Trapped concentrations of oil and natural gas in the earth will sometimes release vapors, whose presence and motion might be used to help infer where resources are located. Tests for carbon anomalies may be applied to search for hydrocarbons in the earth, and alterations in 222Rn in the earth can be used to locate regions of subsurface gas flow. In a recent report we have observed both such anomalies over the Cement, Oklahoma oil and gas fields (Fleischer and Turner, 1984). Because of this result, whose generality is not yet known, it is of interest to know where other similar carbon and gas-flow anomalies exist. (We should note that extensive examples of carbon anomalies in the soil have been presented; many of these are referenced in Fleischer and Turner, 1984.)
This short note describes one such geochemical anomaly that has been observed using three methods of mapping—one radiometric, one isotopic, and one chemical. Testing whether this anomaly is associated with hydrocarbons is a logical next step that has not been taken.