172 ENVIRONMENT OF VERTEBRATE LIFE, ETC. 



In the Skagit Mountain range the following series has been made out 

 (page 546) : 



Unconformity. 



upper Carboniferous j XuMr^"" g-i^^^f one (altered gabbroid rock). 



(. Chilhwack volcanic formation. 



Upper Carboniferous (and older) j Chilliwack series. 



l Hozomeen series. 



The oldest, the Hozomeen series, covers 3 or more square miles north of 

 Glacier Peak and just east of the main divide of the Skagit Range. The 

 prevailing rock is a cherty quartzite, occurring in thin, flaggy beds, from 

 I inch or less to 3 inches in thickness. Occasional bands of probably con- 

 temporaneous and extrusive greenstone occur, but there is no limestone in 

 the main area. 



The Chilliwack is exposed on the Chilliwack River. A typical section 

 about a mile west of monument 48 is as follows: 



Top (?) unconformably overlain by Cretaceous (?). Feet. 



Quartzitic sandstone 50 + 



Dark gray argillite 20 



Light gray limestone, fossiliferous 50 



Gray calcareous quartzite and dark gray calcareous argillite 60 + 



Andesitic tuffs and flows and agglomerates 2,000 + 



Gray and brown shale and sandstone; thin conglomerate bands; crumbling, thin-bedded, highly 



fossiliferous 200 



Light gray, generally crystalline limestone, fossiliferous 600 + 



Shale, sandstone, and grit 90 



Massive, light gray limestone, fossiliferous no ± 



Dark gray and brown shales, fossiliferous 300 + 



Massive hard sandstone 100 + 



Hard sandstone and black and red shales with bands of grit and thin beds of conglomerate; 



roughly 1,400 ± 



Hard, massive sandstone with gritty layers 800 + 



Dark gray to black, often phyllitic argillite with quartzitic bands 1,000 + 



The 2,000 feet of andesitic tuffs and flows and agglomerates near the 

 top constitute the Chilliwack volcanic series. 



Girty, after listing the fossils obtained from above and below the Volcanic 

 series (pages 510-513), says: 



"On the whole, from the little that I understand of the stratigraphic relations 

 and from the relationship manifested by the most marked of your faunas with 

 that of the Nosoni formation, I am disposed to correlate all your beds in a general 

 way with the latter. They may contain measures younger or older than the 

 Nosoni, but from the absence of the well-marked Baird and McCloud facies it 

 seems probable that none of the horizons from which your collections came is 

 as old as the McCloud." 



In the Hozomeen Range east of the Skagit Range the Hozomeen series 

 is typically developed ; because of the absence of fossils its position is uncer- 

 tain, but it is provisionally correlated by Daly with the Cache Creek series 

 for reasons given on pages 502-504 of his Memoir No. 38. 



The series is composed of quartzite, chert, limestone, and dominant 

 greenstone. The limestone occurs as rare intercalations of white or pale 

 gray rock squeezed into "pods" by later movements and deprived of all 



