182 University of California Publications in Geology [ VoL - 7 



Vaqueros-Monterey Series of Monterey-Santa Barbara 

 Coastal Region 



As developed in Santa Barbara County not many miles 

 directly west of the Santa Clara Valley locality, and in San 

 Luis Obispo and Monterey counties to the north, the Vaqueros 

 deposition commences characteristically as a greenish gray to 

 rusty yellow, or whitish, sandstone, with here and there pebbly 

 or conglomeratic layers, especially near the base. As we pass 

 higher into the series terrigenous shales become the dominant 

 type, and finally siliceous (diatomaceous) shales so characteristic 

 of the "Monterey". Fairbanks 3 places the base of the Monterey 

 in the San Luis quadrangle at the base of the clay shale above, 

 the zone of dominant sandstones. Arnold in the Santa Maria 4 

 and the Summerland" districts in Santa Barbara County places 

 the zone of dominant terrigenous shales in the Vaqueros, and 

 considers that the siliceous, biogenic shales usher in the Monterey. 

 Both consider that the Vaqueros and the Monterey form a con- 

 formable series. 



Apparent Contrasts Between the Two Regions 



Without discussing at this point the relative merits of the 

 two systems of criteria, let us compare the general course of 

 events as shown by the Vaqueros-Monterey period of sedimen- 

 tation along the coast from Monterey to Summerland, a distance 

 of about 200 miles, with the series described by Eldridge and 

 Arnold for the region north of Santa Clara Valley, 20 miles or 

 less east of Summerland. 



We note in the latter that the Vaqueros deposition is inaug- 

 urated as a shale, passes into siliceous shale and then the Modelo 

 follows conformably as thick sandstone followed by siliceous 

 shale, then more sandstone and more siliceous shale. The Modelo 

 is correlated with the Monterey by Arnold. 6 



3 U. S. Geol. Surv., folio 101, San Luis, California, 1904, p. 4. 



* IT. S. Geol. Surv. Bull. 322, 1907. 



& U. S. Geol. Surv. Bull. 321, 1907. 



e U. S. Geol. Surv. Bull. 309, 1907, p. 143. 



