一、前言根据对世界各国富铁矿床的综合调查和考察研究,发现这些含富铁矿的大铁矿,差不多都是在“前寒武纪”地层中(主要是距今17-25亿年以前)形成的,如我国鞍山铁矿、苏联库尔斯克铁矿、澳大利亚哈默斯利铁矿、美国上湖铁矿、巴西卡腊贾斯铁矿以及朝鲜、印度和南非联邦(即阿扎尼亚)等一些著名大铁矿,它们的地层时代、矿石成分、矿体大小和矿床 I. Preface According to the comprehensive investigation and study on the iron-rich deposits in various countries in the world, it is found that these iron-rich iron-bearing large iron mines are almost all in the Precambrian strata (mainly from 1.7 to 2.5 billion years ago Years ago) such as the Anshan Iron Mine in our country, the Kursk Iron Mine in the Soviet Union, the Hammersley Iron Mine in Australia, the Upper Lake Iron Mine in the United States, the Kalimazias Iron Mine in Brazil and the North Korea, India and South Africa Federation Zhania) and some other famous big iron mines, their stratigraphic age, ore composition, ore body size and deposit