一个与超基性岩有关的矽卡岩铁矿

超基性岩同围岩接触,一般都很少见到明显的接触变质和接触交代现象,特別是后者更为少见。造成这一情况的原因可能有二:首先,超基性岩浆本身“活动组分”较少,如果沒有特殊有利的条件(包括岩体大小、侵入深度、接触面的形状产状、围岩成分以及构造条件等),这些组分不易集中,也就很难同围岩产生接触交代反应。

A SKARN IRON DEPOSIT RELATED TO THE ULTRABASIC ROCK

In this paper a skarn iron deposit related to certain ultrabasic rocks is described. The iron deposit occurs in the contact zone and near the xenolith of the apophyse of the rock body. The immediate enclosing rock of the deposit is calcareous siltstones. The chief minerals composing the skarn and the ore are almandine, chrompicotite, scapolite, phlogopite, magnetite (includes magnesioferrite), serpentine, chlorite, etc. Some of the serpentine and phlogopite have preserved the original outlines and textures of olivine and pyroxene respectively. According to the occurrence of the ore body and the associated minerals, the author recognizes that the deposit is a skarn iron deposit related to ultrabasic rock, and that the ore formation is probably related to the geochemical process of ultrabasic magma.