Welcome to Newfound Gap, located in the Great Smoky Mountain National Park. The gap is located along the border of Tennessee and North Carolina. The state line crosses the gap here as well as the Appalachian Trail. Because of its nearly mile high elevation, amazing vistas may be seen here of both states.
The Rockefellar Memorial can be found here. This is where President Franklin D. Roosevelt formally dedicated the park on September 2, 1940. (Wikipedia.org)
Because of its elevation, the road to get here is sometimes closed due to snow and ice. Please plan accordingly. Please observe all park rules. Remember to leave only footprints and take away only memories.
Lesson:
Upon arriving to the area, your eye might be drawn to the large cut slope along the parking area. It exposes a variety of different colored rocks with a flat surface. These rocks are metasilstone and slate of the Anakeesta Formation. The majority of the rock strata found in the park are metamorphosed sedimentary rocks, including metasiltone and shale. "The sediments that makeup this rock were eroded from an even older bedrock terrain to be deposited in a rift basin more than 545 million years ago. They were then deeply buried and changed into rocks at high temperatures and pressures. Then, some 300 million years later, during tremendous continental plate tectonic collisions, the rocks were lifted up to form mountains perhaps as much as twice as high as today. Millions of years of erosion and uplift formed the mountains and valleys seen against the distant horizon.(Geology Great Smoky Mountains National Park)
Metasilstone means silstone that has undergone metamorphism to some degree. (wikionary.org)
Silstone is a sedimentary rock composed mainly of silt-sized particles. It forms where water, wind, or ice deposit silt, and the silt is then compacted and cemented into a rock.(geology.com) Thus metasiltone is silstone that has undergone changes (metamorphosed) due to pressure and heat. (Moore, 2004) The metasilstone at this location has a distinguishable blocky appearance. The slate rocks are thin, flat and have a slaty character as well as numerous fractures. The color of the slate is the result of oxidation of the mineral pyrite contained in the slate. Notice the vegetation in the area. Naturally occurring sulfuric acid produced by oxidation and breakdown of pyrite undergoing weathering is the reason for what you observe regarding vegetation. (Moore, 2004)
An interesting observation at Newfound Gap is the existence of metasiltone and slate in close proximity yet they each have a very different appearance. This area is very close to the Mingus Fault which had tectonic shifts millions of years ago forming the mountains nearby. The fact that metasilstone and shale occur side by side but look differently could perhaps be explained by the extreme heat and pressure exerted by tectonic shifts causing the metamorphosis of the siltstone to metasiltone, yet the shale did not undergo the same heat and pressure, thus the shale remained unchanged.
Note: Please submit your answers via our geocaching profile at www.geocaching.com BEFORE logging. Failure to submit your answers may result in your log being deleted without notice. If this occurs, please feel free to relog whenever you have your answers ready to submit. Each geocacher must submit his/her own answers. NO group answers.
Based on your observations:
1. Estimate the height of this formation in feet.
2. Where is the vegetation located in the area of the cut slope? Why has this occurred?
3. Describe the appearance of the metasiltstone (ie., shape, color, location on the cut slope-Left, Center, Right).
4. Describe the appearance of the slate (ie., shape, color, location on the cut slope-Left, Center, Right).
5. Explain what caused the rust color characteristics at this location.
6. Optional picture. NO spoilers please!
References: Geology: Great Smoky Mountains National Park pamphlet Moore, Harry L. (2004). A Roadside Guide to the Geology of the Great Smokey Mountains National Park. Wikipedia.com wikionary.com Permission from the park to share this learning experience has been submitted via a reviewer note.
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