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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