Geochemistry and Petrogenesis of Tertiary Volcanic Rocks of the Eastern Roodbar, Alborz Mountain, North of Iran
| Autor: | Mansour Vossoughi Abedini, zahra Shafeie, Mohammad Ali Arian, Shahrouz Haghnazar |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Basalt
geography Olivine geography.geographical_feature_category 010504 meteorology & atmospheric sciences Andesite Continental crust Geochemistry Pyroxene engineering.material 010502 geochemistry & geophysics 01 natural sciences Volcanic rock Basaltic andesite engineering Petrology Geology 0105 earth and related environmental sciences Petrogenesis |
| Zdroj: | Open Journal of Geology. :1296-1311 |
| ISSN: | 2161-7589 2161-7570 |
| DOI: | 10.4236/ojg.2016.610095 |
| Popis: | In the Alborz Mountains of the eastern Roodbar (north of Iran), Tertiary volcanic rocks have a variety of composition between olivine basalt, basaltic andesite, pyroxene andesite and andesite. The presence of different xenoliths and xenocrysts is among the evidence of crustal contamination of these rocks. The positive correlations of CaO/Al2O3 vs to MgO and Al2O3 vs. SiO2 are of signs of the olivine and clinopyroxene fractionation in the variation trend of the area rocks. Positive correlations K2O/P2O5 vs with SiO2 and La/Sm vs. K2O/P2O5 demonstrate contamination of magma with the continental crust. The incompatible trace element patterns and their comparison with crustal contents indicate contamination of the rocks of the area with the lower and upper continental crust. Linear trends in the variation diagram of Nb/Y vs. Zr/Y, introduce two different source regions: a MORB source and the other continental crust for the rocks which are the genesis. The variations of Y/Nb vs. Zr/Nb and Rb/Y vs. Nb/Y reveal a crustal contamination of the magma originated from the MORB source. Geochemical studies represent that the area’s rocks were derived from the 15% melting of a mantle source of MORB type with spinel facies within a continental environment, which was contaminated by varying degrees of continental crustal rocks. |
| Databáze: | OpenAIRE |
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