A FRA C TURK VALLEY S YS TEM 1 5 



planes of weakness along which subsequent movements of a 

 minor character may take place affecting superimposed rocks, so 

 that a system of Eocene, or even late Cretaceous, joints may be 

 extended upward into overlying rocks in Miocene time provided 

 similar dynamic action of a pronounced character occurs in both 

 periods as it has in this region. 



Joseph P. Iddings. 



