Type of survey: Magnetic gradiometry; Instrument: Geoscan Research FM-36 fluxgate gradiometer; Prospection depth: up to 1.5 m; Sampling interval: 0.5 x 0.5 m; Area surveyed: 40 x 35 m; Date of survey: 8/97
Comments: This site was surveyed during ongoing
excavations by the Smithsonian Institution. Three 4 x 4 m
excavation pits are clearly indicated by the magnetic extremes
associated with grid square corner nails. The small dark linear
feature trending southwest-northeast near the top of the image is
a filled-in backhoe trench. The igneous bedrock, near the
surface on the eastern edge of the survey and the southwestern
corner is highly magnetic, yielding a noisy surface. The more
central northwest-southeast trending smooth and dark zones
contains thicker sediments that mask the more magnetic underlying
bedrock. The strong linear feature within this zone (lightly
shaded and highly magnetic) indicates a swale or erosional cut.
Although some of the localized magnetic highs could be hearths
thay are most likely large magnetic rocks.
(updated: 7/00)
