Geochemical features and tectonic Significance of meta-basalt in Zhoujiawan area of Hubei province

摘要

The meta-basalts in Zhoujiawan area are located at the boundary tectionic melange betwwen Qinling-Dabie microplate and Yangtze plate. The rocks were formed during Indo-Chinese epoch ad belong to subalkaline tholeiite association. They show a flat REE distribution pattern and a slight LREE enrichment. The raitos of Th/Yb, Ta/Yb, Ti/Zr, Ti/Y, Zr/Y and Nb, Th mass density indicate that the meta-basalts in This region are very similar to the MORB originated from depleted mantle of asthenosphere, and imply a Small initial ancient ocean tectonic setting between Qinling-Dabie and Yangtze plates during middle Paleozoic-Early Mesozoic era. This meta-basalt block should be an important evidence, indicating that The Mianlue suture zone had extended to the south of Dabie mountain.