Geology and Rock Deformation

These flashcards cover key concepts from the lecture on geological structures, rock deformation, and tectonic processes.

Rock Deformation

The process by which rocks change shape, structure, or volume due to stress or forces acting upon them.

Isochron Dating

A method used to determine the age of rocks by plotting the ratio of parent isotopes to daughter isotopes.

Half-life

The time required for half of the radioactive nuclei in a sample to undergo decay.

Plate Boundaries

The edges where two tectonic plates meet, which can be divergent, convergent, or transform.

Stress

The force applied to an area of rock, which can lead to deformation.

Strain

The change in shape or size of a rock in response to applied stress.

Normal Stress

Stress that is applied perpendicular to a given surface which can inhibit sliding.

Shear Stress

Stress that is applied parallel to a surface, promoting sliding.

Fault

A fracture in rock along which movement has occurred.

Ductile Deformation

A type of rock deformation where rocks bend and flow rather than break, typically due to high temperature and pressure.

Brittle Deformation

Deformation that occurs when rocks break or fracture under stress.

Convergent Boundary

A plate boundary where two tectonic plates collide.

Divergent Boundary

A plate boundary where two tectonic plates move apart.

Transform Boundary

A plate boundary where two tectonic plates slide past one another.

Dip

The angle at which a rock layer is inclined from the horizontal plane.

Strike

The compass direction of a rock layer as it intersects a horizontal surface.

Fault Scarp

A step-like feature on the ground surface formed by slip on a fault.

Geologic Map

A representation showing the distribution of geological features at Earth's surface.

Geologic Cross Section

A diagram that shows the geological features that would be visible if vertical slices were made through the crust.

Tensional Stress

Stress that leads to stretching and rifting of the earth's crust.

Compression Stress

Stress that pushes rocks together, often leading to mountains or folds.