Welcome to the Soil Sleuths of Beverly Earthcache!
Answer the quesitons below to log this cache!
Welcome to Beverly Lake, a quiet retreat in the northwest suburbs of Chicago—and the setting for a fascinating story hidden just beneath your feet. While this scenic lake offers a peaceful escape, the real adventure lies in discovering what the soil here can tell us about the region’s glacial past, wetland ecology, and ongoing environmental processes.
Thousands of years ago, glaciers carved and shaped this landscape, leaving behind a patchwork of sediments and landforms. As the ice retreated, meltwater collected in low-lying areas, forming lakes and wetlands like Beverly Lake. Over time, layers of soil developed—some rich in organic matter, others saturated and hydric, all carrying clues about how water, weather, and life interact in this ecosystem.
This EarthCache invites you to explore the soil near Beverly Lake, observe its properties firsthand, and think about how geology, biology, and climate have all played a part in shaping the ground beneath your boots.
The Drying Edge: Identifying the Upland-Wetland Boundary
Beverly Lake lies in a glacially carved basin on the Chicago Lake Plain, a region shaped by the retreat of the Wisconsinan ice sheet over 10,000 years ago. This landscape still holds the marks of glacial activity—from flattened plains to lake basins and clay-rich sediments. Beverly Lake is a perfect example of how ancient glacial forces created low-lying, water-retaining environments surrounded by slightly elevated uplands.
As you explore this site, you are standing at the edge of two distinct ecological and geological zones: upland and wetland. The trail you’re walking on lies approximately 15 feet above the lake, and this elevation difference, though modest, marks a significant shift in soil, moisture, and sedimentary processes.
Where Upland Meets Wetland
The boundary between wetland and upland is not always sharply defined—but with careful observation, it reveals itself in the color, texture, and moisture of the soil. This transition zone—often just a few feet wide—teaches us how geology, water, and plant communities interact across landscapes.
Features to Observe and Interpret
1. Soil Color as a Boundary Marker:
- Near the lake’s edge, the soil is typically darker, indicating higher moisture levels or recent saturation. Dark soil may contain more organic matter or iron staining, and it signals the presence of wetland conditions.
- As you walk uphill, the soil becomes lighter, reflecting exposure to air, drying, and oxidation. This indicates a shift into upland conditions, where water drains more quickly and saturation is rare.
- The gradual transition in soil color can help you pinpoint where the wetland ends and the upland begins—a key tool in both geology and ecology.
2. Soil Moisture and Texture:
- At the bottom of the slope, soil may feel sticky, soft, or even squishy if saturated—common in wetland environments with fine-grained sediments like clay and silt.
- Higher up, the soil becomes firmer and drier, often with better structure. This reflects faster drainage and lower water retention, typical of upland soils.
3. Evidence of Drying and Water Movement:
- Look for cracked soil near the lake, especially during dry periods. These polygonal cracks form when waterlogged clay-rich soils dry out and shrink.
- Capillary moisture patterns may create subtle color bands in the soil as water moves up or down with evaporation and rainfall.
4. Sediment and Surface Clues:
- You may also see sediment layering in some areas, especially if past lake flooding deposited thin sheets of silt. These act as natural time markers and reflect seasonal water-level changes.
Why This Transition Matters
The slope between the trail and Beverly Lake is more than just a topographic difference—it’s a natural boundary between two geologic zones. Understanding this upland-to-wetland transition helps us:
- Recognize how water shapes the land today and in the past.
- Predict where wetlands may expand or contract in response to seasonal rain or drought.
- Identify how glacial sediments still influence modern drainage patterns.
Field geologists, wetland scientists, and land-use planners all study this kind of landscape transition to better understand surface processes and environmental change.
LOGGING REQUIREMENTS
Please complete the tasks and questions below, and send me your answers. If logging for a group, please include the names of everyone in your group.
1) Soil Color Observation: Describe the color of the soil near the water’s edge AND at the top of the slope (trail level). What differences do you notice?
2) Soil Moisture Comparison: Examine the soil in both locations. Does the soil appear wet, damp, or dry at each site?
3) Interpreting the Boundary: Based on your observations, where do you think the upland-to-wetland transition zone lies along this slope? What clues led you to that conclusion?
4) Take a photo of yourself (or personal item) with the lake. You can attach it to your found it log (optional).