The Izanagi plate (named after the Shinto god

Izanagi Izanagi (イザナギ/伊邪那岐/伊弉諾) or Izanaki (イザナキ), formally referred to with a divine honorific as , is the creator deity (''kami'') of both creation and life in Japanese mythology. He and his sister-wife Izanami are the ...

) was an ancient

tectonic plate Plate tectonics (, ) is the scientific theory that the Earth's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. The model builds on the concept of , an idea developed durin ...

, which began

subducting Subduction is a geological process in which the oceanic lithosphere and some continental lithosphere is recycled into the Earth's mantle at the convergent boundaries between tectonic plates. Where one tectonic plate converges with a second pla ...

beneath the Okhotsk plate 130–100 Ma (million years ago). The rapid plate motion of the Izanagi plate caused northwest

Japan Japan is an island country in East Asia. Located in the Pacific Ocean off the northeast coast of the Asia, Asian mainland, it is bordered on the west by the Sea of Japan and extends from the Sea of Okhotsk in the north to the East China Sea ...

and the outer zone of southwest Japan to drift northward. High-pressure

metamorphic rocks Metamorphic rocks arise from the transformation of existing rock to new types of rock in a process called metamorphism. The original rock ( protolith) is subjected to temperatures greater than and, often, elevated pressure of or more, caus ...

were formed at the eastern margin of the drifting land mass in the Sanbagawa metamorphic belt, while low-pressure metamorphic rocks were formed at its western margin in the Abukuma metamorphic belt. At approximately 55 Ma, the Izanagi Plate was completely subducted and replaced by the western Pacific plate, which also subducted in a northwestern direction. Subduction-related

magmatism Magmatism is the emplacement of magma within and at the surface of the outer layers of a terrestrial planet, which solidifies as igneous rocks. It does so through magmatic activity or igneous activity, the production, intrusion and extrusion of ...

took place near the Ryoke belt. No marked tectonics occurred in the Abukuma belt after the change of the subducted plate. The discovery of an extinct

Jurassic The Jurassic ( ) is a Geological period, geologic period and System (stratigraphy), stratigraphic system that spanned from the end of the Triassic Period million years ago (Mya) to the beginning of the Cretaceous Period, approximately 143.1 Mya. ...

–

Cretaceous The Cretaceous ( ) is a geological period that lasted from about 143.1 to 66 mya (unit), million years ago (Mya). It is the third and final period of the Mesozoic Era (geology), Era, as well as the longest. At around 77.1 million years, it is the ...

spreading system in the northwest Pacific led to the introduction of the extinct Kula plate in 1972. The Izanagi plate was subsequently introduced in 1982 to explain the geometry of this spreading system. Knowledge of the former Izanagi plate is limited to

Mesozoic The Mesozoic Era is the Era (geology), era of Earth's Geologic time scale, geological history, lasting from about , comprising the Triassic, Jurassic and Cretaceous Period (geology), Periods. It is characterized by the dominance of archosaurian r ...

magnetic lineations on the Pacific plate that preserve the record of this subduction.

References

* *

External links

Geodynamics of Japanlate Cenomanian – early Campanian (PDF)
(not available without registration (free)) {{Tectonic plates Tectonic plates Historical tectonic plates Cretaceous geology Natural history of Japan Natural history of Asia

See also

References

External links