Extrusion Camel at the foot of the Avachinsky and Koryaksky volcanoes , the Kamchatka Peninsula .
Extrusion (volcanic cave) is a type of eruption peculiar to volcanoes with viscous lava . The protruding viscous lava is piled up above the mouth of the volcano in the form of domes, from which or near which from time to time with strong explosions gases are emitted, giving rise to scorching clouds.
Content
Build
For extrusions characteristic:
- Uniform massive lava structure.
- The presence at the foot of a powerful plume of coarse debris.
- The existence of fluid banding.
- Large porphyritic structure of lavas.
- The composition of the lava, ranging from andesites and trachytes to acid rhyolites (Piip, 1955).
Classification
Williams, 1932
- Cork
- Endogenous
- Exogenous
Wlodavec, 1954
I. Extrusive domes (without a channel in the body of the dome and crater)
- Concentric-shelled
- Fan shaped
- Rocky
- Massive
a) breakthrough domes - extrusive bismaliths; b) pyramidal domes (pythons); c) obelisks.
Ii. Extrusive-effusive domes (with a channel in the body), among which stand out: bell-shaped (mamelons), flowing (overlapping), flowing with a lava tongue.
Iii. Extrusive domes
Literature
- Geological dictionary, T. 1. - M .: Nedra, 1978. - P. 380.