THE EARTH MOVEMENT ON THE FAULT OF APRIL 18, 1906. 105 
the time of the rupture yielded and was crusht so as to distribute the displacement thru 
the surrounding soil. In such places, but little or no horizontal thrust appeared at the 
surface. Where the land was well drained and the surface materials were dry, the ground 
held together better except along the fracture itself, and the displacement was more 
apparent. It seems highly probable, however, that, owing to the deep decomposition of 
the rocks and the frequent movements and fractured condition of the beds along the 
fault, the maximum displacement does not appear at the surface anywhere within the 
area of the Santa Cruz quadrangle. Nowhere has the fracture been found passing thru 
freshly broken beds; and in view of the antiquity of the fault itself, and the evidence of 
many movements upon it, such an exposure is not to be expected. 
SOUTH OF WOODSIDE FOLGER PLACE 
STEVENS CREEK 
CANYON 
SOUTH OF C.SPRINGS LAKE 
ALPINE ROAD s SOUTH OF S. JOSE RESERVOIR 

Fia. 41. — Profiles of Rift, showing relation of fault to slopes. 
Crystal Springs Lake to Portola. — Southeast of the southern end of Crystal Springs 
Lake are numerous cracks along the line of the fault. One less than 0.5 mile from the 
southern end of the lake past directly under a house, the chimney of which had fallen, 
and the building had burned to the ground. (28, map 22.) About 100 feet southeast 
of the road near this house (29, map 22) a crack 1.5 feet wide in places runs approximately 
parallel to the road. The cracked belt adjoining is about 4 feet in width, the downthrow 
being about 6 inches on the northeast side, the lateral thrust about 1 foot on the same 
side, the northeast side moving southeast relative to the opposite side. 
About a mile southeast of the lake are large cracks, running approximately north and 
south, in places 1.5 feet wide. At a point 2 miles southeast of the lake, a crack about a 
foot wide is crost by a fence running N. 58° W. (27, map 22.) The top wire of this 
fence was broken by tension during the shock, and the post nearest the crack was snapt 
off at the ground, the adjoining post being uprooted, and bent over in the same direction 
as the broken one. The posts are of split wood about 5 inches in diameter, and the wires 
