SANTA CLARA VALLEY: FERNANDO FORMATION. 
23 
In the vicinity of the Piru Valley the Fernando formation consists 
in ascending order of (1) a thick body of sandstone and conglomerate; 
(2) sandy shale and clay; and (3) heavy-bedded coarse conglomerate. 
These form the northern slope of the ridge north of Camulos, the dis¬ 
tance of about 4,000 feet being equally divided among them. Over- 
lying the upper conglomerate are several hundred feet of greenish-gray 
clay, and it is believed that this is succeeded in turn by 1,500 to 2,000 
feet of alternating sandstone and conglomerate. If the succession is 
continued, clays then follow to the valley of the Santa Clara. In all, 
the formation is fully 5,000 or 6,000 feet thick in this vicinity, and if 
its thickness could be determined over the entire area that amount 
would doubtless be increased by many thousands of feet. The mate¬ 
rials of the conglomerates include granite, shale derived from the 
Miocene, and a few eruptives. 
North of the Santa Clara Valley, extending from the mouth of Sespe 
Canyon westward to the Pacific Ocean at Ventura, is another exten¬ 
sive area of the Fernando. The formation is best developed in the 
hills between Santa Clara River and Sulphur Mountain, where the 
succession consists of sandstones and conglomerates, underlain by a 
thick body of clay dirt-brown to gray in color. This clay is arenace¬ 
ous and grades into sandstone both transverse to the strata and along 
the strike. In places even pebbly layers may be found in this part of 
the formation. Beneath the clay is another mass of heavy-bedded 
sandstone and conglomerate, separated by minor layers of clay, 
resembling that just described. If there are not faults in these beds— 
and none were detected—the thickness can hardly be less than 8,000 
or 10,000 feet, about equally divided between the three varieties of 
sediments mentioned. Some of the lower sands are bituminous and 
their associated clavs are brown or blue. 
On the lower slopes of San Cayetano Mountain, making up a part of 
the area outlined in the preceding paragraph, is a mass of gray clay and 
shale, sandstone, and heavy gravel beds, all more or less hardened 
and resistant to weathering, which belong to the upper Fernando. 
The pebbles making up the gravel deposits are granite, quartsite, sand¬ 
stone, limestone, and the harder shale ail derived from the moun¬ 
tains of the Sespe region. 
PALEONTOLOGY OF THE FERNANDO FORMATION. 
At least three distinct faunas are recognizable in the Fernando, 
representing what are thought to be in a very general way the bottom, 
middle, and top of the formation. The oldest fauna was found in the 
area north and northeast of Camulos, and is, according to J. C. Mer- 
riam, the equivalent of the fauna of at least a part of the San Pablo 
formation. The middle fauna was found well developed in the region 
of Elsmere Canyon and Fernando Pass, and probably represents the 
