30G 



W. II. WELD TWO MONTANA COAL FIELDS. 



^6 



2t 



Figure 2. — Section at 

 Belt Butte. 



22 

 21 



20. 



a 19. 



18 





Belt Butte Section. 



Feet. 



20. Sandstone, gray, slaty and hard, forming cap of the 



butte ' 80 



25. Slate, black 20 



24. Limestone, white ami hard ; forms upper " belt "... 20 

 23. Sandstone, gray, irregularly bedded, breaks into 



shelly detritus 90 



Shale, black and earthy 100 



Sandstone, unevenly and thinly bedded, usually light 

 earthy brown, holding carbonaceous Layers of 1 to 3 

 inches ; principal " belt " of the butte 50 



Sandy shales, black and iron-stained bul hard and 



shelly 20 



Sandy shales, gray, more arenaceous than those be- 

 neath 40 



Sandy shales, fissile and carrying \ proportion black 



shale ; facies decidedly Benton 25 



Shale, black " _ _ _ 75 



Shale, sandy, gray, breaking into cubical hits 50 



Limestone 10 



No good exposures, hut slopes show debris of" white 

 vitreous quartzite resembling novaculite 75 



Shale, black and earthy 10 



Sandstone, marked by fucoidal rolls \ 



Shale, black and earthy, with one 6-inch band of sand- 

 stone 25 



Sandstone 2 



Shales, red and purple to purple-black, with rare layers 



of harder sandy nick whose splinters strew slopes. 140 



Sandstone, gray, weathering light brown; forms top 

 of a broad bench extending back to the base of Belt 



butte 20 



Gasteropod bed ; Goniabasis, Neritina, < 'orbula (?) .... 10 

 Sandstone, dense, lilac-colored, weathering purple- 

 brown 10 



Series of thinly bedded sandstones and limestones"] 

 with alternating beds of shale, well exposed in 

 coulee, but not of sufficient interest to warrant 

 more detailed section, viz : 



k. Xo exposure 21 



/'. Sandstone, gray, cross-bedded ) 



'/. Shale * \ 10 



//. Sandstone, buff, dense, uniform .... J 



g. Sandy lilac-colored ledge 2 



/'. Sandstone 5 



e. Lilac-tinted freestone 20 



</. Sandstone, fissile, gray, quartzose, very 



hard and iron stained 17 



c. Ledge of pink and lilac rock 30 



//. Red and gray sandstones and shales. . . 45 

 a. Shale, sandy, but}', with red blotches. . . 10 



15. Sandstone ledge, prominent stratum that throughout 



the valley lies over coal 50 



14. Coal 10 



16. 



160 



1,092£ 



