Project 10073 Record Card and Analysis — Fairfield, Illinois, October 1963

This document file details the investigation of a rock-like object found in Fairfield, Illinois, on October 29, 1963. A civilian witness reported seeing a burst of blue light and flashes in the sky while driving home, and subsequently discovered an object on the ground that was suspected to be radioactive. The object was recovered by personnel from the 1405th Air Base Wing at Scott Air Force Base and transported to Wright-Patterson Air Force Base for analysis. The Air Force initiated Project 661-02 to evaluate the object. Preliminary analysis was conducted by the Geology Department at Northwestern University, which identified the item as a clay-ironstone concretion with an outer rim of marcasite and an interior of argillaceous siderite, noting that such concretions are common in the Pennsylvanian strata of Illinois. Subsequent spectrographic and X-ray diffraction analyses performed by the Materials Physics Division at the AF Materials Laboratory confirmed these findings, concluding that the object was definitely terrestrial in origin and possessed no scientific value to the Air Force. The file includes correspondence from Captain Hector Quintanilla, Jr., to the witness, informing them of the findings and promising the return of the object. The investigation concluded that the object was a natural geological formation.