|
(Click on photo for enlarged version). |
High
angle contact in the Golden valley Formation truncated by colluvium. Does
this structure represent a fault or a paleoslump?
(Photo Allan Ashworth) |
The strata of the northern Great Plains are generally considered to lack structure. The main question that you will attempt to resolve through your field study is whether the arrangements of strata in the Little Badlands are tectonically deformed. The Paleogene and Neogene strata are prone to slumping but can all the structures be attributed to slumping. You need to think about criteria that you might use to distinguish slumps and faults.
|
(Click on photo for enlarged version). |
High
angle contact in the Golden valley Formation truncated by colluvium. Does
this structure represent a fault or a paleoslump?
(Photo Allan Ashworth) |
| How
would you describe this structure if you determined it to be tectonically
formed?
(Photo Allan Ashworth) |
(Click on photo for enlarged version). |
|
(Click on photo for enlarged version). |
Difference
in lithology can be traced on the ground. They can sometimes be picked
out by plants which prefer some lithologies over others because of their
different water holding capacities. What aspect of a structure does a
compass bearing of this boundary represent?
(Photo Allan Ashworth) |
| Look
for boundaries of the type in this photograph. When you find them you
will need to measure dip and strike of the plane of the structure.
(Photo Allan Ashworth) |
(Click on photo for enlarged version). |
|
(Click on photo for enlarged version). |
Fault
or slump planes can be exposed and their surfaces examined for polishing
and striations. Measurements of striations relative to the dip of the
plane of the structure provide evidence of rotation and are important
in helping to determine stress relationships.
(Photo Allan Ashworth) |
