The cavity’s thermal vent, which had been producing its faint sulfurous exhalation for however many thousands of years.
The geology had been arranged in this particular way, had maintained a micro environment of elevated temperature and mineralrich humidity that had paradoxically partially preserved both organic and inorganic materials within it while rendering the cavity inaccessible to most biological activity.
He had fallen in. The geological analysis of the cavity walls, specifically of the fractured edge of the upper slab where fresh rock was exposed beneath the mineral patina, indicated that the slab had shifted within the past century.
The NPS geothermal team estimated based on the degree of new patina formation between 40 and 70 years earlier.
The shift had been in the inward direction, partially closing the opening. It was possible, it was in fact the considered conclusion of the forensic team, that the cavity had been somewhat more accessible in August 1974 than it was when discovered in 2026, and that the ongoing thermal activity had gradually moved the slab.
