Overprinting of Hydrothermal Regimes in the Palimpinon Geothermal Field, Southern Negros, Philippines

Abstract

Two major hydrothermal regimes are evident from the alteration mineralogy in the Palimpinon Geothermal Field. A relict mineral zonation consisting potassic, advanced argill and propylitic zones appears to have formed in response to the intrusion of a large in the western section of the field. A recent mineral zonation, that is interpreted to have formed during the current geothermal system, is superimposed on the relict system and appears to be centered around the eastern portion of the field. of a failed o r barren porphyry copper system. The i c t advanced i c mineralogy is interpreted to be of magmatic fluid origin and probably has not formed from the present geothermal regime with i t s predominant meteoric fluid component. The abundant anhydrite being deposited in this geothermal system is interpreted to have originated by redistribution of anhydrite formed initially during the relict magmatic hydrothermal system. Most Philippine systems are similar .