DISTRIBUTION OF THE CRETACEOUS. 95 



to the existence of an extensive land area in the region of the central 

 Coast ranges during early JNIesozoic times, one wliich perhaps extended 

 as far west as the Farralone islands, which consist of granite and belong 

 to the continental plateau. To the southeast it was likely continuous 

 with the Peninsula range of Southern California. 



Cretaceous of the Coast Ranges. 

 distribution. 



The Cretaceous is widely distributed in the Coast ranges. It occurs 

 on the eastern slope nearly the whole length of the San Joaquin and 

 Sacramento valleys. Within the Coast ranges it occurs more extensively 

 south than north of San Francisco. The past season the writer dis- 

 covered that a large portion of the high mountains in northern Ventura 

 and Santa Barbara counties consists of Cretaceous and Eocene strata, 

 showing in places an enormous thickness, comparable to that found by 

 Mr Diller in Tehama county. As far as the scanty paleontologic evidence 

 goes, the greater part of this series appears to belong to the Upper Creta- 

 ceous, extending upward into the Tejon or Eocene, with a comparatively 

 small development of distinctly Lower Cretaceous. In northern Ventura 

 county there is an exposed width across the strike of the Chico-Tejon 

 series of twelve miles, but the dip is so irregular that the thickness could 

 not be determined. In Santa Barbara canyon, which cuts somewhat 

 diagonally across the stike of the rocks of the same series, they show an 

 almost uniform dip for a distance of ten miles. The dip is to the south- 

 west at an angle of about forty-five degrees, and the estimated thickness 

 at least twenty-five thousand feet. In San Luis Obispo county the Chico, 

 the Tejon not having yet been recognized, consists largely of sandstone, 

 and is confined to the line of the Santa Lucia mountains, occurring along 

 the eastern slope at least as far north as central Monterey county. The 

 Chico-Tejon is also found in San Benito county on the western side of the 

 Monte Dialjlo range. On the eastern side of the range in Walton canyon 

 there is an exposed thickness of at least twenty thousand feet. The Chico 

 is known to occur on the coast north of San Francisco and in some of 

 the interior valleys. 



H. W. Turner several years ago detected the Lo\yer Cretaceous in the 

 Santa Lucia range near the town of San Luis Obispo. The writer has 

 traced the black shale of this formation along the summit of the range 

 for some miles. Numerous specimens of Aucella were found in it near 

 the Old Padre mine west of Santa Margarita ; also on Toro creek and at 

 an intervening locality, and on Pine mountain near San Simeon. This 

 formation, consisting almost wholly of Ijlack sliale, l^egins a little south- 

 east of the new railroad tunnel, and extending along the eastern side of 



XIV— Bull. Oeol. Soc. Am., Voi-. C, 1894. 



