中国北方早、中前寒武纪磷矿

中国北方早、中前寒武系磷矿有四个层位六种类型。太古代磷矿主要产于中朝地块内的华北陆核、辽吉南部—朝鲜北部陆核及山东陆核等陆核区。早元古代早期,在太古代陆核边缘或中间地块沉积了优地槽型磷矿。早元古代晚期有大陆边缘和拗拉槽白云质碳酸盐建造的磷矿床与克拉通内盆地陆屑和复理石建造的磷矿床,其中大陆边缘型最重要,构成了长约4000多公里的巨大“S”形成矿带。早元古代末期,五台运动之后,有同造山期的山间盆地磷矿床形成。

THE EARLY-MIDDLE PRECAMBRIAN PHOSPHATE DEPOSITS IN NORTH CHINA

The early-Middle precambrian phosphate deposits in North China are essentially laid within and are demonstrated by four Phosphate-bearing beds of six types.These beds are of ( 1 )Archaeozoic (Represented by Fengning type), ( 2 )Lower Proterozoic (Represented by Gixi type), ( 3 )upper Lower Proterozoic (represented by Haizhou,Bulongtu and Bei jiashan types)and( 4 )Lower Proterozoic (Represented by Luotun type) .The Archaeozoic deposits are mainly located on old continental nucleus in North China, South Liaoning, South Jilin and Shandong.In the early Early Proterozoic on the margin of Archeaozoic continental nucleus or on the intermediaty massif Phosphates deposited in eugeosynclinal basins. In the late Early Proterozoic phosphates deposited at continental margin or in aulacogen in association with dolo-mitic carbonates, terrigenous clast and flysch formations. The continental margin phosphates,extending approximately 4000km forming a Ss haped mineralization belt, are most important.After the Wutai orogenic movement in late Early Proterozoic, minor phosph orous mineralizations took place in intermontane basins in association with molasse formation.In the present paper the different deposits have been described in detail in respect of their time-place distribution, composition,mineralization, and evolution.