BASALT GABBRO 



50" 



25 - 







I 



M 



^ 



p^^ 



RHYOLITE GRANITE 



50 



25 



uj o 



Q. 



< 50 



S 25 



§ 



o 



50 



£ 25 

 o 



£ o 



Q_ 



&2l 



i 



1 



SANDSTONE 



i 





SHALE 



I 



l 

 i 



LIMESTONE 



JEZ2. 



50 



25 







M 



1 





12 3 



ESTIMATED INTENSITY 



Figure 10-2. Distribution of natural thermoluminescence. 



181 



