6 University of Washington Publications in Geology [Vol. 1 



Inlet section are identical with those at the well known locality just north of Res- 

 toration Point. 



This faunal zone is represented within the city limits of Seattle, Newcastle 

 Hills, Cathcart near Snohomish and along the Strait of Juan de Fuca from a point 

 two miles west of Gettysburg westerly to a point half way between Twin River 

 and Pysht. The conglomerates and overlying shales exposed along the north por- 

 tion of Cape Flattery and along the Strait of Juan de Fuca easterly to the mouth 

 of Sekiu River also contain faunas belonging to this zone. 



The species which are most commonly and abundantly found within this zone 

 are Acila gettysburgensis Reagan, Macrocallista vespertina (Conrad), Marcia ore- 

 gonensis (Conrad), Modiolus rectus Dall, Panope generosa (Gould), Phacoides 

 acutilineatus (Conrad), Spisula albaria (Conrad), Solemya ventricosta Conrad, 

 Tellina oregonensis Conrad, Thracia trapezoidea Conrad, Thyasira bisecta (Con- 

 rad), Crepidula praerupta Conrad, Eudolium petrosum Conrad, Miopleiona indu- 

 rata Conrad, Turcicula washingtoniana Dall and Turritella blakeleyensis Weaver. 



LOWER MIOCENE 



At the close of the Oligocene epoch there appears to have been a predom- 

 inately upward movement of the sea floor over a large part of western Washington. 

 The present site of the Puget Sound Basin may have become a land area insomuch 

 as no deposits of lower Miocene age are known to occur within it. Marine de- 

 posits of this age occur along the north shore of the Olympic Peninsula between 

 Clallam Bay and Pysht. In this region they possess a thickness of at least 5,000 

 feet and consist largely of coarse grained massive sandstones, conglomerates and 

 minor amounts of shales. Strata of the same age occur in Wahkiakum County on 

 the Alockaman River about twelve miles north of the town of Cathlamet, as well 

 as in portions of the Grays Harbor region. The faunas within these deposits have 

 a very close relationship to the Area montereyana Zone of California. The strata 

 containing them may be the equivalent of the Monterey Formation of California. 

 It is possible, however, that the Lower Miocene strata of Washington may rep- 

 resent a greater or less geologic range than the deposits do in California which are 

 commonly referred to as the Monterey Formation. Temporarily only a suggested 

 correlation is made and the strata containing the Area montereyana fauna in Wash- 

 ington will be referred to as the Wahkiakum Horizon. 2 



A complete list of the species occurring within the Area montereyana Zone 

 may be found in the faunal lists of the Post-Tejon accompanying this report. The 

 following species are most characteristic of this zone: Area montereyana Osmont, 

 Chione securis Shumard, Diplodonta parilis Conrad, Pecten propatulus Conrad, 

 Pecten fucanus Arnold, Tellina arctata Conrad, Panope generosa (Gould), Pha- 

 coides acutilineatus (Conrad), Spisula albaria (Conrad), Tellina oregonensis Con- 



aWeaver, C. E., "A Preliminary Report on the Tertiary Palaeontology of Western 

 Washington," Bull. 15, Wash. Geol. Surv., pp. 19, 1912. 



