摘要
Presenting the analysis data of whole rock chemistry, REE and trace element and Sr, Nd, Pb isotopes of the rhyolite, and 27 isotopic dating of the Cenozoic bimodal volcanic rocks from West Qinling. The studies showed that the Cenozoic bimodal volcanic rocks like to East Africa rift, consisted of kamafugite, carbonatite, shoshonite, rhyolite and/or trachyte. All of these are similar to the feature of Neo-Tethyan mantle geochemical domain, the magma origined from depleted mantle resources like Onto Java and FOZO mantle plum, suggest the origin and genesis of Cenozoic bimodal volcanic rocks related to northeastward migration and upwelling of the India-Asia collision-deduced mantle flow, and also responses to eastward expanding of the Tibetan plateau. Cenozoic bimodal volcanic rocks in West Qinling providing ideal lithoprobes for understanding N-S trending tectonic belt and support for the N-S trending tectonic belt is a continental rift.