Information on past geophysical investigations of the Marfa Basin of Texas is given. Special problems are involved in the application of geophysical methods.

The known geological information, particularly with reference to possible oil‐producing horizons, is discussed briefly. A method is proposed whereby the area is subjected to a reconnaissance seismic survey to determine the location of the major structural features, followed by other methods of successively higher resolving power in the favorable areas outlined by the reconnaissance.

Problems associated with excessive brevity.

No abstract

The results of a gravity meter survey across the Wellington Field, Larimer County, Colorado, both before and after elimination of the regional effect is presented in relation to the subsurface structure of the field. The method of eliminating the regional effect is shown. This information is presented as a “case book” type, illustrating an anomaly related to local structure that is almost obscured by strong regional gradients.