YUCATAN GROUND PENETRATING
RADAR PROJECT 1997:
Additional GPR surveys
at Balankanche, Izamal, and Dzibilchaltun.
The purpose of
this project was to provide new data on caverns and buried cultural features
at Chichen Itza, Balankanche, Izamal and Dzibilchaltun, apply "time slice"
imaging to selected cultural features, evaluate the usefulness of GPR for
analysis of structures, and to develop geophysical operational parameters
for GPR at four different environmental locations in the Yucatan Peninsula.
A Geophysical Survey Systems, Inc., Subsurface
Interface Radar (GSSI SIR-10A+) was used as the survey instrument
with 60 MHz and 300 MHz bistatic antennas. The two 60 MHz antennas were
fabricated in Merida, Yucatan by co-principal investigator William Sauck.
A total of 380 Mb. of Ground Penetrating Radar (GPR) data was collected
from approximately 10 kilometers of transects at the archaeological sites
of Chichen Itza, Balankanche, Izamal, and Dzibilchaltun in Yucatan, Mexico
during the period February 2 through 13, 1997.
Collaborating on the
project with the co-principal investigators Lawrence G. Desmond
of the Princeton University Moses Mesoamerican Archive, and William A.
Sauck of the Institute for Water Sciences at Western Michigan University
were archaeologists Ruben Maldonado, Luis Millet and Dr. Peter Schmidt
of the National Institute of Anthropology and History of Mexico, Centro
INAH Yucatan; Dr. Linda Manzanilla of the Institute of Anthropological
Investigations and Dr. Rene Chavez of the Institute of Geophysics at the
National Autonomous University of Mexico (UNAM), archaeologist David Maki
of the Institute for Minnesota Archaeology, and archaeologist Tim Tucker
of the Mesoamerican Research Foundation in Puebla, Mexico.
At Chichen Itza,
GPR surveys with closely spaced transects using 60 MHz and 300 MHz antennas
were carried out in the Great Plaza adjacent to the east side of the Castillo
Pyramid, and using a 300 MHz antenna in the Plaza adjacent to the west
side of the Temple of Warriors to examine buried cultural features, and
generate dense GPR data sets for 3-D, "time slice" imaging. Time slice
processing will provide improved imaging for interpretation of the cultural
features currently under investigation. Additional surveys were made in
the Great Plaza, Great Ball Court, Sacbe 1, Platform of Venus, the vicinity
of the High Priest's Grave, Observatory, and Akab Dzib, and are under analysis.
At Balankanche Cave,
GPR transects which were made the length of the access road and in the
parking lot allowed for equipment evaluation and calibration based on known
cave parameters, and indicated that more extensive surveys of the archaeological
zone would be useful in locating previously unmapped segments of the Balankanche
GPR transects made on the Pyramid
of Kinich Kak Mooat Izamal penetrated the complete depth of the
structure and a few meters into the bedrock, and demonstrated the structure
is ideally suited for detection of internal features, and the generation
of a 3-D model of the interior.
Lawrence G. Desmond, Ph.D.
44, the plaza north of Structure 44, and Sacbe 1 were surveyed. Penetration
of Structure 44 was limited and indicated that the fill used in the building
probably has a greater soil content, or the soil is more conductive, than
that used within the Kinich Kak Moo pyramid. Caverns or fissures of, as
yet, undetermined size were detected in the plaza north of Structure 44,
and under Sacbe 1. The area appears to be rich in cavern development, and
additional GPR surveys would be useful in locating and mapping the extent
and size of cavern systems and their relation to site architecture.