THE UTILITY OF CARBORNE RADIOMETRIC SURVEYS IN PETROLEUM EXPLORATION OF GLACIATED REGIONS*

Carborne gamma radiation surveys over petroleum reservoirs and faults in the glaciated Michigan Basin suggest that this mobile technique may be useful in reconnaissance subsurface exploration, especially in fault detection. This conclusion assumes favorable surface conditions, as well as proper instrumentation, field procedures, and interpretive techniques. Glaciated regions are relatively undesirable terrains for gamma radiation surveys. Thick deposits of glacial drift appear to repress the detection of subsurface features. Furthermore, extremely heterogeneous soil conditions, which are characteristic of many glaciated regions, result in excessive radiation interference. The operational conditions which produced optimum results consisted of continuous profiling on unconsolidated roads, employing two simultaneously operated scintillation counters. Optimum detection was obtained during relatively cool nighttime traverses.