| Abstract |
The analysis of the 8's isotopic compositions of the surfates and suljides dissolved in the present dqv geothermal jluids and gases of the Palinpinon Geothennal Field, Philippines reveal that a majority of the acidic wells in the field displqv condtions of isoiopic disequilibirum (IS denoted byfiactionation factors that are much smaller than the equilibrium values at the depitional temperatures. Bmed on evidencesfiom other foreign geothennalfields, it is believed that this apparent non-equilibrium condition is caused by the partial oxidation of the geothermal brine along the shallow prt.ons of the reservoir. Other evidences indicating that H S partial oxidation is the main source of acidity among Palinpinon wells include the wide variation in the 8's values in surfate and the apparent genetic connection of these acidfluids with the Kaiphans of Cuernos de Negros based on current #'O and Deuterium data Near equilibrium depositional values in BLID, PN22D, PN2OD and NJ6D are believed to be the result of the re-equilibration of these acidicjluids formed along shallow oxidaton zones) as these percolate down to the deeper portions of the reservoir where prevalent conditions @e., high temperatures, low pH and high Ls) favor the rapid &-equilibration of P S of aqueous surfate with the suljides in HS. |