Mission Gate and Lunette Archaeology - February 3

February 3, 2023

On Monday we finished the documentation of Backhoe Trench 6. This trench was approximately 24 meters (80 feet) in length and 76 centimeters (2.5 ft) in width, with an additional 30 cm (1 ft) bench on each side. The depth ranged from approximately 1 to 1.8 meters (3.5 to 6 ft) below surface.

Both trench profiles were hand cleaned by archaeologists prior to photo documentation. We took photos of the trench walls in 2 meter increments. Leica points were taken of the trench corners and every depth at 1 meter increments. We mapped the entire length of the north profile, which enabled us to identify the various previous disturbances.

There were no features encountered in BHT 6. We were able to identify the Trench A and Trench B from the 1975 excavations. We also identified the excavations done in 2016 by Anderson et al. There were additional disturbances that may have been related to previous construction. Few artifacts were recovered, which corresponds with previously disturbed/excavated soils. The trench was backfilled on Friday.

Due to weather conditions, no work occurred on Tuesday and Wednesday. All day Thursday and Friday morning were spent in the lab processing artifacts.

Friday afternoon archaeologists monitored the backfilling of BHT 6, the hauling off of spoils, and the excavation around the tree slated for relocation. The excavation around the tree went to a depth of 4 ft below the base of the trunk, resulting in approximately 2 ft below the street level. During this excavation no artifacts were observed. Sand from the 1988 excavations was present along the eastern extent of the tree. This was the same sand observed during BHT 5. Also observed during the tree trunk excavation was the profile of the feature encountered by UTSACAR in 2019. Upon further inspection and with a wider perspective, it became apparent that this feature was the natural hardpan which has been identified across the Project Area. The excavation around the trunk was terminated at depth and then the roots were wrapped in burlap.

Dirt in excavation area next to Alamo Street
Figure 1. Completed Backhoe Trench 6, facing west.
Long, narrow hollowed out area in excavation plot
Figure 2. Previous excavations in BHT 6, facing north.
Rust colored rocky area in excavation plot
Figure 3. 1975 trench, possibly where they clipped the lunette trench, facing south.
Black and white pole and whiteboard in excavation area
Figure 4. Plastic at base of 1975 trench, facing west.
Hollowed out circular dirt area in excavation plot
Figure 5. Excavation around tree trunk, facing south.
Dirt in excavation area
Figure 6. The profile of the UTSA-CAR excavation and the hardpan beneath, facing north.