EARTHCACHE REQUIREMENTS
National Historic Park
Each cacher must send his/her own answers BEFORE logging a find. Enjoy the journey (learning adventure) as well as the destination (smiley earned). Remember to take only pictures and leave only footprints. To get credit for this Earthcache, complete the following tasks:
1. MESSAGE …. What are the differences between shale and slate?
2. MESSAGE …. What geological event was responsible for the formation of these shale cliffs?
3. MESSAGE …. Observe both the cliff at the posted coords and the cliff on the other side of the canal. ... a. Give two similarities between the cliffs (other than they are both shale). ... b. Give two differences between the cliffs.
4. MESSAGE …. You will see a shale slab that looks like rusted metal. Explain (scientific or creative) how that occurred.
LOG …. Post a picture of you or your signature item anywhere along the trail. This picture is your log signature.
OPTIONAL - Please respect the time and effort involved in creating this earthcache by adding A and B to your log.
A. JOURNEY OF THE MIND ... Science explains what we observe. Relate (in your own words) something you found interesting in the reading. This adds to your learning adventure and your log.
B. JOURNEY OF THE HEART ... Art shares our personal experience of what we see. Share something special you found on site, and why it is special to you. This is a memorable addition to your log and will make other hearts smile.
Journeys of Heart and Mind ...
Stories to Touch the Heart and Puzzles to Challenge the Mind / Rainbow Tree Story
THE TUNNEL
For more information see Tunnel Hill Trail GC2B02.
- Location Paw Paw Maryland
- This impressive tunnel was built without equipment, is lined with 6 million bricks, and is over 3000 feet long.
- Bring a flashlight to light your way through the dark tunnel.
- You will be walking through some rock depressions providing a water obstacle course adding to your adventure through the tunnel.
SHALE
- A fine-grained sedimentary rock composed of a mixture of clay and tiny fragments of minerals.
- Foliation in thin, parallel bedding.
- Easily broken.
- A thumping sound when hit.
- Dull look in sunlight.
SLATE
- A fine-grained metamorphic rock derived from the original shale and composed of clay or volcanic ash.
- Foliation in planes perpendicular to the direction of metamorphic compression.
- Not easily broken.
- A metallic sound when hit.
- Shines in the sun.
BEDROCK GEOLOGY
Geology of the Chesapeake and Ohio Canal National Historical Park and Potomac River Corridor
"The Cambrian and Ordovician carbonate rocks that make up much of the Great Valley section represent a grand platform in a shallow sea that deepened to the east. These shelly carbonate rocks are overlain by Ordovician shale. The shale was deposited by the erosion of a rising highland to the east and marks the beginning of the Taconian orogeny."
"The stable shelf foundered as the Taconian orogeny (480 to 450 Ma) elevated the rocks to the east and provided a source for the clastic material that makes up the shale of the Middle and Upper Ordovician Martinsburg Formation (the current center of the Great Valley section). "
VOCABULARY
SEDIMENTARY - Rocks formed by the deposition of material at the Earth's surface and within bodies of water.
BEDDING - Division separating it from layers above and below.
FOLIATION - Repetitive layering.
METAMORPHIC - Original rock changed when subjected to very high heat and pressure.
OROGENY - a process in which a section of the earth's crust is folded and deformed by lateral compression to form a mountain range.
RESOURCE
Geology of the Chesapeake and Ohio Canal National Historical Park and Potomac River Corridor, District of Columbia, Maryland, West Virginia, and Virginia
http://pubs.usgs.gov/pp/1691/P1691.pdf