On geochemical prospecting; I

The first type of geochemical prospecting, that of searching for and recognizing visible oil and gas seeps, is one of the oldest methods of prospecting for petroleum deposits. A second type of geochemical prospecting, that of soil gas analysis, has been of record in the literature for some ten years, and depends upon the microanalysis, for hydrocarbons, of “underground” or interstitial soft air. A third type of geochemical prospecting is described, that of soil analysis, which has been recently developed and depends upon the separation, identification and quantitative determination of significant constituents which are entrained, occluded and adsorbed by the soil particles. These significant constituents exhibit a wide range of molecular weights, from hydrogen through gaseous, liquid and solid hydrocarbons and their derivatives. All these constituents tend to show the same significant patterns, which in general fall into two classes, the narrow elongated pattern characteristic of faulting, and the localiz...