Today we're on a field trip to the
southern Appalachian Mountains.
We're in the valley and ridge province of eastern
Tennessee and I'm gonna bring you with
me on this one today.  I've got my
students out here with me
they are currently trying to identify
rock types look at bedding look at the
dip of some some layers and see what
they can find.  We are standing at one of
the important thrust faults of the
Valley and Ridge... this is the Copper
Creek thrust fault.
Copper Creek thrust fault puts Cambrian
Rome Formation in the hanging wall up
over the top of middle Ordovician
limestones which are down over here in the footwall.
Let's go take a look... so here we've got
the limestones of the middle Ordovician
rocks.   They're fairly fine
grained and this nice light gray color.
And you'll see as we walk along here
that they dip prominently to the right in this image.
All right so we've moved
on to the next outcrop just down the road
this is stop 2.  The reason we stop here is
because there is a small fault right
there and this is a back thrust related
to the Copper Creek, which is the main
thrust we saw before.  The small back
thrust is all entirely within the Rome
formation and it doesn't have that much
displacement.
That's pretty neat!!
That's an asymmetric fold because of the
way that it is.
So for our next stop here we are in
Chickamauga group and we're looking at
some deformed mud cracks.  They are therefore a primary structure indicating
sedimentary environment as well as a
secondary structure because they've been
compressed, and so they record the strain
active on these rocks when they were
deformed.  The deformation again here is
all Alleghenian during the formation
of the Valley and Ridge thrust sheets.
So a quick recap: we're in the Copper
Creek thrust sheet in the Appalachian
Valley and Ridge.  We've seen the Copper
Creek thrust fault, then we saw the folds
above that in the Cambrian Rome
formation, now we're farther up in the
stratigraphic section looking at the mud
cracks that have been shortened as a
part of the compression of these rocks. 
Right here we've got the mud cracks
they're shortened this direction and
normal length this direction due to the
compression that they were under.
Now we're going to go on to another
outcrop and we're going to see more
evidence of the compression that
occurred while the Appalachian fold and
thrust belt was being produced.  All right
so we are at the next stop now.  This is a
thrust duplex right across the street
from me over here.  This has got a couple
of thrust faults that are splitting off
from a single fault up top into two
separate faults down below.
In this last set of stops here before we
end our trip for today we're going to
look at the cross-bedded Clinch
sandstone which is Silurian age, we're
also going to look at some slightly
older rocks which are deformed nicely
and there's some really great folds down
here that we'll take a look at.
Right in here we've got a little bit of hint
cross bedding in the Clinch sandstone
the layers coming down... like so.  Right
here we've got some really nice cross
bedding in the clinch sandstone.  We can
see coming down crossing like this and
it comes up in this layer and it's
truncated here at the top which
indicates to us that stratigraphic up is
correct here, it is still in the right direction,
it's up.  Down in the valley the Clinch
sandstone is overturned in the limb of a
syncline
and the cross bedding over there is
upside down.
Right here we've got a really nice fold
that shows some tensile cracking right
here in the hinge... they're spreading and
fracturing and cracking along the outer
arc of the hinge of the fold and then
they are closed down on the interior
part of the fold as this layer is
buckled around and it it is taking up
all of the strain in the hinge here.
Well I hope you guys enjoyed this tour of
the Valley and Ridge of eastern
Tennessee to see some of the geologic
structures that make up the Alleghenian
deformation here in this region of
the world -  it's a beautiful place.
Well I hope you enjoyed this video and if you
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