Geothermal Geology and Review of Exploration, Biliran Island

Abstract

Biliran Island has been the subject of a geoscientific exploration programme, and the most promising area is currently being drilled. The first exploratory well has confirmed high temperatures at depth, although it did not encounter significant permeability. The major thermal features of Biliran are located close to a fault, and their chemistry (acid-sulphate-chloride) indicates an input of magmatic volatiles. It is conjectured that magmatic volatiles are rising on the fault, but that away from this zone a more typical convective hydrothermal system exists. There are similarities to the Krafla Geothermal Field in Iceland.