Bald Rock Earthcache EarthCache

Bald Rock Earthcache

I recently hiked to Bald Rock in Cheaha State Park and was taken with the beauty of this wonderful place.  The views of the rocks and trees along the trail were refreshing as well as the views of the valley below Mt. Cheaha.  I hope you enjoy being here as much as I did. 

Parking and Hiking:

There is paved parking lot at the parking coordinates and a nice wooden elevated deck you can walk to Bald Rock or you do as I did and walk on the trail that parallels the wooden deck.  I rated the terrain for this earthcache for the route that I took.  The boardwalk is considerably easier.  While at Bald Rock Earthcache, you can also find the nearby “Cache Across America – Alabama” (GCWXQ4) traditional cache.  Before driving to the parking lot, you can also go to first stage of the multicache, “Assignment: Fire Tower – Cheaha Mountain” (GCYEVR) and work out the coordinates for stage 2, which is located along the walking trail to Bald Rock. Find three cache types on one hike.

Walking Back In Time:

While standing at Bald Rock enjoying the views, I looked around and was a little astonished to see that I was standing on a large formation of Metamorphic Rock known as Gneiss.  The process of geologic metamorphism has always fascinated me in that this beautiful rock here at Bald Point was once a Sedimentary rock called Sandstone that was formed from grains of sand that were deposited and then were cemented together.  That Sandstone was then by the process of plate tectonics buried deep inside the earth’s crust where that Sandstone was slowly transformed by HEAT and PRESSURE into a type of Metamorphic Rock called Gneiss.  In other words, these rocks here were cooked or baked deep within the earth’s crust into a new rock sometime long ago.  As the old sandstone was slowly heated and put under great pressure from the weight of the overlaying rock, the grains of sand in the sandstone gradually recrystallized into Metamorphic Gneiss.  Then again, due to the continued process of Plate Tectonics, the Metamorphic Gneiss was brought back to earth’s surface to form Mt. Cheaha that we see here today.  If these grains of sand could talk and tell us their story, what a story it would be.

Educational Component:

Metamorphism:  A metamorphic rock is formed as a result of a transformation of a pre-existing rock. The original rock is subjected to very high heat and pressure, which cause obvious physical and/or chemical changes.  The pre-existing rock can be Igneous Rock, Sedimentary Rock (like Sandstone), or it could be Metamorphic Rock that has already undergone a previous transformation.  Metamorphic Rock may be formed simply by being buried deep beneath the Earth's surface, subjected to high temperatures and the great pressure of the rock layers above it, or they can form from tectonic processes such as continental collisions, which cause horizontal pressure, friction and distortion. This type of Metamorphism is called Regional Metamorphism. They are also formed when rock is heated by a large mass of hot molten rock called magma that has risen from the Earth's interior. This type of Metamorphism is called Contact Metamorphism. Metamorphic Rock makes up about 12% of the rocks in the earth’s crust.

Foliated and Non-Foliated Metamorphic Rock:  Foliated metamorphic rocks such as gneiss, phyllite, schist, and slate have a layered or banded appearance that is produced by exposure to heat and directed pressure. You can see the bands or layering of the rocks.  The layering often has a swirled or twisted like appearance to the banding.  Non-foliated metamorphic rocks such as hornfels, marble, quartzite, novaculite, and metaconglomerate do not have a layered or banded appearance.  The recrystallization process has left the rock with a more uniform appearance. 

To get credit for a find a this earthcache, please email or message me the answers to the following questions.

Please preference your Answers with the name of this Earthcache – Bald Rock Earthcache

1.  What colors are present in the metamorphic rocks here?

2.  Are these metamorphic rock crystals here Foliated (layered) or Non-Foliated (non-layered)?

3. Can you see the original grains of sand that made up the Sandstone before metamorphism took place or have the sand grains completely recrystallized into a new uniform mineral?

4.  What two factors must be working on Pre-Existing Rock for Metamorphic Rock to form?

5.  Do you think that the Metamorphic Gneiss rock formation here at Bald Rock was formed from Regional Metamorphism or from Contact Metamorphism (hint- this rock formation is located along a ridge of a long mountain range)?

6.  Optional: Take of picture of yourself in front of the “Bald Rock” rock sign and post that picture on the Bald Rock Earthcache cache page.