Relation of Isotope Geochemical Steep Zones with Geophysical Fields and Tectonics in the J

Relation of Isotope Geochemical Steep Zones with Geophysical Fields and Tectonics in the Junction Area of the Cathaysian, Yangtze and Indochina

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【期刊名称】《地质学报（英文版）》 【年(卷),期】2000(074)002

【摘要】Through lead isotope geochemical mapping in the Yunnan-Guizhou area geochemical steep zones (GSZ) have been established, which clearly reveal the junction relationship of the Cathaysian, Yangtze and Indo-China plates. GSZ are closey related to gravity Moho gradient zones and lithospheric thickness. The GSZ between the Yangtze and Cathaysian plates is consistent with the Shizong-Mile tectonic belt, where island arc basalts are well developed. The Yangtze-Indo-China GSZ is parallel to the Jingdong-Mojiang volcanic belt in rift-island arc environments. The evidence of geology, geophysics and geochemistry all indicates that Cathaysia was subducted towards the Yangtze plate and that the Yangtze plate was underthrust beneath the Indo-China, which took place from the Early Carboniferous to the Early Triassic. 【总页数】5页(236-240)

【关键词】junction relationship of the Cathaysia;Yangtze and Indo-China plates;geochemical steep zone;gradient zone of gravity Moho