Geologic Structures, Maps and Block Diagrams
Assignment: 10.4, pg. 243 a-e only, 10.5, pg. 245.
Structural geology- the study how geologic units are arranged when deformed.
Attitude- the ___________ of strata which is comprised of three parts
- Strike- _________ direction of a line formd by the intersetion of a horizontal plane and an inclined stratum, fault, fracture or other surface.
- Dip- the ______ between a horizontal plane and the inclined stratum, fault or fracture.
- Dip direction- the direction that water would run down the inclined geologic surface (perpendicular to the horizontal plane).
Unconformity- a surface which has been exposed to ________, causing an undetermined amount of rock to be missing.
There are three types:
- Disconformity- where there are missing rocks due to erosion, but the strata above and below are __________ to each other.
- Nonconformity- where sediments cover a metamorphic or ________ erosional surface.
- Angular Unconformity- where sediments have been deposited over a previously __________, erosional surface.
- Normal fault- caused by the _______ of the hanging wall due to tension
- Reverse fault- compressional forces cause the hanging wall to ______ ____ over the footwall.
- Hanging wall- _______ surface of the fault
- Footwall- ________ surface of the fault
- Strike slip fault- shear causes this fault to ________ laterally
Folded Structures
- Anticline (antiforms)- an upfold or convex fold. Oldest rocks are in the ________
- Syncline (synform)- a downfold or concave fold. Youngest rocks are in the __________.
- Fold Axis- the imaginary ________ along which the fold appears to have bent
- Symmetric fold- a bend in the stratum that has a _______ image
- Asymmetric fold- a bend that is not _______ opposite on each side
- Plunging fold- a fold that has an axis that is at an ______ with the horizontal plane
- Plunging anticline- dip towards the nose (closed end)
- Plunging syncline- dip towards the open end of the strata.
