SANTA CLARA VALLEY: MODELO FORMATION. 17 
In the region of Pico Canyon and to the southeast the beds 
mapped as Yaqueros consist of a great mass of thin-bedded shale 
overlain by brown shale, with some more or less important sand¬ 
stone layers. Above these occur conglomerate, sandstone, and are¬ 
naceous clay, which are believed to belong to the Fernando forma¬ 
tion, and are so mapped, although no sharp line of demarcation was 
discovered between the two formations. 
The following fossils have been obtained from beds mapped as 
Yaqueros in the region south of Santa Clara River. Owing to the 
limited number of species represented the correlations are necessa¬ 
rily very broad. The identifications are by Ralph Arnold. 
Fossils from Yaqueros formation south of Santa Clara River. 
ELKIN’S RANCH, OAK RIDGE, EAST OF GRIMES CANYON. 
Ostrea eldridgei Arnold (PI. XXIX, figs. 2, 2a). 
Turritella ineziana Conrad var. (PI. XLI, fig. 4). 
i 
GULCII EAST OF WILEY CANYON. 
Pecten (Hinnites) giganteus Gray (PI. XXXII, fig. 1). 
Turritella ineziana Conrad var. (PI. XLI, fig. 4). 
CHAFFEE CANYON. 
Cardium n. sp. 
Dosinia n. sp. 
Ostrea sp. aff. titan Conrad. 
Panopea generosa Gould var. 
Phacoides sp. 
Acmsea or Trochita sp. 
Turritella cf. ineziana Conrad. 
TORREY CANYON AND VICINITY. 
Scutella fairbanksi Merriam (PI. XXIX, fig. 3, and PI. XXX, fig. 3). 
Mytilus mathewsonii Gabb var. expansus Arnold (PI. XXX, fig. 2). 
Ostrea sp. aff. titan Conrad. 
Pecten sespeensis var. hydei Arnold (PI. XXXI, fig. 2). 
MODELO FORMATION. 
GENERAL CHARALTER. 
The Modelo formation embraces at least two prominent bodies of 
sandstone and two of shale. The shale at many points bears a 
marked resemblance to that of the Monterey (middle Miocene), both 
from a lithologic and a paleontologic standpoint, and it may be that 
it is the correlative of that formation. The Modelo is distributed 
over a broad area north of the Santa Clara Yalley and through folding 
and faulting its members are brought into most complex relation¬ 
ships. However, it is believed that the distinctions given below 
will serve as a satisfactory means of differentiation. 
