Volcanic Materials and Mass Wasting Flashcards
Lava
Molten rock expelled by a volcano during an eruption and the resulting rock after solidification and cooling.
Pyroclastic Rock
Clastic rocks composed solely or primarily of volcanic materials.
Tephra
Fragmental material produced by a volcanic eruption regardless of composition, fragment size or emplacement mechanism. Once on the ground, it can fuse together to create pyroclastic rocks.
Volcanic Ash
Consists of fragments of pulverized rock, minerals and volcanic glass, created during volcanic eruptions and measuring less than 2 mm (0.079 inches) in diameter.
Lapilli/Cinder
Tephra ranging from 2 to 64 mm in diameter.
Volcanic Bomb
a mass of molten rock (tephra) larger than 64 mm, formed when a volcano ejects viscous fragments of lava during an eruption. They cool into solid fragments before they reach the ground.
Mafic Lava is also called ____.
Basaltic Lava
Dacitic Lava
Lava heavy in dacite that forms Rhyolitic lava.
How do pillow basalts form?
When basalt erupts underwater or flows into the sea, contact with the water quenches the surface and the lava forms a distinctive pillow shape, through which the hot lava breaks to form another pillow.
Lahar/Mudflow
A hot or cold mixture of water and rock fragments flowing down the slopes of a volcano and (or) river valleys.
What does a lahar look like?
When moving, it looks like a mass of wet concrete that carries rock debris ranging in size from clay to boulders more than 10 m
Mass Wasting
is the geomorphic process by which soil, sand, regolith, and rock move downslope typically as a mass, largely under the force of gravity, but frequently affected by water and water content as in submarine environments and mudslides.
How does the interaction between volcanoes and glaciers create floods?
The heat produced by the fault of a volcano can progressively melt glaciers until the water builds up and is released, creating a flood.
