Sunday, June 28, 2009

Return to Area A

Once the surface collection and shovel testing was complete in Area D, we returned to Area A to pick up where we left off. The students completed the 56 shovel tests at 10 meter intervals, lending to an overall total of 166 completed shovel tests for the survey portion of field school.

The 10 meter interval shovel tests provided additional artifacts and spatial data to better understand what is going on this area. The data suggests that we have multiple households especially due to the variation and spatial distribution of artifacts. Once the shovel tests were complete, we began clearing to conduct geophysical survey. Geophysical survey is a non-intrusive tool for investigating sub-surface archaeological features. We will be conducting resistivity and ground-penetrating radar surveys in hopes to delineate sub-surface structural features.

Resistivity involves the measurement of resistance to an electrical current, which is passed through the ground. The amount of resistance is affected by how much moisture is present in the soil. The photo to the left shows a resistivity meter.

Ground-Penetrating Radar (GPR) involves an antenna which sends out electromagnetic pulses into the ground, which reflect off objects and are picked up again by a receiving antenna. The photo to the right shows the antenna for a GPR unit.

Friday, June 19th we spent all day clearing a 20 meter by 20 meter area within the artifact concentration to prepare for geophysical survey. In order to get the best data, we must clear an adjacent 20 meter by 2o meter area to conduct geophysical survey on a 40 meter by 40 meter grid. Our excavation plans will be based on the geophysical survey in combination with the artifact data from the shovel test survey.

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