Principle of Original Horizontality at Jasper, AL - Earthcache
This Earthcache is meant to be wheel-chair accessible. You can park off the Highway along either the West-Bound or East-Bound lanes of Highway 78, You can get out of your vehicle if on the westbound side of the highway and examine the rock wall more closely. I think stopping along the east-bound side of the road works best as this position puts you further away from the wall and give you a better overall view. There is plenty of room to safely park off the roadway here along the highway.
This is an Earthcache and as such is a kind of virtual cache in that there is no physical container to find and log to sign. You must answer the questions below and then email or message the correct answers to Papa Bear 204. Any “Found Log” that is not accompanied with an email with the answers will regrettably be deleted. Please take care of this task within 5 days of logging a find.
Tools Needed: It might help to have a straight edge tool such as a straight aluminum hiking pole to hold up at arm’s length, horizontal and parallel to the rock layers. This will help in answering the questions below. A protractor might also be useful here in determining the angle of change.
Questions for Logging Credit:
1. What has happened to the rock layers in the rock wall on the north side of the road cut of the highway here.
2. Estimate the angle of change in the rock layers from the right and left side of the rock wall. A protractor will be helpful here. (Remember that these rock layers were once straight and horizontal).
3. What Geology Principle best describes how the material that formed these rocks were originally deposited.
4. From your answer in question #3, what has happened to these rocks since they were originally formed?
5. Count or estimate the number of individual rock layers that you can see. Are these rock layers of the same relative thickness?
DO NOT POST A PICTURE OF THE ROCK WALL HERE! I will have to delete your log if you post a spoiler pic. You may post a pic of yourself or your group, but the rock wall cannot be shown. Thanks.
If you enjoyed your stop here at this Earthcache, please post a Favorite Point. The Earthcache will appreciate this gestor.
Educational Reading: In geology, The Principle of Original Horizontality states that layers of sediment are originally deposited horizontally under the action of gravity. The principle is important to the analysis of folded and tilted strata that we see on the surface of the earth’s crust and this helps us to understand what has happened to these layers of rocks here in Jasper, AL. The earth’s great dynamic internal forces and resulting plate tectonics cause movement and collisions of large plates of the Earth's crust. The collisions of these plates result in rock strata being folded, tilted, broken, uplifted, and subducted. The rocks that you see here were originally formed from horizontal deposits of fine mud and silt on the seafloor. Those deposits of mud and silt formed the Shale that you see here. The Earth’s dynamic tectonic forces most likely resulted in COMPRESSIONAL FORCE being focused here in Jasper, AL to altered these layers of shale to their present position. That is, a pushing force from the east and a pushing force from the west acted on this area and caused these rocks layers to be altered from being horizontal. These rocks were at some time in the distant past horizontally laying shale. Erosion is now gradually causing the brittle shale stone here to break apart and gravity is working to deposit the shale stone again horizontally somewhere else downslope of here.
Sources: https://en.wikipedia.org/wiki/Principle_of_original_horizontality http://www.thisoldearth.net/Geology_Online-1_Subchapters.cfm?Chapter=4&Row=2