CARBONIFEROUS 331 



this section is shown by tlie following section, exposed on the north bank 

 of the river about one-fifth of a mile below the Eaniparts : 



Section onc-fiftJi Mile below Lower Ramparts 



Feet 

 f. Black shale and tbiu bands of sandstone (top) 55 



e. Dark, nearly black, toiagh, calcareous shale, with occasional bauds of 



limestone .-« 



(1. Black fissile shale 9q 



c. Thin-bedded saudstone and shale 25 , 



b. Covered ' " ^^ , 



a. Black shale o- 



- ^j* 



The resemblance of this section to the Carboniferous of the Calico 

 Bluff section on tlie Yukon river is seen in the alternating black shale and 

 limestone of e, which is the most characteristic feature of the Calico Bluff 

 beds. 



The beds outcropping just above the Indian village also belong to the 

 Lower Carboniferous series, as shown by their fossils, but lie a little 

 above the section just given. Thin bands of limestone alternating with 

 shales likewise characterize this portion of the section, as shown in the 

 following described beds : 



Section just above Indian Village 



Feet 

 0. Bluish gray to blackish sandy shale, drab at base and locally rather 



fissile (top) ' 200 + 



u. Tough, gray, sandy shales, with G-inch bands of limestone at intervals 



of 5 to 10 feet 50 



Opposite the Indian village several hundred feet of black Carboniferous 

 slates outcrop on the south bank of the river. 



Interbedded quartzites and shales characterize the Carboniferous beds 

 which form the westernmost bedrock outcrops on the river. 



Upper Carlioniferous horizons are represented, according to Doctor 

 Girty's determinations of the fossils, by most of the Carboniferous lime- 

 stone and shales occurring east of the Lower Eamparts. The most ex- 

 tensive bed of Carboniferous limestone observed occurs 4 miles above the 

 Coleen or Succor river. The blue limestone beds exposed here are prob- 

 ably 200 feet or more in thickness. They are overlain by fissile black and 

 tough drab shales._ The whole mass is embraced in a partially overturned 

 fold, which makes impossible the measurement of the thickness of the 

 beds. This limestone, although classed as Upper Carboniferous, has a 

 different fauna and belongs at a somewhat lower horizon than the lime- 

 stone of Xation river. 



XXXII — Bull. Geol. See. Am.^ Vol. 19, 1907 



