THE RED BEDS OF COLORADO 193 



tion. Yet the following section, made 500 feet north of Gregory- 

 Canyon, west of Boulder, fairly represents the beds in the strip from 

 Cache la Poudre River to Canyon City. 



Lyons Sandstone, Conformable ( ?) upon Feet 



u Arkose to conglomerate, massive, reddish, cross-bedded (torrential); 

 pebbles qz. and orth., the former subangular to well rounded, and 

 up to 3 in. in diameter, the latter chiefly angular cleavage fragments; 

 also granite and pegmatite pebbles, and muscovite flakes | in. long; 

 iron stained, slightly calcareous arkosic matrix; breakage across 



pebbles 35 



/ Sandstone, chiefly massive, traces of j-in. to 2-in. beds; red, with areas 

 leached to gray and with greenish perfectly rounded ^-tn. fragments 

 of arkose apart from leached areas; hard, fine-grained, slightly cal- 

 careous, ferruginous (ferric iron); breaks to angular blocks and 



varies laterally to arkose 10 



s Arkose, massive, dark, pink, coarse — ^much as in bed u 10 



r Sandstone to arkose, red to whitish — much as in beds t and u 2 



q Sandstone, massive, red; fine grained, dense, firmly cemented (see also 



bed /) 3 



p Mainly covered; near top, various massive coarse arkose beds, cross- 

 bedded; at about middle a massive 8-ft. arkose, with what may be 

 laminations of varying coarseness; lower part much as upper, 

 pebbles averaging i in. in diameter, not firmly cemented in an 



arkosic matrix 200 



Partly covered; arkose in 3-ft. to 5-ft. beds, reddish or leached (?) to 

 gray; fairly even-grained, subhard, grains averaging less than 

 I in., but with pebbles up to 2 in.; 



arkose much as above, with thin beds of reddish shale, highly 

 muscovitic, and thin beds of red sandstone, platy, muscovitic 92 

 n Partly covered; arkose much as in bed u; 



arkose as above, with sandstone and shale (see also bed i) . . . 90 

 m Conglomerate, arkosic, massive, reddish — much as in bed u, with 2-ft. 

 lenses of well-rounded, coarse gravel, containing granite and white 



qz. pebbles up to 3 in. in diameter 30 



/ Sandstone, deep red to purple, seemingly massive but leached in streaks 



possibly parallel to obliterated bedding-planes (see also bed t) 5 



k Conglomerate, much as in bed m, torrentially cross-bedded 60 



j Shale ( ?), thinly and unevenly bedded, dark red; very arenaceous, with 



flakes of muscovite 3 



i Shale ( ?) as above, but evenly laminated 3 



h Sandstone, massive, dark red; fine grained, with muscovite flakes 5 



g Sandstone, massive but seemingly thin bedded (| in. to 8 in. thick); 



see also bed / 7 



