Silver Mound ~ Legend of an Outlier EarthCache
Silver Mound ~ Legend of an Outlier
Please note Use of geocaching.com services is subject to the terms and conditions
in our disclaimer.
Welcome to the next edition of Doc.’s Roadside Geology Tour: Jackson County!
The above listed coordinates will bring you to a rustic picnic area with a sign standing in the shadows of the great Silver Mound of Jackson County, WI. Silver Mound is a protected site at this point in time and access is limited to supervised tours, due to the sensitive nature of the archeological discoveries deep within the hillside.
Early settlers initially thought veins of silver ran through this mound, thus the name. Instead, the mound possessed a thick layer of extremely rare quartzite which glittered in the light and was quarried by early Native Americans to create highly sought after tools, such as spears tips and arrowheads.
******************************************************************
This area of Jackson County marks a unique transition of Wisconsin's Geological Provinces from the Central Plains to the Western Upland, as well as traveling from the Glaciated region into the Un-glaciated region known as the Driftless Area.
As you survey the surrounding countryside from this site, other Mounds are visible on the horizon to the east. The balance of the landscape is noted for the broad valleys and gentler slopes. As you progress west 1.5 miles on 121 you will transition very quickly into the Driftless Area marked by steep hillside displays of ancient rock formations and dazzling outcrops untouched by the last glacial advance 12,000 years ago.
During the pre-Cambrian era, this entire region was a primitive inland sea, and the rocks we see today are the results of millions of years of metamorphic changes within layers of sandstone and sedimentary limestone. The minerals deposited with the superfine silica created a cementing medium between the granules, increasing the hardness of the resultant sandstone. As the rapidly thinning and weakened edge of the last great ice sheet advanced and retreated through the area, less resistant material, such as loess and till, was removed and these mounds and ridges were exhumed from their entombment.
These isolated sandstone mounds are referred to as “outliers”, as they are located some distance from the continuous sandstone ridge they originated from. The exposed sandstone, quartzite and limestone creating these mounds continues to suffer the effects of the erosive forces of wind and water. Their size diminishes year after year. What once resisted the forces of a glacier is now slowly succumbing to the forces of Mother Nature.
To claim credit for this EarthCache, please email to me:
1. Given that the peak elevation of Silver Mound is 1250' above sea level, please take an elevation reading at the sign and calculate the height of Silver Mound.
2. As you look east, how many Mounds do you see in the distance and are they of the same height?
3. Are the peaks pointed, rounded or flat?
4. Please post a photo of Silver Mound to document your visit to this site.
Buckle up for the next stop on our Roadside Geology Tour of Jackson County, WI!
Additional Hints
(No hints available.)
Treasures
You'll collect a digital Treasure from one of these collections when you find and log this geocache:
Loading Treasures