测量了山东某凹陷地表下氡（２２２Ｒｎ）浓度和γ辐射强度，由它们的异常值圈定了含油气沉积区域．实验结果表明，油气沉积上方的近地表呈现低值的２２２Ｒｎ浓度和γ辐射场，表现“晕状”模式，即相对于背景值，在油气沉积上方强度偏低，而在其周边区域偏高． The concentrations of radon (222Rn) and γ radiation in the surface of a depression in Shandong Province were measured, and the delineation of hydrocarbon-bearing sedimentary areas by their anomaly values. The experimental results show that the near surface above the oil and gas deposition presents a low value of 222Rn concentration and gamma radiation field, showing a “halo” pattern, ie, the strength above the hydrocarbon deposition is low relative to the background value and higher in the surrounding area.