Cross section across the Mariana Plate
The Mariana Plate is a small tectonic plate located west of the Mariana Trench and forms the basement of the Mariana Islands. It is separated from the Philippine Sea Plate by a long divergent boundary with numerous transform fault offsets. The boundary between the Mariana and the Pacific Plate to the east is a subduction zone with the Pacific Plate subducting beneath the Mariana. The Mariana Trench forms the southeastern boundary and the Izu-Ogasawara Trench the northeastern boundary.