必经过繁琐的计算,可得出成岩成矿的氧逸度、二氧化碳逸度、还原电位、平衡温度和平衡压力。本文还举例作了说明,并对几个矿床的形成,得到了成功的解释。

A great wealth of analytical data for fluid inclusions in minerals indicate that the major species of gases in fluid inclusions are H20, C02, CO, CH4, H2 and 02. Three basic chemical reactions are supposed to prevail in rockforming and ore-forming fluids:H2 + 1/2 02 = H20,CO + 1/2 02 = C02,CH4 + 202 = C02 + 2H20,and equilibria were reached among them. Ig fo2-T, Ig fco2-~T and Eh-T diagrams for petrogenesis and minerogenesis in the supereritical state have been plotted under diffe-rent pressures. On the basis of these diagrams fo2 fco2 Eh equilibrium temperature and equilibrium pressure can be readily calculated. In this paper some examples are presented to show the successful application in the study of the ore-forming environme-nts of ore deposits.