14 
OIL DISTRICTS OF SOUTHERN CALIFORNIA. 
the Franciscan formation not far distant. The matrix of the con¬ 
glomerate is composed of the same materials as the pebbles. 
The sandstone bears a striking resemblance to that in the lower 
portion of the Vaqueros formation in the vicinity of Tar Creek, with¬ 
out, however, the strong development that it has there. 
The shale is argillaceous, fissile, and primarily of a blue-gray color, 
but this is modified to such an extent by the presence of iron that 
weathered surfaces and hill slopes are prevailingly rusty. Here and 
there faint tinges of red, pink, purple, and green are to be observed, 
shades that characterize the formation in the Tar Creek and Fourfork 
region. 
The limestone beds of the formation vary from a few inches to 6 
feet in thickness. They carry a large proportion of quartzose mate¬ 
rial and commonly show the presence of comminuted to more or less 
perfect oysters. Locally, also, they are found rich in other remains, 
notably pectens, turritellas, and barnacles, all of enormous size. 
The following list of fossils, collected by the writer and identified 
by Ralph Arnold, indicates the general character of the fauna in these 
beds: 
Fossils from the Vaqueros formation of the Ojai Valley. 
SOUTH FORK AT HEAD OF LOWER VALLEY, ONE-FOURTH OF A MILE ABOVE OLD 
REFINERY. 
Chione temblorensis Anderson (PL XXX, fig. 1). 
Mytilus mathewsonii Gabb var. expansus Arnold (PI. XXX, fig. 2). 
Neverita sp. indet. 
Pecten magnolia Conrad (PI. XXVIII, fig. 1). 
Pecten vaughani Arnold (PI. XXXIII, figs. 3, 3a). 
Tritonium, three sp. 
Trophon n. sp. (large). 
Turritella ineziana Conrad (PI. XLI, fig. 5). 
EAST END OF CREST OF RIDGE BETWEEN UPPER AND LOWER VALLEYS. 
Balanus sp. 
Chione sp. 
Dentalium sp. 
Leda sp. 
N'assa sp. 
Ostrea sp. 
Pecten crassicardo Conrad (PI. XXXI, fig. 1). 
Pecten lompocensis Arnold (PI. XXIX, fig. I). 
Phacoides sp. (flat). 
Tritonium or Fusus sp. 
Turritella cf. ineziana Conrad (young). 
The precise area of outcrop of the supposed Vaqueros beds in the 
Ojai Valley has not been defined, but one of the principal exposures, 
which afforded the fossils above enumerated, occurs along Refinery 
Gulch on the south'side of the upper portion of the Lower Ojai Valley. 
A second exposure is that in the locality of the section illustrated in 
