Acquisition
During the 1963 seismic retrofit of the Salt Lake Temple, contractors extracted thirty-seven foundation core samples. Thirty-six were catalogued, photographed, and stored in the Church History Library’s materials vault. The thirty-seventh — labeled only CS-37 / NORTH CORNER / DEPTH 14'2" — was misfiled into a box of discarded window glazing samples and discovered by a graduate intern in 2008.
The intern wrote a three-page note. The note was never filed. The core sample was returned to the vault. The intern left the program the following spring.
What CS-37 shows
Cross-section microscopy (committee, 2012; independent lab, 2015) shows:
- Ordinary 1850s granite aggregate for the first 11 inches of the sample.
- A 0.4 mm band of sintered silica glass at 11.2 inches — continuous across the full diameter of the core.
- Below the band: ordinary aggregate again, with no thermal gradient into the deeper stone.
A thermal event capable of sintering silica in situ, without melting the surrounding granite, is difficult to produce with nineteenth-century kiln technology. It is not difficult to produce with a brief, high-flux radiation pulse.
What we will not claim
We will not claim CS-37 is evidence of a nuclear detonation under the Salt Lake Temple. The band is thin. The thermal signature is ambiguous. Alternative explanations include:
- Accidental inclusion of industrial slag during construction.
- Localized lightning strike during the 1850s build.
- A laboratory contamination event during the 1963 extraction.
The committee’s position is only that the band exists, it has been independently photographed, and no public institutional report has ever mentioned it.