Reading...
Play button
Play button
Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
18 Cards in this Set
- Front
- Back
|
elastic deformation
|
stress causes the atomic
bonds within a solid to bend, stretch, or flex, but not break. Thus, when the stress is released, the solid snaps back into its original shape. EX: rubber band, ruler, spring |
|
|
stress def.
|
application of a force to change the shape of a material
|
|
|
brittle deformation
|
when a solid is stressed so much it suddenly breaks
EX: glass,shattered rock,snapped rubberband |
|
|
ductile deformation
|
stress causes a
permanent change in shape (strain) without causing a break. EX: clay, gum, crushed pop can, bent wire. |
|
|
What determines how a rock responds to stress?
|
Rate of Stress & Temperature
|
|
|
What is the difference between faults and joints?
|
Joints - fractures across which there is NO slippage or movement. Stretching causes joints that are perpendicular to the stretching direction.
Faults - fractures across which there IS slippage or movement. Hanging wall & foot wall |
|
|
What is the difference between dip-slip and strike-slip faults?
|
Dip-slip faults: fault
movement occurs up or down the slope of the fault surface. Strike-slip: when rock is put under shear stresses (one side slides by other w/o squeezing/pulling). Vertical. |
|
|
Normal vs. Reverse Faults
|
Normal: extensional stress, hanging wall drops relative to footwall.
Reverse: compressional stress, hanging wall rises relative to footwall. |
|
|
Thrust Faults
|
Like a reverse, but the fault surface makes a lower angle relative to horizontal
|
|
|
Left lateral strike-slip and right lateral strike-slip
|
left - the block on the far side has moved to the left
right - block on far side has moved to the left |
|
|
Anticline & Syncline
|
Anti - /\\, arch;limbs dip away from hinge
Syn - U,trough; limbs toward hinge |
|
|
Plunging vs nonplunging folds...
|
plunging create curved ridges & mountains
non create straight ridges & mountains |
|
|
Western South America, plate boundary & geologic structure
|
subduction of Nasca Plate under South America.
compression is actively thrusting and folding rocks Andes Mountains |
|
|
Himalayas, plate boundary & geologic structure
|
India subducting under Asia.
Indian thrust sheets pushed south |
|
|
East Africa, plate boundary & geologic structure
|
rift valleys with mountain ridges on either side.
Extensional Fault Block Mountains |
|
|
Basin and Range Province in U.S.
|
Tilted fault-block mountains (stretching)
Some areas are uplifted when their mantle lithosphere is sheared off or falls away, or is eroded by a mantle plume (Colorado Plateau). |
|
|
What are exotic terranes and why did western North America end up with so many?
|
Subduction and right lateral strike-slip motion causes a collage of terranes.
oblique subduction of western coast |
|
|
Erosion plus what other process is required to expose metamorphic rocks?
|
Uplift from thrust faulting
|
