* 1 Formation of Japanese Islands
* 2 Geological composition
* 2.1 General information
* 2.2 Geological structure
* 3 Research on Geology of
* 4 Current geological hazards of Japanese Islands
* 5 See also
* 6 References
* 7 Further reading
* 8 External links
FORMATION OF JAPANESE ISLANDS
The islands of
Japan are primarily the result of several large ocean
movements occurring over hundreds of millions of years from the
Silurian to the
Pleistocene as a result of the subduction of the
Philippine Sea Plate
Philippine Sea Plate beneath the continental
Amurian Plate and Okinawa
Plate to the south, and subduction of the
Pacific Plate under the
Okhotsk Plate to the north.
Around 23 million years ago, the now Western
Japan was a coastal
region of the
Eurasia continent. The subducting plates, being deeper
than the Eurasian plate, pulled parts of
Japan which become modern
Chūgoku region and
Kyushu eastward, opening the Sea of Japan
(simultaneously with the
Sea of Okhotsk
Sea of Okhotsk ) around 15-20 million years
ago, with likely freshwater lake state before the sea has rushed in.
Around 16 million years ago, in
Miocene period, a peninsula attached
to the eastern coast of the Eurasian continent was well formed. About
11 million years before present, the parts of
Japan which become
Hokkaido were gradually uplifted from the seafloor,
and terranes of
Chūbu region were gradually accreted from the
colliding island chains. The
Strait of Tartary
Strait of Tartary and the Korea Strait
opened much later, about 2 million years ago. At the same time, a
severe subduction of
Fossa Magna graben have formed the
Kantō Plain .
Overall, the geological composition of
Japan is poorly understood.
Japanese islands are formed of several geological units parallel to
the subduction front. The parts of islands facing oceanic plates are
typically younger and display larger proportion of volcanic products,
while the parts facing Sea of
Japan are mostly heavily faulted and
folded sedimentary deposits. In north-west Japan, the thick quaternary
deposits make determination of the geological history especially
The Japanese islands are divided into three major geological domains:
* Northeastern Japan, north of Tanakura fault (which had high
volcanic activity 14-17 million years before present )
* Central Japan, between Tanakura fault and Itoigawa-Shizuoka
Tectonic Line .
Fossa Magna graben
* Southwestern Japan, south of
Itoigawa-Shizuoka Tectonic Line
Itoigawa-Shizuoka Tectonic Line . The
Japan is further subdivided into several metamorphic
belts stretched along
Japan Median Tectonic Line .
* Hida orogenic belt
* Sangun orogenic belt
* Maizuru orogenic belt
* Tanba-mino orogenic belt
* Ryoke orogenic belt
* Shimanto orogenic belt
* Sambagawa orogenic belt
* Chichibu orogenic belt
* Sambosan orogenic belt
RESEARCH ON GEOLOGY OF JAPAN
The Geology of
Japan is handled mostly by Geological Society of Japan
(日本地質学会), with following major periodicals:
* Geological Journal (地質学雑誌) - since 1893
* Geological Studies (地質学論集) - since 1968
* Geological Society of
Japan News (日本地質学会News) - since
CURRENT GEOLOGICAL HAZARDS OF JAPANESE ISLANDS
Japan is situated in a volcanic zone on the
Pacific Ring of Fire
Pacific Ring of Fire .
Frequent low intensity earth tremors and occasional volcanic activity
are felt throughout the islands. Destructive earthquakes , often
resulting in tsunamis , occur several times a century. The most recent
major quakes include the
2011 Tōhoku earthquake and tsunami
2011 Tōhoku earthquake and tsunami , the
2004 Chūetsu earthquake and the
Great Hanshin earthquake
Great Hanshin earthquake of 1995. Hot
springs are numerous and have been developed as resorts.
* Seismicity in
* List of earthquakes in
* List of volcanoes in
* List of mines in
* ^ Barnes, Gina L. (2003). "Origins of the Japanese Islands: The
New "Big Picture"" (PDF).
University of Durham
University of Durham . Retrieved August 11,
* ^ "Formation history of the Japanese Islands (4) -- GLGArcs".
glgarcs.rgr.jp. Retrieved July 16, 2017.
* ^ "Geology of Japan｜Geological Survey of Japan,
AIST｜産総研地質調査総合センター / Geological Survey of
Japan, AIST". gsj.jp. Retrieved July 16, 2017.
* ^ "Yurie SAWAHATA, Makoto Okada, Jun Hosoi, Kazuo Amano,
"Paleomagnetic study of Neogene sediments in strike-slip basins along
the Tanakura Fault". confit.atlas.jp. Retrieved July 16, 2017.
* ^ email@example.com. "Southwest Japan". geo.arizona.edu.
Retrieved July 16, 2017.
* ^ A. Taira, H. Okada, J. H. McD. Whitaker & A. J. Smith, The
Shimanto Belt of Japan: Cretaceous-lower
* ^ "Sanbagawa belt (Sambagawa metamorphic belt), Shikoku Island,
Japan". mindat.org. Retrieved July 16, 2017.
* ^ "Chichibu belt from geo.arizona.edu". geo.arizona.edu.
Retrieved July 16, 2017.
* Hashimoto, M., ed. (1990). Geology of Japan. Dordrecht: Kluwer
Academic Publishers. ISBN 9780792309093 .
* T. Moreno (Editor), S.R. Wallis (Editor), T. Kojima (Editor), W.
Gibbons (Editor) (ed.). Geology of
Japan (Geological Society of
London)(2015). ISBN 978-1862397439 . CS1 maint: Multiple names:
editors list (link )CS1 maint: Extra text: editors list (link )
by - (Author),
* Takai, Fuyuji; Tatsurō Matsumoto; Ryūzō Toriyama (1963).
Geology of Japan. University of California Press.
* Geological Survey of
Japan - English homepage