|
Pound Gap Sandstone on Pine Mountain in Kentucky |
| Newly exposed beds due to recent
construction
on US Hwy 23 in Kentucky |
| Moderatly tilted beds of Pennsylvanian age are exposed for almost 100 meters with some exposures reaching more than 50 meters |
| The exposed beds are part of the
leading
edge of the Pine Mouintain thrust fault on the border of eastern
Kentucky
and West Virginia |
| Students taking strike and dip measurements from Pound Gap sandstone |
| Data will be used along with
stereographic
projection to find the true dip of the tilted strata |
| Stereographic Projection is a
useful
method for finding the true dip of a bed when the strike and apparent
dip
are known |
| Stereographic Projection uses
what
is known as an equal area Lambert Net |
| Lines and planes are plotted on
a
net consisting of great circles that run north-south and small circles
that
run east-west |
 |
|
 |
Step 2. Rotate dip direction
to
the east-west line and count in the number of degrees for dip angle |
 |
Step 3. Rotate back to
original
direction |
 |
Step 4. Plot cross-bed dip and
dip
directiion in the same way |
 |
Step 5. Rotate the bed back to
east-west
line and rotate cross-bed with the bed |
 |
Step 6. Rotate bed to
horizontal
and crossbed is rotated the same number of degrees along a small
cirlce. |
 |
Step 7 Rotate bed back to the
original
azumith and carrying a cross-bed along with the rotation. |