Series in Kansas, Oklahoma and New Mexico. 209 
UG. Osstitieraus shalom. a2 2 206 2 Lise ks by ol ly 16 
17. From No. 16 to the top of the large butte 4 mile 
to the west the thickness of shale is _______- 32 
Making of blue shale with indurated fossil 
lawets avtotaleaf 4a soe at 2a! ose2 106 
In the shale near the summit of this butte specimens of the 
large Gryphea dilatata var. tucumcariw Marcou, were found.* 
As we approach Belvidere the Cheyenne sandstone begins 
to form the principal slope of the river basin, and west of 
that village the bed of the river rises until it is upon the 
Cheyenne sandstones, while some bluffs and castellated rem- 
nants of the sandstones are beautifully exposed in the north 
side of the valley. 
Five miles west of Belvidere the railroad has made magnifi- 
cent cuts into the beds so that they are there seen better than 
at any other locality. Here the comparatively steep wall of 
the valley affords a fine section from the old deposition plane 
of the Great Plaims Tertiaries down into the Cheyenne sand- 
stone, the buttes on the south margin of the river valley being 
remnants of the main body of the plains to the northward. It 
is here that Prof. Cragin made his Blue Cut mound section,+ 
omitting from it, however, the basal sandstones which are 
revealed in the floor of the valley near by. Following is the 
section as measured by Mr. Gould and the writer: 
Blue Cut Section. 
IJ. The Cheyenne Sandstone—bottom not exposed. Re. Tne. 
1. The Cheyenne sandstones are well shown west 
of Belvidere in the bluffs on the north side of 
the river valley, especially in the cliffs of 
Thompson’s Creek. About two and one-half 
miles west of Belvidere a small creek from 
_ the south emptying into the river makes good 
cuts through the sandstone, showing the same 
general detail as at Black Hills section. 
2. Sandy shale band above the basal sandstone the 
same as No. 2 of Black Hills section______-- 8 
3. Thin sandstone layers of the plant beds{ of Nos. 
3. ana 4) of the black. Gills/section __.. === --=- 6 
* See remarks on this species, p. 38. 
+ Bull. Washburn Laboratory, vol. ii, No. 11, p. 77, 1890. 
¢ These beds constitute alow bench immediately adjacent to the river, and 
the clay shales succeed them, forming the higher outer slope of the valley. I 
made a general study of the section to the summit; Mr. C. N. Gould made the 
succeeding accurate measurements and minute collections. 
