This cache is winter friendly and you'll enjoy
the scenic walk - I promise!
This is not your typical
geocache. It is an earthcache. You will not find a "cache
container" at the listed coordinates. An earthcache is
designed to bring you to a geological feature and educate you. Of
course, as with any geocache you can earn a "find" if you
complete the requirements listed at the bottom of the
page.
Lime Kiln Natural Area in
Menomonee Falls, Wisconsin
The kilns at this site
The park
derives its name from two historic lime kilns located within the
park, which along with the quarry, date from the 1845 and are in
the National Register of Historic Places. In 1845 businessman
Frederich Nehs began quarrying limestone in Menomonee Falls. The
kilns worked for 49 years until they closed in 1894. About 9.5
acres of the lands along the river gorge are embedded with fossils
that date from the Silurian Era, 45 million years ago. These acres
have been designated a geological area of state wide significance.
See the old photo below of the original lime kilns.
Lime Kiln Natural Area is
a diverse natural area with a cattail marsh, fresh (wet) meadow,
forested drainage, hardwood deciduous forest and the Menomonee
River. In 2007 there began a five year management
project to return native plants and animals back to the
area.
Wisconsin's early lime industry
Years before Wisconsin became a state the early settlers were
mining and firing limestone to create quick-lime for use as mortar
and whitewash. In the 1850's the commercial production of lime was
concentrated mainly in the eastern counties where some of the
state's most abundant limestone deposits were located. By the late
1800's Wisconsin had become one of the countries leading lime
producers shipping over one million barrels annually.
As transportation methods improved commercial lime production
began to spread to other counties of the state especially Fond du
Lac, Door and Manitowoc. Competition, hardwood shortages, increased
transportation costs and the growing use of Portland cement made
small-scale kilns become increasingly unprofitable and many ceased
production by the early to mid 1900s. The final nail in the coffin
for many kilns was the beginning of the Great Depression which saw
a near standstill in the construction industry.
The firing process
Simplified, a lime kiln is an oven used to produce quicklime by the
"calcination" of limestone. Limestone is made up mainly of three
components: calcium, carbon and oxygen. When limestone is heated
the carbon escapes as carbon dioxide, leaving lime. This reaction
takes place at 750°F, but a temperature up to 2,000°F is usually
used to make the reaction proceed more quickly. The process of lime
burning was carried out by a kilnsman who was experienced in the
reduction of limestone. An experienced kilnsman was required to
monitor many variables in order to reduce the amount of "dead
burnt" lime which was not useful as an end product. The heating and
cooling process took several days.
These kilns were "draw" kilns. Draw kilns operate under the
principal of gravity. Limestone is fed into the top of the kiln and
the cooked stone is removed from the bed of the kiln. Fireplaces
were located at the sides of the kiln where fuel was burnt to cook
the limestone. One advantage of the draw kiln was that it could be
operated on a continual basis. Even though this type of lime kiln
was more effective than past versions, it was still extremely
inefficient and the lumber needed to fire it could easily
necessitate the clearing of large tracts of woodland.
After the lime was fired it was cooled in cooling sheds and
slaked. Slaking involves adding moisture to the lime; this occurred
in a number of possible ways from sprinkling water on the lime to
letting it sit and absorb water from the atmosphere. The correct
mix is approximately one part lime to one part water. Other
additives were combined with the lime to create various
products.
Limestone (Calcium carbonate)
The limestone mined here dates back to the Silurian Period of the
Paleozoic Era (410-438 million years ago). A common sedimentary
rock, limestone was formed when a shallow sea (possibly as little
as 70 feet in depth) existed over Wisconsin. In this sea
accumulations (reefs) were created by shell and shell fragments
consisting of corals, brachiopods, crinoids and other types of
early life. Many marine organisms extract calcium carbonate from
the seawater to make shells or bones and when these organisms die
their shells and bones accumulate on the seafloor. Over millions of
years these sediments harden into what we see today as limestone.
Calcium carbonate is found naturally as a component of aragonite,
calcite, chalk, marble and travertine. See the photo below of the
quarry today.
Uses of Calcium Carbonate-
· As a filler in plastics.
· As an extender in paints.
· As an ingredient of cement.
· To treat animal hides and leather.
· In swimming pools as a pH corrector.
· In agriculture to improve acidic soils.
· In forensic science to reveal fingerprints.
· As a major component of blackboard chalk.
· In adhesives, sealants, and decorating fillers.
· In water and sewage treatment to reduce acidity.
· As a building material in the form of marble or limestone
aggregate.
· Medically as a calcium supplement, antacid or as a base material
for pills.
*Special thanks to the geocacher Lostby7 for use of some of the
cache page text.
LOGGING THIS
EARTHCACHE
In order to log this earthcache you must
complete two tasks:
1. Email me the answers to
these questions:
a. Explain in your own
words how the process of calcination works.
b. Lime stone can be used
in its natural form. Name a few of its uses.
c. When were the kilns
built at ground zero and by whom? The answer is on the sign at
ground zero.
d. How did did they get
the limestone across the river? The answer is on the sign at ground
zero.
e. When was the placard at
ground zero placed by the Park Board?
2. Optional: Take a self photo
with your GPS or your team with a GPS at ground zero with
the kiln placard in the background. Then post the photo with your
log. Try to get at least one person and a GPS in the photo. If
you are geocaching alone, hold you camera at arms length to take a
self photo, please.
Failure to complete the task as listed
above (emailing the answers) will result in log deletion without
notice.
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