含矿相从酸性熔体中分离出来的条件

摘要

热液学说不能完全解释金属从岩浆(或岩石)中分离和富集的自然条件.酸性岩中包体研究表明,存在特殊的硅酸盐熔体卤水(silicate-salt melt-brine)相,它在熔体结晶早期即从中分离出来,其中富含盐类(质量分数可达70%)、金属、水、F 、Cl、B等.而实验研究显示,原始的酸性熔体在冷却过程中分裂为硅酸盐熔体(silicate melt)和熔体卤水(melt-brine),熔体卤水还可进一步分离出更多的熔体卤水系列(melt-brines),它们也富含金属元素.熔体中高度富集的流体是产生这一过程非常有利的条件.%The hydrothermal hypotheses can not completely explain natural conditions of metal separation from magma (or rocks) and their concentration. Investigations on inclusions in acid rocks give evidences that there exists a specific phase-silicate-salt melt-brine, which is very rich in salts (70%,mass fraction), metals, water, F, Cl, B etc. It separates from the melt before the beginning of its crystallization. Experimental studies show that the initial acid melt in the cooling process divides into different silicate melt(s) and melt-brine, which in turn, may divide into different melt-brines also rich in metal. The presence of high concentration fluids in the melt is a very favorable factor for the process.