超大型矿床全球背景——大陆板块源于天外的探讨

GLOBAL BACKGROUND OF SUPERGIANT DEPOSITS: THE VIEWPOINT THAT CONTINENTAL PLATES ORIGINATE FROM OUTER SPACE

作者根据碳酸岩、金伯利岩、金刚石矿床和大型、超大型硼矿床与碳质球粒陨石的成因联系,根据超大型矿床密集区中超大型矿床组合与某些陨石中相对富集元素组合的一致性,对全球主要矿床分布规律进行了综合研究,提出地球大陆岩石圈可能主要是由碳质球粒陨石组成的星子(C群星子)演化而来。论文认为,4100—3900Ma时,(群星子陨击地球,形成主要由C群星子组成的原始微板块。富含水、碳和有机物的C群微板块在局部熔融的过程中形成绿岩、花岗岩,并释放出大量水和二氧化碳,形成双层结构的大陆岩石固、原始的酸性水圈和二氧化碳气圈。不同星子形成的大陆岩石圈,成矿元素背景不一致,导致在大陆的不同部位形成不同的超大型矿床密集区。

Based on the genetic relationship of carbonate rocks, kimberlite, diamond deposits nd large or supergiant boron deposits to carbonaceous chondrite, and in the light of the onsistency between the association of supergiant deposits in their concentrated areas and the ssociation of relatively enriched elements in some meteorites, the author has made an ntegrated investigation into the distribution regularity of the major ore deposits all over he orld and, on such a basis, put forward the viewpoint that the continental lithospheres of the arth were formed mainly through the evolution of the planetesimals(those of Group C) composed f carbonaceous chondrites.This paper holds that during 4100—3900Ma the planetesimal of Group ell from the outer space and rammed the earth, forming primitive microplates composed mainly f lanetesimals of Group C. In the process of their localized melting, the microplates rich in ater, carbon and organism formed greenstone and granite and released large quantities of water nd carbon dioxide, generating continental lithospheres with double-layer structure, primitive cid hydrosphere and carbon dioxide atmosphere. Continental lithospheres formed by different lantesimals had different backgrounds of metallogenic elements, resulting in the formation of ifferent concentrated areas of supergiant deposits at different places of the continent.