OHSU-El-80-004
c.2
EVIDENCE OF
Susan Leach
by
Upper Arlington Public Schools
and
Victor J.
Mayer The Ohio
State University
OEAGLS-
Oceanic
Education
Activities
for
Great
Lakes
Schools
CIRCULATING
COPY
Sea
Grant Depository
‘ANCIENT SEAS
IN
OHIO
Ohio
Sea Grant Program
Charles
E.
Herdendorf, Program Director
Victor J. Mayer, Principal Investigator
TEACHER GUIDE
OEAGLS
INVESTIGATION
#lO
Completed May, 1979
Revised June, 1980
This instructional activity was prepared with the
support of National Oceanic and Atmospheric Administration
Grant
Nos.
'04-158-44099,
04-8-MOl-170
and NA
79AA-D-00120,
and from The Ohio State University.
However,
any opinions,
findings,
conclusions,
or recommendations expressed herein
are those of the authors,and do not necessarily reflect
the views of NOAA or the University.'
Copyright,
aThe
Ohio
State University Research Foundation,
1980.
All rights reserved.
OVERVIEW
PREREQUISITE
STUDENT
BACKGROUND
MATERIALS
OBJECTIVES
In this investigation,
students study the sedimentary rocks
commonly found in Ohio.
These rocks are then related to the
geologic history of the state and to the types of environments
that must have existed when they were formed.
The presence of
many mineral resources, especially oil and gas, under Lake Erie
is mentioned and students are asked to discuss problems with
exploiting those resources.
Students should have had some experience in identifying
sedimentary rocks and the common minerals.
They should also be
familiar with the geologic time scale.
Each lab group should have:
1)
a set of rocks including; shale, sandstone, limestone,
dolostone, salt, gypsum and coal.
Be certain that
the samples you use exhibit the characteristics given
in the student guide.
These are the rocks that outcrop
at the surface in Ohio and therefore can be collected
by the teacher.
The Ohio Geological Survey, Fountain
Square, Columbus, Ohio will provide a set of single
specimens of Ohio rocks on request.
They can be pur-
chased, if necessary, from Ward's Scientific, Rochester
New York.
2) A small jar filled with water and sediment.
The sediment
should be of mixed sand and clay.
3) A binocular microscope with watch glass and saturated
salt solution.
4) A heat source: a candle,
alcohol lamp or
bunsen
burner.
When students have completed this investigation they will be
able to:
1) Describe the environments in which each of the following
sediments would be deposited: clay, silt, mud, shale,
sand and sandstone; limestone and dolostone; salt and
gypsum; coal, oil, natural gas.
2) Explain the relationship between the geological history
of Ohio and its mineral wealth.
3) Explain why some areas of Ohio do not have as much
mineral wealth as other areas.
2
SUGGESTED
APPROACH
ACTIVITY A
The investigation can be used in either an individualized
format with each student having access to the necessary labora-
tory materials,
or in a group laboratory with pre-lab and
post-
lab discussions. In the latter case,
the student guide will
have to be redesigned by pulling out the questions and duplicating
them separately.
The text information should be presented during
the pre-lab or post-lab discussion.
If used in an individualized format, each pair of students
should have available the set of rocks, since these are the most
heavily used materials.
One or two jars with sediment, and 4
or 5 microscope-and-salt-solution set-ups should be available at
stations placed around the classroom.
The investigation could be preceded by the film Rocks that
Form on the Surface,
available from Encyclopedia Britannica
Educational Corporation.
The film describes sedimentary rocks,
where they come from, what they are composed of, and how they are
formed. It is 16 min. long.
You might want to use this investigation as an introduction
to a unit on Ohio's energy supply.
There is a great deal of
concern about full exploitation of natural gas in Ohio.
Ohio's
coal has a great deal of sulfur in it which adds to pollution.
Therefore,there is a problem in its use.
The two methods now
being used to reduce sulfur in coal are stack scrubbers and
fluidized-bed boilers. Both use limestone to remove the sulfur.
In this activity students examine and describe the
sedimentary rocks found in Ohio.
common
Keywords:
Shale, sandstone, limestone, dolostone,
oil,
gas,
coal,
salt, gypsum,fragmental rock, organic rock,
chemical rock.
1.
Students should note that the fragments of rock in the jar
settle out according to size.
The sand settles first in
a layer on the bottom and the clay settles last forming a
layer on top.
2-3.
The descriptions that students write of the types of rocks
should be similar to those in the student guide but in
their own words.
4.
Note that no distinction is made in the activity between
limestone and dolostone.
If you want, you can provide some
3
ACTIVITY B
PROCEDURE
dilute hydrochloric acid. A drop on limestone will
fizz rapidly, whereas on dolostone it will fizz very
slowly and many times only if the dolostone is scratched
first.
This is the easiest way the two can be told
apart.
5.
Try this out before you do it with your students. It
may be that the tap water will have contaminants that
would mask the precipitation and growth of salt crystals.
If so, you may need to use distilled water.
6.
Warn the students not to touch the watch glass with
their fingers after heating it.
They must use a set of
tongs to hold the watch glass over the flame and to insert
it under the microscope.
The salt crystals should appear
to be perfect cubes.
You may want to have some table salt
for the students to look at under the microscope.
7.
Their descriptions should be similar to those in the
student guide.
8.
The coal is black and relatively light weight (low density).
Students may discover vegetative remains in their samples.
You might want to discuss the types of coal.
Most coal in
Ohio is bituminous.
Other types are lignite which is very
low grade and anthracite.
Anthracite has undergone a
certain amount of metamorphism and will be shiny black
and quite hard.
WHAT DO OHIO'S MINERALS TELL ABOUT ITS HISTORY?
The answers to these questions will depend upon the county
of residence of the student.
1.
Figure 1 is used to answer this question.
In Franklin
County, for example,
most of the surface rock is
Devonian.
2.
Answer will vary.
In Franklin County shale and limestone
are produced.
3.
To answer this question students will have to refer
to the information in Activity A.
Both the shale and
limestone, for example, form in either lakes or seas.
This
would be the appropriate response of the students. In
reality, fossils of marine animals have been found in both
REVIEW
QUESTIONS
the Ohio Shale and the Columbus Limestone found in
Franklin County.
Therefore,
seas once covered that
area.
Actually,
all of the rocks in Ohio that are
older than Mississippian were denosited in a marine
environment
4.
Since coal formed in swamps, you would need to go to
the eastern part of the state where the coal mines are
found,
as indicated in Figure
4.
5.
Most shale seems to be mined in the northeastern part of
the state.
6.
This shale was deposited either in seas or lakes.
7.
Figure
1
indicates that the oldest rocks are found in
the southwestern part of the state.
8.
The mine is located on the shore.
Figure 1 indicates
that the surface rock is Devonian.
9.
By referring to the cross section, students should infer
that Silurian rock would be found below the mine
under
the Devonian
and that it would come to the surface some-
where under the lake.
10.
The area north of
Cuyahoga
Countv would seem to be the most
likely
spot for gas since the gas fields trend north-south
through the county and, therefore, also go out under Lake
Erie to the north.
For a similar reason, the western basin
of Lake Erie would seem to be the most likely place for oil.
11.
Students might suggest problems of floating rigs in the lake
and the expense of drilling from such platforms.
Also,
possible pollution problems.
12.
From the geologic maps,
students should surmise that the
islands in the lake off Sandusky are composed of limestone
or dolostone.
13.
No.
Students should realize from Figure 1 that Pennsylvanian
rock
does not underlie the lake.
1.
Although most of the following are not technically minerals
they are usually regarded as part of the state's mineral
resources: limestone, sandstone,
shale,coal,
oil, natural
2.
3.
4.
5.
6.
gas,
rock salt, gypsum.
Fragmentary rocks are formed from the cementing of
fragments of pre-existing rocks.
Organic rocks are formed
from the remains of plants and
animals that die and fall to the bottom of lakes, swamps
and oceans.
Chemical rocks are formed from minerals that precipitated
out of evaporating water.
Coal is formed from plant matter that accumulated in
ancient swamps.
Oil and gas are formed in mud deposited at the bottom of
oceans and seas and later move into sandstones and lime-
stones.
Rock salt, gypsum, sandstone, shale, limestone, oil and gas.
Limestone is likely to be forming in shallow tropical
waters,
such as around Florida, the West Indies,
Australis
and other places where reefs are forming.
Coal is being
formed in places where there are extensive swamps, such
as in eastern Florida, the Gulf Coast,
Central America and
south-
east Asia.
Coal can also result from peat deposits in
temperate and even arctic climates.
Sandstone is being
formed wherever sand is being deposited, such as deserts,
stream beds, beaches and in near-shore shallow water of
lakes and oceans in any climate.
This will be a difficult question for students to answer.
You may have them do Activity C (p. 6 of this guide) first. It
could
be
done orally by the teacher if there is a time
constraint.
From Ordovician time through Devonian time Ohio
was
covered by oceans that may have varied in depth.
Beginning in Mississippian time, the ocean was much
shallower and Ohio was still under water, but was close
to a dry continent resulting in the deposition of sandstone.
In Pennsylvanian and Permian time much of Ohio was still
under this shallow sea.
Eastern and southeastern Ohio
had become part of a swampy coastline where coal was
deposited associated with some sandstone and limestone.
6
ACTIVITY
C
(Supplement)
MATERIALS
REFERENCES
Figure 1, 4 co
County
ored
pencils.
Table 1
Rock
type(s)
Hamilton
Shale, limestone
Shelby
Limestone
Franklin
Shale, limestone
Ashland Shale, Sandstone
Guernsey
Shale,
sandstone, coal
Washington
Shale,
sandstone, coal
Color
A.
Fill in the third column of the table by selecting one of the
colored pencils and placing the name of its color in the blank
for each county.
Use the same color for each county that has
exactly the same rock types.
For example, Hamilton and Franklin
counties should be the same color since they both have shale
and limestone at the surface.
You should end up with only four
different colors for the six counties.
B.
Using the color scheme you just devised, color in each of the
six counties using the appropriate color for each, on Figure 1.
C.
Using the appropriate
pencil,
color in all the areas of Ohio
that are the same age as the rocks in the 6 selected counties
in Table 1,
so that rocks of the same age will be the same color.
D.
Describe Ohio's environment and how it changed from Ordovician time
to Permian time.
Lafferty, Michael B.
Ohio's Natural Heritage.
The Ohio Academy
of
Science, Columbus, Ohio, 1979.
Copies
have
been distributed by
Nationwide Insurance Co.
to all Ohio School Systems.
*LaRocque, A. and Marple,
M.
F., 1966, Ohio
Fossils
Ohio Geological
Survey Bulletin 54, 8th Printing, Columbus, Ohio, illustrated, 152 pages.
*Melvin, Ruth, 1970.
A Guide to Ohio's Outdoor Education Areas, Ohio
Department of Natural Resources, Ohio Academy of Science, Columbus,
Ohio,
illustrated, 143 pages.
7
*Noble, A.G. and Korsok, A.J., 1975, Ohio
-
An American Heartland,
Geological Survey Bulletin
.65,
Columbus., Ohio, illustrated, 230 pages.
*Available from the Publications Office, Ohio Department of Natural
Resources,Fountain Square, Columbus, Ohio 43224.
EVALUATION
ITEMS
1.
Salt and gypsum deposits may form sea water as it
1.
settles
2.
cools
3.
heats up
*4.
evaporates
2.
Clay, silt,
and mud that are deposited far from the shore of
lakes and oceans may eventually form
*1.
shale
2.
coal
3.
sandstone
4.
limestone
3.
A rock that is formed from plant matter that accumulated in
large swamps is called
1.
limestone
2.
shale
3.
sandstone
*4.
coal
4.
A mineral that is mined from beneath Lake Erie is
1.
limestone
2.
coal
*3.
rock salt
4.
shale
5.
Which of the following is an important source of energy found
below Lake Erie?
1.
uranium
2.
salt
3.
coal
4.
limestone
*5.
oil and gas
EVIDENCE OF ANCIENT SEAS IN OHIO
INVESTIGATION
INTRODUCTION
OBJECTIVES
ACTIVITY A
MATERIALS
PROCEDURE
Did you know that you may be living on a sea bottom? Did
you know that Ohio is a major producer of minerals?
In 1969,
Ohio was fifth among all states in the amount of coal mined, second
in the amount of clay, dolostone, and limestone, and third in the
amount of salt, sandstone, sand and gravel.
Most of these sediments
as well as shale. clay. oil,
and natural gas which are also mined
here indicate
seas.
When you
have completed this investigation you will be able to:
1.
2.
3.
.
that Ohio has in the past been covered by shallow
Describe the environments in which each of the
following sediments would be deposited: clay,
silt, mud, shale,sand and sandstone; limestone
and dolostone:
salt and gypsum: coal, oil, na-
tural gas.
Explain the relationship between the geological
history of Ohio and its mineral wealth.
Explain why some areas of Ohio do not have as
much mineral wealth as other areas.
HOW WERE OHIO'S MINERALS FORMED?
Jar with sediment and water; samples of rock; microscope,
Pyrex
watch glass,
salt solution,
and heat source.
All of the rock types common to Ohio are sedimentary in origin.
One type is made of pieces of rock that were broken or worn from
larger chunks. Clay,sand and gravel are examples of sediments that
are fragments of rock.
These fragments are then cemented together
to form rocks such as shale and sandstone.
These are called fragmental
rocks.
Other types of sedimentary rocks form from plants and animals
which died and fell to the bottom of lakes, swamps and oceans.
Their
hard parts are cemented into rocks such as limestone, and dolomite.
These types of rocks are called organic rocks. The soft parts of the
plants or animals form coal, oil, and natural gas. The third type
of sedimentary rock forms from the evaporation of water. Minerals
that are dissolved in the water precipitate to form minerals such as
salt and gypsum. These are called chemical rocks.
Scale
in
Miles
0
20 40
60
LEGEND
Permian
Pennsylvanian
Mississippian
Dcvonian
Silurian
Ordovician
BELL
Et-ON
TA
INE
DELAWARE
Figure 1. GEOLOGIC MAP OF OHIO
6.
What was the environment of that area of Ohio (from
question 5) when the sediments were being deposited.
7.
Refer to Figure 1.
Where are the oldest surface rocks
found?
Salt is found in two types of deposits.
Rock salt is found
--
in strata like other sedimentary rocks.
Natural brines are mixtures
of water and salt that fill the pore spaces of sedimentary rocks.
Approximately
$
of Ohio is underlain by rock salt.
This area
extends east of a line from
Lorain
(on Lake Erie) to Marietta (on
the Ohio River).
The Morton Salt Company mine at Fairport actually
obtains its salt from a mine in the rocks below Lake Erie.
Piles of
Salt
Mine
-
--
--
--
-
-
Lake
>rwl\
-------
-
Salt
Picture above is a cutaway view of the mine and the rocks below it and
Lake Erie.
Natural brine is found under about half of the state.
It
is
found east of a line from
Lorain
to Portsmouth (on the Ohio River).
These natural brines are sea water that was trapped as sediments
were deposited and changed into rock.
They are "fossil sea water."
During early times in Ohio,
those brines were used as a source of
salt.
Now they are important sources of a variety of chemicals used
in industry.
Figure 2.
Active sandstone quarries
(Ohio Division of Mines, 1970); no
counties reported three active quarries.
Figure 4.
Coal deposits in Ohio
(Brant and
DeLong,
1960).
Figure 3.
Shale production in 1969 (Ohio
Division of Mines, 1970); no counties re-
ported between 200,001 and 300,000 tons.
Figure 5.
Active limestone quarries in
Ohio in 1969 (Ohio Division of Mines,
1970).