Glassy Mountain EarthCache The Hard Way (Pickens) EarthCache

NOTE: Doing this EarthCache requires you to take a short hike from the parking area to the rock face.
Difficulty: Moderate Hike required (Rated 2 Terrain)                Length: ~0.8 miles (1.3 km) one way

There are TWO Glassy Mountains located in Upstate South Carolina. This Glassy Mountain is a mountain close to Pickens, in northwestern South Carolina. It has a summit elevation of 1,703 feet (above mean sea level). While it is an isolated monadnock, it is still close to the Blue Ridge, providing views of nearby summits such as Table Rock and Caesar's Head. The mountain gets its name from a large, bare, granite face on its north side. At the top of this rock face are small springs that trickle down the mountain, giving it a "glassy" appearance in the sun. It is easily accessible, as a small service road for the transmitter towers located on the summit.

THIS Glassy Mountain is GLASSY MOUNTAIN HERITAGE PRESERVE, and was acquired May 8, 1990 as part of the SCDNR (South Carolina Department of Natural Resources) and is one of only a few Monadnocks in South Carolina. This type of landform is rare in South Carolina. Glassy Mountain's north face has extensive bare rock areas with steep inclines that drop nearly 400 feet in places.The preserve comprises 65 acres in Pickens County. The area is open during daylight hours year-round.

This is an Earthcache! An Earthcache is a special type of geocache where there is no container to find - instead you are looking for unique geological features of the area and need to answer questions and/or posting a photo to your log in order to claim the find.

IN ORDER TO COMPLETE YOUR FIND OF THIS EARTHCACHE: DO AT LEAST 2 OF THE FOLLOWING QUESTIONS/TASKS:
Send the answers to me in a message or email through geocaching.com (OR POST a PHOTO TO YOU LOG IF DOING THE PHOTO OPTION) The SAME DAY YOU LOG YOUR FIND is preferable:

EarthCache Questions:

1. Take a photo (including you/others of your group if you prefer) somewhere near the coordinates. Post this photo in your log and it will qualify as one of your answers/tasks.

2. How can you tell that Glassy Mountain’s quartzite is more resistant to weathering than the surrounding rocks? ________.

3. What evidence of past sedimentary layers or features can be observed in the quartzite rock face? ________.

5. At the base of the rock face, you may notice features like small cracks or seams in the quartzite. What causes these features to form in hard rocks like quartzite? ________.

************NOW FOR THE EARTHCACHE************

Location: Glassy Mountain Summit Trail, Pickens, SC (N 34° 54.045′ W 82° 39.658′)
Elevation: Approx. 1,703 feet
Difficulty: Moderate to Hard (Hike required)
Length: ~0.8 miles (1.3 km) one way

Introduction and Geological Background:

Glassy Mountain's geology is deeply connected to the Appalachian Orogeny, a major mountain-building event that occurred between 300 and 500 million years ago. During this period, the collision of tectonic plates caused immense pressure and heat, which led to the transformation of sedimentary rocks (such as sandstone) into harder, metamorphic rocks like quartzite. The Appalachian Orogeny also resulted in the formation of a wide range of geological features, including folds, faults, and fractures, which are visible throughout the region.

The hike to the rock face of Glassy Mountain offers a closer and more intimate look at the geological features that make this monadnock so distinct. While my other EarthCache nearby ("Glassy Mountain EarthCache The Easy Way") focuses on the mountain's appearance from afar, this EarthCache takes you directly to the Glassy Mountain's exposed quartzite rock face. As you hike the short but somewhat steep trail from the parking lot and out to the rock face itself, you are able to observe firsthand the rock's physical characteristics, its relationship to the surrounding environment, and the unique erosion processes that have shaped this geological feature.

The rock that makes up Glassy Mountain is primarily quartzite, a hard metamorphic rock that forms when sandstone undergoes intense heat and pressure. The quartzite here has a distinctive appearance—it is usually light-colored, with a glossy, almost glass-like sheen (hence the name "Glassy Mountain"). This quartzite is much more resistant to weathering and erosion than the surrounding rocks, which is why Glassy Mountain stands out as a prominent peak while the surrounding landscape has been eroded away over millions of years.

The rock face of Glassy Mountain provides a clear view of how the quartzite is layered and weathered. You can also observe how the mountain's hard quartzite has protected it from erosion, while softer rocks in the surrounding area have been worn away.

As you approach the rock face, take a moment to observe the different weathering patterns visible in the rock. The top of the mountain might show signs of frost wedging, where water seeps into cracks, freezes, and expands, causing the rock to slowly break apart. On the lower slopes, you might observe chemical weathering, where acidic rainwater reacts with minerals in the quartzite to produce small amounts of clay and dissolve certain minerals.

The quartzite at Glassy Mountain is primarily composed of interlocking quartz crystals, which give it a dense, hard texture. This is why Glassy Mountain has resisted erosion and remains as an isolated peak in a landscape where the surrounding, softer rocks have eroded away.

1. Folds, Faults, and Fractures: As you descend the trail toward the rock face, take a moment to observe the structure of the quartzite. The rock is likely to show evidence of past tectonic forces that folded, faulted, and fractured the original rock layers.
   • Folds are bends or curves in rock layers caused by compressional forces during tectonic plate collisions. In some areas, you may be able to observe subtle folding of the quartzite, where the rock layers appear to be "bent."
   • Faults are fractures in the Earth’s crust along which movement has occurred. These can cause large vertical displacements, often leading to dramatic geological features. In some cases, you may observe evidence of faulting in the quartzite, where blocks of rock have shifted in relation to each other.
   • Fractures are cracks that formed due to stress from tectonic forces. These are especially important for understanding weathering, as they allow water, ice, and other agents of erosion to infiltrate the rock and break it down over time. The fractures you see along the trail are likely remnants of the tectonic forces that have been at work for hundreds of millions of years.
2. Erosion and Weathering: While quartzite is highly resistant to weathering, it is not impervious to it. Over time, even the hardest rocks experience gradual breakdown due to environmental factors such as water, ice, temperature fluctuations, and plant activity.

Along the trail, you may notice several types of weathering occurring on the quartzite:

2. • Physical weathering: This includes processes like freeze-thaw weathering (or frost wedging), which occurs when water seeps into cracks in the rock, freezes, and expands, breaking the rock apart. This is especially common in areas with significant temperature fluctuations. In higher elevations, where the temperature can fluctuate around freezing, this process is particularly noticeable, and the quartzite may appear more fragmented.
   • Chemical weathering: Over time, chemical reactions between the minerals in the quartzite and water (especially slightly acidic rainwater) can lead to the breakdown of the rock. While quartzite is more resistant to chemical weathering compared to other sedimentary rocks, you may still observe slight discoloration along fractures and joints where minerals have been dissolved by acidic rain or groundwater.
   • Biological weathering: This is caused by plant roots or burrowing animals that infiltrate cracks in the rock. As roots grow, they exert pressure on the rock, slowly breaking it apart over time. On the lower slopes of the mountain, look for plant life that may be growing in cracks in the rock, as these roots contribute to the weathering process.
3. Stratigraphy and Sedimentary Features: Although quartzite is a metamorphic rock, traces of its sedimentary origins can still be observed. As you approach the rock face, look closely for sedimentary features like cross-bedding, ripple marks, and bedding planes. These remnants are a clue to the past environments in which the original sandstone was deposited before it was transformed into quartzite.
   • Cross-bedding: This occurs when sand grains are deposited in angled layers, often by wind or water currents. When the sandstone was forming, currents in ancient rivers or deserts would have deposited sand in layers that slanted in a particular direction.
   • Ripple marks: These are small ridges formed by the movement of water or wind across a sandy surface. You may be able to observe these patterns preserved in the quartzite, which suggest that the sandstone originally formed in a shallow water or desert environment.
   • Bedding planes: These are the flat, horizontal layers that represent periods of sedimentary deposition. Though the quartzite is now solid and tightly bonded, you may still see faint bedding planes that mark the transitions between different layers of sediment that were originally deposited.
4. The Role of the Quartzite’s Resistance to Erosion: One of the most fascinating features of Glassy Mountain is how the quartzite has resisted erosion in a landscape of softer rocks. Over millions of years, water, wind, and ice have worn away the surrounding rock layers, creating a differential erosion landscape. The surrounding areas, composed of softer shale and sandstone, have eroded more quickly, while the quartzite has remained relatively intact, forming a dramatic inselberg (isolated mountain) or monadnock.

Additional Information:

• Weathering and Erosion: While quartzite is highly resistant to erosion, it is still subject to weathering processes such as physical weathering (e.g., freeze-thaw cycles) and chemical weathering (e.g., acid rain). These processes can cause small cracks to form and gradually widen, even in hard rocks like quartzite. Look around you for visible fracturing and other examples of this weathering. Many cracks have over time allowed vegetation to become established in them.
• Erosion of Surrounding Rocks: The softer rocks surrounding Glassy Mountain, such as shales and sandstones, are more easily weathered by wind, water, and other erosive forces. Over time, these rocks break down, leaving the more resistant quartzite as an isolated peak.

Summary:

Glassy Mountain is a fascinating geological feature in Pickens County, SC, providing an excellent opportunity to explore the processes of erosion and rock metamorphism and tectonic activity. I hope you are able to visit both of them on your visit. This EarthCache, and my other one nearby, are designed to give cachers different perspectives on the same mountain, from the easy-to-reach, distant observation point (Glassy Mountain EC The Easy Way), to this more challenging, up-close examination of the rock face itself (Glassy Mountain EC The Hard Way).

Both EarthCaches provide a deeper understanding of the processes that have shaped Glassy Mountain and the surrounding landscape, making this area a great example of how geological forces have created distinctive landforms.

FTF Honors Go To  . . .RobinMohawk!!!