PROCEEDINGS 



OF THE 



CALIFORNIA ACADEMY OF SCIENCES 



Fourth Series 



Vol. VI, No. 1, pp. 1-17, pi. 1. May 6, 1916 



EOCENE OF LOWER COWLITZ RIVER VALLEY, 

 WASHINGTON 



BY 



Charles E. Weaver 

 Assistant Professor of Geology, University of Washington, Seattle 



INTRODUCTION 



The purpose of this paper is to place upon record the re- 

 sults of geologic and faunal studies made by the writer during 

 the past three years in portions of the lower Cowlitz River Val- 

 ley. The area under investigation is of special interest because 

 of the large number of exposures of Eocene strata and the ex- 

 ceptionally well preserved faunas contained within them. 



Surface outcrops of Tertiary formations in western Wash- 

 ington are largely obscured because of the heavy overburden 

 of Pleistocene deposits. In King and Pierce counties much de- 

 tailed work has been done so that the lithology and structure 

 of the Eocene rocks is fairly well known.' The strata in this 

 region are, however, almost entirely of estuarine origin, ren- 

 dering it impossible to make satisfactory correlations with the 

 Eocene of other parts of the Pacific Coast. Isolated outliers 

 of Eocene rocks occur in many localities such as Crescent Bay 



>WiIlis, Bailey, and Smith, Geo. O., Tacoma Folio, U. S. Geol. Surv. 1899. 



May 6, 1916 



