Deadman's Fen EarthCache
-
Difficulty:
-
-
Terrain:
-
Size: 
(not chosen)
Please note Use of geocaching.com services is subject to the terms and conditions
in our disclaimer.
This area is easy to get to but the nature of fens makes them a difficult surface to walk. Visitors will want to make sure to wear proper shoes for getting wet. Parking for this fen is in Pilot Knobs State Park at or near N 43 14.043 W 93 34.146
As part of the Des Moines Lobe region of Iowa, the park is filled with interesting geologic features. While the park is named for its isolated cone-shapped hill, this EarthCache will have you examine a fen within the park.
Pilot's Knob State Park is part of the Des Moines Lobe region. This is a unique area because at this point in the state all three of the glacial advancements come together (Algona, Altamont, and Bemis). Recent studies have identified this 25-acre wetland to be a fen. Fens are wetlands where groundwater flows to the surface creating a habitat that is constantly saturated. The soil in a fen is permanently waterlogged and due to slow decomposition rates.
Water in fens is slightly alkaline due to the dissolved carbonates in the groundwater. Fens are typically found on hillsides or along streams. The western portion has a 3-acre floating mat of vegetation dominated by Sphagnum moss. Due to slow decomposition rate, mounds of peat often form and are prominent in the landscape of a fen. Since the last glacial episode, many changes have occurred in the vegetation assemblages at Pilot Knob. Studies of fossil pollen grains in soil cores collected from Deadman’s Lake indicate that vegetation around the lake changed from oak savanna to prairie about 8,000 years ago. By 3,000 years ago, the prairie was replaced by oak forest.
A typical fen in Iowa may contain 75 species or more. Approximately 1/3 of these species are considered to be threatened or endangered. Fens are a rare ecotype, which accounts for so many plant species. This fen hosts a floating mat of unusual vegetation including Sphagnum moss and sundew, which is not found anywhere else in the state.
In order to receive credit for this Earth Cache, please send an email to the cache owner with answers to the following questions:
1) Once you are at the coordinate, continue at least another 10 feet into the fen. Than take a few jumps. Describe what happened and what it felt like.
2) Estimate how deep you think the fen gets in the middle?
3) What type of plant is most abundant in this area?
4) Take a walk around the trail that goes around Deadman’s Lake. Notice the difference between the western and eastern parts of the lake. Describe why you think this looks this way?
Additional Hints
(No hints available.)