Daerah penyelidikan terletak di Kabupaten Donggala, Sulawesi Tengan meliputi luas lk. 624km2, termasuk kedalam mendala Barat Sulawesi yang dicirikan oleh komplek batuan metamorf dinamotermal dan instrusi granodiorit. Komplek batuan metamorf berumur pra kapur termasuk kedalam tipe Barrow (tipe tekanan menengah), terdiri dari sekis-biotik, amfibolit, genes-biotik, sekis-khlorit, sekis-aktinolit, …
The volcanic rocks mainly consist of lava flows and pyroclastic deposits that are exposed at the bridgewater, Nelson and Grant volcanis compoxes. Yhe pyroclastic deposits resulting from phreatomagmatic eruption varu in physical characteristics that are likely caused by fluctuation of magma/water ratio during interaction.