302 



CLARK AXD ARXOLD ^EARIXE OLIGOCEXE 



s^^nclinal trough of the Lower Miocene epoch of deposition, as shown by 

 the distribution of the organic shales, was in the area of what is now the 

 western Coast Eanges. It is to be noted that this Lower Miocene Sea 

 extended mucli farther to the nortli and to the south than did that of the 



Figure 2. — Outline of isea in Monterey Time (Lower and Middle Miocene) 



Oligocene, and apparently the Lower Miocene geosynclinal trough was 

 also wider than that of the Oligocene; this was especially so in the north- 

 ern part of the State. 



Tliese differences in the distribution of the Oligocene and Lower Mio- 

 cene make it presumal)le that there must have been crustal movements of 



