48 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL, 75 



Range. Prior to this I found in September, 1922, in Sinclair Canyon 

 at the south end of the Brisco Range, a Hmestone ^ carrying abundant 

 specimens of corals (Halysites, Palseofavosites, etc.) and beneath it 

 a quartzite that occupied an equivalent position to the quartzite at the 

 base of the " Silurian " described by Allan. This limestone is now 

 placed in the Beaverfoot formation and the great limestone above, 

 carrying a Silurian fauna, is placed in the Brisco. Above these Silu- 

 rian limestones at the north end of the Beaverfoot Range there 

 appears to be a quartzite that possibly may be at the base of the 

 Devonian. In Sinclair Canyon, a band of thick layers of a hard black 

 argillaceous rock occurs interbedded in the massive magnesian lime- 

 stones. The layers 2 to 3 feet (.6 to .9 m.) thick break down into 

 thin layers on weathering, and these split into shaly pieces, on the 

 surface of vv'hich numerous graptolites of Silurian age are abundant. 

 (See p. 12.) 

 Dr. Edwin Kirk reported on the Silurian Brisco as follows : 

 " The most complete section of the Silurian seen in the upper por- 

 tion of Windermere Creek gave a thickness of between 1,000 feet and 

 1,200 feet. The section is incomplete in its upper portion, being faulted 

 against the Ordovician. The Silurian consists in the main of grayish 

 to brownish fine grained limestones, some layers being slightly 

 dolomitic. 



" The fauna in the basal portion of the Brisco (Middle Silurian) is 

 scant consisting mainly of very poorly preserved cyathophylloid corals. 

 However, within 50 feet above the top of the Beaverfoot (Richmond) 

 in the Windermere Creek section, Pentamerns was found. Slightly 

 higher stratigraphically but below the Monograptus horizon, Virgiana 

 was found in abundance m Sinclair Canyon. In the upper portion of 

 the Silurian a more abundant fauna was collected near the head of 

 Windermere Creek, which included : 



Halysites sp. 



Syringopora sp. 



Favosites sp. 



Atrypina sp. 



Spirifer sp. 



Stropheodoiita sp." 



Beaverfoot Formation ^ 

 (redefined) 



Type locality. — Crests of Beaverfoot Range east of Columbia River 

 Valley and south of Canadian Pacific Railway line in Kicking Horse 



* Smithsonian Misc. Coll., Vol. 74, No. 5, 1923, p. 17. 



" Burling-, Geol. Mag. London, Vol. 59, 1922, p. 454. Smithsonian Misc. Coll., 

 Vol. 6y, No. 8, 1923, p. 463. 



