LECTURE 06

This set of flashcards covers essential vocabulary related to surface and volcanic environments, sedimentary processes, and various geological formations.

Magma

Completely or partly molten material found beneath the surface of the Earth.

Volcanism

The eruption of magma onto the surface of the Earth, forming lava and volcanic rock.

Pyroclastics

Pulverized rock, lava, and glass fragments ejected during a volcanic eruption.

Effusive eruptions

Eruptions that produce lava flows, typically less explosive.

Explosive eruptions

Eruptions characterized by the ejection of pyroclastic materials, such as ash and tephra.

Viscosity

A measure of a fluid's resistance to flow; in magma, high viscosity leads to more explosive eruptions.

Volatiles

Gases such as H2O, CO2, and SO2 dissolved in magma that can influence the violence of eruptions.

Caldera

A large depression formed when a volcanic chamber empties and the roof collapses.

Sedimentary rocks

Rocks formed by the lithification of sediment; they preserve records of changing environments.

Eolian processes

Processes involving sediment formation, transport, and deposition by wind.

Mass Wasting

Gravity-driven down-slope movement of rock, debris, and soil.

Bar

An elongate accumulation of sediments confined to low-velocity areas along a stream channel.

Delta

A fan-shaped deposit of sediment at the mouth of a river.

Alluvial Fan

A fan-shaped deposit formed when a flowing stream slows as it spreads onto a plain.

Glaciofluvial deposits

Sediments formed, transported, or deposited by glaciers or glacial meltwater.

Horn

A high peak formed by the intersection of three or more cirques.

Cirque

A bowl-shaped depression formed on the side of a mountain by glacial erosion.

Pahoehoe lava

A type of lava with a low viscosity that has a ropy surface.

Aa lava

A type of lava with a rough, rubbly surface that moves as a partly solidified mass.

Plateau basalts

Extensive flows of mafic lava forming thick layers, not associated with volcanic cones.