Magnetic Field Gradient Survey
Correlation between magnetic anomalies (blue) and resistance anomalies (red)
Numerous circular, rectangular, or square magnetic field gradient highs, 6-8m across, appear in the data that are thought to represent semi-subterranean pit house features. Most of these anomalies have a direct correlate in the electrical resistance survey results. This correlation significantly increases the degree of certainty of our interpretations. Many of these positive anomalies are bounded by linear field gradient lows. These lows may represent a building material composed of a lower susceptibility material, or they may simply be a non-cultural negative component of the complex induced magnetic field created by these archaeological features.
Many of the magnetic anomalies interpreted as semi-subterranean
pit house features possess an small internal, higher amplitude magnetic
high. These may represent internal hearth features within the houses.
Numerous high-amplitude (generally in the red/blue
range of the color scale), short wavelength anomalies are visible
in the magnetic data. Anomalies with these characteristics usually
are created by modern ferrous iron debris at or close to the ground
Numerous small circular magnetic field gradient highs
are visible throughout the survey area. These anomalies often seem
to appear in pairs, and are often clustered around the perimeter
of the apparent semi-subterranean pit houses. These anomalies are
interpreted to represent possible storage/refuse pits, burial pits,
external hearth features, or similar features.
Many small circular magnetic field gradient highs may
form alignments or patterns of significance. These anomalous patterns
may represent the remains of structures external to the semi-subterranean
pit houses such as corrals or stockades.
Numerous subtle magnetic field gradient highs in the vicinity of N100/E980 form patterns that may be significant. These patterns are often circular, and in some cases have a small central magnetic field gradient high. These anomalies may represent small structures external to the semi-subterranean pit houses. Those with central magnetic highs may have internal fire hearths.