Determination of lithology of geological core samples with γ-spectrometry

An analysis method which uses the gamma spectrometry to determine the K, U and Th of cores and distinguishes the lithology of rock samples is Introduced. The author uses the inverse matrix method, and obtains the corresponding scale coefficient by measuring the standard substance, and then builds the K, U, Th peak count rate range of some common rocks and minerals to distinguish the lithology of rock samples. Experiment verifies the applicability and reliability of the method by measuring mudstone samples and concludes that in the mudstone the lighter color the rock is and the higher gray matter content, the lower radioactivity it will be. (authors)