Definition: Lava Dome
From Open Energy Information
Lava domes, also known as volcanic domes, are bulbous mounds formed via the slow eruption of viscous lava from a volcano. They are commonly encountered in the craters or on the flanks of large stratovolcanoes.
- In volcanology, a lava dome or volcanic dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano. The geochemistry of lava domes can vary from basalt to rhyolite although most preserved domes tend to have high silica content. The characteristic dome shape is attributed to high viscosity that prevents the lava from flowing very far. This high viscosity can be obtained in two ways: by high levels of silica in the magma, or by degassing of fluid magma. Since viscous basaltic and andesitic domes weather fast and easily break apart by further input of fluid lava, most of the preserved domes have high silica content and consist of rhyolite or dacite.Existence of lava domes has been suggested for some domed structures on the Martian surface in the western part of Arcadia Planitia and within Terra Sirenum.
- Also Known As
- Volcanic Dome
- John Watson. Principal Types of Volcanoes [Internet]. 2011. U.S. Geological Survey. [updated 2011/01/03;cited 2013/12/24]. Available from: http://pubs.usgs.gov/gip/volc/types.html