CRETACEOUS SYSTEM 445 



Feet 

 21. Bluish greeu clay with very small concretions, dino- 

 saurs, and molluscs 30 



20. Fissile, brownish sandstone ; no fossils 4r-5 



19. Drab clay, brontosaurus remains 30^0 



18. Sandstone, grayish to light brown, part cross-bedded, 



on 2% feet of conglomerate; fossil wood and cycads. . 10--20 

 17. Purplish to greenish clay, with dinosaurs in upper part. GO 

 16. Grayish white sandstone, fine-grained, part cross-bedded, 



moderately soft 10-125 



Bed number 16 is only 10 feet thick at Dyer ranch, but Increases to 125 

 feet a few miles south. It is separated from beds carrying Sundance fos- 

 sils by 40 feet of purplish clays which may belong to the ^Morrison for- 

 mation. A section in Como ridge is as follows : 



Section of Morrison Formation in Como Ridge East of Medicine Bow, Wyominy 



Feet 

 White, massive sandstone, conglomeratic (Cloverly). 



Bluish to greenish shales 50 



Limestone, lumpy '. 1 



Bluish to. olive green shales 30 



Limestone, lumpy 1 



Blue and red shale 120 



Total 202 



Laramie basin. — The Morrison formation outcrops on the west bank of 

 Laramie river just below the bridge a mile northwest of Laramie. There 

 are 3 feet of dark shale at base, then 20 feet of soft, massive light colored 

 sandstone, and at top 10 feet of gray shale with several thin, slabby lime- 

 stone layers, one of which is pebbly, and a thin layer of gray sandstone. 

 In slopes 11/2 to 2 miles south-southwest of Howell station are soft, mas- 

 sive buff sandstones overlain by typical gray and greenish gray massive 

 shale or clay with thin limestone, cherty, and sandstone layers. One of 

 the latter is 2 to 3 feet thick. At the top are very dark shales, which 

 have been prospected for coal; these are overlain by coarse Cloverly 

 sandstone. 



Section of Morrison Formation on East Slope of Ridge West of Doioney Soda 



Lakes, Wyoming 



Cloverly sandstones and shales. . Feet 



Drab to olive green shale 30 



Soft, coarse-grained, disintegrated sandstone, with cal- 

 careous matrix containing teeth and bones 6 



Drab to blue shale 15 



Nodular limestone 1-2 



