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一、引言世界上超基性岩的分布同不同时代的褶皺山带有密切的关系,主要的超基性岩都产生在地槽中。根据不完全資料,中国主要的超基性岩也分布在地槽中。如中国北部超基性岩产在古生代地槽华力西褶皺带中;西北超基性岩产在加里东褶皺带中;西南超基性岩侵入于中生代地层中(属于中生代末期燕山褶皺带);也有侵入于新生代可能属于喜馬拉雅造山期的地层中。超基性岩在我国地盾区中也有分布,如西北、东北、华北及西南某些超基性岩均产在震旦纪地盾中。产在地盾区的超基性岩一般规模都很小。分布在地槽区的超基性岩,其所占面
I. INTRODUCTION The distribution of ultramafic rocks in the world is closely related to the folds in different times. The major ultrabasic rocks are all produced in the earth’s trough. According to incomplete information, the major ultrabasic rocks in China are also distributed in the trough. For example, the ultrabasic rocks in the northern part of China are located in the Paleozoic Devonian fold belt in the Paleozoic; the ultrabasic rocks in the Northwest China are in the Caledonian fold belt; the southwest ultrabasic rocks intrude into Mesozoic strata (belonging to the Yanshan fold belt in the late Mesozoic) ; Also invaded the Cenozoic may belong to the Himalayan orogenic strata. Ultrabasic rocks are also distributed in China’s shield zone. For example, some ultrabasic rocks in Northwest, Northeast, North China and Southwest China are all produced in the Sinian shield. Produced in the shield area of ultrabasic rocks are generally small scale. The ultrabasic rocks distributed in the terrain area account for the surface area