400 University of California Publications in Geology [Vol. 13 



faulted against the schist, and these are south of the main fault accord- 

 ing to its alignment east of Cottonwood Canon and west of Stubby. 

 They do, however, line in with another fault on the east side of Stubby 

 Canon south of the main fault. By another small fault farther south 

 schist has been overthrust on the fanglomerate from the south at an 

 angle of about 40° (fig. 10). The schist has been badly crushed and 

 slickensided within itself and only at the bottom of the exposure is 

 the contact sharp. It thus appears that there are several minor blocks 

 along the fault zone. 



Between Cottonwood and Whitewater canons two straight streams 

 mark the line of dislocation. North of this sharp line the rocks are 

 schists and gneisses, while fanglomerate is found on the south side. 

 The rocks south of Painted Hill have been displaced, but because of 

 their lithologic similarity the exact nature of the disturbance was not 

 determined. 



There is an east-west fault between San Gorgonio and Millard 

 canons just north of the two hills at the mouth of Hathaway Canon. 

 Along this, between Hathaway and Millard canons, the schists and 

 gneisses on the north have been raised into juxtaposition with the 

 Cabezon fanglomerates on the south. East of Millard Canon the Deep 

 Canon fanglomerate and Hathaway sediments have this same relation- 

 ship. Two miles west of Stubby Canon the fault joins into the San 

 Andreas fault. 



At the head of Hathaway Canon is a large open valley formed, at 

 least in part, by faulting. The line of dislocation on the south is 

 marked clearly by the straight eastern branch of Hathaway Creek, 

 which separates the high ridge of schist on the south from the low 

 south-dipping Cabezon fanglomerates on the north. Furthermore, the 

 parallel streams flowing to the south indicate tilting. On the north 

 side of the valley is the San Andreas fault. The western limit of the 

 block is perhaps just west of Hathaway Creek and the eastern the east 

 side of Potrero Canon ; but these relations are not entirely clear. The 

 floor of the northern part of the valley is of schist and gneiss and is 

 rather rolling. In a region of such rugged topography it is difficult 

 to conceive of such a valley as formed by erosion. In consideration 

 of other signs of faulting it is far more probable that a portion of 

 an old surface has been dropped downward with respect to the sur- 

 rounding country. 



There is evidence of a fault along the south front of the hills from 

 a point two miles east of "Whitewater Canon to a point two miles west 

 of San Gorgonio Canon. North of this, Cabezon fanglomerate lies 



