Message #121076

[dhill757]

Before continuing our description of the process of excavation let us consider the conditions that existed in the world during the Ice Age. In that period tremendous quantities of water were taken out of the oceans and locked up on the land in the form of glacial ice. About one-sixth of all the lands now in existence were blanketed with ice. About one-half of North America was covered. The ice extended from Alaska to Greenland and southward to the Ohio and Missouri Rivers. South Carolina was not glaciated but it felt the effects in a somewhat cooler climate and in the fact that the sea was lowered at least 150 feet, possibly much more. This latter, as previously mentioned, greatly extended the land area to the southeast. From what is now the coast of South Carolina a broad flat extended seaward for more than 50 miles. This area lay close to sea level and parts of it doubtless were swampy traps for unwary animals, as are parts of the Coastal Plain today.

We should mention at this point there was not just one epoch of glaciation --- there were four. These cold epochs were separated by warmer inter-glacial epochs. During these times the ice melted, the glaciers retreated northward and sea level came back to normal. In South Carolina during each warm epoch the sea rose to cover the shelf that had been exposed during the preceding glacial stage. Sea animals flourished and shell beds were formed. As the glaciers re-advanced the sea retreated and the land animals that lived along the margin of the glaciers retreated southward ahead of the invading ice. They inhabited parts of the newly exposed land and left their bones to mingle with those of sea animals. These changes took place slowly, of course, and it is estimated that the entire Ice Age (not counting the present epoch, which may be just another inter-glacial stage) occupied a span of 2,000,000 years.

The fact that the Edisto deposits that now are being excavated contain the remains of bison and bears --- animals that apparently did not migrate into America until the closing stages of the Ice Age --- suggests that our deposit is fairly young. It is difficult to determine the exact age because the fauna that is being washed up is considerably mixed. The waves may have access to two or more thin deposits of different ages. Some of the sharks' teeth belong to species that antedate the Ice Age but these teeth are resistant objects that may have been reworked --- mixed up with Ice Age deposits during the Ice Age. Likewise, it is known that some of the typical Ice Age mammals that are now extinct -- American horses, the Giant Sloth, Mastodon, and Woolly Mammoth --- persisted in North America until a few thousand years ago. These particular animals were still in existence following the retreat of the last glacier and some, at least, after the arrival of the earliest human beings on this continent. You may ask, is it, then, not possible that the Edisto waves may uncover human artifacts or actual skeletal remains? It is possible but very unlikely.

We shall not attempt in this brief account to describe the appearance or the habits of all of South Carolina's numerous extinct animals but Mr. Kiener has sketched some of the commoner ones, basing his sketches on well known restorations. Only bones and teeth and plates are found at Edisto and Irving Gladstein has kindly photographed a number of these. Of particular interest are the tiny milk teeth of the elephants2 --- one from the browzing mastodon, the other from the mammoth, a grazing animal. Bones of the former have been found associated with human artifacts in Florida; frozen bodies of the latter have been recovered in arctic regions. The Giant Sloth that lived in the Edisto region bore little resemblance to his modern tree-dwelling relative. The Ice Age sloth was a ground-dweller that stood erect to pull down branches with its claws. It probably lumbered awkwardly on all-fours, walking on the outer edges of its feet. Some of the horses were as large as those living today.