The role of shoshonitic and calc-alkaline suites in the tectonic evolution of the Carajás District, Brazil |
| |
| Authors: | MA Dardenne CF Ferreira Filho MR Meirelles |
| |
| Abstract: | In the Carajás District, the Bahia Prospect and Grão Pará volcanosedimentary sequences, both of Archean age, have been the object of extensive petrochemical studies for major, trace, and rare earth elements. In spite of the widespread spilitization that affected the volcanic mafic rocks, the petrochemical nature of the mafic volcanism may still be assessed on the basis of the less mobile elements like P, Cr, Zr, Nb, Ti, and REE. The Bahia Prospect basalts have a petrochemical affinity with Phanerozoic island-arc calc-alkaline basalts. The Grão Pará basalts and basaltic andesites, on the other hand, have a petrochemical affinity with Phanerozoic basalts of a mature island arc environment. The petrochemical data presented here lead to a new geotectonic interpretation of the area, where the volcanic sequences are genetically linked to Archean subduction processes. |
| |
| Keywords: | |
| 本文献已被 ScienceDirect 等数据库收录！ |
|
