| Geochemistry of Two Types of Basalts in the Emeishan Basaltic Province: Evidence for Mantle Plume-Lithosphere Interaction |
| |
| 作者姓名： | ZHANG Zhaochong and WANG Fusheng Institute of Geology Chinese Academy of Geological Sciences Beijing Liu Shuchun Liu Xinzhu |
| |
| 作者单位： | ZHANG Zhaochong and WANG Fusheng Institute of Geology，Chinese Academy of Geological Sciences，Beijing 100037 Liu Shuchun Liu Xinzhu |
| |
| 摘 要： | 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 pa
|
Geochemistry of Two Types of Basalts in the Emeishan Basaltic Province: Evidence for Mantle Plume-Lithosphere Interaction |
| |
| Authors: | ZHANG Zhaochong and WANG Fusheng Institute of Geology Chinese Academy of Geological Sciences Beijing Liu Shuchun Liu Xinzhu |
| |
| 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. |
| |
| Keywords: | Emeishan basalts HPT basalt LPT basalt mande plume crystal fractionation |
| 本文献已被 CNKI 万方数据 等数据库收录！ |
| 点击此处可从《Acta Geologica Sinica》浏览原始摘要信息 |
| 点击此处可从《Acta Geologica Sinica》下载免费的PDF全文 |
|
