North American Database of Archaeological Geophysics
North American Database of Archaeological Geophysics
Abstract/Summary:
Project Name: Aztec Ruins National Monument, NM;
Reference: Johnson, W.J. (2003). Geophysical Survey of LA 1674, Aztec Ruins National Monument, D'Appolonia, Monroeville, PA. Submitted to Aztec Ruins National Monument.
This project was undertaken
as one part of a series of activities related to the realignment of Ruins Road
along the eastern and southern boundaries of Aztec Ruins National Monument.
The proposed alignment of the road will traverse LA 1674, which has long been
known as related to the main site. Limited subsurface archeological investigation
of the project area in 2000 - 2001 documented the presence of archeological
features (i.e., sections of cobble wall remnants) related to the Pueblo II-III
occupation at Aztec Ruins, but the extent and form of structures and other associated
cultural elements remained largely obscure.
Two geophysical techniques were applied. The first was the measurement of magnetic
intensity and gradient with an EG&G Geometrics Model G858G magnetometer.
The second was the measurement of ground resistance with the Geoscan RM15 twin
probe resistance system. The resistance survey was incomplete because of the
onset of subfreezing temperatures resulting in frozen ground that was impenetrable
with the resistance electrodes.
The magnetometer survey provided more definitive results than the resistance survey. It identified several previously unknown structures at the site. Two of these structures were tested by excavations. The structures that were best defined by the geophysical surveys appear as two adjacent six-room structures. The corner of one of the structures was tested by excavations to determine whether there were two separate structures or one large one. The excavations showed that they were not connected. Another excavation block confirmed that other magnetometer anomalies were also due to structures.
The use of the geophysical
survey not only mapped several structures, but made it possible to use a very
limited excavation program to answer specific questions regarding the nature
of the structures.