METAMORPHIC SERIES OF SHASTA COUNTY. 59 1 



through ; the limestone was sunk down into these troughs and 

 thus preserved against erosion, while the strata have been eroded 

 away from the rest of the country. 



These limestones are therefore not lenticular masses, where 

 shales take their place in the strike, for at the ends of the lime- 

 stone ridges only the underlying shales are seen, and frequently 

 there are detached masses of limestone with strike directly 

 across the main trend. 



Stratigraphy. 

 The Sacrame?ito Formation? 



Kennett limestones and shales. Along the Sacramento river, 

 above Redding-, is a thick series of dark contorted siliceous 

 shales, with occasional masses of limestone. H. W. Fairbanks 2 

 describes these strata and mentions the occurrence of numerous 

 corals in the limestones between Squaw and Backbone creeks, 

 about four miles west of Kennett. This was the first discovery 

 of Paleozoic fossils in Shasta county west of the Sacramento 

 river. No fossils were found in the slates, and in the limestones 

 only corals were found. 



The writer did not visit this locality, but Mr. Fairbanks 

 generously gave the use of his information and collections. The 

 fossils proved to be : 



Favosites canadensis, Billings. 



Favosites conf. heinispharicus, Troost. 



Cladopora couf. labiosa Billings. 



Cyathophyllnm sp. 



Chonophylhim (?) 



Aulopora sp. 



Alveolites sp. 



Diphyphyllum conf. archiaci Billings. 



This limestone therefore seems to be of Devonian age, and 

 probably from the middle division, but this is by no means cer- 

 tain, since we know so little of the range of Paleozoic fossils in 



1 H. W. Fairbanks, Ms. 



2 California State Mining Bureau, Eleventh Annual Report, 1893. Geology and 

 Mineralogy of Shasta County, pp. 47-49. 



