The Comb Wash Kivas:

Tiffany Osburn, for her masters thesis at University of Denver, studied many of the "kiva depressions" that had been located by other archaeologists in Comb Wash, Utah (just south of Blanding).  For many years these had been thought of as "Chaco outliers" because of their size (many of the surface depressions were up to 15-20 meters across).  Also, the concentration of many of them (at least 5) in a small area potentially made Comb Wash a very important place in the ancient Chaco World.

So, with that working hypothesis in mind, Tiffany set out to study them, using GPR.  Here are her results:

These are the sketches of some of these kivas, all of which show a large surface depression, and other surface finds indicating possible underlying architecture:

But the GPR reflection profiles indicate something much different:

Notice how the walls, which show up at stacked hyperbolic reflections, are much more closely spaced than we expected.  When they were being colleted, we could see the walls were far within the surface depressions!  Not at all where we expected them to be, which was along the edge of the depressions.

And when these profiles are sliced horizontally, and the reflection amplitudes are mapped, this very different picture is confirmed.  In all cases the "Great Kivas" turned out to be very small kivas or other pit structures, with other older pit features nearby, which had been abandoned.  Often, what were interpreted as kiva antechambers, turned out to be room block buildings, which were constructed near the small kivas, probably as "unit pueblos", in the classic Pueblo site sense.

The conclusion here is that GPR mapping, which took about 4 days of field work for these sites shown above, has the potential to test hypotheses about architecture, and how it is related to cultural interactions across areas and through time, very quickly.

This is the article we published on this subject as a pdf file