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Lannon Stone: Dolomite Unearthed

Hidden : 9/28/2007
1 out of 5
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Geocache Description:

Lannon Stone: Dolomite Unearthed


As this is an EarthCache there is NO container. To claim this as a find you will need to complete the tasks outlined below. Failure to complete the tasks may result in the deletion of your log without notice.

While there are some places where the Niagara Escarpment can be seen above ground (such as at BRADY'S ROCK ), there are many more places where the Niagara Dolomite (limestone) is buried under dozens of feet of soil. The Sussex / Lannon area is geologically unusual due to the high quality of the limestone which is located there as well as the fact that the limestone is just below the surface making it easy to mine. As the layers of Dolomitic limestone are so easily obtained here, quarrying has been a large part of this areas history.

-Ancient History-

Niagara Dolomite (limestone) forms a prominent land-form in eastern Wisconsin. When exposed to the surface an escarpment can be seen. In Lannon the Dolomite formations are close to the surface. The picture above depicts the Dolomite deposit during the Silurian Age.

The origin of the limestone found in Lannon dates back to the Silurian Period of the Paleozoic Era when a warm shallow sea existed here. More than 400 million years ago Dolomite was formed from accumulated sediments of the ancient sea. These sediments are made up of calcium and magnesium carbonate which came from the decomposing algae, shells and skeletons of primitive sea life.

Fossils abundant in the limestone include brachiopods, cephalopods, crinoids, and corals. These fossils represent creatures that lived in the sea and helped to create the materials that made up the stone. Over time these sediments gathered into a limey mud that would years later become the hardened limestone we see today.

-Quality of Lannon Stone-

Lannon limestone is considered to be one of the strongest and most dense limestone's in North America. As you can see from the table below, the properties of Lannon's limestone far exceed the ASTM standards* for limestone building materials.

*ASTM International is one of the largest voluntary standards development organizations in the world, and is a trusted source for technical standards for materials, products, systems, and services.

Property Value
Density 171.0 lbs/cu ft
160 lbs/cu ft
Compressive Strength 30,000 psi
8,000 psi
Modulus of Rupture 3600 psi
1000 psi
Water Absorption 0.95%
Abrasion Resistance 25.0 hardness
10 hardness
Flexural Strength 3,200
no standard

Properties of Lannon's limestone

To help you understand the real strength of Lannon's limestone, the table below shows how it is categorized according to density quality. Keep in mind that Lannon Stone can have a density of 171.0 lbs/cu ft

Product Quality
Property Values
Limestone having a density ranging from 110 through 135/lb/ft3 (1760 through 2160 kg/m3)
Limestone having a density greater that 135 and not greater than 160 lb/ft3 (2160 through 2560 kg/m3)
Limestone having a density greater than 160 lb/ft3 (2560 kg/m3)

-Recorded History-


Lannon excavation

When Lannon was first settled by Europeans in the 1830's, it became clear immediately that the easily found stone slabs could be dug up and used for construction of buildings and roads. By 1838 the stone was already being bought and sold as a consumer good. In 1855 there were at least a dozen quarries shipping stone out the Lannon area, and by 1959 there were more than thirty stone companies located near this rich source of high quality stone.

At one time stone provided a livelihood, in one way or another for almost everyone in the village of Lannon. Now less than 20 percent of the population depends on stone for a job. Today there are few (albeit very large) mining companies left in the area.

In addition to being easily mined, the limestone's extremely high quality, makes it a much sought after stone. "Lannon Stone" as it would eventually be uniquely named, is among the hardest and most versatile varieties of limestone available. The crushed lime is still among the whitest and strongest on the market and throughout history it has been in high demand regardless of cost.

Normally used in landscaping and for building, it is interesting to note that beginning in 1881 until it's completion in 1930, the Milwaukee Breakwater was built from stone mined in Lannon. While stone is generally thought of as a construction material, crushed lime is also used by farmers to neutralize acidic soil which helps improve soil quality and crop yield.

Considering the strength and durability of Lannon limestone it should come to no surprise that it is one of the most sought after forms of limestone by builders throughout the world.

Located at the listed waypoint is St. John's, Lutheran church. Lead Pastor, Gary Koschnitzke has graciously allowed us to visit the church so that we may get a look at the stonework on the exterior of the building. Please be respectful during your visit. Church services are Saturdays at 5:30pm, Sunday at 8:00 & 10:30am and Mondays at 7:00pm so please try to visit outside of those times.

There are two requirements that MUST be fulfilled in order to log this cache as a find:

You must complete #1 below AND either #2 or #3

#1 At St. John's Lutheran Church you must answer the following questions:

a.) What color is the stone / is the color uniform?
b.) Describe the stone's texture; is it smooth, rough, pitted...?
c.) Does the stone appear to be eroding?

#2 Post a picture of yourself with your GPS (or your GPS alone) in front of a structure made from Lannon Stone.
The picture cannot be of the church and must meet both of the below requirements:

a.) This structure must be located within 5 miles of the posted coordinates.
b.) The photo must be of a stone wall, home or a place of business.

(Please stay off of private property and use due caution when taking pictures.)

*** OR ***

#3 If you would like to take pictures of a quarry or the Lannon stone in its natural state, I will allow those to be taken and I highly recommend your doing so at Menomonee Park. This park is an exceptional place to take photos, and is a superb example of an old Lannon stone quarry. Menomonee Park, once known as Stone City, was mined extensively in the late 1800's. Coordinates for the park entrance are at N43 09.634 W88 11.009. There is a fee to enter this county park. Park Hours are Sunrise to 10 p.m. year-round.

A few words about the picture requirement:

Please make an attempt to capture a unique picture and not just the nearest Lannon Stone building. The purpose of taking the picture is so that you are able to see exactly what kind of impact the quarrying of this stone has made in the area in terms of both construction and commerce. With so many buildings to choose from please explore a bit and find just the right one.



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Coordinates are in the WGS84 datum

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