The Cascades Conservation Area is located in the Appalachian Mountains in Giles County near Pembroke, Va. The area is bounded on the north by Pacers Gap Road (SR 714), on the west by Butt Mountain, and on the south and east by Doe Mountain.
The hike is along a shaded mountain creek that leads you to a waterfall within Jefferson National Forest. It is 4 miles round trip and is rated low to moderate difficulty. There is a Picnicking area at the beginning of the trail. The area offers native trout fishing available in Little Stony Creek. Accessible restrooms are also at the trailhead. There is a water hydrant for filling water bottles available in the recreation area at the beginning. The trail is only for hiking, no bicycles or horses are permitted. The view is absolutely gorgeous along the creek on the way to the falls. The trail branches off at a bridge a little less than a mile in which you can take the scenic route to the right of the bridge(on the way in) or the quicker easier trail that stays to the left.
The cascades were formed based on three key factors. They were tectonics, deposition, and erosion. The falls are part of Little Stony Creek, which spans over 60 miles. The creek has its water supply through it through two tributaries. They are Laurel Creek and Pond Drain and they eventually flow all the way out to the New River. Little Stony Creek has eroded a basin through the plateau over millions of years and is visible in satellite imagery.
The large boulders you see in the creek actually prevent erosion. The boulders are deposited into the creek via landslides. The boulders are remnants of resistant caprock forming the plateau and came down as the river incised a softer underlying rock. The rocks also display evidence of ancient life if you look around for it.
The surrounding topography is a strong and resistant rock called quartzite.(see pictures below).
The other main type of rock you will see is Tuscora Sandstone. The Tuscora is a light grey, fine-to-course grained sandstone. It can also have cross-bedding structures. A cross bedding structure is bedding that is deposited at an angle or horizontal. It is a good indicator of an ancient current. A picture of Tuscora Sandstone is posted below.
As you approach The Cascades you will notice that the geology changes considerably. A lot of the rocks and boulders you may see in the area were deposited through rock slides, some fairly recently it seems. When it rains it adds weight to the soil it decreases the rock's resistance to move. Eventually, the rock will overcome that resistance and drag a bunch of mud and debris down with it. If the rock slide is big enough it can change the flow of the stream or even block off the stream flow completely.
What you see around the waterfall is not Tuscarora Sandstone and quartzite. What you see at the top of the falls is another thick layer of sandstone they named The Keefer. Then at the bottom of the formation are layers of sandstone, clays, and siltstones. So the sandstone at the top is where the water is cut off, then it breaks through all the weaker rocks at the bottom. The sandstone at the top is hard so the water doesn't erode it away. The middle section is shale so it caved in. Then the bottom section juts out again because it's interbedded sandstone and shale. The whole waterfall itself is a nick point, which is created by the rock strength surrounding the area. A nick point is basically any part of a river that is really steep or steeper than it should be. Sometimes it looks like a waterfall but sometimes it just may be rapids. They can form in a few different ways. Sometimes the river basically cuts down so if sea level was dropping the river would inside and retreat back into the waterfall. However with the cascades, the rocks are resistant so they create a cap, then over time it holds up as a waterfall and retreats backward.
Over millions of years, Little Stony Creek will erode away the Cascades' caprock. Because of this, the nick point created in the Cascades will retreat upstream. Thus the waterfall itself will move with it. This goes to show how the area is always dynamic and changing. What will the cascades look like thousands of years from now? It is unlikely it will remain the iconic image that we all know today but time will tell.
When ou get to GZ you must answer the following questions and post with your log, a picture of you or your shoe with the falls. If you fail to do this your log will be deleted.
1. What are the three key factors that formed the Cascades?
2. What two tributaries flow into Little Stony Creek and where do they wash out at?
3. What are the events that deposit rocks and boulders into and around the creek? What process do the rocks and boulders help prevent?
4. What is a nickpoint? Where do you see one and how was it created?