456 LIST JOWIKINAUL (O12 (CIR OILOE NY, 
into which one may look down from the cars when near the little 
station of Siskiyou. Two or three miles below the town of Ash- 
land some granitic ridges from the south come down abruptly to 
the creek, almost severing this upper portion of the valley from 
the main valley beyond. West and northwest of these 1idges 
the valley expands again until, in the vicinity of Medford, its 
width is from eight to ten miles, while from this point to the 
summit just mentioned the distance is something like twenty- 
five miles. In this valley the Cretaceous beds appear mainly on — 
the eastern side, or on the side east of Bear Creek, and probably 
also occupy the floor of the valley where they are overlain by 
Pleistocene deposits. 
It has been thought that these beds, which are of Upper Cre- 
taceous or Chico age, extend indefinitely eastward under the 
lavas of the Cascades.* It cannot be said, however, that the 
facts observed during this study confirm this opinion. On the 
contrary, the true relation of the sedimentary rocks here 
described to the rocks of the Cascades is so apparent and so 
uniform that one cannot fail to be convinced that at least this 
portion of the Cascade range is older than the Chico portion of 
the Cretaceous. 
PRE-CRETACEOUS. 
Underlying the Cretaceous are three distinct series of rocks 
which may be called the granite series (including the schists), 
the basalt series and the slate series. The point of junction 
between these series is probably not far from the town of Talent ; 
and from this point lines separating approximately the three 
pre-Cretaceous series may be drawn as follows: Toward the 
southeast the general course of Bear Creek, or, still better, an 
irregular line between that and the line of the railway divides 
the granite on the west from the basalt on the east; toward the 
southwest the line separating the granite on the south from the 
slates on the northwest follows the course of Wagner Creek 
southward for a mile or more, then swings toward the west and 
UGeol. Sur; Cali, Volo, p.354.) ‘seventh An @Rep./U. S. Geolasur,.p.98i= Unis: 
Geol. Sur., Bull. 33, p. 20. 
