SECTION OF THE BELT TEE.RANE 209 



Feet Feet 



Limestones and shale 20 



Shales, slaty, in part indurated ; dijj, 20 degrees south ; strike, 



south 80 degrees east 15 



Slaty shale, gray in color and well indurated ' 30 



Limestone in 3-foot beds of dark gray color, with crystalline 



markings , 8 



562 



Chamberlain shales : 



Gray shale, no massive exposure was seen * 1,095 



Black shale, exposure being a quarter of a mile below a western 



branch of the creek 363 



Massively bedded black shale ; dip, 20 degrees upstream 40 



No exposure 190 



Black shale 40 



Black crumblj' shale ; dip, 14 degrees 54 



Black shales 229 



Thinly bedded and fissile quartzite 5 



Black shale, somewhat slaty, carrying beds of green quartzite. . 40 



Shale, not exposed 22 



Neiiiakt quartzite: 



Quartzite 2 



Micaceous shale with fucoidal markings, resembling Cambrian. 1 

 Quartzite, greenish in color, occurring in beds 6 to 8 inches 



thick, with intervening black carbonaceous shale 7 



No exposure 95 



Shales, micaceous, dark colored, generally green and carrying 



thinly bedded quartzites, so that the entire series might be 



classed as quartzite 15 



No exposure 1 70 



Green micaceous shale in micaceous quartzite, occurring in beds 



4 to 12 inches in thickness, in alternate layers 8 



Micaceous shales resting upon basal quartzites 104 



Quartzite series, forming base of formation 300 



2,078 



702 



Total section 4,607 



AGE OF CAMBRIAN BEDS RESTING ON BELT TERRANE 



The fauna of the shales and limestones immediately above the Flat- 

 head sandstone is of middle Cambrian age, and, as shown in a number 

 of sections, the fossils in the lowest horizons belong to the oldest part of 

 the middle Cambrian fauna, as the latter occurs a short distance above 

 the Olenellus horizon in Utah and Nevada. Near Logan, on East Gallatin 

 river, the fauna was found in the sandstone about 25 feet above the contact 

 with the Belt rocks. The Cambrian sandstone is formed of beach sand, 



♦Probably a considerable portion of this should be included in Newland limestone series. 



