Archaeology Update — Documenting the Monel Plate in the South Transept of the Church

Around the Plaza, the installation of the safety bollards was active in several of the fenced areas. Installations occurred along the southern portion, the western side, and a small area on the north side of the Plaza. The University of Texas at San Antonio’s Center for Archaeological Research (UTSA-CAR) has had archaeological monitors on site at times that the installations have needed to impact soils that had not already determined to be culturally sterile. During the week of January 6, 2020, no significant finds were made during the work associated with the installation of the bollards.

The archaeological investigations conducted by Raba Kistner associated with the preservation work focused on backfilling units, and excavations in units on the north and south side of the Church. During the week, no significant finds were made, but time was spent on documenting the monel plate on the south side of the Church. The monel plate is a steel sheet of metal coated in copper and nickel that was inserted horizontally into the wall of the south transept of the Church in 1995.

In 1995, historic architects investigated ways to prevent or lessen the rising damp that plagues the limestone structures like the Church. The idea was that if the rising damp (the capillary action of moisture being drawn from the ground into the stones) could be reduced, the damage that results from the mineral salts depositing in the stone would be reduced.

The concept of the monel plate was designed for other historic sites, and in 1995 was considered a new method to help prevent the rising damp. Archaeological excavations were undertaken to expose the buried portion of the wall of the south transept and allow for the installation of the monel plate. The monel plate was revealed in the units in and outside of the south transept. The plate was installed to span the entire length of the wall.

In the unit on the exterior of the south transept, evidence of the stone kick-out was uncovered, revealing more information concerning the construction methods of the Church. In addition, it appears that the current excavations have just gotten out of the area that had been previously impacted by the 1995 investigations. This means that the next levels should show less signs of disturbance, and hopefully reveal intact deposits.

Excavations that started during the previous week on the north side of the Church were well underway by the end of the week of January 6. Much of what has been encountered to date is disturbed soils related to the various landscaping activities that have occurred in the area since the early 1900s. Previous investigations in this area have noted this layer of disturbed soils as well. On the west side of the unit, a concrete utility vault was uncovered. The vault appears on a 1936 map concerning the installation of a heating system. The heating system appears to have been abandoned, but the vault was never removed.

Excavations are planned to continue in these areas during the following week.