1918] 



Fan Winkle: Paleontology of the Oligocene 



79 



occur in the middle or lower portion of the Porter beds nor in the fauna of the 

 Molopophorous lincolnensis Zone. These forms are, however, characteristic of the 

 entire Acila gettysburgensis Zone. It would seem therefore that the Molopophorous 

 lincolnensis fauna is to be correlated with the lower part of the upper Porter 

 beds and that the uppermost portion of the Porter beds are correlative with the 

 lower portion, of the Acila gettysburgensis Zone. 



The fauna represented at the Greece ranch locality at the south end of the 

 Chehalis Valley embayment is subtropical and lived in shallow water. This fauna 

 consists of fifty-seven species, five of which are common to the Molopophorous 

 lincolnensis Zone. However, a more detailed study of the fauna in this locality 

 will result in the finding of a larger number of species, many of which will probably 

 be common to the Lincoln Creek beds. The reason for the small number of species 

 in common between the Greece ranch fauna and the Molopophorous lincolnensis 

 fauna can probably be accounted for in the fact that the former lived in comparatively 

 shallow water, while the Molopophorous lincolnensis fauna is typically a moderate 

 to deep water facies. 



CORRELATION TABLE OF THE OLJGOCENE IN WASHINGTON 



CONCLUSIONS 



(1) Following the close of the Tejon epoch in Washington the upper portion 

 of Eocene time was characterized by uplift, folding, faulting and erosion of the 

 Tejon sediments. 



(2) Early in the Oligocene epoch a marine embayment was formed in the 

 Grays Harbor region and extended inland along the present site of Chehalis Valley 

 at least as far south as the Cowlitz River. 



