coulée flow

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coulée flow A very thick, and relatively short, blocky lava flow formed from viscous lava, usually rhyolite or dacite in composition, which has been extruded from a volcanic cone or fissure. The short flows can be up to 100m thick and hence have a morphology lying between that of a dome and a flow. (When used in the French literature, the term ‘coulée’ is applied to lava flows in general.)