Folds

Question 1

Fold with beds that young away from the core

Answer 1

Anticline

Question 2

Surface fold where there is no strain

Answer 2

Neutral-surface fold

Question 3

Large scale antiform formed from smaller scale antiform and synform

Answer 3

Anticlinorium

Question 4

Fold with the hinge zone at the top

Answer 4

Antiform

Question 5

Fold that doesn’t have their axial surfaces approximately perpendicular (± 10 degrees) to the enveloping surface

Answer 5

Asymmetric fold

Question 6

Box-shaped fold detached from the underlying and overlying layers

Answer 6

Box fold

Question 7

Large-scale fold with straight limbs and sharp hinges

Answer 7

Chevron fold

Question 8

Structures with hinge lines that laterally change curvature (< 50 degrees)

Answer 8

Doubly plunging fold

Question 9

Fold produced near fault surfaces that appear to be pulled into a fault during movement

Answer 9

Drag fold

Question 10

Fold that forms when a normal fault breaks and displaces between rocks but die upward into the sedimentary cover

Answer 10

Drape fold

Question 11

Gradually opening fold is replaced by a neighboring, gradually tightening fold of opposite form

Answer 11

En echelon fold

Question 12

Thrust sheet wherein dip flattens as it passes over a ramp

Answer 12

Fault-bend fold

Question 13

Accommodation structures above the frontal top of a thrust

Answer 13

Fault propagation fold

Question 14

Fold that forms from slip between layers

Answer 14

Flexural slip fold

Question 15

Fold with 120 - 180 degrees interlimb angle

Answer 15

Gentle fold

Question 16

Fold that plunges nearly to entirely horizontal (0 - 10 degrees)

Answer 16

Horizontal fold

Question 17

Fold with 60 - 120 degrees interlimb angle

Answer 17

Open fold

Question 18

Asymmetric fold in which one limb has been tilted beyond the vertical

Answer 18

Overturned fold

Question 19

Fold with dip isogons perpendicular to the bedding throughout the fold

Answer 19

Parallel fold

Question 20

Smaller fold related to a large structure

Answer 20

Parasitic fold

Question 21

Irregular and isolated fold structures that typically occurs as a tightly folded vein or thin later of strongly contrasting lithology

Answer 21

Ptygmatic fold

Question 22

A steeply plunging, inclined fold

Answer 22

Reclined fold

Question 23

Fold with a horizontal (0 to 10 degrees) axial surface and horizontal hinge line

Answer 23

Recumbent fold

Question 24

Fold plunging at 10 - 30 degrees

Answer 24

Shallow Fold

Question 25

Fold with a hinge line showing extreme curvature, to the extent that the hinge line curvature approaches parallelism ( change in plunge up to 180 degrees)

Answer 25

Sheath fold

Question 26

Fold with dip isogons parallel to each other

Answer 26

Similar fold

Question 27

Fold steeply (60 to 80 degrees) punging

Answer 27

Steep fold

Question 28

Fold that has their axial surfaces approximately perpendicular (± 10 degrees) to the enveloping surface

Answer 28

Symmetric fold

Question 29

Fold with beds that young toward the core

Answer 29

Syncline

Question 30

Large-scale synform formed from smaller-scale antiform and synform

Answer 30

Synclinorium

Question 31

Fold with an inclined (10 - 70 degrees) axial surface

Answer 31

Inclined fold

Question 32

Fold plunging at 30 - 60 degrees

Answer 32

Intermediate fold

Question 33

Fold with 0 - 10 degrees limb angle or beds on both limbs are nearly parallel whether upright, overturned or recumbent

Answer 33

Isoclinal fold

Question 34

Small fold (less than a meter) characterized by straight limbs and sharp hinges

Answer 34

Kink fold

Question 35

Fold structure with only one tilted limb, with one limb being horizontal

Answer 35

Monocline

Question 36

Fold with hinge zone at the bottom

Answer 36

Synform

Question 37

Fold with 10 - 60 degrees interlimb angle

Answer 37

Tight fold

Question 38

Fold with an axial surface nearly to entirely dipping upright (70-90 degrees)

Answer 38

Upright fold

Question 39

Fold vertically (80-90 degrees) plunging

Answer 39

Vertical fold