Geological Structures

Question 1

Dip

Answer 1

Maximum inclination of a bed measured from the horizontal

Question 2

Strike

Answer 2

The horizontal line in a bedding plane measured as a bearing from North

Question 3

Stress

Answer 3

The force applied to rocks

Question 4

Strain

Answer 4

A change in the shape of a body as a result of applied stress

Question 5

Competent rock

Answer 5

Rock that stat the same thickness when decried and react in a brittle way

Question 6

Incompetent rock

Answer 6

Vary in thickness when deformed as they behave plastically

Question 7

Plastic

Answer 7

Stress and strain are not directly proportional

Question 8

Elastic

Answer 8

Stress is proportional to strain

Question 9

Uncomformities

Answer 9

Represent a period where no sediment was deposited

Question 10

Joints

Answer 10

A fracture in competent rock along which no observable movement has occurred

Question 11

Faults

Answer 11

Brittle fractures where there is a displacement which can be horizontal or vertical

Question 12

Fault plane

Answer 12

A plane of fracture along which the rocks have been displaced

Question 13

Upthrow

Answer 13

The side of the fault where the movement is upwards in relation to the other side

Question 14

Downthrow

Answer 14

The side of the fault where the movement is downward in relation to the other side

Question 15

Throw

Answer 15

The vertical displacement of the roads along the fault plane

Question 16

Footwall

Answer 16

The side of the fault that is below the fault plane of the fault is not vertical

Question 17

Hanging wall

Answer 17

The side of the fault that was above the max inclination of the fault plane as measured from the horizontal

Question 18

Anticline

Answer 18

An upright fold with the oldest rocks in the centre

Question 19

Anti form

Answer 19

A upward closing fold

Question 20

Syncline

Answer 20

A downward closing fold with youngest rocks in the core

Question 21

Synform

Answer 21

A downward closing fold

Question 22

Fold limb

Answer 22

The section of a fold between 1 hinge and the next forming the side of the fold

Question 23

Hinge

Answer 23

The line along which there is a change in the amount of dip forming the most sharply curved part of the fold

Question 24

Crest

Answer 24

The highest point of a folded bed

Question 25

Trough

Answer 25

The lowest part of a folded bed

Question 26

Axial plane

Answer 26

A plane that joins the hinges of all the beds

Question 27

Axial plane trace

Answer 27

The outcrop of the axial plane at the earths surface

Question 28

Plunge

Answer 28

The angle of dip of the axial plane from the horizontal

Question 29

Dome

Answer 29

An anticline which dips away from the centre in all directions

Question 30

Basin

Answer 30

A syncline which dips towards the centre from all directions

Question 31

Overfolds

Answer 31

Folds which have both fold limbs dipping in the same direction by different amounts

Question 32

Recumbent

Answer 32

Folds that have axial planes and fold limbs which close at the horizontal

Question 33

Nappe

Answer 33

Recumbent folds that are broken along thrust planes

Question 34

Isoclinical

Answer 34

Folds have parallel limbs that are nearly vertical and in very tight folds