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dc.contributor.authorPattan, J.N.
dc.contributor.authorPearce, N.J.G.
dc.contributor.authorParthiban, G.
dc.contributor.authorSmith, V.C.
dc.contributor.authorMudholkar, A.V.
dc.contributor.authorRao, N.R.
dc.date.accessioned2013-12-10T05:55:27Z
dc.date.available2013-12-10T05:55:27Z
dc.date.issued2013
dc.identifier.citationQuaternary International, vol.313-314; 2013; 230-239
dc.identifier.urihttp://drs.nio.org/drs/handle/2264/4400
dc.description.abstractPumice clasts, partially and fully coated with ferro-manganese oxide from the Central Indian Ocean Basin (CIOB) were analysed for major, trace and rare earth elements; and glass and mineral grain chemistry to assess their possible source. These pumice clasts have approx95% glassy matrix with approx5% of plagioclase, ortho-pyroxene, amphibole, and spinel mineral grains. Pumice is rhyolitic, with high content of silica and total alkalis and show strong light rare earth element enrichment, with La approx100 times enriched compared to chondritic abundance and exhibits a pronounced negative Eu-anomaly. Both the partially and fully coated pumice clasts have a similar composition, but this, and their, glass and mineral (orthopyroxene) chemistry differs from all tuffs known to have erupted from the Toba Caldera Complex. The partial to complete Fe–Mn oxide coating suggests the pumice probably predates activity from the Toba caldera. Their general composition is consistent with a volcanic arc origin, and show similarities to rhyolitic eruptives from Sumatra. The distribution of partially and fully coated pumice in the CIOB overlaps with that of uncoated pumice from the voluminous YTT eruption, suggesting that other large rhyolitic calderas active in Sumatra/Indonesia. Similarities in composition to ash layers from the CIOB suggest a possible Late Miocene – Late Pleistocene age for these pumices.
dc.language.isoen
dc.publisherElsevier
dc.rightsAn edited version of this paper was published by Elsevier. Copyright [2013] Elsevier
dc.subjecttrace metals
dc.subjectearth elements
dc.subjectferro-manganese oxide
dc.subjectpumice
dc.titleThe origin of ferro-manganese oxide coated pumice from the Central Indian Ocean Basin
dc.typeJournal Article


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