THE RED BEDS OF COLORADO 203 



THE LYKESrS TOEMATION 



Description: typical Lykins. — The tj^Dical Lykins material is 

 both very different from, and much more variable than that of, 

 the Fountain or Lyons series. Yet, except in one important 

 particular, the following section, made at Bear Creek, 3 miles south 

 of Boulder, is representative of the strip from Lyons to some dis- 

 tance south of Colorado Springs. 



Morrison Sandstone, Unconformable on Feet 



k Sandstone, slabby (2-in. to 4-in. beds), rich brown-red, weathering to 

 red; fine-grained, subhard, ferruginous, somewhat calcareous, 

 sKghtly argillaceous, breaks in little blocks; rare, comminuted 

 muscovite fragments; ferruginous mud lumps and ripple marks 

 (current type, setting north) 20 



j Shale, fissile, red, sandy 10 



i Sandstone, massive, especially the lower 10 ft.; brown, with green dots, 

 splotches, and lenses, the latter up to 20 ft. long, and passing laterally 

 into sandy shale, almost fissUe; no ripple marks observed; mud 

 lumps common. Otherwise, much as in bed k 30 



h Shale, red, weathering red, thin bedded to fissile; splotched and lensed 



with green, varying laterally to shaly sandstone 10 



g Sandstone, almost massive, red — much as in bed i, but no mud lumps 60 



/ Covered; undoubtedly sandstone and shale, as in beds g and h, the 

 sandstone predominant, with delicate laminae (sV in.) on ^-in. beds, 

 the laminae finely cross-bedded 150 



e Sandstone, known as "crinkled" and an important horizon-marker from 

 at least west of Fort CoUins to points south of Pueblo; very finely 

 laminated in twisted, broken, and brecciated folds, the average 

 thickness being iVin., colors alternating red and white; fine grained, 

 hard to superhard, highly calcareous; blocky, shaly sands may be 

 intercalated ; upper 6 ft. here limestone, grayish, hard, arenaceous, 

 somewhat brecciated, with calcite crystals in veins 18 



d Sandstone, massive, weathers in blocky fragments, simulating f-in. to 

 I -in. beds; red, with less green splotches than in upper beds; 

 variant to k type 40 



c Sandstone, massive, red, hard 6 



b Sandstone, much like k, but with few mud lumps or ripple marks; green 



splotches as in bed d 34 



Sandstone, massive, red, weathers in blocky fragments, much as in bed d 20 



390 



As revealed in this section, the characteristics upon which the 

 interpretation of the Lykins depends are (i) seeming conformity 



