A StiKbj of the Bi'liu'dere Beds. — Crmjiii. 361 
Elk-Otter Section of the 
Belvidere Beds : 
III. Kiowa shales. 
4. Tueumcari shales (or zone of Gvyphfea tiieiinic((rii.) 
.3. FuWmgton shi\\eB {oT zone of GryjJhcea roemeri.f 
b. Blue Cut shales (or zone of typical and abundant 
G. roemeri.) 
a. Black Hill shale (or Wafer-shale zone.) 
II. Champion shell-bed (or zone of Gryplieea hilli.) 
I. Cheyenne sandstone. 
2. Elk Creek beds. 
/>. Stokes sandstone. 
(I. Lanphier beds (or Carbopyrite zone.) 
1. Corral sandstone. 
These subdivisions may be conveniently discussed in the 
order in which they are grouped, beginning with the k)wer. 
THE CHEYENNE SANDSTONE. 
The C'/iei/einie sandsfotie is a white to yellowish-gray sand- 
stone, often gaily colored with variations of red and purple in 
certain horizons, much cross-bedded, locally but not coarsely 
conglomeratic, and again very fine (almost floury) in certain 
eastern exposures. It is veiy porous and its locally phenom- 
enal display of colors, while perhaps in part due, as suggested 
by the writer in 1885, to chemical reactions following the 
infiltration of mineral-charged waters from superjacent form- 
ations, seems to be largely attributable to oxidations and 
reactions of substances native to the sandstone itself. At 
certain localities where the overlying sediments have been 
Neocene sands and the invading waters siliceous, infiltration 
has converted lenses of the Cheyenne sandstone into light 
bluish-gray quartzyte. One of these lenses, now broken (h>wn 
into blocks, covers the sides of a conical hill on the Ilavard 
slope of the Havard-South Elk creek divide. To see a 
reported "blow-out •', this hill was visited by the writer in 
the winter of 1884:-'5, and described in No. 3 of the JinUet'ni 
of the Washl)nrn ColleifC Laboratory of Xaturol History. 
where the earliest notice of the Cheyenne sandstone appeared. 
A second lens of this sort is found near South Elk creek not 
far distant from the former. This is partly undermined and 
broken into blocks, but a considerable part of the ledge is 
still /// situ. The qiiartzyte is not all perfect. It contains 
more or less soft spots, consisting of unmetaiiiorpliosed or 
