C.W. Adkisson G. Michael Reimer 1977 <p>A reconnaissance survey of the helium content of soil gas was performed in parts of Black Hawk, Eldorado Springs, Evergreen, Golden, Morrison, Ralston Buttes, and Squaw Pass quadrangles, Colorado. The intent of this survey was to obtain initial background information on the gross effects of structure, underlying rock type, and soil moisture content on the helium content of the soil gas. Sample localities were adjacent to roads and trails. The results, tentatively categorized as qualitative, suggest that structure and soil moisture content have pronounced observable effects, whereas effects of rock type could not be recognized in this study.</p> application/pdf 10.3133/ofr77464 en U.S. Geological Survey Reconnaissance survey of the helium content of soil gas in Black Hawk, Eldorado Springs, Evergreen, Golden, Morrison, Ralston Buttes, and Squaw Pass quadrangles, Colorado reports