NATURE OF BATHOLITHTC INTRUSIONS 



36? 



country rocks are Cretaceous argillites and sandstones, so folded and 

 faulted as to present dips varying from 40 to 90 degrees. Lines of strike 

 and characteristic dips are illustrated in the diagrammatic map. 



It can be seen from the map that the stock is not in laccolith ic rela* 

 tions; but only in the field, as one follows the wonderfully exposed contact 





Figure 10. — Plunging Contact Surface between intrusive Granodiorite (on the right) 

 and Cretaceous Formation (on the left). 



Drawn from a photograph taken on the north side of the Castle Peak stock, near the 

 point "C," figure 7. View looking east. Contact shown by heavy line in middle of 

 view. Granodiorite on right and Cretaceous formation on ieft. The vertical distance 

 between the two ends of the contact line as drawn is 1,700 feet ; contact also located in 

 the background with broken lines. 



line, does one appreciate the fullness of the evidence that the plutonic 

 mass is a cross-cutting body in every sense. Even where the contact line 

 locally coincides in direction with the strike of the sediments, as at the 

 eastern end of the stock, the dipping strata are sharply truncated by the 



