Volcanic Features
Volcanism: The transfer of lava from one location to another.
Lava
Lava is simple molten rock from the earth's mantle that has found a way to
the surface. Sub-surface lava is called magma
When there is only a small opening in the curst, a volcano is formed. Lava
and other material form a cone shaped structure surrounding the opening.
Crater: Funnel shaped opening at top of cone
Caldera: Great basin formed when a portion of the crater or vent
blasts off
Intrusive Volcanic Activity
- Dyke: Magma that cools in a vertical crack.
- Sill: Magma that cools between strata forming a sheet
- Laccolith: a sill with a large enough volume to raise the
overlaying strata.
- Batholith: Huge mass of magma that has intruded into a wide area
with no known depth.
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