To prepare for the excavation, the limestone floor stones between the central support piers and the sanctuary were photographed, drawn, numbered, and removed. The test unit was then laid out 40 centimeters east of the sanctuary. Next a tin roof was then constructed above the area to be excavated, and a limestone rock and cement rain barrier was constructed to channel rain water away from the excavation.
A protective barrier of foam and wood planks was then constructed to protect the stucco carvings at the base of the sanctuary. Also, plaster "witnesses" were placed on the support piers and the walls of the sanctuary as a precaution to indicate if any movement or settling should occur during excavations. Finally, a metal fence with an iron, padlocked gate was constructed around the entire area to prevent tourists from entering the excavation area.
The construction fill within the 2 x 2 m test unit is remarkably homogeneous. It consists of flat laid, rough cut stones set in a matrix of light brown clay mixed with crushed limestone and limestone pebbles. This fill remained consistent through both bodies of the basemento to a depth of 4.5 meters.
At the division between the upper and lower bodies of the basemento, a line of flat laid stones was noted. This indicates that the lower body of the basemento was built and surfaced before the upper body was constructed.
At a depth of 2.7 meters, excavations within the test unit were halted and the west and south wall of the excavation were photographed and drawn. The entire test unit was then consolidated with hard cement as a precautionary measure to prevent any possibility of collapse while excavating deeper into the basemento.
At a depth of 4 meters to the south of the test unit was a stratum of crushed limestone mixed with light brown clay. This stratum was virtually identical in composition to the plaza ballast encountered in our plaza excavations, and it was found to rest directly atop bedrock to the north, and atop an east-west alignment of faced stones, one course high, that extends beyond the eastern and western limits of the test unit.
These faced stones rest directly atop, and parallel to, an artificial cut in the bedrock which is 30 centimeters above the level of the bedrock to the north of the feature. This feature slopes slightly upwards to the west and was completely covered by the crushed limestone ballast.
At the base of the artificial cut in the bedrock, and just below the stone alignment, a concentration of large incensario fragments and the partial remains of two "cajetas" (the vessels that actually contain the charcoal and incense) were documented and collected. A carbon sample associated with this deposit was also collected. In addition, the upper third of an apparently complete incensario was found protruding from the eastern wall of the test unit.
The incensarios identified here differ from others found in association with the Cross Group structures in that the relief is lower and the appliqu elements are shallow by comparison. These incensarios were also fired at a much lower temperature, resulting in a paste preservation that is extremely soft and friable.
It is possible that these incensarios represent an earlier developmental stage relative to the incensarios associated with the Cross Group structures. The forthcoming results of a radio carbon test of the carbon sample associated with these incensarios should help to clarify this hypothesis.
The test unit was backfilled utilizing the same materials that were originally removed. The witnesses were still intact, and no evidence of settling or movement was detected in the structure.