CRETACEOUS AND TERTIARY FORMATIONS 521 



Feet 



Drift gravel and sand 2 



Shale, dark colored 27 



Sandstone, soft, with many thin, brown, carbonaceous laminae n 



Sandstone, yellow, soft , 16 



Shale, brown, carbonaceous, with two coal seams, one 3 inches and the 



other 7 inches thick 8 



Shale, gray 3 



Sandstone, gray 8 



Shale, gray 4 



Shale, brown, carbonaceous 3 



Sandstone and shale in alternating layers, the former predominating; 



colors, dark gray, brown, and yellow 57 



Shale, dark gray, with a few brown bands 22 



Sandstone, Fox Hills 80 



Total 24 



From the lower sandstone of this section, Fox Hills shells were 

 collected. The Lance beds here rest conformably on this sandstone, 

 and there appears to have been a gradual change from the marine 

 conditions of Fox Hills time to the fresh-water conditions under 

 which the Lance beds accumulated, with continuous deposition 

 throughout. 



The strata forming the upper 350 feet of the Lance formation, 

 comprising the upper, massive sandstone, and the underlying 

 dark shales, are very well exposed in the valley of the Heart River, 

 in Morton County. For a distance of five or six miles below the 

 bridge on the Glen Ullin-Leipzig road, this valley is a narrow 

 gorge walled in by sandstone cliffs. This rock, which forms the 

 upper member of the Lance formation, is -a massive, gray, brown, 

 and yellow sandstone, having a thickness of approximately one 

 hundred feet. The underlying shales are dark gray to black, 

 when moist, and weather to a yellow color. They are cut by 

 several sets of joint cracks and along these cracks the change 

 from gray to yellow first takes place, the gray, unweathered material 

 being left in the areas inclosed by the joints. Near the surface 

 the shales are weathered and oxidized throughout, but at some 

 depth the yellow color is confined to narrow bands on either side 



