Map And Cross-section Interpretation

Question 1

Allocthon

Answer 1

A fault block or rock mass moved from its place of origin.

Question 2

Autochthon

Answer 2

A rock mass underlying a thrust fault that has not moved from its location of origin.

Question 3

Blind thrust

Answer 3

A thrust fault that dies out in the subsurface as it loses slip and stratigraphic separation.

Question 4

Detachment fault

Answer 4

A low-angle normal fault associated with regional extension.

Question 5

Dip-slip fault

Answer 5

A fault in which the movement is parallel to the dipof the fault plane, such as normal, reverse, or listric fault.

Question 6

Fenster

Answer 6

A window into rocks underlying a thrust fault.

Question 7

Footwall block

Answer 7

The block that underlies a non-vertical fault.

Question 8

Growth fault

Answer 8

A fault that forms contemporaneously with deposition in sedimentary rock. The throw increases with depth and the sedimentary units on the downthrown side are thicker than the corresponding units on the upthrown side.

Question 9

Hanging wall block

Answer 9

The block that overlies a non-vertical fault

Question 10

Heave

Answer 10

The amount of horizontal displacement on a fault.

Question 11

Klippe

Answer 11

An outlier of a thrust sheet completely surrounded by the exposed footwall

Question 12

Key beds

Answer 12

A well-defined, easily identified strata that is distinctive enough to be useful in corellation in mapping.

Question 13

Listric fault

Answer 13

A fault with a curved fault plane. Near the surface the fault plane is steeply dipping, but it becomes progressively flatter with depth. Listric faults may be normal or reverse.

Question 14

Nappe

Answer 14

A sheetlike rockunit that has moved over other rocks (allochthonous) on a predominantly horizontal surface

Question 15

Net slip

Answer 15

The distance between two formerly adjacent points on either side of a fault, measured on the fault surface.

Question 16

Nonconformity

Answer 16

An unconformity formed by older igneous rocks in contact with younger sediments, indicating a missing time after the igneous intrusion.

Question 17

Normal fault

Answer 17

A dip-slip fault in which the hanging wall has moved down relative to the footwall. The dip of the fault is between 45 and 90 degrees.

Question 18

Oblique-slip fault

Answer 18

A fault in which movement is not parallel to the strike or dip of the fault plane.

Question 19

Offset

Answer 19

The horizontal component of displacement measured perpendicular to the strike of the disrupted unit.

Question 20

Reverse fault

Answer 20

A dip-slip fault in which the hanging wall has moved up relative to the footwall. The dip of the fault is between 45 and 90 degrees.

Question 21

Rule of v’s

Answer 21

The outcrop pattern of a formation as it crosses a valleyforms a v shape. The v points.in the direction that the formation underlies the valley

Question 22

Strike separation

Answer 22

The horizontal distance between a stratigraphic unit offset by a fault, measured along the strike of the fault. It is an apparent displacement.

Question 23

Strike-slip fault

Answer 23

A fault in which movement is parallel to the strike of the fault plane.

Question 24

Throw

Answer 24

The amount of vertical displacement on a fault, also, the vertical component of net slip.

Question 25

Thrust fault

Answer 25

A reverse fault in which the fault.plane dips less than 45 degrees.

Question 26

Type locality

Answer 26

The place where a geological feature (such as a fossil species) was first recognized and described. It contains the type section.

Question 27

Type section

Answer 27

The originally described strata that constitutes a stratigraphic unit to which other parts of the unit may be compared. It is preferable to describe the location where the unit attains maximum thickness and where the top and bottom unit are exposed

Question 28

Unconformity

Answer 28

A gap in the geological record; an interruption in the depositional sequence that implies uplift and erosion have removed part of the geologic record.or non-deposition has occurred.