Exam Study Guide 1

What is the definition of a mineral?

A naturally occurring, inorganic solid with a specific chemical composition and crystalline structure.

What is the definition of a rock?

A solid aggregate of one or more minerals, formed through geological processes and often composed of different mineral grains with no single, defined crystal structure.

Bowen's Reaction Series

Describes how solids turn to liquids by temperature changes.

Elastic Rebound Theory

Explains how earthquakes occur when stress builds up along a fault line, causing rocks to deform until reaching a breaking point and releasing energy as seismic waves.

Richter scale magnitude

Measures the size of an earthquake and the potential damage it may cause.

What controls the explosiveness of volcanic eruptions?

The explosiveness is primarily controlled by the magma's viscosity, gas content, and the rate at which gas can escape.

Low silica magma

Also known as mafic magma; less viscous, allows gas to escape easily, leading to less explosive eruptions.

High silica magma

Also known as felsic magma; more viscous, traps gas readily, resulting in highly explosive eruptions.

High gas content in magma

Indicates more potential for explosive eruptions as gas expands rapidly when pressure decreases.

Low gas content in magma

Indicates less explosive potential.

High viscosity magma

Impede gas escape, leading to more explosive eruptions.

Low viscosity magma

Allows gas escape more easily, resulting in less explosive eruptions.