Vol. VI] WEAVER— POST-EOCENE OF WESTERN WASHINGTON 33 



those of the ChehaHs Basin. Detailed studies at each of those 

 locahties will be required to determine that point. 



No marine deposits are known to occur within the state 

 younger than those near the mouth of the Queniult Basin ex- 

 cept late Pleistocene beach sands around the shores of Puget 

 Sound. 



CORRELATION 



Sufficient evidence is not as yet at hand to warrant a direct 

 correlation of the faunas or faunal zones of western Wash- 

 ington with those of California. The great unconformity ex- 

 isting between the upper and lower Miocene is general through- 

 out the Pacific coastal region. The faunas of both the upper 

 and lower Miocene are distinctly different in California and 

 Washington. The upper Miocene fauna of Washington ap- 

 pears to have its closest resemblance to the San Pablo of Cal- 

 ifornia, but more detailed evidence must be secured before 

 such a definite correlation can be made. The Area montereyana 

 zone of Washington appears to be the equivalent of the same 

 zone in California. It is possible, however, that more or less 

 may be included within the faunal zone in the north than in 

 the south. The Molopophorus lincolnensis and the Turritella 

 porterensis zones of Washington may be the equivalent of the 

 Agasoma gravidum zone of California. It is possible that the 

 Acila gettysburgensis zone is in part higher than the Agasoma 

 gravidum zone in the south. 



CONCLUSIONS 



The post-Tejon formations of western Washington consist 

 of shales and sandstones of marine origin. These deposits con- 

 tain a well-developed fauna which at the present time is im- 

 perfectly known. The total maximum aggregate thickness 

 of the sediments is approximately 20,000 feet. 



Five well-marked faunal zones are present, the uppermost 

 of which is separated from the lower four by a well-marked 

 unconformity and difference in character of species. This line 



