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. The scale and type of volcanism varies from monogenetic cinder cone fields to large stratovolcanoes and calderas. Composition of volcanic rocks range from tholeiitic basalt to andesite to shoshonite . Plates and micro-plates shown in different colors. Volcanism associated with this subduction zone began about 10 million years ago.