SANTA CLARA VALLEY I TORREY-EUREKA-TAPO FIELDS. 81 
fold, although at the southeast end of the syncline, on the south¬ 
ern slope 6f Oak Ridge, a considerably greater thickness has been 
folded in. 
The direction of the Chaffee syncline is at variance with that of 
every other fold that has been observed in the ranges south of Santa 
Clara River. Moreover, it lies between two systems of folds, either 
of which might be said to terminate against it. One of these systems 
includes the anticline traceable from Wiley Canyon westward to the 
end of South Mountain; the other is that passing from the region of 
Torrey Canyon in a S. 65° E. direction to the west end of the Santa 
Susana Mountains. It is worthy of note, too, that the position of the 
Chaffee syncline is nearly in direct line with the principal fault in the 
hills north of the Santa Clara. 
In the region of Torrey and Eureka canyons the geology is extremely 
complicated, but the general facts appear to be as follows: The for¬ 
mations exposed include 150 or 200 feet of red and gray banded 
sandstone and arenaceous clay of the Sespe, about 600 feet of fos- 
siliferous sandstone and chocolate-colored and gray sandstone and 
shale of the Vaqueros, perhaps 400 feet of siliceous shale and chalk 
rock of Modelo type, and a great body of heavy-bedded sandstone 
and conglomerate, in some of which have been found fossils identif sung 
them as the Fernando (Pliocene). These formations are shown in a 
section of Oak Ridge across the Torrey field—the oldest beds at the 
heart of an anticline at the northern edge of the productive area, the 
youngest on the southern slope of the ridge and again at its northern 
base, the siliceous shale and “chalk rock” at the mountain crest, and 
the Vaqueros on the upper and lower middle slopes of the northern 
front. 
The structural lines of the Torrey field have a trend approximating 
N. 65° W., contrasting in this respect with those of Oak Ridge to the 
west and in harmony with those to the east, the dividing line between 
the two systems being the Chaffee syncline, already described. 
The principal fold of the Torrey field (see PI. IV, sec. H-EP) is an 
anticline that crosses the ridge between Torrey and Smith canyons 
at the summit of the easterly grade leading to the developed territory. 
This anticline has not been traced eastward to the edge of the Torrey 
basin, but directly in line with it at this point is a similar fold, which 
is probably its continuation. To the west the anticline crosses Torrey 
Canyon, being particularly conspicuous in its lower slopes, becoming 
less so in the ridge between Torrey and Chaffee canyons, and disap¬ 
pearing to a mere trace in the lower portion of Chaffee Canyon as it 
approaches the Chaffee syncline. The trend of this anticline, which 
may be designated the Torrey, is N. 65° W. The inclination of the 
strata on either limb varies from point to point, but in general may 
