Articles written in Proceedings – Section B
Volume 64 Issue 5 November 1966 pp 267-272
The study of the riebeckite syenite from Idamakallu-Racherla area shows interesting textural and microstructural features. Based on the petrographical and petrochemical evidence, it is surmised that a rock, which was originally a hornblende syenite, has been transformed into riebeckite syenite through soda-metasomatism. The way in which the mineral transformations took place and the secondary minerals have developed is discussed.
Volume 67 Issue 4 April 1968 pp 174-179
The occurrence of some nickel silicate minerals as encrustations along joint planes and shear zones of the chromite bearing ultrabasic rocks of Nuggihalli schist belt is described. Chemical and X-ray study shows besides amorphous nickel silicate, the presence of granierite, nepouite or nickel antigorite. The nickel minerals are secondary developed by the action of circulating waters. The source of nickel is olivine, in the structure of which Ni is known to be present, either as camouflaged or captured ion.
Volume 72 Issue 1 July 1970 pp 41-46
Minerographic study of the ore samples collected from Ingaldhal copper mines shows that the ores are largely massive, banded and disseminated in structure. Pyrite, arsenopyrite, cobaltite, sphalerite, pyrrhotite, galena and chalcopyrite as primary minerals and pyrrhotite, chalcopyrite, stromyerite, bornite, chalcocite and tennantite as secondary minerals are present. The ores exhibit inclusion, panidiomorphic, mutual boundary, exsolution and replacement textures. From the mineralogical assemblage and the textures it is inferred that the ore deposits were formed inthe temperature range of 350°–500° C.