216 J. S. DILLER — GEOLOGY OF CALIFORNIA AND OREGON. 



contact immediately underneath the Knoxville beds would be Less con- 

 spicuous than that between the Horsetown beds and the metamorphic 

 rocks or between the Chico and the metamorphics. This would follow 

 from the fact that the Knoxville beds, having been deeply buried by 

 later sediments, were subjected to more intense metamorphic action, 

 which tends to render the original contact less evident. 



In Siskiyou county, California, upon the eastern slope of the Klamath 

 (Scott) mountains, adjoining Shasta valley, there are a number of impor- 

 tant exposures of Cretaceous rocks. Dr D. Ream, of Yreka, kindly fur- 

 nished me a section of the rocks penetrated by Mr King's well at the salt 

 works in Shasta valley, where over 500 feet of fossiliferous sandstonewas 

 observed beneath the lavas of Shasta valley. The same rocks are exposed 

 at the surface near Yreka and on Willow creek, where they contain 

 Chico fossils. On the edge of Shasta valley the Cretaceous strata dip 

 to the eastward and lap up over the lower slopes of the Klamath (Scott) 

 mountains, which lie upon its western border. The tilting evidently 

 occurred at the time the Klamath mountains were upheaved, and the 

 unconformably overlapping Cretaceous strata have since been nearly all 

 eroded. A few conspicuous remnants, however, are still there to tell the 

 tale. The best of these are at Cave rock, three miles north of Gazelle, 

 and near the summit on the road from Yreka to Fort Jones. The last 

 is at an elevation of 2,000 feet above Shasta valley and over 5,000 feet 

 above the sea. The mass is about 400 feet in thickness, and the conglom- 

 erate at its base is composed chiefly of white quartz and unassorted angu- 

 lar fragments of schistose rocks like those in place near by. Although 

 fossils were not found at either of these localities, there can be scarcely a 

 doubt that they represent the overlapping Cretaceous strata from the 

 foot of the same slope. 



In Douglas county, Oregon, along Olalla creek, slates have been found 

 containing . I uct lla alone, and the rocks are considerably metamorphosed. 

 At Buck mountain, a few miles further southeast and twelve miles west 

 of Riddles, AuceUa occurs alone in coarse, pebbly sandstone, which has 

 a slightly metamorphic aspect. This appearance, however, is due not 

 so much to actual metamorphism since deposition as to the fact that the 

 rock is composed chiefly of residuary material removed but a short dis- 

 tance from its original position: consequently its contact with the oldgr 

 metamorphic rocks is not sharply defined. The same is true at some 

 localities, but not all, about Kiddles, in the valley of Cow creek, where 

 both AuceUa and Horsetown fossils occur in abundance. Still further 

 eastward, on Grave creek, an area of Shasta beds occurs. AuceUa is 

 absent, and there are some Chico forms present, with thoseof the Shasta 

 group, so that the horizon must be near the top of thai group. These 



