TEST 3 STUDY GUIDE
Chapter 8: Deformation and metamorphism
8.1 C How do rocks respond to force and stress?
• Displacement: Movement
• Rotation: Volume of rock is rotated in response to stress - Example: Hogback
• Strain: Change size and shape of rock
What processes affect rocks at different depths?
• Temperature: Increase with depth
• Pressure: Increase with depth
• Rocks break at shallow depth and flow (ductile) in deep conditions
• Shallow, low temperature minerals are stable
• Deep, higher temperature and pressure-minerals can recrystallize or grow
DEEPER – FLOW
8.2 A 3 kinds of differential stress and resulting structures
• Compression (Convergent)
o Fracture and faulting-shallow
o Flow and folds-deep
• Tension (Divergent)
o Stretch-deep • Shear (Transform)
o Shear zone-deep – ductile
8.3 A Type of fractures
• Joint: A place where the rock has pulled apart by a small amount
• Fault: When rocks slip past one another (up/down, side-side, angles)
8.4 C 3 main types of faults
• Dip-slip (VERTICAL MOVEMENT) – diagonal
o Normal: Hanging wall drops. DIVERGENT
o Reverse: Hanging wall moves up. CONVERGENT
o Thrust: Hanging wall moves up and over
• Strike-slip: Horizontal movement
• Oblique-slip: Horizontal and vertical movement
8.5 What are folds and how are they shaped?
• Anticline: Rock layers warp up in shape of an A
• Syncline: Rock layers fold down in the shape of U
8.6 A What are some metamorphic structures?
• Cleavage: Perpendicular to fold
8.9 B What activity occurs along ocean-continent convergent boundaries? • Burial: Oceanic plate subducts beneath a continental plate, forming magma that
invades the overriding continental plate.
Younger rock or features
• can contain pieces of older rock
• can cross-cut an older rock or feature
9.4 B How are ages assigned to rocks and events?
• Common radioactive decay series and what they are used to date
o Cenozoic and Mesozoic rocks: K
o Old granites and metamorphic rocks: Rb
o Old rocks and magma sources: Th and U