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Authors
Affiliations
1 National Mineral Development Corporation Limited, Khanij Bhavan, Masab Tank, Hyderabad - 500 028, IN
2 Department of Geology, PG College of Science Saifabad, Osrnania University, Hyderabad - 500 004, IN
Source
Journal of Geological Society of India (Online archive from Vol 1 to Vol 78), Vol 68, No 2 (2006), Pagination: 201-206
Abstract
The Velugumetla barite deposit, Khammarn district is studied for fluid inclusions, sulphur and strontium isotopes The inclustons that are random in distnbution and varying in size from 15-30 μ are classed as primary and the inclusions le ss than 15 μ in size and having linear trails as secondary Heating runs of the primary and secondary inclusions show peaks at 235° C to 245 °C(Th) and 130°C to 140°C respectively Both the primary and secondary biphase liquid rich(L+V) inclusions hornogenized by the disappearance of the vapour phase The composition of fluid has been surmised as H2O+NaCl+KCl The salinity was calculated as 12 7 wt% NaCI eqv The minimun depth of precipitation of barite was estimated to be 300 m and the density calculated as 0 94g/cm3 with a fluid pressure of 31 2 bars The fluid inclusion data of barite veins of vein bantes of Velugumetla, Khammarn district and other vein deposits of the Cuddapah Basin are correlatabte in terms of composition, salinity, density, pressure depth of entrapment and temperature of homogenization.
The δ
34S values for barite varies between +23 5 to+25 6 %O and pyrite has values between -0 9 to + 1 9 %O in case of the barite pyrite pairs that were studied from six different localities of the Cuddapah Basin and Khammam The δ<sup34 S values of the vein barite deposits of the Cuddapah Basin and Khammam area similar to the contemporaneous sea water The strontium isotope (
87Sr/
86Sr)ratios) show wide variation 0 705 to 0 722 for the vein barites of Cuddapah Basin and Kharnmam and indicates significant contribution of radiogenic Sr from older continental crust.
Keywords
Fluid inclusions, sulphur Isotopes, Strontium Isotopes, Velugumetla, Khammam district, Cuddapah Basin, Andhra Pradesh.
