THE SAN ANDREAS RIFT AS A GEOMORPHIC FEATURE. Bb 
to the creek. Near Burrell the slope is very gentle at the Rift, for from 20 to 50 feet, 
but is steep above and below. Looking up the Rift and the creek from this point, one 
gets the impression of a long straight creek, but in reality the view is over the divide, 
down a small tributary of Soquelle Creek to its junction with the main stream and thence 
up the main Soquelle Creek. About 2.5 miles from Burrell the Rift follows a small 
gully into Soquelle Creek, which it crosses where the creek makes a sharp turn to the 
west. For the next 4 miles, or to the point where the new county road crosses the divide 
between a branch of Soquelle Creek and Eureka Creek, it follows near the top of the 
timbered ridge to the southwest of Soquelle Creek. The heavy timber obscures the topog- 
raphy, but the Rift, wherever crost, is marked by a bench or trough on the hillside. 
Following the Rift to the southeast, it passes at the divide into the head of Eureka 
Canyon, rises on the northeast bank, and slowly gets farther away from the creek, cut- 
ting across the tributary creeks and rarely following one of the smaller gulches for a short 
distance. The typical section here gives a steep slope on the high hills to the northeast, 
then about 0.25 mile of gently sloping, rolling hills, and finally the steep slope to the 
creek itself. The Rift is on the gentle slope, generally at some distance from either of 
the changes in slope. This continues for about a distance of 2 miles on to Grizzly 
Flat. Here the high steep hills to the northeast are separated from the lower hills to 
the southwest by a flat about 500 feet across. The Rift is on this flat near its center, 
and usually marks the northeast boundary of a series of low knolls. It continues on the 
flat for about 0.5 mile to where the hills close together and leave a rather steep-walled 
gulch. The Rift follows up this gulch for about a mile, and then crosses into the head 
of another creek, which it follows down for about 3 miles, where the stream turns sharply 
to the north. For the upper mile the gulch is rather sharp and deep, but at Hazel Dell 
the hills on both sides are low and rolling, while the lower mile is again rather steep, 
opening at the turn to a rather flat country. At Hazel Dell and other points, the Rift 
occupies a small but distinct trough very near the southwest bank of the creek. _ From 
here to Chittenden, a distance of about 8 miles, it follows parallel to Pajaro Valley, well 
up on the hills, and cuts across the canyons at almost right angles. 
The typical section up one of these ridges gives a gentle slope from the valley to an 
elevation of about 1,000 feet; a steep slope for about 50 feet in the opposite direction, 
which marks the Rift; a very gentle slope for about 1,000 feet across; and finally, the 
steep upper slope of the hills. Over this area the Rift is nearly always marked by a 
trough, which often gives rise to a small lake perched ona ridge between two steep canyons. 
At a few points, especially about a mile northwest of Chittenden, small streams and 
gullies tend to follow the Rift, and they then make a sharp turn where they leave it. 
At Chittenden the Rift again passes thru a pronounced notch in the crest of the range 
occupied by the canyon of Pajaro River (plate 174), from the western flank of the domi- 
nant ridge of the Santa Cruz Range to the eastern flank of the Gavilan Range. 
The rocks traversed by the Rift from Mussel Rock to Pajaro River are, so far as known, 
almost wholly confined to the Franciscan and Monterey series, the former prevailing in 
the northern part and the latter occurring only in the southern. At Pajaro River the 
Rift encounters the granitic rocks of the Gavilan Range, but these lie wholly on its 
western side. é 
