A THANK YOU GOES OUT THE SOUTHCENTRAL REGION OFFFICE OF THE PENNSYLVANIA FISH AND BOAT COMMISSION FOR ISSUING PERMIT NUMBER 6065 FOR THIS CACHE. PERMIT WAS RENEWED FOR 2020 AND IS VALID UNTIL DECEMBER 31, 2020.
This Earth Cache is located on Pennsylvania Fish and Boat Commission Property. A PERMIT has been issued by the PFBC for this Earth Cache
All regulations established by the Pennsylvania Fish and Boat Commission must be followed. This would include having a valid Pennsylvania Fishing License if any fishing is done.
Park only in the designated parking areas and be aware that the parking area close to GZ is reserved for Handicap Parking.
Make sure that you practice cache in and trash out and leave only your foot prints behind.
Be watchful of where you are walking and any young children that you may have with you as their is no fencing between you and Big Springs Creek
This Earth Cache is a container less cache located at the posted coordinates. Like all Earth Caches you will be at a location that will provide you with a chance to observe and learn a little about the geology of the area and what you are observing. In order to get credit, or earn your smile you will need to read the information, observe the area and provide me with the answers to the questions you will find at the end of this description.
The coordinates will bring you to Big Springs, the 5th largest spring in the State Of Pennsylvania. If you look to the southeast, you will see a cliff and coming out of the bottom you will see the springs that supply Big Spring Creek with water at an average flow of 222 gallons per second (27 cubic feet of water per second). We have all learned about the water cycle where water falls from the sky, flows into streams, rivers and lakes and eventually evaporates back into the air to form clouds. In most areas some of the water that hits the ground is absorbed into the soil and eventually reaches the underground water table. But what happens to the water after it is absorbed into the ground?
To answer this question in this particular area, we must go back about 480 million years ago when the Appalachian Mountains were formed. At one time, these mountains reached elevations similar to those of the Alps and the Rocky Mountains. With natural erosion over the 480 million years since their origin, they are now a series of alternating ridgelines and valleys that parallel the Atlantic Coast line. Of interest to us at this location is the resulting Great Appalachian Valley. This valley as can be seen on the above image runs from the Champlain Valley in northern New York to the Coosa Valley in Georgia and Alabama.
You will notice on the above image of the Great Appalachian Valley that number 7 is the Cumberland Valley. The Cumberland Valley is bounded on the Northwest by Blue Mountain and on the Southeast by South Mountain. It has two major drainage basins, the Yellow Breaches Creek on the Southeast side and the Conodoguinet on the Northwest. Both of these flow in a Northeasterly direction into the Susquehanna.
The geology of the Cumberland Valley is for the most part, to the north consisting of quartzite sandstone underlain by shale and greywacke of the Martinsburg formation. To the south it is underlain by a sequence of carbonate rocks overlain with a wedge of colluviums ,a loose, unconsolidated sediments that came from South Mountain. This carbonate rock mantle is very thick at the boundary of South Mountain (resistant quartzite) and thins gradually to limestone just south of Interstate 81.
While the water itself is protected from acidity, natural occurring acids readily dissolve the carbonate rocks, creating flow paths of water through channels, that typically occur along crevasse and fractures. This activity is responsible for caves, caverns and sinkhole formation in the area. These features, along with closed depressions, dry valleys, and springs of substantial discharge are typical of karst environments.
Looking at the above diagram, you will see the allogenic recharge area. Here at Big Spring, this would be the area about 10 miles to the south which is known as South Mountain. The next area on the diagram is the autogenic recharge area. In the Big Spring area, this would be the portion of Cumberland Valley that extends between here and the base of South Mountain. Looking at the diagram, you will notice infiltration points in what is know as the epikarst. These are the points where surface water runoff flows directly into the limestone karst aquifer. Once the water enters the ground, it will flow to the aquifer and then through the underground aquifer and conduits. In some cases, the water may never reach the surface. However as shown in the diagram, the water flows through the conduits and surfaces at the spring at the base of the steep slope. This steep slope is known as an escarpment.
As a result of several studies that have been done on the water source for Big Springs, it has been shown that the karts environment of this portions of the Cumberland Valley is a partial source of the water. It is quite common to have water that has fallen on the groundflowing into a sink hole or rock crevasse and reaching the water table without being filtered through the soil.
It is an interesting note about the Big Springs Creek in that it is great stream to fish for Brook Trout. In the 1800s Big Springs Creek was one of the best fly fishing areas in the country. The PF&BC had a fish hatchery adjacent to this Earth Cache that had a negative effect on the native Brook Trout. As a result of the decline of the natural Brook Trout, the hatchery was closed in 2001. Since the closure, the native Brook Trout have made a strong recovery.
To get credit for this Earth Cache, send me a message through the message the owner link at the top of the discription answering the following questions:
1. How many sources of water can you visually see that feed water into Big Spring Creek (you may want to look down from GZ)?
2. What natural feature does the majority of the water flow from?
3. Looking to the southeast estimate how high the escarpment is.?
4. Again, looking to the southeast at the water source, tell me if the water is clear or cloudy.
Hope you enjoyed the visit to this location</>
As with Earth Caches, a photo of the area is always appreaciated