"International Journal of Geography, Geology and Environment"

Author(s): Prashant Uttamrao Terker

Abstract: Many mafic dykes in the Marathwada region of the Deccan Trap Province give important information about petrogenetic and magmatic evolution of this large igneous province. They are one of many dykes composed of tholeiitic basalts that acted as feeder channels for Deccan volcanism, and show distinct textural and mineralogical characteristics. Mineral assemblage consists of plagioclase, clinopyroxene, and olivine with zeolites and calcite as secondary phases indicating post magmatic alteration. Vesicular and porphyritic textures presence indicates variability in cooling rate and degassing during emplacement. Understandably, study of dykes is important for reconstruction of the regional tectonic framework, whose orientation and distribution are related to extensional stress regimes active at the time of Late Cretaceous. Major, trace, and rare earth element (REE) analyses of these dykes from petrochemical investigations have indicated similar geochemical characteristics of these dykes as compared to Deccan basaltic flows, with variation in elemental concentrations, showing fractional crystallization and crustal contamination. Geochemical ratios including Fe/Mg and LREEs vs. HREEs suggest a heterogeneous mantle source in which Réunion hotspot plume was involved. Partial melting and magma differentiation are shown by the study to control chemical evolution of these intrusions. Knowledge of Deccan magmatism is improved by understanding the petrology and petrochemistry of dykes in the Marathwada region and can also be applied more broadly to continental flood basalt provinces and mantle dynamics.

DOI: 10.22271/27067483.2022.v4.i2a.342

Pages: 84-89 | Views: 123 | Downloads: 46

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