Fluid Inclusion Study of Vinjamuru Precambrian Stratiform Baryte Deposit, Nellore Schist Belt, A.P., India

The fluid inclusions in Vinjamuru baryte can be broadly classified into primary and pseudo-secondary types. Primary inclusions are represented by monophase carbonic and mixed carbonic-aqueous types. CO₂ densities lie in the range of 0.78-0.88 g/cm³. The pseudo-secondary inclusions are represented by aqueous bi-phase type, coexisting with vapor-rich inclusions. Their Th overlaps in the range of 220-230°C suggestive of entrapment from boiling fluids. The primary carbonic inclusions appear to be volcanic entrapments and the fluids in pseudo-secondary inclusions were entrapped from hydrothermal solutions.