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一、概述分布在阿勒太地区北西向狭长带上的火山岩系中的铁矿床,其成因可能是不尽相同的。而本文仅只论述其中阿巴宫地段的磷灰石—磁铁矿床的成因。该矿床在阿尔太下泥盆统的火山岩系中产出。火山岩为石英角斑岩、火山熔岩和凝灰岩等,以及大理岩、石英云母片岩等变质岩。而且,后期岩浆活动频繁,发育酸性与基岩脉岩,以及浅成侵入体(微花岗岩)。该地区岩层直立,片理发育、折皱断裂均甚强烈。构造线方向趋向一致,为290～310°。岩石的区域变质一般为绿片岩相、个别可达角闪岩相。据观察,这阿勒太狭长成矿带实际上是在区域变质的基础上,再迭加热力变质和动力变质的一个带。这个带在阿巴宫宽约2Km。带的东北边为花岗岩体,南西为中上泥盆统地层出露区,而中上泥盆统地层为浅变质的板岩、千枚岩所组成。且岩浆岩和火山岩均不发育,岩层产状平缓。以此同前者成矿带成为鲜明的对照。
I. Overview The iron deposits in volcanic rocks distributed along the NW strike in the Aletai region may vary in their genesis. However, this paper only discusses the genesis of the apatite-magnetite deposit in Aba Palace. The deposit is produced in volcanic rocks in the Altai-Lower Devonian. The volcanic rocks are quartz horn porphyry, volcanic lava and tuff, and metamorphic rocks such as marble and quartz mica schist. Moreover, the later magmatism was frequent with acidic and bedrock veins and shallow intrusions (micro-granites). The rock strata in this area are upright, developed and ruptured. The tectonic line tends to be in the same direction, which is 290 ~ 310 °. The regional metamorphism of rocks is generally greenschist facies, and some reachable amphibolite facies. It is observed that this Allergy slender metallogenic belt is actually a zone of metamorphism and dynamic metamorphism based on regional metamorphism. This belt is about 2Km wide in Abba Palace. The northeastern margin of the belt is a granite body, the southwest is the outcropping area of the middle-upper Devonian strata, and the middle-upper Devonian strata are composed of super-metamorphic slate and phyllite. And the magmatic rocks and volcanic rocks are not developed, rock formation smooth. With the former metallogenic belt become a sharp contrast.