Significance of assimilation and fractional crystallization (AFC) process in the generation of basaltic lava flows from Chhotaudepur area,Deccan Large Igneous Province,NW India |
| |
| Authors: | K R Hari Vikas Swarnkar M P Manu Prasanth |
| |
| Institution: | 1.School of Studies in Geology and Water Resource Management,Pt. Ravishankar Shukla University,Raipur,India;2.Department of Civil Engineering,Yugantar Institute of Technology and Management,Rajnandgaon,India |
| |
| Abstract: | Basaltic and basaltic andesitic flows have been identified from the Chhotaudepur area in the Deccan Large Igneous Province. The \(\hbox {SiO}_{2}\) content of these flows varies from 46.7 to 53.7 wt%. None of the samples have primary magma signatures as they exhibit low Mg# (0.42–0.68), Ni (4.8–33.4 ppm) and Cr (33.08–143.06 ppm). Highly variable concentrations of the LILE Rb (2–74 ppm), Ba (52–351 ppm), Cs (0.1–1 ppm) and Sr (273–745 ppm)] and relatively enriched LREE are also noticed. The coherent chondrite normalized REE diagram and primitive mantle normalized multi-element diagram suggests a consanguinity among the flows. Low (Nb/Th)\(_{\mathrm{PM}}\) (0.30–1.09), high (Th/Yb)\(_{\mathrm{PM}}\) (3.09–16.58) ratios and marked variations in Rb concentration (2.4–74.11 ppm) with variable La/Yb (5.5–23.7) ratios suggests that magmas in the Chhotaudepur region were assimilated by the crustal components. The elevated Th/Ta and La/Yb relation further indicate concurrent assimilation and fractional crystallization process was involved in the genesis of the flows. Assimilation and fractional crystallization modelling of the flows was carried out with 20% olivine, 25% clinopyroxene, 45% plagioclase and 10% titano-magnetite as fractionating minerals and upper continental crust as the assimilant. The results reveal that all the flows were modified by AFC process. |
| |
| Keywords: | |
| 本文献已被 SpringerLink 等数据库收录！ |
|
