318 University of California Publications in Geology [Vol. 12 



Two roads connect San Jacinto Valley and San Timoteo Canons, 

 crossing the formation in the general direction of the dip. The west- 

 ern road, Moreno Grade, allows but a poor opportunity for the study 

 of the structure, its main exposures occurring in massive deposits of 

 compact, gray-brown sandstone, which passes southwestwardly into an 

 equally massive gray- white area. The more eastern road by way of 

 the new Rabbit Cut (San Gorgonio Drive) fortunately affords splendid 

 exposures for the examination of the strata and for the study of the 

 marvelous series of folds and faults which have taken place in this 

 particular region (pi. 44, fig. 3). 



The lower hills on the San Jacinto-JMoreno Valley-side are formed 

 of a series of fine and coarser sandstone interstratified with layers of 

 clay. North across the strike the latter are followed by the sharp 

 south-dipping beds of the central area, remarkable for their broad 

 layers of heavily cemented fanglomerate, which, more resistant to 

 erosion than the interbedded graj'-brown and yellow clay sands and 

 sandstones, project in bold weathered bands. Still more to the north 

 the sharply south-dipping beds of the mid-elevation are followed first 

 by a more gently dipping series and then by a broken indeterminate 

 area that apparently represents the axis of the anticline. The present 

 crest of the ridge lies 500 feet higher, and in the mid-extent of the 

 Badlands a quarter of a mile to the northwest of the axial line. The 

 iipper and more recent beds of the north-dipping layers of the crest 

 are more brightly colored and sandy than the older beds lying im- 

 mediately below both to the north and south, tending to pink-reddish 

 instead of yellowish tones. They lack, too, the great gray inter- 

 stratified bands of cemented angular rock fragments so prominent in 

 the lower southern area. 



The San Timoteo deposit as a whole is strongly characterized by 

 the coarse sand and cobble beds which appear running through the 

 yellowish and pinkish browns of the bluffs, as well as by fragments 

 of the same which form a characteristic litter throughout much of the 

 top soil. The constituent cobbles of the coarser layers while consider- 

 ably worn on the edges are hardly as uniformly rounded as the average 

 resultant of stream deposition. Their angularity as well as the preva- 

 lence of mica and occasional considerable amounts of gypsum, forbid 

 the consideration of the deposit as of purely alluvial formation. The 

 evidence points rather to its origin as the great slope-wash of a semi- 

 arid region, the formation for which Professor Lawson has proposed 

 the term "fanglomerate." 



