•I9I3-] STRATIGRAPHY OF PACIFIC COAST OF AMERICA. 585 



Locality 120; clay shales, seacliffs west of Twin for a distance of three 

 fourths of a mile along shore, Olympic Peninsula, Washington. (A. B. 

 Reagan, H. Hannibal.) 



Locality 121; clay shales and sandstone, seaclififs at Arc Reef Point two 

 and one half miles west of Twin, Washington. (H. Hannibal.) 



Locality 122; shaly sandstone, seacliffs one half to three miles east of 

 Twin, Washington. (A. B. Reagan, H. Hannibal.) 



Locality 158; sandstone and shale, seacliffs at small point west one mile 

 from Deep Creek, Twin, Washington. (H. Hannibal.) 



Locality 139; shale and sandstone, seacliffs one and one half miles east 

 of Pillar Point, Twin, Washington. (H. Hannibal.) 



of Washington and extending from about three miles east of Twin 

 River west nearly to Pysht Bay where it is faulted against the 

 Monterey, is a stretch of soft clay-shales perhaps 2,000 feet thick 

 intercalated with occasional thin beds of sandstone that wash out on 

 the beach as flags. These beds, both shales and sandstone, contain 

 a fauna of a marked boreal type. Most of the species are unde- 

 scribed, but the few already known indicate that it is quite as closely 

 allied to the Vaqueros and Monterey as to the San Lorenzo and 

 Seattle faunas, yet sufficiently distinct from all of these. 



The horizon is named from the locality where the best fossil 

 collecting was obtained. 



The Monterey Formation (Oligocene-Miocene). 

 The term " Monterey Shales " has long been current in the geo- 

 logical literature of California for the great series of diatomaceous 

 shales first described by Blake^^ and Lawson^*^ from Monterey in 

 that state. While these deposits are particularly interesting to the 

 oil geologist on account of their petroliferous character, their affini- 

 ties have long been uncertain owing to the impoverished molluscan 

 fauna. Dr. J. P. Smith^^ was probably the first writer to correctly 

 interpret their relations, considering them as simply an ofif-shore 

 facies of the beds variously called the Upper Vaqueros, Temblor, 

 Agasoma zone, and Turritella ocoyana beds. Recently the junior 

 writer visited the type section and had no difficulty in securing a 



35 Blake, W. P., Proc. Phila. Acad. Nat. ScL, VII., 1855, p. 328-331. 

 3^ Lawson, A. C, Bull. Geol. Univ. Cal., I., 1893, p. 22. 

 ■^"^ Proc. Cal. Acad. Sci. (4th Ser.), HI., 1912, p. 161-182. 



