The East Terrace Site

The East Terrace Site
Dating

drawing

The Late Archaic/Initial Woodland camp sites at East Terrace represent very short visits, although the actual number cannot be determined. Many clues help us date the visits and reconstruct some of the activities taking place at the site. Other sites in the Midwest and Plains were used to indirectly cross-date the points found at East Terrace, in the same manner that the Paleoindian points were dated. The Pelican Lake and Dickson/Wabesa spear points found at East Terrace are two styles from Late Archaic/Initial Woodland camp sites that are particularly diagnostic of this period.

In order to directly date the camps, a second kind of information was obtained. These were radiocarbon dates on charcoal and organically stained soil samples from three fire hearths. Two of the dates, AD 59 and 927 BC, fall within the range of the Late Archaic/Initial Woodland period. The third date, 3343 BC, shows that there was an earlier Archaic occupation near the end of the Middle Archaic period (5000-3000 BC). This was a surprise, for no points or other diagnostic artifacts from this period were found.

Radiocarbon or C14 dating is performed on organic matter associated with artifacts or features. Burned materials like wood charcoal, carbon residues on ceramic pots, and burned seeds are usually used to obtain radiocarbon dates because they resist decay.

The general principles of C14 dating are fairly simple. C14 is present in the atmosphere at known levels through time. it is absorbed by plants which are eaten by animals. During the life of a given organism, its C14 level parallels the level in the atmosphere. When a plant or animal dies, C14 begins to decay at a constant rate. The half life of C14 is 5730 years. When a laboratory dates a sample of organic material it measures how many C14 atoms decay in a given period of time. Since the rate of C14 decay is fixed, an estimate of the date at which the organism died can be determined based on the amount of C14 remaining.

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