caa a22 4500 606149724 CHVBK 20210128100535.0 cr unu---uuuuu 210128e20151101xx s 000 0 eng 10.1007/s00531-015-1244-5 doi (NATIONALLICENCE)springer-10.1007/s00531-015-1244-5 Natural glass from Deccan volcanic province: an analogue for radioactive waste form [Elektronische Daten] [Nishi Rani, J. Shrivastava, R. Bajpai] Deccan basaltic glass is associated with the differentiation centres of the vast basaltic magmas erupted in a short time span. Its suitability as a radioactive waste containment chiefly depends on alteration behaviour; however, detailed work is needed on this glass. Therefore, the basaltic glass was treated under hydrothermal-like conditions and then studied to understand its alteration. Moreover, comparison of these results with the naturally altered glass is also documented in this paper. Solutions as well as residue obtained after glass alteration experiments were analysed. Treated glass specimens show partial to complete release of all the ions during alteration; however, abundant release of Si and Na ions is noticed in case of almost all the specimens and the ionic release is of the order of Na>Si>K>Ca>Al=Mg>Fe>Mn>Ti. Scanning electron images of the altered residue show morphologies of smectite, montmorillonite and illite inside as well as outside of the secondary layers, and represent paragenesis of alteration minerals. It has been noticed that the octahedral cation occupancies of smectite are consistent with the dioctahedral smectite. The secondary layer composition indicates retention for Si, Al, and Mg ions, indicating their fixation in the alteration products, but remarkably high retention of Ti, Mn and Fe ions suggests release of very small amount of these elements into the solution. By evolution of the secondary layer and retention of less soluble ions, the obstructive effect of the secondary layer increases and the initial constant release rate begins slowly to diminish with the proceeding time. It has been found that devitrification of glass along the cracks, formation of spherulite-like structures and formation of yellowish brown palagonite, chlorite, calcite, zeolite and finally white coloured clays yielded after experiments that largely correspond to altered obsidian that existed in the natural environment since inception ~66Ma ago. Springer-Verlag Berlin Heidelberg, 2015 Obsidian nationallicence Hydrothermal-like conditions nationallicence Alteration nationallicence Microtexture nationallicence Secondary layers nationallicence Clay mineralogy nationallicence Rani Nishi Department of Geology, University of Delhi, 110007, Delhi, India aut Shrivastava J. Department of Geology, University of Delhi, 110007, Delhi, India aut Bajpai R. BETDD, Nuclear Recycle Group, BARC, 400008, Mumbai, India aut International Journal of Earth Sciences Springer Berlin Heidelberg 104/8(2015-11-01), 2163-2177 1437-3254 104:8<2163 2015 104 531 https://doi.org/10.1007/s00531-015-1244-5 text/html Onlinezugriff via DOI BK010053 XK010053 XK010000 Metadata rights reserved Springer special CC-BY-NC licence nationallicence 1 research-article jats NATIONALLICENCE NATIONALLICENCE NL-springer NATIONALLICENCE 856 40 https://doi.org/10.1007/s00531-015-1244-5 text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Rani Nishi Department of Geology, University of Delhi, 110007, Delhi, India aut NATIONALLICENCE 700 1- Shrivastava J. Department of Geology, University of Delhi, 110007, Delhi, India aut NATIONALLICENCE 700 1- Bajpai R. BETDD, Nuclear Recycle Group, BARC, 400008, Mumbai, India aut NATIONALLICENCE 773 0- International Journal of Earth Sciences Springer Berlin Heidelberg 104/8(2015-11-01), 2163-2177 1437-3254 104:8<2163 2015 104 531