322 THE CAMBRIAN. [bull. 81. 



Below this last layer there are probably the limestones of the Bed 

 Kock Pass. 



This section is one of considerable interest, from the fact of its hav- 

 ing the Upper Cambrian fauna in the upper portion and an alternating 

 series of limestones, shales, and quartzites below, which, from a com- 

 parison with the sections of western Utah and central Nevada, occupy 

 the stratigraphic position of the Middle Cambrian. In their downward 

 continuation, they may also include the Lower Cambrian zone. This 

 is a question which is to be settled by future investigation. 



In the adjoining Bannock range to the west, Dr. Peale studied a section 

 of the series of quartzites and slates that apparently correspond to those 

 of Nevada and Utah, occurring beneath the Lower Cambrian (Olenellus) 

 zone. The section figured by Dr. Peale includes 5,710 feet of quartzites 

 and slates, with a little interbedded limestone. He compares it with 

 the section on the western side of the Wasatch range, referred to the 

 Cambrian by Messrs. Emmons and Hague. 1 In his resume of the for- 

 mations, the Cambrian or Primordial is made to include the quartzites 

 and slates that may be tentatively assigned to the Algonkian, or to the 

 Cambrian, but preferably to the latter. To the Canadian Period there 

 are referred 1,300 feet of interlaminated limestones and quartzites that 

 occur above the quartzite and slate series now referred to the Cambrian. 

 Dr. Peale states that west *f Malade City the section gives 2,000 feet 

 of strata placed in the Quebec series by Prof. Bradley. 2 



The northern end of the Port Neuf range was studied by Prof. Orestes 

 St. John, in the vicinity of Mount Putnam. He there found the section 

 to be formed of quartzites, chloritic schists, slates, and micaceous shales 

 at the base, above which comes the dark red, finely laminated sand- 

 stone in thick beds. These he referred to the Potsdam with a query. 

 In speaking of this section, Dr. Peale says he thinks Prof. St. John is 

 inclined to refer the base of the section to the Huronian. 3 



With the information afforded by his own survey and that of Prof. 

 St. John, Dr. Peale constructed the following table as embodying their 

 knowledge of the Lower Paleozoic section of Idaho : 4 



1 Op. cit., p. 570. 2 Op. cit., p. 6U. » Op. cit., p. 615. * Op. cit, p. 615. 



