Sangihe Plate has recently (1990s) been postulated to be a

microplate A microplate, also known as a microtiter plate (''Microtiter'' is a registered trademark in the United States, therefore it should not be used generically without attribution), microwell plate or multiwell, is a flat plate with multiple "wells" ...

within the

Molucca Sea Collision Zone The Molucca Sea Collision Zone is postulated by paleogeologists to explain the tectonics of the area based on the Molucca Sea in Indonesia, and adjacent involved areas. Tectonics The tectonic relationship of the Sangihe Plate, Halmahera Plate, a ...

of eastern

Indonesia Indonesia, officially the Republic of Indonesia, is a country in Southeast Asia and Oceania between the Indian and Pacific oceans. It consists of over 17,000 islands, including Sumatra, Java, Sulawesi, and parts of Borneo and New Guine ...

Regional tectonics

The tectonic setting of the

Molucca Sea The Molucca Sea (Indonesian: ''Laut Maluku'') is located in the western Pacific Ocean, around the vicinity of Indonesia, specifically bordered by the Indonesian Islands of Celebes (Sulawesi) to the west, Halmahera to the east, and the Sula Islan ...

region is unique. It is the only global example of an active arc-arc collision consuming an oceanic basin via

subduction Subduction is a geological process in which the oceanic lithosphere is recycled into the Earth's mantle at convergent boundaries. Where the oceanic lithosphere of a tectonic plate converges with the less dense lithosphere of a second plate, the ...

in two directions. The

Molucca Sea Plate Located in the western Pacific Ocean near Indonesia, the Molucca Sea Plate has been classified by scientists as a fully subducted microplate that is part of the Molucca Sea Collision Complex. The Molucca Sea Plate represents the only known example ...

has been subsumed by tectonic microplates, the

Halmahera Plate Halmahera Plate has recently (1990s) been postulated to be a microplate within the Molucca Sea Collision Zone of eastern Indonesia. Regional tectonics The tectonic setting of the Molucca Sea region is unique. It is the only global example of an ac ...

and the Sangihe Plate. The whole complexity is now known as the

. The existence of Sangihe as a tectonic plate separate from the

is not yet entirely agreed upon by geologists. Some see Sangihe as a western slab of the Molucca Sea Plate, just as they regard Halmahera as an eastern slab of the Molucca Sea Plate. What is apparent to date is that Sangihe was part of the Molucca Sea slab subducted during the

Neogene The Neogene ( ), informally Upper Tertiary or Late Tertiary, is a geologic period and system that spans 20.45 million years from the end of the Paleogene Period million years ago ( Mya) to the beginning of the present Quaternary Period Mya. ...

between 45 Ma and 25 Ma.R. Hall and W. Spakman, ''Australian Plate Tomography and Tectonics'' in R. R. Hillis, R. D. Müller,''Evolution and Dynamics of the Australian Plate,'' Geological Society of America Special Papers 2003, #372, p. 377

Seismicity Seismicity is a measure encompassing earthquake occurrences, mechanisms, and magnitude at a given geographical location. As such, it summarizes a region's seismic activity. The term was coined by Beno Gutenberg and Charles Francis Richter in 19 ...

shows the west-dipping Sangihe reaches a depth of about . Both Sangihe and Halmahera are exposed to the surface while the Molucca Sea plate is completely subsumed below these two microplates. The southern boundary of the Molucca Sea Plate is also the boundary of the

Philippine Sea Plate The Philippine Sea Plate or the Philippine Plate is a tectonic plate comprising oceanic lithosphere that lies beneath the Philippine Sea, to the east of the Philippines. Most segments of the Philippines, including northern Luzon, are part of ...

and the

Australian Plate The Australian Plate is a major tectonic plate in the eastern and, largely, southern hemispheres. Originally a part of the ancient continent of Gondwana, Australia remained connected to India and Antarctica until approximately when India broke ...

, and is moving northwards. Since the Sangihe Plate and the Halmahera Plate are in continuity with the Molucca Sea Plate, this implies all three slabs are moving northward in mantle with the

References

Tectonic plates Geology of the Pacific Ocean Geology of Indonesia Geology of the Philippines Molucca Sea {{tectonics-stub

Regional tectonics

See also

References