CCSP: Sitton's Cave EarthCache

There are over 513 known caves in northwest Georgia – most of them in Dade and Walker counties. (You are now in Dade county. Walker is next door.) These caves are what is known as solution caves, formed by underground water dissolving the rock material. They are only one feature of what geologists know as karst topography, a land surface characterized by bedrock which has been dissolved by chemical weathering rather than worn away by abrasion. Karst surfaces are commonly marked by sinkholes, caves, and an absence of surface streams. Although karst topography may form on any type of soluble rock, it is most extensively and intensively developed in limestone – a form of calcium carbonate (CaCO3). The solution of limestone is actually a chemical reaction involving the gas, carbon dioxide (CO2). Limestone is only sparingly soluble in pure water, but when carbon dioxide is added, a weak acid, carbonic acid, is formed. This acid attacks the limestone and transforms it into water-soluble products. When rainwater percolates through the soil, it absorbs carbon dioxide produced by the decay of plant material. There is plenty of year-round plant growth here, and plenty of rain.

Underground rivers sometimes flow for great distances through caves – such as this one – and may emerge unexpectedly as waterfalls and surface springs. But the ground water in karst is easily and rapidly contaminated, having few opportunities to be filtered as it passes through the ground. The State of Georgia passed the Caves Protection Act of 1977 partly in recognition of issues relating to water supply and groundwater contamination, as well as to protect the irreplaceable, fragile delicacy of the caves themselves.

Most limestone is not porous, but is cut by numerous cracks called joints. Water seeps through these cracks, reaches a water-filled zone known as the water table, then moves horizontally along other cracks, gradually widening them into larger and larger conduits that eventually form caves. As we will see, the dissolving-away limestone can undercut other rock layers, causing them to fall. The limestones here are very old, hard and dense: Knox Dolostone and Chickamauga Limestone. Water sometimes flows long distances down through these strata, creating in nearby Walker County some of the deepest known pits in North America. When water seeping from a joint enters a cave room, it creates speleothems, including stalactites, stalagmites, and curtains. These phenomenon will only be found in interior rooms of a cave.

Collapse is an integral part of cave development, as you will soon see here. In many caves – including this one – the floor is piled high with breakdown: blocks of collapsed material from the ceiling and walls. Caves are also well-known as natural air conditioners, and some enterprising settlers in cave country drilled into caves beneath their homes to tap into the always-cool air currents flowing naturally through them.

Today, many organizations work to protect the caves in this area and the watersheds above them. The Southeastern Cave Conservancy, Inc. is the largest land conservancy solely dedicated to the protection of caves and karst environments. The National Speleological Society promotes the exploration, study, and protection of caves.

Citation:   An Introduction to Caves and Cave Exploring in Georgia, by Dr. Barry F. Beck, Georgia Southwestern College, Americus, 1980.

The posted coordinates will take you first to the Lower Entrance. Your journey in completing this Earthcache will take you safely near – but, not into – both of the two entrances to Sitton’s Cave in Cloudland Canyon State Park. It is very important that you follow this course as stated and do not deviate from it, nor permit your children to do so.

Important:  Both Cloudland Canyon State Park policy and Georgia State Law – the Caves Protection Act of 1977 – prohibits entry without permission and a guide. (For information about guided tours, inquire at the park main visitor center.)

Although the distance to be hiked is relatively short, the use of a hiking stick and sturdy shoes with good traction is recommended.

Your journey begins at the Sitton’s Gulch parking area – see parking coordinates – where you will be obliged to pay a $5-per-day parking fee in the drop-boxes provided (if you have not already done so today), unless you have an annual pass provided by the Friends of Georgia State Parks. The trail begins close to the entrance gate, directly opposite the first set of signs that you will pass on the way in.

Step One:

Walk along this trail until you come to the Lower Entrance waypoint. The lower cave entrance is at the bottom of the cliff in front of you. Because the rocks here are exceptionally slippery, even in dry weather, stay on the trail where your footing is sure.

1. From this position, what natural phenomenon informs you that a cave entrance is nearby?

2. What distinctive characteristic of this phenomenon informs you that this cave has another, much larger entrance elsewhere?

3. What temperature is this phenomenon, and why do you think so?

4. The lower cave entrance is at the base of the ledge in front of you. Is the color of the rocks on the ledge above the entrance area mostly the same, or noticeably different, from the color of the fallen rocks surrounding the entrance?

The lower entrance, which was probably formed by water, is modest and unassuming. But the “natural phenomenon” aforementioned immediately informs you that the cave must have more than one entrance. The interior temperature of a cave is always more-or-less 58ºF, which means that air entering another, higher entrance will naturally cool down, then descend, then be exhausted out of some other hole. The cave will not “breathe,” but will exhaust air night and day. Also, if the upper entrance is larger, the air flow will always be strong.

Step Two:

Turn to your right and proceed toward the cache final coordinates – the Upper Entrance.   This will be a steep ascent of a few hundred feet with few hand-holds. Do not let your children run ahead of you.

When you arrive at the final coordinates, you will still be standing on the trail, safely behind a row of waist-high boulders. Stay where you are, safely on the trail, and keep your children close at hand as you take it all in. This is the second largest cave entrance in the State of Georgia. It's quite the sight to see.

The upper cave entrance is a prime example of a process of upward collapse known as stoping, which can create entrances from underground chambers that did not originally form as entrances. As one layer of rock collapses, it exposes the next layer above it to the pull of gravity. Eventually this layer cracks and weakens and the process continues until a hard layer of rock is encountered or the surface is breached. The process narrows upward, since the edges are supported by the underlying layer and thus tend to remain in place. Evidence of stoping includes blocks of stone which fell from the roof – they may be of noticeably different stone than the floor on which they now lie. The edges of the blocks remain rough, unlike surfaces carved by flowing water. Stoping exposes passages which were originally formed by other means, and which may contain features such as flowstone or stalagtites which are found only in underground passages formed by water.

1. What color is the rock layer above the mouth of this cave entrance? What color are the rock walls within the opening? What color are the rocks piled on the bottom floor below? How does this tell you that stoping has occurred?

2. What do you see on the wall of the cave opposite from where you now stand? (Look to the right.) How does this tell you that this was once an interior room of the cave?

3. Do you feel a cool wind coming out of this entrance to the cave? Why or why not?

Return – very carefully – the way you came.