NATR - Fall Hollow EarthCache

For 100 years, the National Park Service has preserved America’s special places “for the enjoyment, education, and inspiration of this and future generations.” Celebrate its second century with the Find Your Park GeoTour that launched April 2016 and explore these geocaches placed for you by National Park Service Rangers and their partners.

The Natchez Trace Parkway is a 444-mile drive through exceptional scenery and 10,000 years of North American history. Used by American Indians, "Kaintucks," settlers, and future presidents, the Old Trace played an important role in American history. Today, visitors can enjoy not only a scenic drive but also hiking, biking, horseback riding, and camping. For more information about the Natchez Trace Parkway visit:
Website: www.nps.gov/natr
Facebook: www.facebook.com/NatchezTraceParkwayNPS
Phone: 1-800-305-7417.

The posted coordinates will take you to the parking area and trailhead of Fall Hollow on the beautiful Natchez Trace Parkway in central Tennessee. I hope you learn about the area and enjoy your hike of this wonderful place.

WALKING TO THE BOTTOM OF THE HOLLOW IS NOT NECESSARY TO COMPLETE THIS EARTHCACHE.

When you get to the trailhead, you will have a short walk down into the hollow to a view of one of central Tennessee's natural treasures. When you arrive at this location, you will see two beautiful waterfalls that flow into one stream. Please be careful as you walk on the trail. This is an un-improved trail that will be wet. The further you walk into the hollow, the less maintained the trail becomes. Please watch your step, and stay on the trail.

Waterfall definition:

A waterfall is usually a geological formation resulting from water, often in the form of a stream, flowing over an erosion-resistant rock formation that forms a sudden break in elevation. Types of waterfalls are based on how the water falls or passes through it's course, how much water is flowing, the surface beneath it and the geological processes that created it (geomorphology). These all together form a waterfall's unique shape. Water as a whole, is a great tool when it comes to carving out this great planet we live on.


Waterfall formation:

Waterfalls are often formed where a layer of harder rock overlays a layer of softer rock. As the river or stream passes over the softer rock, it is able to erode it at a faster rate, forming a step in the river or stream bed. The force of hydraulic action does two things: 1) At the notch grows, eventually there isn’t enough support under the harder rock and it collapses into the plunge pool, and 2) this adds rocks and boulders to the plunge pool, and so the process of corrosion works with hydraulic action to further erode the plunge pool and notch. The processes of erosion continue, further eroding the notch and plunge pool. Eventually the harder rock above will collapse again, meaning the waterfall will retreat upstream over time.


Types of Waterfalls:

Block: Water descends from a relatively wide stream or river.

Cascade: Water descends a series of rock steps.

Cataract: A large waterfall.

Fan: Water spreads horizontally as it descends while remaining in contact with bedrock.

Horsetail: Descending water maintains some contact with bedrock.

Plunge: Water descends vertically, losing contact with the bedrock surface.

Punchbowl: Water descends in a constricted form, then spreads out in a wider pool.

Segmented: Distinctly separate flows of water form as it descends.

Tiered: Water drops in a series of distinct steps or falls.

Multi-Step: A series of waterfalls one after another of roughly the same size each with its own sunken plunge pool.

Geological significance:

Fall Hollow, like all of the waterfalls in this area, is located in the Highland Rim, primarily the Western Highland Rim. The Highland Rim is a geographic term for the area in Tennessee surrounding the Central Basin. Geologicially, the Central Basin is actually opposite, being a dome. The Highland Rim surrounds the basin, and the border where the difference in elevation is sharply pronounced is called an escarpment. Nashville is located in the northwestern corner of the Basin. The Western Rim is located a few miles west of Nashville, and extends to the western valley of the Tennessee River. Underlying bedrock of the region is primarily composed of limestone. Limestone is a sedimentary rock composed largely of the minerals calcite and aragonite, which are different crystal forms of calcium carbonate. Many limestones are composed from skeletal fragments of marine organisms such as coral or foraminifera. These streams and waterfalls of this region cut their way through these hills creating hollows like the one you see here.


Logging requirements:

To get credit for this EarthCache, please answer the following four questions and send them to me in a message:

1) What is the color of the rock(s) in the stream bed?

2) At the bottom of the waterfalls, what damage has the falling water caused to the rock below?

3) The underlying bedrock in this region is composed of what?

4) This hollow was created by these waterfalls. How deep would you say the hollow is where these two waterfalls are located?

Once you have sent the answers of the four questions in a message, please post a photograph of yourself with the Fall Hollow sign (pictured above) behind you. The photograph is NOT required.