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Layers in Time at Clifty Falls State Park | Indiana DNR


We’re Clifty Falls State Park in
southeastern Indiana Clifty Falls provides a great window into
Indiana’s geologic history. We are mostly known for our rugged
trails our cascading waterfalls and all the
fossils that can be found here in the park. Now how did it all get here? Would you
believe that over four hundred million years ago
all of this that you see in front of you was actually at the bottom a shallow
sea. The rocks here and the fossils tell us that. So by what we find here in the
park we know that all of this was once
underwater. So all the fossils that we find here in the park actually represents the plants in the
animals that lived in that shallow sea millions
and millions of years ago. If you’ve ever been swimming in a lake
or pond and felt that mud between your toes you
might have had that exact same sensation right here millions of years ago. That
mud compacted, smushed together really tight, and actually form part of our bedrock
known as shale. So another type of bedrock that we have
here at Clifty is limestone. Limestone is something that you
probably see every day and may not even realize it. Limestone is
used in the construction of roadways and entire buildings.
Limestone was formed from the calcium deposits of the skeletons of the marine organisms
that live here long ago. The rocks and fossils found here at Clifty
Falls tell us that our rock formations are from
the Ordovician and the Silurian periods in geologic
time. Now to understand when those periods happened, when they existed, our rock formations that
you see here at the park are actually older than dinosaurs by
over a hundred and fifty million years. Now that’s pretty old. As you hike along our
trails or overlook any of our waterfalls, you will
see layers in the bedrock. The study of these
players is called stratigraphy. Now by studying these rocks, or strata, you can actually determine what these
rocks are made of and how old they are. So the rocks that
you see on the top layers are actually from the
Silurian period. The rocks below that, which are older, are from the Ordovician
period. You can think of rock layers like a layered cake. So with rock layers the oldest rock is on the bottom and with
cake, the first layer that you lay down is the bottom layer and you have to have
that in order to put anything else on top of it. Within the rock layers you’re going to
find different types a rock so this example would be the yellowcake could be
limestone, if you were here Clifty Falls, and the
chocolate icing could be shale. You’ll have different
layers mixed in with each other and in those
layers that’s where we find fossils. So just
like this cake with the chocolate chips you would find fossils in rock layers.
In front of me I have some examples that you are likely to come across on
the trails. One of the first ones that you might see is a cephalopod. This is much like
our modern-day squid or octopus. We also have horned corals and you can
remember this name because these fossil actually kinda look like
their namesake so they can look like a horn. We also have mollusks. This one kinda looks
like our modern day snail shells. Another one more of a common one that you
might find along the trails are brachiopods. So here’s an intact
brachiopod they have a shell that you can find or you might find them in rock formations
and just find a shell imprint. And if you’re really lucky and you really keep your eyes peeled you
might even find a trilobite. This is a possible that
we have here Clifty that is very rare. now trilobites are in the arthropods family so they’re kinda related to
today’s modern insects and they look a little bit like
roly-polys or sow bugs. There’s so much that we can learn about
our Earth through the study and geology in just
exploring the world around us. Clifty Falls State Park is an exciting
and beautiful place to visit full of rich history and natural wonders.

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