250 G. R. MANSFIELD IGNEOUS GEOLOGY OF IDAHO 



R.42 E. 30 



EXPLANATION 



SEDIMENTARY ROCKS 



TERTIARY PRE-TERTIARY 



Alluvium hillwash Salt Lahe Carboniferous to Cre 



travertine etc. formatron taceous formations 



IGNEOUS ROCKS 



Basalt Basalt Rhyolite Rhyolite Andesite 



(SrapCive center (Flans) (Eruptive center) iF/owl 

 y chtef/jf pyroclastiO / 



J Faults Concealed faults Dikes 



= A-Andesita 



6 Basalt 



^ ; 5 



4 1 3 ; 8 1 1 







7 1 8 



9 1 ICi II i 12 







19 1 (7 



16 : 15 1 i» I 13 







19 ; ZO^ 



21 |_22| Z1\Z-. 



lo\zs 



28 1 27 '; 86 1 2i. 



31 ;32 



33'iJ<.; 35;36 



Diagram of township 

 I -Fort Mall Indian Reservation 

 2-Crane3 Flat Quadrangle 

 index map 3-Henry Quadrang 



4-Lane5 Creek Quadrangle 



R.42E. 30 



Figure 1.— General geological Map of the Cranes Flat, Henry, and Lanes Creek 

 Quadrangles, Idaho 



