500 PROCEEDINGS OF THE ALBANY MEETING 



by light, silty lands, the "truck lands" from which San Francisco markets are 

 snpi)lied. Along the foothills of the Sierra there lies a belt, of varying width, of 

 heavy red clay lands, })robabl3' derived from lone formation and frequently closely 

 packed with gravel. Tliese matei'ials are intrinsically poor in plant food, and, 

 being difficultly penetrable by roots, have caused much disappointment to settlers, 

 and were the first to be treiited by the energetic method of blasting with dynamite 

 for fruit culture. They improve materially toward the south, and in Fresno county 

 form tbe basis for successful citrus culture. Higher up in the foothills come the 

 characteristic red soils, the gold-bearing earths, mostly derived from the older 

 slates and sedentary thereon. They are interspersed with patches of gray " gran- 

 ite" lands, which are ver}'^ much less productive, being derived from the grano- 

 diorites, deficient in potash and phosphoric acid. 



The soils of the Coast ranges vary greatly, with their varying rock formations, 

 among which are much clay and clay shale, forming correspondingly heavy soils; 

 but the valleys also are filled with deep silty or sandy deposits. Southward the 

 Coast ranges are continued in the Sierra Madre, which forms the northern wall of 

 the valley of southern California. 



This valley, now subdivided into the drainage basins of the Santa Ana and San 

 Gabriel, was undoul)tedly originally a unit. This is proved by a terrace of " red 

 lands," which extends all around from Redlands and Riverside to Los Angeles. 

 Its subdivision was efiected in late times by the great debris cone of the San Anto- 

 nio creek, which, abutting against the Puente hills, cuts the drainage in two. The 

 red soils are the special ones for citrus culture, but the sandy and silty alluvium of 

 the two rivers also serves the same purpose. 



NEOCENE BASINS OF THE KLAMATH MOUNTAINS 

 BY F. M. ANDERSON* 



[ A hstract] 



This paper is an attempt to show some of the more salient structural features of 

 the Klamath mountains, including not only their basins, but also their principal 

 ranges. The three chief ranges of the group, extending in a northeasterly direction 

 from the coast, and the drainage basins intervening and otherwise associated form 

 the main subject of discussion. Of the two systems of ranges crossing each other 

 nearly at right angles, the northeast and southwest ranges are the older and have 

 exerted a controlling influence over the drainage since their beginning. The prin- 

 cipal rivers of the region — the Rogue river, the Klamath, and the Trinity — cut 

 transversely across the more nearly north and south ranges, showing them to be 

 younger in age than the lines of drainage followed by these streams, and accord- 

 ingly younger in age than the east and west ranges. 



The historical development of these drainage basins is shown by the deposits 

 contained in them, and for some of them it antedates the later Cretaceous epochs 

 at least. The earliest drainage of the basin of the Klamath lakes is shown to have 

 been through the valley of Rogue river, and to have been diverted from that course 

 to its present by some of the later lava flows from the Cascades. Evidence is cited 

 to show that during the Chico epoch this basin was not connected with that of the 



* Presented bv A. C. Lawson. 



