Igneous Rocks and Magma lec 3

These flashcards cover key vocabulary and concepts related to the formation, classification, and behavior of igneous rocks and magma, as discussed in the lecture.

Silicon Undersaturated

Minerals that do not have enough silica (SiO2) to saturate with silica, allowing them to coexist with silicon-saturated minerals.

Mafic Minerals

Minerals that are rich in magnesium and iron and have a lower silicon content, making them denser and darker.

Olig

A mineral found at the top of Bowen's reaction series, which reacts with quartz to form paroxetine.

Total Alkaline (Ta)

The sum of sodium and potassium content in rocks, affecting their composition and characteristics.

Pyroclastic Rocks

Formed from explosively erupted volcanic fragments instead of crystallization, classified by the size of volcanic fragments.

Felsic Rocks

Rocks that are rich in silica (up to 80%) and low in magnesium and iron, characterized by light colors and containing minerals such as quartz.

Ultramafic Rocks

Rocks primarily composed of olivine and pyroxene, containing very low amounts of silica and high amounts of magnesium and iron.

Volcanic Ash

The smallest fragments of pyroclastic material, less than 2 millimeters in size, that can be compacted to form tuff.

Lava Viscosity

A measure of a liquid's resistance to flow; in lava, it is influenced by composition, temperature, and volatile content.

Bridging Oxygen

Oxygen atoms that link together two silicon tetrahedra in a melt, contributing to the polymerization of silicate networks.

Caldera

A large, often steep-walled depression formed when a magma chamber empties, causing the ground above to collapse.

Intrusive Igneous Rocks

Rocks that form from magma cooling slowly beneath the Earth's surface, characterized by coarse-grained texture.

Stratovolcano

A composite volcano formed from alternating layers of lava flows and pyroclastic materials, often explosive in nature.

Eruption Geometry

The shape and structure of the openings through which magma reaches the Earth's surface, influencing eruption style.

Effusive Eruption

A quieter type of volcanic eruption where low-viscosity magma flows easily, typically producing lava flows.

Felsic Magma

Magma with high silica content, high viscosity, and typically results in explosive eruptions.