Volcanic Arc

Published on 12 Nov 2025

• Recently researchers have uncovered a massive, 400-mile-long chain of extinct, fossilized volcanoes deep under South China.

• This ancient volcanic arc was formed around 800 million years ago during the early Neoproterozoic era, when two tectonic plates collided during the breakup of the supercontinent Rodinia.

• A volcanic arc is a chain of volcanoes, hundreds to thousands of miles long, that forms above a subduction zone.

• They are mainly two types:

• Continental Volcanic Arc: formed when an oceanic plate subducts (slides) beneath a continental plate resulting magma to rise to the continental crust.

 Eg: Andes Mountains (Andesitic arc), Cascade Range (in North America) etc

•  Oceanic Volcanic Arcs (Island Arcs): formed when one oceanic plate subducts beneath another oceanic plate resulting magma to rise to the oceanic crust forming volcanic islands. Eg: Aleutian Islands, Japan, and the Philippine Islands.

https://onlinelibrary.wiley.com/cms/asset/da6b18e2-6980-4c7d-b5cb-6b966b45de3a/gj4847-toc-0001-m.jpg?trick=1750344830456

Keywords:

Volcanic Arc Volcanoe Neoproterozoic era Rodinia subduction Continental Volcanic Arc Oceanic Volcanic Arcs Island Arcs Plate tectonics