DISTRIBUTIOX OF THE SERIES. 453 



directly and with a marked unconformity on the metamorphic rocks. 

 In like manner the Chico extends beyond the Horsetown in Oregon, for 

 at Jacksonville and Ashland, southeast of the Horsetown locality on 

 Graves creek, we find the Chico beds resting with a conspicuous uncon- 

 formity directly on the metamorphic rocks. This overlapping to the 

 northeast in California and southeast in Oregon finally resulted during 

 the Chico epoch in connecting the two areas through Lassen strait,* which 

 separated the Klamath mountains from the Sierra Nevada. 



To the southward the Shasta-Chico series has been identified by 

 Turner,t Lindgren,;|: White,§ Fairbanks,! | and Dall^ in the Coastal region 

 as far as Todos Santos bay of Lower California. Emmons ** and Merrill 

 have recognized it as far south as 29° 30', and believe it extends still 

 further in the same direction. 



Deformations. 

 subsidence during the shasta-chico epoch. 



On the accompanying map are indicated the coast lines at the close of 

 the Horsetown and Chico epochs. The Knoxville coast has been traced 

 both in Oregon and northern California to but a limited extent. The 

 same is true also of the Horsetown shoreline, which lay only a short dis- 

 tance farther inland, but during the Chico epoch the invasion of the sea 

 reached its maximum and extended far inland, as indicated by the posi- 

 tion of the coast line at the close of that time. This successive over- 

 lai)ping landward of the newer and newer beds of the Cretaceous S3''stem 

 shows that during the period of deposition of the Shasta-Chico series the 

 continent was subsiding and the sea transgressing. 



Dr Dawson "j t has shown from observations in British Columbia that a 

 similar movement was in progress at the same time in that country. 

 The sea was trans^iiressin": to the soutliward in the Puojet Sound reo;ion 

 during the Chico, and the concomitant sul)sidence was undoubtedly con- 

 nected with that great invasion, which reached as far eastward as the 

 Blue mountains, in Oregon. 



To the south, as in the north also, the sea was evidently transgressing. 

 From Tehama county, in California, the Knoxville, Horsetown and Shasta 

 beds may be traced southward through Colusa, Napa and other counties 



* U. S. Geol. Survey, Eighth Ann. Rep., p. 412, 



tThe American (xeologist. May, 1893, pp. 307-:i2-l. 



JProc. Cal. Aead. Sci., 2<1 ser.. vol. i, pp. 180-182. 



2U. S. Geol, Survey, Bulletins 22 and 82. 



II Am. Jour. Sci.. vol. xlv, pp. 475-477, June, 18!):}. 



^Bull. Geol. Soo. Am., vol. 4, p. 207. 



**Bull. Geol. Soc. Am., this vol.. post. 



ft Trans. Roy. Soc. of Canada, vol. viii, see. iv, 1890, pp. 3-75. 



