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dc.contributor.authorDoley, B.
dc.contributor.authorSaha, A.
dc.contributor.authorRamMohan, M.
dc.contributor.authorSen, Koushick
dc.contributor.authorPeketi, A.
dc.date.accessioned2024-10-03
dc.date.accessioned2024-10-10T11:46:02Z
dc.date.available2024-05-10
dc.date.available2024-10-10T11:46:02Z
dc.date.issued2024
dc.identifier.citationChemical Geology, vol.659; 2024; Article no: 122118
dc.identifier.issn0009-2541
dc.identifier.otherhttps://www.sciencedirect.com/science/article/pii/S0009254124001980
dc.identifier.urihttps://doi.org/10.1016/J.CHEMGEO.2024.122118
dc.identifier.urihttp://drs.nio.res.in/drs/handle/2264/9283
dc.descriptionIF2022= 3.9
dc.description.abstractThe present study provides new petrological and geochemical data of the dredged rocks from submarine volcanoes along the Andaman arc and describes the petrogenetic evolution of the arc system in terms of mantle wedge characteristics, nature and quantitative input of subducted slab components, and fractionation processes of precursor magma. The studied rocks include basaltic andesite, andesite, dacite and rhyolite. These volcanic rocks exhibit LILE, LREE enrichments and HFSE depletion, corroborating their generation through subduction processes. High abundances of Th/Nd, La/Sm(N), LREE/HFSE than LILE/HFSE, LILE/LREE suggest a substantial contribution of sediments from the subducting slab over slab-dehydrated aqueous fluids to the mantle wedge. The 87Sr/86Sr-Ba/La mixing model suggests 0.6-0.8% addition of slab fluid (90:10 AOC: sediment fluid) to account for the fluid signature, whereas the 143Nd/144Nd-La/Sm(N) mixing model envisages ?3-4% addition of sediment melt to the mantle source, reconciling the sediment signature in Andaman submarine volcanic rocks. The presence of N-MORB type mantle is attributed to the absence and/or inefficient convection of asthenospheric material from the Andaman back-arc basin to the mantle wedge. This ineffective convection can be equated with the flat subduction of the Indian Plate, caused by the convergence of the aseismic Ninety East Ridge. The non-modal batch-melting model suggests that 13-24% partial melting of the spinel lherzolite mantle beneath the Andaman submarine volcanic arc formed the parent magma. The crystallization model invokes up to 60-70% of fractionation of olivine, plagioclase, clinopyroxene, orthopyroxene, sanidine and magnetite in all the rock types with subordinate proportions of amphibole, biotite, apatite, ilmenite, and sanidine in rhyolites. The basaltic andesites, andesites and dacites do not show upper crustal input, while rhyolites indicate crustal contamination from an upper crust and/or arc crust.
dc.languageen
dc.publisherElsevier
dc.relation.isreferencedbySCI
dc.rightsOnly the author version of the copright reserved papers uploaded. Contact drs@nio.org for any complaints regarding copyright violations
dc.titlePetrogenesis of submarine volcanic arc rocks from Andaman subduction zone, Northeast Indian Ocean: Constraints from slab components and mantle wedge characteristics
dc.typeJournal Article
dc.affiliation.authorCSIR-National Institute of Oceanography, Dona Paula, Goa, India


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