As I was going for a milestone cache #5,000, I thought this awesome area deserved an Earthcache.
A rock shelter or abri is an overhanging cliff face, which is actually not what we would call a cave. The term rock shelter is pretty descriptive. The term abri is the French word for rock shelter which is often used in scientific papers. This is simply because of the fact that in early 20th century, when the first important archaeologic discoveries were made in rock shelters, they were concentrated to central France. So the term abri became an international scientific term.
A rock shelter is not at all what most people associate with a cave: a dark confined space, where sunlight does not reach. But rock shelter actually do fit the definition of a cave******. Rock shelters are formed by erosion. If there are weaker and stronger rocks, the weaker rocks will erode faster and form indentations. If the layers are horizontal the indentation will be a ledge. This is a common situation with all kinds of sedimentary rocks, so rock shelters are common in any kind of sedimentary rock. They are most common with sandstones and with interbedded limestones and marls.
A second kind of erosion forming rock shelters is the force of the sea and of rivers. In both cases the force of the water works on the rock, and causes the normally horizontal indentation just by concentrating its energy at the same point for quite some time. The kind of rock and its weakness are not important for this process. When the land is elevated from the sea, or when the river continues to cut deeper, the rock shelter will become a fine living place.
And finally there are lots of rock shelters formed by karst processes. They are the remains of eroded karst caves, cave ruins, which are often described as the last stage of cave development. A former cave, which was much bigger, is slowly destroyed by ongoing erosion. The ceiling collapses and only the concave walls remain of a vaulted dome. Often the former caves can be recognized as caves by the remains of speleothems.
The most important rock shelter of the world are located in France, the abris along the Vezere valley in the Perigord. This is the place where abris were discovered for archaeologic research. Many locations are actually typesites or type locale for archaeologic eras. Famous are also the cliff dwellings of the Mesa Verde National Park in the U.S.A.. Then there are the important dwellings and cave entrances of the Lone and Blau valleys in southern Germany, where the oldest artworks of mankind were discovered.
*****A cave is a natural opening in the ground extending beyond the zone of light and large enough to permit the entry of man. Occurring in a wide variety of rock types and caused by widely differing geological processes, caves range in size from single small rooms to interconnecting passages many miles long. The scientific study of caves is called speleology (from the Greek words spelaion for cave and logos for study). It is a composite science based on geology, hydrology, biology, and archaeology, and thus holds special interest for earth scientists of the U.S. Geological Survey.
Caves have been natural attractions since prehistoric times. Prolific evidence of early man’s interest has been discovered in caves scattered throughout the world. Fragments of skeletons of some of the earliest manlike creatures (Australopithecines) have been discovered in cave deposits in South Africa, and the first evidence of primitive Neanderthal Man was found in a cave in the Neander Valley of Germany. Cro-Magnon Man created his remarkable murals on the walls of caves in southern France and northern Spain where he took refuge more than 10,000 years ago during the chill of the ice age.
Sandstone caves are shallow caves that form at the base of cliffs, carved out by water and wind. The water loosens the natural cement holding the sand particles together, then the moving water and wind carry away the grains of sand. Native Americans used these sandstone caves for shelter, or built their homes inside caves with the appropriate orientation for protection from the weather.
If/when you are exploring the creek and falls, BE CAREFUL AS THE ROCKS HERE ARE VERY SLIPPERY!
Please do not post any spoiler photos or information in your log. In order to get credit for this Earthcache, please email me the answers to the following questions:
1. What type of rock is dominant here? Describe the texture and color.
2. How do you think the rock formation came to be? Give the above information, do you think this is an abri or a cave?
3. Looking at the opening, there is a large rock overhead sloping downward from top left to lower right. There are several areas of chisled grafitti near to it. There are several layers of rock at the bottom of the right side of lean, just underneath. They vary in size from 1 inch to 6 inches. Look at the different layers and tell me how many there and what is the various thickness of each layer.
4. What colors are there in these layers of rock and why do you think they are this color?
5. Given the current route of the creek, is the formation of the cave finished or will it continue to grow? Why do you think this?
6. REQUIREX: post a picture of yourself ir a personal item outside of the opening. Please upload your photo(s) with your "found it" log.
Be sure to e-mail me within 7 days of logging the cache to get credit for your work. I will only contact you if there are issues with your answers. If the rules of finding an Earthcache and e-mailing the owner is not followed your log will be deleted without notice.