WHY LITTLE HAS LASTED FROM EARLY TIMES
Except for the rare find-spots mentioned above, all our very early finds come from geological deposits, or from the wind-blown surfaces of deserts. Here is what the business of geological deposits really means. Let us say that a group of people was living in England about 300,000 years ago. They made the tools they needed, lived in some sort of camp, almost certainly built fires, and perhaps buried their dead. While the climate was still warm, many generations may have lived in the same place, hunting, and gathering nuts and berries; but after some few thousand years, the weather began very gradually to grow colder. These early Englishmen would not have known that a glacier was forming over northern Europe. They would only have noticed that the animals they hunted seemed to be moving south, and that the berries grew larger toward the south. So they would have moved south, too.
The camp site they left is the place we archeologists would really have liked to find. All of the different tools the people used would have been there together—many broken, some whole. The graves, and traces of fire, and the tools would have been there. But the glacier got there first! The front of this enormous sheet of ice moved down over the country, crushing and breaking and plowing up everything, like a gigantic bulldozer. You can see what happened to our camp site.
Everything the glacier couldn’t break, it pushed along in front of it or plowed beneath it. Rocks were ground to gravel, and soil was caught into the ice, which afterwards melted and ran off as muddy water. Hard tools of flint sometimes remained whole. Human bones weren’t so hard; it’s a wonder any of them lasted. Gushing streams of melt water flushed out the debris from underneath the glacier, and water flowed off the surface and through great crevasses. The hard materials these waters carried were even more rolled and ground up. Finally, such materials were dropped by the rushing waters as gravels, miles from the front of the glacier. At last the glacier reached its greatest extent; then it melted backward toward the north. Debris held in the ice was dropped where the ice melted, or was flushed off by more melt water. When the glacier, leaving the land, had withdrawn to the sea, great hunks of ice were broken off as icebergs. These icebergs probably dropped the materials held in their ice wherever they floated and melted. There must be many tools and fragmentary bones of prehistoric men on the bottom of the Atlantic Ocean and the North Sea.
Remember, too, that these glaciers came and went at least three or four times during the Ice Age. Then you will realize why the earlier things we find are all mixed up. Stone tools from one camp site got mixed up with stone tools from many other camp sites—tools which may have been made tens of thousands or more years apart. The glaciers mixed them all up, and so we cannot say which particular sets of tools belonged together in the first place.