200 A. J. TIEJE 



westward would dip eastward — though at a higher angle than that 

 of the true bedding. 



Description: variants of the Lyons formation. — Ks has been 

 suggested, south of Colorado Springs and north of the Cache la 

 Poudre River, the Lyons beds are not easily recognizable. The 

 southern region may be disposed of briefly. Lateral tracing of the 

 Lyons beyond Colorado Springs is impossible, and certain "coarse 

 deep-red sandstones,"^ overlying the Fountain sediments west of 

 Pueblo, and "containing a considerable mixture of clay"^ may be 

 either of Lyons or Lykins time. The same is true of loo feet of a 

 brick-red sandstone north of Badito; of 30 feet of a massive pinkish- 

 gray sandstone on Grape Creek in the Royal Gorge region; and of 

 certain brick-red material in the Purgatoire Canyon. 



The area north of the Cache la Poudre River has been most 

 closely examined by Butters and George; issue is taken with their 

 view with caution, though in this divergence Henderson is again in 

 accord with the writer. Butters' view of this region is as follows. 

 Overlying the typical Fountain material (with its intercalated 

 limestones), he finds a thin series of sandstones and limestones, 

 which he believes to represent a distinct time-unit and which he 

 calls "Ingleside"; the deposition of this material transpired, he 

 thinks, between the end of Fountain time and the time of deposi- 

 tion of higher beds supposed to merge southward into material 

 like that of the Lyons. 



The writer investigated this region under unfavorable conditions. 

 He is inclined however to follow Henderson in denying validity to 

 the term, "Ingleside," and in considering that, to the south, the 

 lowermost "Ingleside" merges into topmost Fountain and the high- 

 est "Ingleside" into lowermost Lyons. The bearing of the dis- 

 cussion on a possible unconformity between Fountain and Lyons 

 is manifest. 



Interpretation: the marine hypothesis. — The traditional explana- 

 tion of the Lyons formation is that it, like the Fountain material, 

 is marine. Fenneman supposes that an eastern sea still encroached 

 upon the land and that waves and currents rolled about the latest 



I C. E. GHbert, The Pueblo folio (unpaged). 

 ' R. M. Butters, op. clL, p. 75. 



