Portage River - An Erratic Adventure
(TWO STOP EARTH CACHE)
Glacial erratics are rocks that have been transported by glaciers and deposited far from their original source. These rocks are often different in composition from the surrounding bedrock and can be used to trace the path of ancient glaciers.
• Transportation:
Glaciers, whether they be ice sheets or valley glaciers, pick up rocks of various sizes and transport them as they move.
• Deposition:
As the glaciers melt and retreat, they deposit these rocks, called erratics, in their new locations.
• Different Composition:
Glacial erratics are often different in composition from the bedrock of the area where they are found, making them stand out.
• Geological Significance:
They can provide valuable information about past glacial movements, the extent of past glaciation, and the direction of ice flow.
• Size and Shape:
Erratics can range in size from pebbles to large boulders, and they often have rounded or smoothed surfaces due to abrasion during transport.
- Glaciers transported various types of rocks, known as glacial erratics, into Ohio from other regions, primarily from Canada and the Great Lakes region. These erratics are typically igneous and metamorphic rocks, distinct from Ohio's native sedimentary bedrock. Common examples include granites, tillites, and schists.
- Ohio's bedrock is primarily sedimentary, consisting of rocks like shale, sandstone, and limestone.
Questions:
To log this cache, attach required photo(s) to your log entry and email or geocache message me, the answers to the following questions:
Stage 1(posted coordinates):
1. Examine the erratic. Is it smooth? Rough like sand paper? Jagged?
2. Identify the type of rock from the photo above?
3. Do you see signs that the river is weathering the erratic?
4. Do you see signs of weathering that took place during glacial movement or prior to reaching this resting place?
5. Post a picture of yourself or personal item with the glacial erratic. (REQUIRED). You MUST be AT the posted coords.
Stage 2(Waypoint):
6. Examine the erratic. Is it smooth? Rough like sand paper? Jagged? How is it different from the erratic at posted coords?
7. Identify the type of rock from the photo above?
8. Do you see signs that the river is weathering the erratic?
9. Do you see signs of weathering that took place during glacial movement or prior to reaching this resting place?
10. Post a picture of yourself or personal item with the glacial erratic. (REQUIRED). You MUST be AT the stage 2 coordinates.
**** Don't forget your photo at BOTH locations ****
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