CHICOTfiJUX SERIES. 215 



New Idria affords a fine exposure of tliese rocks, which at tliis point 

 appear to be not less than 10,000 feet in thickness. The heds are tilted 

 at angles reaching 45'^ and are so little concealed by soil that a continuous 

 stratum may often be followed for a considerable distance. There is no 

 indication at this point of any break in the continuity of deposition of the 

 sandstones, which carry a sufficient number of fossils to show that both the^ 

 Chico and the Tejon are represented. At Mt. Diablo, too, tliese formations 

 appear exactly conformable, and, so far as is known, this is the case whev- 

 ever they are found tog-ether. The difference in color is the only jdiysical 

 peculiarity by means of which a division can be made. 



Near the Vallecitos Canon, a few miles northwest of New Idria, and 

 therefore close to the locality known as Griswold's in the reports of the 

 State survey, the Tejon and IVIiocene occur near to each other and both 

 are fossiliferous. This region appeared to me well adapted to test the 

 fpiestion whether or not there existed between the Tejon and Miocene any 

 fossiliferous strata or any barren strata which might represent an interme- 

 diate age, for Messrs. Whitney and Gabb, regarding the Tejon as Creta- 

 ceous and Eocene fossils as absent, believed that there were unfossiliferous 

 beds in the position which the Eocene should have occupied. Mere col- 

 lections of fossils would scarcely be adequate to determine this point, and 

 at my request Dr. White examined this locality with the special purpose of 

 determining the presence or absence of an intermediate fauna. He found 

 the Miocene and Tt^on conformable here, as they usually are elsewhere, 

 and traced the fossiliferous Tejon beds so close to the fossiliferous Miocene 

 beds as to leave no room for an intermediate series. 



The ao-e of the Chico-Tejon series has been much discussed. Conrad 

 first determined fossils from the Tejon Avhich were collected by Prof. W. P. 

 Blake near Ft. Tejon.' Of these specimens Conrad wrote: "The Eocene 

 period is unequivocally represented by the beautifully perfect shells from 

 the Canada de las Uvas." Either tin-ough a misunderstanding or a difference 

 of opinion these are referred to in the reports of the State survey as a "few 

 imperfect fossils."^ Conrad repeatedly reasserted, but never ret racted, his 



' PaciGc R.iilroad Reports, vol. .">, p. ;U8. 



-GpoI. Snivoy Califoriii.n. Geology, vol. 1, p. 191. 



