1. n. [Formation Evaluation]

A log obtained in the laboratory by moving the core past a gamma ray detector. The log can be of the total gamma ray in API units, or of the spectral response in weight concentrations of thorium, uranium and potassium. The main purpose is to correlate the depth of each section of core with the depth of a log.

See: gamma ray log,  natural gamma ray spectroscopy,  potassium,  scintillation detector,  thorium,  uranium