Testing of Borehole Gamma-ray Spectrometry Method in the North Calotte Region. Final report.

Abstract

(Forkortet) NGU has carried out new test measurements using av borehole gamma-ray spectrometer from IFG Corporation at different sites inthe North Charlotte Region. Improved calbrations of the instruments were made doing long term measurements on calibration pads at NGU. In situ calculations of K, U and Th content gave promising results as long as only one radionucleide was present. Calculating the K content in a situation where higher energy radiating elements were present, proved difficult. This problem is caused by large stripping ratios and poor energy stabilisation in the instrument. The obtained data will be of great value when the new borehole gamma-ray probe developed by the Finnish company Astrock OY will be evaluated.