Ohio Rocks!
Lynda Price
The Wilderness Center
This Rocks!
Sedimentary
Igneous
Metamorphic
Sedimentary
Rocks
Weathering
Erosion
Deposition
Sediments
cemented by
pressure
over time.
Sandstone
Limestone
Shale
Igneous
Rocks
Cooling
magma or
lava forms
Igneous
rock.
Granite
Pumice
Metamorphic
Rocks
Changed by
heat and
pressure.
Slate
Gneiss
Geologic Time
1 million days = 2,740 years
1 million hours = 114 years
Precambrian
•Basement rocks
•13,000 – 2,500 feet
deep.
•Igneous and
metamorphic rocks
Ohio earthquakes
are caused from
faults in these
rocks.
Mississippian
Pennsylvanian
•Cambrian rocks not exposed.
•Oil and gas from abundant marine life.
•Warm shallow sea
•Limestone and shale
•Ohio is world famous
for its fossiliferous
Ordovician rocks in
the Cincinnati area.
Cephalopods squids in a shell
Crinoids – sea lilies
Limestone
Dolomite
•Driveways, concrete
•Building stone
•Fertilizer
•Toothpaste, lipstick
Ocean
mud
Shale
Claystone
•Pottery
•Bricks
•Concrete
•Antacids
Mud
•Dry land, then warm,
shallow to deep seas
•Reef building formed
barriers, restricted
water flow: salts
accumulated.
•Limestone, dolomite,
shale, gypsum.
Salt deposits under
lake Erie.
Gypsum
Ocean
brine
•Drywall
•Plaster of Paris
•Bakery products
Rock Salt
Ocean
salt
•Snow and ice control
•Seasoning
•Water softening
•Dry land at first, then
warm shallow seas.
(Deposited the Columbus &
Delaware limestone.)
•Seas became stagnant
and “anoxic”. (Deposited
the Ohio Shale.)
The Ohio Shale:
• Huron Shale Member
• Chagrin Shale Member
•Cleveland Shale Member
Dunkleosteus
•Muddy to sandy
seas deposited shale
and sandstone.
•Appalachian Mts.
begin to form as
plates collide.
Supercontinent Pangea
begins to form.
Berea sandstone
economically important.
Black Hand sandstone
Hocking Hills & Mohican
Sandstone
Sand
•Building stone
•Glass
•Golf sand traps
•Furnace liners
Hocking Hills State Park
Flint
Volcanic ash
in streams
•Ohio’s official gemstone
•Spearpoints
•Flintlock guns
•Tropical forests and
swamps.
•Seas level rises and
falls.
•Appalachian Mts.
continue to rise.
Supercontinent Pangea
complete.
Marine rocks:
shale, limestone,
flint.
Non-marine rocks:
conglomerate,
sandstone, shale,
clay and coal.
Coal
Decayed
plants
•Electric power
•Heating
•Steel production
Permian
•Coastal plains
swamp.
•Sandstone, shale,
coal.
• Uplift and erosion
• No dinosaur fossils in
Ohio
Clay
Sand & Gravel
Sand and Gravel
•Road building
•Concrete
•Groundwater source
Sedimentary
Igneous &
Metamorphic
rocks
Ohio Geology
Lynda Price
The Wilderness Center
Clifton Gorge State Nature Preserve