Structural Exam 2

Question 1

Vergence

Answer 1

Direction relating to the sense of asymmetry folds

Question 2

Antiform

Answer 2

Rainbow shaped, age is unknown

Question 3

Fold axis

Answer 3

Straight hinge on a cylindrical fold

Question 4

Concoical fold

Answer 4

Doesn’t have a fold axis, but has a hinge line

Question 5

Hinge

Answer 5

Top of a fold where the direction changes

Question 6

Axial Plane

Answer 6

Successive hinge line lie on the same plane

Question 7

Axial Trace

Answer 7

The intersection of the axial surface with any other plane

Question 8

S-Fold

Answer 8

The right side of a parasitic fold

Question 9

Z-fold

Answer 9

The left side of a parasitic fold

Question 10

How is the attitude of a fold defined and described?

Answer 10

Hinge and axial surface orientation

Question 11

Requirements of Buckling

Answer 11

1. Active folding
2. Layer has mechanical significance
3. layer is shortened parallel to layering
4. layer must be more competent than the surrounding material

Question 12

Parasitic folds

Answer 12

Small folds related to larger folds

Question 13

M-Folds

Answer 13

Top of the parasitic fold

Question 14

Anticline

Answer 14

Rainbow shaped, age is known

Question 15

Synform

Answer 15

Smile shaped, age is unknown

Question 16

Syncline

Answer 16

Smile shaped, age is known

Question 17

Synformal Anticline

Answer 17

Upside down anticline

Question 18

Antiformal syncline

Answer 18

Upside down syncline

Question 19

Cylindrical fold

Answer 19

Straight hinge line

Question 20

Limb

Answer 20

Area between hinge areas

Question 21

Axial surface

Answer 21

The surface containing hinge lines fro consecutive folded surfaces

Question 22

Passive folding

Answer 22

Layer with no mechanical significance

Question 23

Bending

Answer 23

Forces acting across layers causing folding, active folding mechanism

Question 24

What effects the wavelength of a fold?

Answer 24

Thickness of the bed, strength of the bed, strength of the surrounding material

Question 25

What mechanisms affect folding?

Answer 25

Orthogonal flexure, flexure shear (slip or flow buckling)

Question 26

Where is strain concentrated in folding?

Answer 26

The Crux

Question 27

What is the anticline symbol?

Answer 27

Line with perpendicular arrows that point outwards

Question 28

What is the syncline symbol?

Answer 28

Line with perpendicular arrows that point inwards

Question 29

Aysmmetric fold symbol

Answer 29

line with perpendicular arrows on each side pointing outwards

Question 30

What is the overturned fold symbol?

Answer 30

Line with a U-shaped double arrow

Question 31

Fabric

Answer 31

Geometric arrangement of penetrative and distributive components

Question 32

Foliation

Answer 32

FAbric elements that is planar and parallel

Question 33

Cleavage

Answer 33

Fabric elements that impacts a splitting property

Question 34

How can cleavage be used to interpret folding patterns and younging directions?

Answer 34

the acute angle closes and whatever direction it closes in points to the hinge

Question 35

Small crinkly lineation

Answer 35

Crenulation lineation

Question 36

Large uniform scratches from glaciers

Answer 36

Glacial Striations

Question 37

Grooves from the movement of a fault

Answer 37

fault slickenlines

Question 38

intersection of 2 planar features

Answer 38

intersection lineation

Question 39

layers show causing lineation

Answer 39

Bedding/cleavage lineation

Question 40

The result of 2 equally developed tectonic cleavages

Answer 40

Mullion structures

Question 41

layer sets compressed in some spots, beaded necklace like

Answer 41

Boudinage

Question 42

Fabric element, slightly metamorphosed

Answer 42

stretch pebble conglomerate

Question 43

Class 1a fold

Answer 43

Limbs are thicker than the hinge

Question 44

Class 1b fold

Answer 44

Limb thickness is constant

Question 45

Class 1c fold

Answer 45

Hinge is thicker than limbs

Question 46

Class 2 fold

Answer 46

Inner and outer arcs have identical curvature

Question 47

Class 3 fold

Answer 47

Curvature of outer arc is greater than the inner arc

Question 48

Chevron folds

Answer 48

sharp hinges, straight limbs

Question 49

Box fold

Answer 49

Two planes fold inwards, making omega sign

Question 50

Ptygmatic Folds

Answer 50

irregular, chaotic, no constant thickness; usually found in metamorphic rocks. Looks like a wiggle worm

Question 51

Order of major foliation types based on temp and depth

Answer 51

Compaction -->Cleavage -->Pencil -->Slaty -->Phylittic -->Schistosity -->Gneissic

Question 52

What leads to the presences of more cleavage

Answer 52

High clay content

Question 53

Primary Fabric

Answer 53

Original to when the rock formed

Question 54

Tectonic Fabric

Answer 54

results from stress/deformation/metamorphism