502 CARBONIFEROUS ROCKS IN CUMB, CO. — LOGAN & FLETCHER. 



Ft. In. 



28. Reddisli-gray, very fine sandstone in flaggy layers. 4 



29. Liglit-gray fine sandstone Avith comminuted jilants 16 4 



•30. Greenish argillaceous shale 3 



SI. Rusty-gray, fine sandstone, massive, passing in 



1 places into conglomerate, and in other places 



altogether into gi'eenish argillaceous shale 5 



32. Gray, very coarse, pebbly sandstone, full of pros- 



trate trees, with veins of bright coal half an inch 



thick 10 



33. Greenish, very fine sandstone, replaced by coarser 



sandstone 1 



34. Greenish and reddish rusty-weathering marl, 



replaced by sandstone • 1 



35. Greenish and reddish, very fine, argillaceous 



sandstone, replaced by greenish-gray, pebbly 

 sandstone 3 



36. Red marl with layers of jointed sandstone and shale. 7 



37. Very fine, coherent, calcareous sandstone, in two 



or three layers 9 



38. Red marl 4 7 



39. Gray flags, verv fine and sandy, replaced on the 



strike by gray sandstone 6 9 



40. Gray massive sandstone. Much thicker in places, 



but replaced by the lower Imnd of red marl 3 



41. Greenish crumldy marl 3 



42. Red marl with a layer of harder rock 6 



43. Reddish and greenish, mottled, flaggy, rubbly rock ; 



replaced by greeniish sandstone 2 6 



44. Greenish-gray very fine sandstone, passing into 



gray pebbly sandstone 6 6 



45. Gray and rusty pebbly sandstone, with very 



irregular surfaces. The rocks are unfit for grind- 

 stone; many of the layers show broken leaves and 

 fruit of fossil plants, with sometimes large 



