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1.火山岩主要形成于早元古代以来的各个时期,并以早元古代及古生代最发育.据已有资料,火山成因的富铁矿主要分布于晋宁期(或更古老的元古界构造运动)的地槽
1. Volcanic rocks are mainly formed in various periods since the Early Yuan Dynasty and are most developed in the Early Proterozoic and Paleozoic. According to the available data, volcanic iron-rich ore deposits are mainly distributed in Jinning Period (or more ancient Proterozoic structures Movement) of the trough