Geological Papers. 163 



black vesicular basalt. Another small exposure is also found on 

 the coast about a mile west of Tongue Point. 



The age of this series of rocks is easily determinable. The 

 roughly bedded tuffs in their upper portion are fossiliferous; In 

 them Doctor Arnold found Venericardia planicosta hnmaik, lur- 

 ritella uvasana Conrad, and other characteristic fossils which in- 

 dicate the Eocene age of the series and its general contemporaneity 

 with the Tejon of California.^- 



This volcanic formation is very extensive, but is mostly covered 

 up with later deposits; the conglomerate series of the next forma- 

 tion above it, even to Cape Flattery, is made up in part of fragments 

 of basalt and basalt tuff, and is the only volcanic rock exposed in 

 situ in the region. The portion exposed is separated from the later 

 rocks by an erosive period and by faults. 



Oligocene- Miocene: Clallam^'^ Formation. — This formation is 

 extensive and is found superimposed upon the Eocene and older 

 rocks from Freshwater Bay to Cape Flattery along the Strait of 

 Fuca, extending to the Pacific in the Cape Flattery promontory.'^* 

 It is composed of conglomerates, sandstones, and shales, the latter 

 two being rich in fossils. The conglomerates are found mostly at 

 the base and near the top of the series along the strait and in the 

 middle of the Cape Flattery series. A generalized section of this 

 formation, from Freshwater Bay toWaatch Strait, by Doctor Arnold^ 

 gives the following :^'^ 



Coal-bearing coarse sandstones and conglomerates . . 500 feet. 



Massive gray shales and fine gray sandstones 1,300 " 



Fine gray shale, massive at top, thin-bedded below, 975 " 

 Coarse conglomerates, with occasional sandstone 



layers and lenses 875 " 



Total 3,650 feet+ . 



And the Waatch-Neah Bay section gives 15,000 feet of conform- 

 able strata, all of which seem to belong to this age of rocks. 



Along the coast the shales occur principally in the middle of the 

 series. In the vincinity of Crescent lake they seem to be wanting 

 altogether; the walls of the lake where exa"toined at the eastern 

 terminus of the lake were composed of a dark- colored coarse to 



22. Bull. Geol. Soc. Am., vol. 17, p. 460. 



23. Following Doctor Arnold, it is deemed best to use the above term, as the separation of 

 the two members of the group will necessarily have to be made on paleontological grounds, and 

 the writer does not feel that material enough has been collected to make that possible at the 

 present time. 



24. Since this paper was written a fossil, Thyasira bisecta Con., has been found in the shale 

 on the Pacific front three miles south of La Push and one and a half miles south of the old oil- 

 well prospect. This would seem to place even the coast series (supposed Cretaceous) in the Mio- 

 cene, at least all the rocks above the conglomerate series exposed on the coast. 



25. Coal in Clallam county, Wash., U. S. Geol. Surv., Bull. No. 260, p. 415. 



