Chapter 2 - Structural Geology

Front 1

Accuracy

Back 1

How close a measurement conforms with a standard or accepted value.

Front 2

Apparent Dip

Back 2

The inclination of a plane measured in a direction not perpendicular to strike.

Front 3

Apparent Dip Direction

Back 3

The bearing of the vertical plane containing the apparent dip angle.

Front 4

Attitude

Back 4

The orientation in space.

Front 5

Beta

Back 5

The angle between strike and apparent dip direction.

Front 6

Bearing

Back 6

The horizontal angle between a line and a specified coordinate direction, usually north or south.

Front 7

Depth (d)

Back 7

The vertical distance from the ground surface downward to a feature of interest.

Front 8

Dip

Back 8

The inclination of the line of greatest slope of an inclined plane, measured perpendicular to strike.

Front 9

Directed Line

Back 9

A line described by its bearing and plunge.

Front 10

Fold Line

Back 10

A hinge line along which a vertical cross section may be constructed and then flattened out to a horizontal or map view.

Front 11

Inclination

Back 11

A general term for the vertical angle between the horizontal and a plane or line, measured downward.

Front 12

Outcrop Width (w)

Back 12

The width of an outcrop, as measured on map view, perpendicular to strike.

Front 13

Pole

Back 13

A line perpendicular to a plane, and represented as a point on a stereographic projection.

Front 14

Plunge

Back 14

The vertical angle between a line and horizontal.

Front 15

Precision

Back 15

The degree of agreement or consistency of repeated measurements.

Front 16

Projection

Back 16

The process by which points on one surface are transferred to another surface, such that in each view (map or cross section) the points correspond.

Front 17

Rake (pitch)

Back 17

The angle measured in a specified plane, between a line and horizontal.

Front 18

Slope Angle

Back 18

The angle from the horizontal down to the slope.

Front 19

Stereonet

Back 19

A representation of angular relationships between planes and lines. In structural geology, a stereonet is synonymous with Wulff net, an equal angle stereographic projection.

Front 20

Strike

Back 20

The bearing of a horizontal line on an inclined plane.

Front 21

Thickness (t) Trench

Back 21

The perpendicular distance between the top and bottom or a geologic unit.

Front 22

Trend

Back 22

The bearing of the vertical plane containing a line.