Structural Geology

Question 1

Structural Geology

Answer 1

The study of the form, arrangement and internal structure of the rocks

Question 2

Outcrops

Answer 2

-Natural exposure of rocks.
“Sticking out” above earth.
-Enable one to recognize fold structures

Question 3

True dip

Answer 3

Maximum inclination(°) of stratum from horizontal.
Includes: 1. Direction
2. Amount

Question 4

Strike

Answer 4

Direction in which dip is zero- direction of the line of intersection of the bedding plane with the horizontal, given compass bearing.

Question 5

Folds

Answer 5

Confined rocks subjected to immense forces that slowly build up rocks can be folded.

Question 6

Elements of a fold

Answer 6

1. Axial plane- Divides fold symmetrically.
2. Axis- Line along which greatest curvature exists.
3. Plunge angle- Angle between axis and horizontal.
4. Limbs- Sides of a fold.

Question 7

Types of fold

Answer 7

1. Anticline- Strata folded to give convex upward struc.
2. Syncline- Concave upward strata
3. Homocline- Dip in one direction only.
4. Monocline- Local steepening of dip, one limb
   horizontal the other inclined.
5. Isocline- Limbs dip in same direction at same angle
   and parallel to axial plane.
   6.Overfold- Fold that is asymmetrical to extent that order
   of beds is reversed in one limb.
6. Recumbent- Fold in which axial plane is more or less
   horizontal.

Question 8

Fissure/Joint

Answer 8

Simple crack (fracture) along which no displacement has occurred.

Question 9

Faults

Answer 9

When there is relative movement across the plane of fracture.
Common where high compressional and tensional forces have acted.

Question 10

Bed

Answer 10

The smallest rock unit of a body of sediment or sedimentary rock. It typically has characteristics that differ from underlying and overlying beds and is bounded at its bottom and top by bedding surfaces, usually bedding planes.

Question 11

Discontinuity

Answer 11

Represents a plane of weakness within a rock mass across which the rock is structurally discontinuous. They are often planes of separation and possess little-no tensile strength.