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Geology & Earth Sciences vocabulary · Rocks & Minerals

Basalt

Meaning in geology & earth sciences, with examples

/bəˈsɔːlt/nounCore term

In geology & earth sciences, basalt means: A dark, fine-grained igneous rock formed when lava cools quickly at or near the surface. It is the most common volcanic rock and makes up the ocean floor.

In Turkish: bazalt

How it is used

Used in volcanology, petrology and marine geology: basalt flows, basaltic lava, columnar basalt. Basalt is the volcanic equivalent of gabbro. In Turkey it is widespread in eastern and south-eastern Anatolia; the city walls of Diyarbakır are built of it.

Example sentences

  1. The plateau is covered by thick basalt flows.

  2. Columns in basalt form when a thick lava flow cools and contracts.

Common collocations

  • basalt flow
  • basaltic lava
  • columnar basalt
  • flood basalt
  • igneous rockRock that forms when molten magma or lava cools and becomes solid. Granite forms slowly underground, while basalt forms quickly at the surface.
  • lavaMolten rock that has come out of a volcano onto the Earth's surface, and also the solid rock that forms when it cools.
  • graniteA light-coloured, coarse-grained igneous rock made mainly of quartz, feldspar and mica, formed when magma cools slowly deep in the crust.
  • crustThe thin, rocky outer layer of the Earth. It is about 5 to 10 km thick under the oceans and usually 30 to 50 km thick under the continents.

More terms: Rocks & Minerals

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