Geology Rocks! | NewsDepth: Spot on Science


(upbeat music) – Ever get a pebble stuck in your shoe? It can be annoying for sure. But even the smallest rocks
can teach us a big lesson. To learn a little more,
I invited Kevin McGee, President of the Cleveland
Geological Society, to rock it out in the studio. I started by asking him,
what exactly is geology? – So geology. Geology is technically the study of rocks, but I really look at it as the
study of the earth’s history. The rocks when they were laid down, the minerals were deposited, the world was very
different then it was now. And they can tell us a lot
about what the earth looked like when those rocks were
put down on the surface. – Neat, so you brought
in a lot of Ohio rocks. So if we look at them
like clues we can find out some more about Ohio’s history. – We can, we can tell what
Ohio was like two, three, four hundred million years ago. – [Margaret] Awesome,
well let’s get digging. – Okay, so we have sandstone. This is Berea Sandstone from
just south of Cleveland. Berea, Ohio. And at the time when
this rock was laid down, we were a river delta
with the division between the ocean and the land,
we’re right on the edge. And big rivers were carrying
eroded rock from big mountains that no longer exist in
Canada to the north, down here and deposited it as its
rivers went into the ocean. And then, this right here is coal. And the coal was deposited
when we were more inland. We were swamps. And again, south of the
equator, 300 million years ago, and it’s all ferns and trees
that don’t exist today. All dead and compacted and forming coal. And then we have salt here. Salt was laid down in the Silurian about 425 million years ago. And the salt was from this
area being an ocean and then being dried up and then an
ocean and then drying up and then an ocean. And we just got layer upon
layer upon layer of salt. And some of it is light colored,
some of it is dark colored depending on the minerals that
were in the water when the salt evaporated, or the water evaporated. – [Margaret] And so this
isn’t the kind of salt I can put on my french fries? – [Kevin] No, I don’t recommend putting it on your french fries. It’s not the type of salt you eat. But it’s very similar related and it’s wonderful for road salt. – [Margaret] A lot of the
salt that we see in the winter time getting spread on the roads, is from right here in Ohio. – [Kevin] That’s where it comes from. 2000 feet under Lake Erie, in Cleveland. – Neat, what about this next guy? – So that is world famous Cleveland shale. It’s a very black flakey rock
and it tells us the world back then was under three or
400 foot of ocean at least, in your Ohio. And it was interesting
because it was a stagnant sea. There was no oxygen on
the bottom of the sea. And nothing could live there
and it forms a very dark rock when it does that. But we know that there was
life in the upper waters because large fish like
Dunkleosteus, the big armored fish, when it died would drift
to the bottom of the sea and get buried and fossilized. And so we know that there
were animals living in the upper waters but in the
lower waters it was just all black salty rotten stuff
that eventually became rock. – Oh wow, and how about this
one ’cause this guys got some interesting kind of sea shells on it. – It does, yeah this is limestone. 400 to 450 millions years old. And it actually has all sorts
of little creatures in it. Some you can’t even see. Little diatoms, things
that live in the water. When they die they drift to
the bottom, they formalin mud and then within that there’s
also corals and shells and things like that. And they all eventually get
turned into rock, together. – And what do some of these
rocks get used for today? – So limestone you see a
lot on graveled driveways, on break walls along the lake front. For the sandstone, it was
used a lot in the past for grindstones and also for buildings. You would see it in building materials and even making curbs, they
used it for curbs as well. – And then, what about the shale? What is that used for? – There really is nothing
that shale is used for. It’s just too flakey and too
soft and so it just sits there. Nobody uses it for anything. – Well we can use it for
figuring out more about Ohio, so it’s great.
– You know, it does. – Awesome, well thank you
so much for coming in. It’s been really interesting. – Thank you, my pleasure. (upbeat music)