Guidelines for radioelement mapping using gamma ray spectrometry data International Atomic Energy Agency (2003)
https://www-pub.iaea.org/mtcd/publications/pdf/te_1363_web.p...
Or go full Aussie, Aussie, Oy, Oy, Oy
https://www.ga.gov.au/scientific-topics/disciplines/geophysi...
and read the three publications linked at bottom and get the high res A0 wall map for the dorm room !
( A GUIDE TO THE TECHNICAL SPECIFICATIONS FOR AIRBORNE GAMMA-RAY SURVEYS Grasty + Minty
https://d28rz98at9flks.cloudfront.net/14861/Rec1995_060.pdf
and the other two )