Compare the above maps to the map below, which shows where limestone
is mined or excavated. Notice that the mines are located near major transportation
arteries, or on the Great Lakes proper. This is because these rocks,
like many rocks, are so heavy that they do not bear the cost of transportation
well. That is, they have a low value/weight ratio; such products either
cannot be moved very far from where they occur (or are manufactured), or
they must be transported by very inexpensive means, such as large freighters.
LIMESTONE QUARRIES OR MINES IN MICHIGAN, AS OF 1939
Limestone Quarries in Michigan, as of 2003
· Located in Cedarville, MI
· Produces dolomite and limestone
· Ships from 3 to 4 million net tons per year
· Located near Gulliver, MI
· Produces both high calcium carbonate limestone and dolomite
· Ships 3 to 4 million tons per year
· Located in Rogers City, MI (Presque Isle County)
· Worlds largest limestone quarry
· Produces high calcium carbonate limestone
· Ships from 7 to 10.5 million net tons per year
The next series of images depict various means by which limestone
is quarried or processed, beginning with the oldest technologies and continuing
up to the present.
In the years following 1900, new uses have not only resulted in the utilization of Michigan limestones on a gigantic scale, but also in a demand for limestones with special characteristics that meet the exacting specifications of the different types of use. Consequently, closer and closer attention has been paid to the physical and chemical qualities of the stone quarried. Most of the chemical uses of limestone, and these are by far the most important, require the stone to be as nearly pure and high in calcium content as possible. Michigan is fortunate in having large deposits of very pure, high calcium stone in the northern part of the state, some of which are conveniently located on or near the shores of the Great Lakes. Thus, quarries were opened in these deposits early in the 20th century. As the competitive advantages afforded by the cheap water transportation possessed by the water front quarries became evident, interior quarries (far from the Great Lakes) were later abandoned. This has resulted in the eventual concentration of the major part of the Michigan production in a few large highly mechanized quarries operated in the rich and extensive lake side deposits. Because of their suitable location and high quality, and because of other factors favoring quarry development, these deposits have come to produce stone for use not only in Michigan, but in the entire Great Lakes region.
Below you can see the remains of a small kiln, used to turn limestone (CaCO3) into lime (CaO), by heating it up and driving off the CO2). Small kilns were often located right at the minesite, reducing transportation costs, since the raw stone did not need to be moved far, and the processed lime weighed substantially less than did the raw material.
The stones below were quarried for building stone, and then left behind. Many buildings in NE lower MI are made of limestone.
Below, two carloads of limestone await transport to the rock crusher. Large cars such as these were typical of limestone mining operations in the mid-20th century.
This old photo provides a good example of a mine, located far from the lakes, which was opened early because it had high quality limestone and thin overburden, reducing quarrying costs. However, because it was not near a Great Lake, transporting the low value, heavy stone to markets was too costly, and the mine soon closed.
Below is a photo of a steam shovel loading limestone onto a railroad car. Transporting stone and aggregate by rail was an economical alternative for mines not located near the Great Lakes.
Later on, the size of the excavating equipment grew and grew. This large electric shovel could load more stone with one scoop than a person could in one day.
The most economical way to move limestone long distances was by boat. Here, two large freighters are ready to be loaded.
Below is a typical loading dock. Limestone was moved by belt to the docks, and then dumped down the large "chutes" into the cargo holds of the Great Lakes' freighters. Docks like these are still commonplace today.
Source: Photograph by Randy Schaetzl, Professor of Geography - Michigan
In addition to limestone, Michigan also produces pure lime
as well. Lime is purified limestone, and is often of more value to
industry than is limestone. The map below shows where lime is produced.
Some of the lime comes from marl--limey ooze that was depoisted on the bottoms
of lakes, often glacial lakes.
Today, Devonian outcrops in Wayne, Charlevoix, Emmet,
Cheboygan, Presque Isle, and Alpena Counties are quarried for limestone and
dolomite. These rocks are then used for flux in steel mills, as agricultural
lime and in sugar refining. They are a large resource in the production of
cement, crushed stone, in the chemical industries; in glass and paper manufacture;
for water softener, gas purifier, and for construction purposes. To
make Portland cement, clay, shale and
limestone is ground to a powder and baked in a kiln. The baked mixture forms
clods (clinkers), which are then ground up and mixed with gypsum. Most of
the raw materials are mined in open pits. Michigan traditionally ranks in
the top five states in terms of cement production. One of the largest cement
plant in the state is in Alpena.
Source: Photograph by Randy Schaetzl, Professor of Geography - Michigan State University
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