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Stock-like granite plutons in the Eastern Ghats belt and their host granulites exhibit similar solid state fabric. Both mineralogically and chemically these plutons are peraluminous and granitic in composition with S-type granite affinities. The granite plutons are product of a variety of mica dehydration melting reactions, as evident from their (1) compositional plots in the (FeO + MgO) - NaO.AlO - KO.AlO (MNK) pseudoternary diagram and (2) trace element contents. Muscovite and/or biotite breakdown reaction with or without plagioclase are the characteristic melting reactions. Restitic signature is evident in the host metapelitic granulites, locally known as khondalites (Qtz-Kfs-Grt-Sil-Fe-Ti oxides-bearing gneisses). The compositional variability of the associated khondalites can be a result of (1) original compositional variation and (2) they represent different stages of restites. Trace element monitoring following restite separation model suggests that these granite plutons are largely saturated equilibrium melts. The granites are chemically discriminated as syn-collisional. The plutons could also be the product of segregation during the regional exhumation of the Eastern Ghats terrain. [ABSTRACT FROM AUTHOR]

Abstract: The present work is contributed for the softening of water using natural sand materials taken from Rameswaram Island, South India. After the study on the water quality parameters from well, tank, pond and spring sources, the sand materials from the respective sites were identified to be the able candidates as water softeners. The Si/Al ratio for the sand material from Sethumadhava tank was found to be closely resembling zeolites, majorly the clinoptilolite type. The surface area, pore volume and cation exchange capacity of Sethumadhava sand was greater than the from Uchipuli sand. From the column studies, the parameters viz., q tot, column performance and q eq were calculated as a function of particle size, source, regenerant, initial Ca2+ concentration and bed depth. The water softening efficiency was increased according to the increase in sodium chloride concentration, initial Ca2+ concentration and bed depth. The dissolution of Al and Si during the softening process has also been discussed. The sand materials have been characterized with FTIR, SEM, XRD, solid state MAS NMR and solid state DRS techniques before and after the softening process. [Copyright &y& Elsevier]