THE APPLECATION OF THE GAMMA SPECTROMETRYIN THE MAPPING OF HIERARCHICAL UNITS OF INTRUSIONS

In the 1∶50 000 regional geological mapping, the gamma spectrometer has been used to determine on the spot the U,Th and K contents,U/Th,K/Th and U/K ratios and gamma irradiation rate of various types of intrusions.By means of an intergrated analysis of ground spectrometric data and regional geological features,the intrusions in the Panzhihua area are divided into 19 units,6 superunits and one superunit group.Besides,the authors consider the Seyao granite and Ailanghe granite to be of Indosinian age and the Huatan granite and the Tongde diorite to be the Archean products, both of which are component parts of a paleocontinental nucleus.