South Dakota School of Mines 31 



Section at White Butte. 



11. Sandstone, rather fine grained, light greenish 

 gray in color, weathering into a greenish 



sand, to top of White Butte 105 feet 



10. Clay, gray to light greenish color 2 5 



9. Clay, hard and compact, calcareous, light 

 gray, almost white; forms hard ledges which 

 make low vertical cliffs toward the top of 



the butte, and weathers irregularly 3 4 



8. Clay, dark gray, calcareous; the line of sep- 

 aration between this clay and Xo. 7 is sharp 

 and distinct, the clay being considerably 



darker than the underlying sandstone 46 



7. Sandstone, light gray, rather coarse grained. . 2 

 6. Sandstone, very coarse grained and pebbly: in 

 places the pebbles are so abundant as to form 

 a conglomerate. Shows cross lamination. 

 Pebbles composed of quartz, silicified wood, 

 many varieties of igneous rock, among which 

 porphyry is common, etc. Pebbles range 

 in siz-S' up to two and three inches in 



diameter 2 6 



5. Clay, very light gray, slightly sandy 5 



4. Sandstone, light gray, very fine grained and 



argillaceous 5 1-3" 



3. Clay, light gray to white, slightly darker than 



Xo. 2; contains some white sand 10 1-2 ' 



2. Clay, very white and pure 6 1-2 " 



1. Clay, white, containing some fine ■s'and, hard 

 and very tough when dry: rests directly on 

 the sandstone of the Fort Union 14 1-3 



Total 298 feet 



Concerning the above section. Prof. Leonard says : "These 

 deposits represent all three divisions of the White River group, 

 the lower or Titanotheriura beds, the middle or Oreodon beds, 

 and the upper or Protoceras beds. In the foregoing sections 

 Xos. i to 7 probably belong to the lower, Xos. 8 to io to the 

 middle, and Xo. 1 1 to the upper division." 



For a more detailed section and a fuller description of the 

 extinct animals found, the reader is referred to the Annals of 

 the Carnegie Museum, Vol. IV. 1908. and Vol V. 1909. 



The deposits within the borders of the main Black Hills 

 uplift have been more fully studied than those farther north, 

 hut with the exception of two unique little deposits near Lead 

 and the much larger areas along the southeastern border con- 

 necting the Hills with the Big Badlands, they have not been 

 differentiated sufficiently to admit of definite correlation. 



On the higher tables of the Bear Lodge mountains the 



