METAMORPHIC SERIES OF SHASTA COUNTY. 593 



the West, which is often quite different from their range in the 

 Eastern states. 



A recent paper by J. S. Diller and Charles Schuchert 1 makes 

 the Middle Devonian age of these rocks more certain, since they 

 found several of these species and others more characteristic on 

 Hazel creek and Soda creek, in Shasta county. They also found 

 near Gazelle, in Siskiyou county, a younger Devonian fauna, 

 with only one species in common with the Shasta localities. 



The Mc Cloud Formation? 



Occurrence and character. The McCloud formation is espe 

 cially well developed in the region of the McCloud river in 

 Shasta county, and from this it receives its name. The forma- 

 tion consists entirely of Carboniferous strata, the Baird siliceous 

 shales, overlain by the heavily bedded McCloud limestone, with 

 some beds of igneous rock. The thickness is estimated at about 

 2,500 feet, but this may be far from the true thickness. 



The rocks are fossiliferous from bottom to top, and the faunas 

 give divisions as well characterized as those given by the litho- 

 logical characters. J. S. Diller 3 considers the strata of the 

 McCloud formation as equivalent to those of the Caribou forma- 

 tion, as they certainly are in part. But the McCloud series is 

 much more complete than any Carboniferous known in the Las 

 sen Peak or the Taylorsville region, since the horizons of th 

 Upper and the Lower Carboniferous are well defined faunally 

 and stratigraphically. 



These strata were first studied by Trask 4 who recognized 

 them as Carboniferous, and thought the limestones belonged just 

 below the Coal Measures, from the evidence of fossils collected 

 by him near Stillwater. He noted too that the formation extends 

 from Stillwater northward across the Pitt river, on both sides of 



1 " Discovery of Devonian Rocks in California," Am. Jour. Sci., Vol. XLVII., 

 June, 1894, pp. 416-422. 



2 H. W. Fairbanks, Ms. 



3 Geological Atlas, U. S. Geological Survey, Lassen Peak Sheet, 1892. 



4 Report on the Geology of the Coast Mountains, 1855. 



