The Chilung Volcanic Group or Keelung Volcanic Group () is a group of extinct

volcano A volcano is commonly defined as a vent or fissure in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most oft ...

es located in northern

Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The main geography of Taiwan, island of Taiwan, also known as ''Formosa'', lies between the East China Sea, East and South China Seas in the northwestern Pacific Ocea ...

, lying to the east of

Taipei , nickname = The City of Azaleas , image_map = , map_caption = , pushpin_map = Taiwan#Asia#Pacific Ocean#Earth , coordinates = , subdivision_type = Country ...

and

Keelung Keelung ( ; zh, p=Jīlóng, c=基隆, poj=Ke-lâng), Chilung or Jilong ( ; ), officially known as Keelung City, is a major port city in northeastern Taiwan. The city is part of the Taipei–Keelung metropolitan area with neighboring New Ta ...

(Chilung), and adjoining the northern coast of the

island of Taiwan Taiwan, officially the Republic of China (ROC), is a country in East Asia. The island of Taiwan, formerly known to Westerners as Formosa, has an area of and makes up 99% of the land under ROC control. It lies about across the Taiwan Strait f ...

. Together with Mount Guanyin and the

Tatun Volcanic Group The Tatun Volcanic Group () constitutes a group of volcanoes located in northern Taiwan. It is located 15 km north of Taipei, and lies to the west of Keelung. It just adjoins the northern coast of the Taiwan island. The volcanic group was a ...

, it belongs to the northern Taiwan volcanic province, constituting the western end of the island chains of the Ryukyu arc. Five separate bodies can be distinguished: Chilungshan (Mount Keelung), Penshan, Wutanshan, Tsaoshan and Chimuling. The group is mainly composed of

andesite Andesite () is a volcanic rock of intermediate composition. In a general sense, it is the intermediate type between silica-poor basalt and silica-rich rhyolite. It is fine-grained (aphanitic) to porphyritic in texture, and is composed predomina ...

, although there is some heterogeneity caused by the mixing between mantle-derived and continental material. Aging of andesite,

biotite Biotite is a common group of phyllosilicate minerals within the mica group, with the approximate chemical formula . It is primarily a solid-solution series between the iron- endmember annite, and the magnesium-endmember phlogopite; more al ...

, and

zircon Zircon () is a mineral belonging to the group of nesosilicates and is a source of the metal zirconium. Its chemical name is zirconium(IV) silicate, and its corresponding chemical formula is Zr SiO4. An empirical formula showing some of th ...

samples have yielded age estimates between 0.8 and 1.7 Ma. It comprises the largest gold-copper deposits of Taiwan.

References

{{Topography of Taiwan Landforms of New Taipei Pleistocene volcanoes Volcanoes of Taiwan

See also

References