What caused the formation of Mount Pinatubo?
Mount Pinatubo is one of a chain of composite volcanoes that constitute the Luzon volcanic arc. The arc parallels the west coast of Luzon and reflects eastward-dipping subduction along the Manila trench to the west. The plate tectonics in the Philippines is complex and includes plate boundaries that are changing rapidly. Several micro-plates are getting squeezed between two convergent plate margins. Stratigraphic evidence indicates cessation and reactivation of subduction at some trenches. The currently active volcanoes in the Philippines define two north-south trending arcs. Mount Pinatubo is among the highest peaks in west-central Luzon. Its former summit, at 1,745 meters elevation, may have been the crest of a lava dome that formed about 500 years ago during the most recent previous major eruptive episode. See the links below for additional information. Hope this helps.
