1. Types of Metamorphism Regional metamorphism
Large scale – large volume of rock is affected
Associated with convergent plate margins and mountain building
Folding and faulting increase thickness of the crust
Occurs over a range of temperatures and pressures
Fluids are also present
Low grade to high grade metamorphism
Will have zones of contact metamorphism

2. Regional Metamorphism

3. Metamorphic Grade

5. The following diagram illustrates the rock cycle
The following diagram illustrates the rock cycle. Match the lettered responses to the blank ovals on the diagram. (Note: some letters are used more than once.)
Magma 1 2
Metamorphic rock 3
Igneous rock
a) Cementation & Compaction (lithification)
b) Heat and Pressure
c) weathering, transportation, deposition
d) Cooling and solidification
e) Melting E D B C A
Start with 10 points – for each wrong answer subtract 1. 4 6 5 7
Sedimentary Rock
Sediment 8

6. Rock Cycle

7. Geologic Structure

8. Rock Deformation Stress Rock Strength Force applied to an area
Pressure
Differential stress – magnitude of stress is greater in one direction
Rock Strength
Rock’s resistance to deformation (stress)

9. Rock Deformation Cont. Strain Elastic deformation Plastic deformation
A rock’s response to stress
Deformation resulting in change of shape or position
Elastic deformation
Deformation is reversible, after stress is removed, materials return to original shape, i.e. A rubber band
Plastic deformation
Deformation is permanent
Rock flow in response to stress
Need high pressures and temperatures, generally deep in earth’s interior, i.e. Taffy

10. Rock Deformation Cont. Brittle deformation Deformation is permanent
Rock break (fracture) or lose cohesion
Generally low temperature and low pressure, common in shallow crust, i.e. Peanut brittle

11. Types of Stress Tensional (Extension) Stress Compressional Stress
Shear Stress

12. Tension or Extensional Stress
Stress move away from each other (pull apart)
Rock lengthens
Common in divergent boundaries, but not sole locale
Ductile deformation – stretching and thinning of rock
Brittle deformation – fracturing and faulting

13. Compressional Stress Stress presses (squeezes) rock together
Rock shortens
Common at convergent boundaries
Ductile deformation – shortening and thickening of rock – rock folds
Brittle deformation – fracturing and faulting

14. Shear Stress Stress creates a lateral shift in the rock
Rock slides past other rock
Common at transform boundaries
Results in faults

15. Folds Ductile deformation Compressional stress
Horizontal rocks are deformed

16. Fold Terminology Limb – the sides of the fold
Axial plane (hinge plane) – imaginary plane that divides the fold into two equal parts, marks location of maximum curvature
Fold axis (hinge line) – the line formed by the intersection of the hinge plane and a bedding plane

17. Syncline A fold with the youngest beds in the middle
Generally trough shaped, with limbs dipping toward the center

19. Anticline A fold with the oldest beds in the middle
Generally arched shaped, with limbs dipping away the center

21. Monocline
Folds with only one limb
Often Associated with faults

22. Fold Symmetry
Symmetrical fold – limbs of the fold dip at the same angle
Asymmetrical fold – limbs of the fold dip at different angles

23. Overturned Fold
Fold where one limb has been tilted beyond vertical

27. Plunging Fold
The hinge line or fold axis is inclined

32. Daily Exercise-Complete the concept map 1 2 3
Applied
to a
causes 1 2 3
At low T & P or
high stress rate
At high T & P or
low stress rate 5 4
The material
The material
no displacement 7 6 8
Joints
Deformation
Folds
Normal
Anticline
Reverse
Tension
Rock
Faults
Compression
Break
Plastic deformation
Syncline
Brittle deformation
Force/stress
displacement
Defined by youngest
rock in middle
Defined by oldest
rock in middle 11
1 – j
2 – n
3 – k
4 – g
5 – I
6 – f
7 – a
8 – b
9 – h
10 – c
11 – e
Start with 10 points and subtract accordingly. 9 10
Each letter can be used only once, and it is possible that it will not be used.

33. Faults A results of brittle deformation
Fractures in the Earth's crust where displacement has occurred

34. Fault Terminology Hanging wall – block that lies below the fault plane
Footwall – block that lies above the fault plane

35. Classes of Faults Dip-Slip Strike Slip Oblique-Slip
Movement is primarily vertical
Strike Slip
Movement is along strike
Oblique-Slip
Movement is both vertical and along strike

36. Dip-Slip Fault – Normal Fault
Extensional Stress
Hanging wall moves down with respect to footwall

37. FOOTWALL
HANGINGWALL

39. Normal Fault
Horst – raised block of material bounded by two normal faults
Graben – trough (valley) bounded by two normal faults

41. Dip-Slip Fault – Reverse Fault
Compressional Stress
Hanging wall moves up with respect to footwall

43. Dip-Slip Fault – Thrust Fault
Compressional Stress
Low-angle reverse fault (fault plane < 45o)
Displacement can be 100’s km (~60 miles)
Typically associated with folds

45. Strike-Slip Fault Shear Stress No vertical movement
Left-lateral strike-slip faults: movement of opposite plate is to the left
Shear Stress
No vertical movement
Movement parallel to fault plane
Right-lateral strike-slip faults: movement of opposite plate is to the right

47. Joints Brittle deformation at low pressure
Tension fractures with NO DISPLACEMENT