What is Under Ohio?
Just the Facts, Ma’am.
Ohio’s Surface
1. North of Ohio is Lake Erie
2. Western Ohio is farm fields
3. Eastern Ohio is Valleys, hills, coal mines
4. Southern Ohio is steep cliffs, Ohio River, caves and streams
Under Ohio’s Surface
A. Igneous Rock-deep deep down underground, layers of younger rock are on top.
Called basement rock. Igneous rocks you find in Ohio were probably brought by
glaciers from Canada.
B. Sedimentary Rock-most rocks we see in Ohio are sedimentary. This includes
fossils, flint, limestone, sandstone, shale, and coal. Salt mine cave in Cleveland.
C. Metamorphic Rock-deep down underground. Canadian glaciers brought small
pieces that you may find on Ohio’s surface.
Timeline
 1.5 billion years ago-The land under Ohio was pushed up and then stretched out
east and west.
o A continent smashed into Ohio and it created the Grenville Mountains.
Over time, these mountains have weathered and eroded away.
o The movement of the continents made cracks under Ohio which makes
small earthquakes in Ohio now.
 570 million years ago -Shallow seas flowed across Ohio leaving sediments which
turned to sedimentary rock, including fossils such as trilobites, horn coral,
brachiopods, and crinoids.
 300 mya-Ohio was near the equator and Eastern Ohio was covered in swamps
which later turned into coal that we now mine in Ohio.
o Western Ohio was pushed up and the layers of rock that can now be seen
at the surface are older layers. In the east, we still see those younger
rocks.
 2 mya-Ice Age occurred. It snowed and snowed and it didn’t melt during cool
summers and turned into ice. Glaciers from Canada pushed down over Northern
and Western Ohio. That is why Ohio has rolling hills and fine soil for farming.
 24,000 years ago-Glaciers still heading through Ohio.
 20,000 years ago-Northern and SW Ohio, covered in glacier.
 10,000 years ago-glaciers melted leaving glacial till (sediment and sometimes
gold and diamonds) and glacial grooves at Kelleys Island.
Natural Treasures of Ohio
 Toledo-Limestone quarries with lots of trilobites
 Ohio’s highest point-Campbell Hill in Northeast, has high and wide shale
formations that made the glaciers go around it.
 Cincinnati-Glacial till where the glacier stopped and began to recede
 Columbus-roots of Grenville Mountains. They were once higher than the Rocky
Mountains
 Akron and Youngstown (Eastern Ohio)-very old rocks formed by ancient sea and
swamps that later turned into coal
 Ashtabula-clay deposits from the once larger Lake Erie
 Cleveland-salt mine down 1000 feet and shale with fossils.
What is Under Ohio?
Just the Facts, Ma’am.
Critical Thinking applying the Facts
1. Has Ohio land always been the same as it is now? How do you know? (two
points)
2. Has Ohio always been in the Northwestern Hemisphere? Explain. (two points)
3. Does Ohio have all three types of rocks (S, M, I) on it’s surface? How did each
type get there?
Rock Type
Found on
Ohio’s
surface?
How did they get there?
S
M
I
4. What caused the good farm land on the western side of Ohio? Explain. (two
points)
5. What caused the rolling hills on the eastern and southern parts of Ohio? Explain.
(two points)
6. How did the coal seams develop under southwest Ohio?
7. What are the features and fossils of Ohio that were created by the ancient seas
that once covered the land? (three points)
8. In what order did Ohio land form?
a. swamp, glacier, sea, mountains
What is Under Ohio?
Just the Facts, Ma’am.
b. mountains, swamp, glacier, sea
c. mountains, sea, swamp, glacier
d. sea, glacier, swamp, mountain
Matching.
9. ______ formed by the smashing of a continent
A. mountains
10. ______ Appalachian mountains weathered
and eroded down depositing silt and
sediment where it was a hot, steamy,
and stinky area
B. glaciers
11. ______ ancient body of water that flowed
over the land and later dried up
leaving sedimentary rock and fossils
C. swamps
12. ______ it snowed and snowed and Earth’s
temperatures cooled making the large
piles of snow turn into ice
D. seas