THE MARINE TERTIARY OF THE WEST COAST 597 
crustal movements just previous to the deposition of the Vaqueros. 
However, that there was an important hiatus following the deposi- 
tion of the San Lorenzo is brought out by a comparison of the 
San Lorenzo and Vaqueros faunas. Very few of the species of the 
San Lorenzo (Upper Oligocene) have been found in the Vaqueros, 
_ while a very large percentage of the species of the latter horizon 
are common to the Temblor. It is this great faunal change 
between the San Lorenzo and Vaqueros that is most significant and 
indicative of one of the major breaks.t 
Correlation of the Temblor and Vaqueros.—As in the case of the 
Oligocene, very little direct evidence has been obtained for the 
correlation, on the basis of the invertebrates, of the divisions of 
the Monterey series with the Lower-Middle Miocene of the 
eastern province and Europe. ‘These deposits of the Monterey 
series were first referred to the Miocene by Conrad? as early as 
1837. This determination was made chiefly on the general sim- 
ilarity of the generic assemblages to the faunas of the Atlantic 
Coast Miocene. Following Conrad, the beds here referred to 
the Monterey series were determined by Whitney and Gabb, 
both of the old California State Geological Survey, as Miocene. 
No attempt was made by these pioneers to recognize any sub- 
divisions in the Miocene. Beds now recognized as Upper Miocene 
(San Pablo) were called Pliocene by Whitney and Gabb. 
The first announcement of a correlation which gave a fairly 
definite position to the Temblor group appeared in a paper by 
Professor J. C. Merriam, entitled “‘Tertiary Vertebrate Faunas of 
the North Coalinga Region of California.”4 Previously the 
Temblor had been referred by some geologists to the Lower Miocene 
and by others to the Oligocene. In the region of North Coalinga 
«B. L. Clark, ‘San Lorenzo Series of Middle California,” Bull. Dept. Geol., 
Univ. Cal., Vol. XI (1918), No. 2, p. 105. 
2T. A. Conrad, ‘‘Fossils from Northwestern America,”’ Geol. U.S. Ex. Exped., 
Vol. I (1849), App., pp. 723-29, Pls. 17-20; Proc. Acad. Nat. Sci. Phila., Vol. VII 
(1837), Pp. 441. 
3W. M. Gabb, California Geological Survey: Palaeontology, Vols. 1 and IL 
(1864-69). 
4]. C. Merriam, ‘‘Tertiary Vertebrate Faunas of the North Coalinga Region of 
California,” Trans. Am. Phil. Soc., New Series, Vol. XXII (1915), Part III, pp. 1-44. 
