UPPER RED BEDS OF THE BLACK HILLS 



373 



Gypsum ... - 



Light red shale 



Gypsum - - - - 



Red shale 



Gypsum . - - - 



Red shale with some gypsum 



Gypsum - - - - 



Red shale 



Feet. Inches. 



8 

 237 



7 

 58 . 



4 

 78 

 12 



Purple limestone (Permian) ------- 42 



XV. SEVEN MILES SOUTH OF SUNDANCE. 



Drab sandy shales (Jurassic) ------- io-|- 



Chocolate-brown sandy shale ------- 10+ 



Streak of green clay ----- - - . _ _ 



Chocolate-brown sandy shale with few green streaks - - 3 



Green clay - - - - - - - - -- 



Red sandy shale ------... ^ 



Green streak. 



Red sandy shale -------- -i 



Green streak. 

 Concealed. 



XVI. ONE MILE NORTHWEST OF SUNDANCE. 



Covered to top. 



Red sandy shale. 



Impure gypsum ......... ^ 



Red sandy shale with network of gypsum veins - - - 20 



Massive white gypsum - - - - - - - - 2 



Red sandy shale --------- 5 



White gypsum ---------- i 



'(These two gypsum beds are connected by a vein of gypsum 2 



inches thick with branches.) 

 Chocolate-brown sandy shale - - - - - -'3 



White gypsum ---.-.-.. i 



Red sandy shale with small specks of green clay - - - 5 

 Concealed 



Purple limestone (Permian). 



XVII, SEVEN AND ONE-QUARTER MILES NORTHWEST OF SUNDANCE. 



' Fissile drab-green shales - - - - - - 40 



Jurassic 



Buff, friable sandstone - 

 Gray-green mudstone 

 Thin-bedded buff clay sandstone 



10 

 6 



3 



