地质学报（英文版）2002，Vol.76Issue(2)：229-237,9.
Geochemistry of Two Types of Basalts in the Emeishan Basaltic Province: Evidence for Mantle Plume-Lithosphere Interaction
Geochemistry of Two Types of Basalts in the Emeishan Basaltic Province: Evidence for Mantle Plume-Lithosphere Interaction
摘要
Abstract
Based on the temporal-spatial distribution and geochemical characteristics, the Emeishan basalts can be divided into two types: high-P2O-TiO2 basalt (HPT) and low-P2O5-TiO2 basalt (LPT), which differ distinctly in geochemistry: the LPTs are characterized by relatively high abundances of MgO, total FeO and P2O5 and compatible elements (Cr, Ni, Sc), and relatively low contents of moderately compatible elements (V, Y, Yb, Co), LREE and other incompatible elements compared with the HPT. On the diagrams of trace element ratios, they are plotted on an approximately linear mixing line between depleted and enriched mantle sources, suggesting that these two types of basalts resulted from interactions of varying degrees between mantle plume and lithospheric mantle containing such volatile-rich minerals as amphibole and apatite. The source region of the LPT involves a smaller proportion of lithospheric components, while that of the HTP has a larger proportion of lithospheric components. Trachyte is generated by partial melting of the basic igneous rocks at the base of the lower continental crust. Both the two types of magmas underwent certain crystal fractionation and contamination of the lower crust at high-level magma chambers and en route to the surface.关键词
Emeishan basalts/HPT basalt/LPT basalt/mantle plume/crystal fractionationKey words
Emeishan basalts/HPT basalt/LPT basalt/mantle plume/crystal fractionation分类
天文与地球科学引用本文复制引用
张招崇,王福生..Geochemistry of Two Types of Basalts in the Emeishan Basaltic Province: Evidence for Mantle Plume-Lithosphere Interaction[J].地质学报（英文版）,2002,76(2):229-237,9.基金项目
This paper presents part of the result of the National Key Project (G1999043205). The authors are grateful to Sichuan Bureau of Geology and Mineral Resources and Yunnan Bureau of Geology and Mineral Resources for their support to this project during the f （G1999043205）
