Type of survey: Resistivity; Instrument: Geoscan Research RM-15; Prospection depth: 1 m; Sampling interval: 1 m x 0.5 m; Area surveyed: 184 x 110 m; Date of survey: 7/97 & 7/98.
Comments: This site is buried under approximately one
meter of alluvium as revealed by limited excavations on the banks
of the Missouri River in the late 1970s and recent tests. The
resistivity survey was performed by the University of North
Dakota Archaeological Field School. The
data clearly reveal the complete fortification ditch,
5 bastion loops, numerous earthlodge (house)
locations, possible middens, and other features. Of particular
importance is the suggestion of an inner fortified village, with
perhaps 4 bastion loops and a greater density of houses. The
1970s excavations of burned houses suggested that this village
was attacked. This evidence may indicate subsequent reoccupation
and reorganization of this village. For additional details, see
The Whistling Elk Subsurface Imaging
Project.
Type of survey: Conductivity; Instrument: Geonics EM-38; Prospection depth: 1.5 m, peak sensitivity at 0.4 m; Sampling interval: 1 m x 0.5 m; Area surveyed: 170 x 120 m; Date of survey: 7/97 & 7/98.
Comments:That conductivity is the inverse of resistivity
is clearly shown in the reversal of the darkness scale assigned
to the measurements (compare above) and by a graph of the
conductivity and resistance data in two survey grids (second
figure). Although obtained much more rapidly, conductivity data
represent an average over a larger volume of earth than
resistivity, making edges and boundaries somewhat less distinct.
Moreover, with a peak sensitiviy at 0.4 m depth, features in the
nearby plow zone are much more apparent. In the left figure, two
former fields, unused since the 1960s, are indicated by
differences in plow mark directions. For additional details, see
The Whistling Elk Subsurface Imaging
Project.
Type of survey: Magnetic gradiometry; Instrument: Geoscan Research FM-36 fluxgate gradiometer; Prospection depth: up to 1.5 m; Sampling interval: 1 m x 0.25 m; Area surveyed: 170 x 120 m; Date of survey: 7/97 & 7/98.
Comments:The magnetic survey, although appearing noisy at
a global scale, reveals faint traces of the bastion shown by the
resistivity and conductivity data (see above). Many of the
magnetic extremes represent prehistoric burned features,
including houses, palisades, and hearths. They also represent
historic iron farming artifacts like broken plow parts. At a
larger scale, the magnetic data are rich in detail. The second
figure shows an Initial Coalescent square house and linear
entranceway as revealed by the resistivity data. The
correpsonding magnetic data indicate its central hearth, that its
walls were burned, and there are even indications of the 4
central support posts which are known to have existed in each
quadrant of a house of this period (verified through
excavation). For additional details, see
The Whistling Elk Subsurface Imaging
Project.
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