Welcome to a part of the Mon River Trail North!
As this is an Earthcache, there is no physical container. Answer the quesitons below to log this cache!
This EarthCache will help you explore how erosion and geological processes shape the layered rock walls of this area, from the 10-foot formation along the trail to the towering 100-foot cliff across the river. These natural sculptures reveal a story of time, weather, and the forces of nature that continually reshape our planet.
This location provides a great opportunity to compare and contrast small-scale and large-scale rock wall formations. At the given coordinates, you’ll examine the 10-foot rock wall beside you, noting its layers, textures, and unique extrusions caused by erosion. From this spot, you’ll also look across the Monongahela River to observe the larger cliff face, which shares similar origins but exhibits different characteristics due to its scale and exposure.
Geological Lesson: Small Rock Wall Formation
The 10-foot rock wall near the trail is a textbook example of sedimentary rock layering. These rocks were formed millions of years ago when sand, silt, and clay settled in ancient rivers, lakes, or seas. Over time, these sediments were compressed into layers of rock, creating the stratified structure you see today.
How is it shaped?
Small rock walls like this are often carved by surface erosion:
1. Rain and Water Flow: Rainwater seeps into cracks, carrying away small particles and expanding fractures. Repeated freezing and thawing (freeze-thaw weathering) can further break apart rock.
2. Wind Erosion: Winds carry fine particles like sand, which grind against the rock surface, slowly wearing it down.
3. Biological Activity: Plants growing in cracks and roots spreading can force rock layers apart, contributing to their shape.
The extrusions on the wall are likely harder rock types or mineral deposits that are more resistant to erosion. Over time, softer layers erode away, leaving these features protruding.
Geological Lesson: Large Cliff Face Across the River
The towering cliff face across the Monongahela River shares the same sedimentary origins but tells a broader story of geological forces. Large-scale cliffs are often shaped by:
1. Mass Wasting: Gravity-driven movements like landslides or rockfalls remove large sections of rock, leaving vertical or steep faces.
2. Water Erosion: The Monongahela River below contributes to undercutting the base of the cliff, destabilizing layers above and leading to periodic collapses.
3. Structural Variability: The cliff likely contains varying rock types—harder layers resist erosion, while softer ones weather more quickly, creating ledges and irregularities.
Similarities and Differences:
• Both formations reveal sedimentary layering, with harder and softer rocks shaping the textures.
• The larger cliff face experiences more dramatic erosion events, like rockfalls, while the smaller wall shows subtle erosion patterns caused by surface processes.
• Scale affects the visible features: the cliff face may display talus slopes (fallen debris) at its base, while the smaller wall lacks these due to its limited size.
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) Texture and Layering Observation: Examine the 10-foot rock wall near the trail. Describe the texture, layers, and any extrusions. What signs of erosion can you see?
2) Cliff Comparison: Look at the larger rock wall across the Monongahela River. How does it compare in terms of shape, texture, and erosion patterns? Identify one similarity and one difference.
3) Erosion Reasoning: Based on what you’ve learned, explain why the small rock wall’s features are less dramatic than the larger cliff face.
4) Key Inference: Based on your answers to questions 1-3, why do you think the small rock wall and the large rock wall each have their own respective shape? The large rock wall is hard to tell the exact shape from this distance, but use the general shape of it to answer this question.
5) Take a photo of yourself (or personal item) with either rock wall or anything else that sparks your interest along the trail. You can attach it to your found it log (optional).
Enjoy unraveling the geological story carved into Morgantown’s rocks! Best of Luck and Happy Caching!