FLUID INCLUSION STUDY OF VEIN FILLINGS WITHIN KURRAT METAVOLCANICS, SONRAI BASIN, LALITPUR DIST., U.P., INDIA

Abstract

Fluid inclusions are small amount of fluid that were trapped within crystals during initial growth from solution or during localized crystallization along fractures at some later time. The minerals suitable for study of fluid inclusions are quartz, calcite, fluorite, topaz etc. Among them quartz offers the best chance of success because of its widespread geological occurrence, transparency and tendency to trap relatively large inclusions. Though fluid inclusions represent minuscule fraction of the fluid that was present, yet careful study of them can yield valuable information about that fluid. The information obtained from these fluid inclusions give an aid to geologist for understanding the fluids which existed in past. Kurrat Metavolcanics in Sonrai Basin contains some veins filled with quartz and calcite. Five samples have been taken from vein material. From petrographic study it is observed that both primary and secondary biphase inclusions rich in liquid are present. Ten primary inclusions larger than five micron form quartz vein in SAMPLE-1 has been selected for thermometric analysis. All the inclusions homogenize in liquid phase at temperature ranges from 117°C tol64°C. Homogenization temperature and salinity of the fluid inclusions falls within the field of Mississippi Valley-type (carbonate hosted) Zn-Pb-fluorite-barite deposits. The parental fluid was interpreted to be formational fluid as there is no evidence of boiling.