FLORA OF THE CHEYENNE SANDSTONE OF KANSAS. 
ranging and more or less well known Creta- 
ceous types. The collections include a sup- 
posed cycadophyte seed, but this is of doubtful 
relationship. There is also a fragment of a 
trunk of the genus Cycadeoidea, which is of 
somewhat uncertain value, as its exact. strati- 
graphic position has been questioned. There 
aré four coniferophytes and eleven angio- 
sperms. One of these is a supposed monoco- 
tyledon, ten are dicotyledons, and there are 
two forms of uncertain botanic relationships. 
The dicotyledons represent the orders Sapin- 
dales, Malvales, Thymeleales, and Umbellales 
and are remarkable for the total absence of a 
large number of elements generally found in 
floras of this age. This absence can not be 
wholly explained by accidents of preservation 
and discovery and is due, I believe, to the pecu- 
liar ecologic grouping resulting from the en- 
vironment: 
The arenaceous portions of the Cheyenne 
sandstone are very conspicuously cross-bedded. 
The material is very friable, and the vegetable 
remains are embedded in all sorts of positions 
and curled as they are when covered in a dry 
condition by wind-blown sands. ll are coria- 
ceous forms, and the abundant Sequoia 
cones all have their scales shrunken and widely 
distended as in thoroughly desiccated modern 
cones. They appear to have blown about and 
collected in hollows along with the coriaceous 
leaves that are found in association with them. 
With a single exception the ferns are found in 
the clays and evidently were confined largely 
to stream banks. 
The variety of plants in such situations may 
have been larger than the discovered flora 
indicates, but it would seem as if in collections 
so extensive there should be some traces of the 
other plants preserved if they were growing 
near at hand. 
Although the flora is too small and too remote 
in time from existing floras to afford satisfac- 
tory ecologic data, it does furnish some sug- 
gestions. It seems to me to indicate a warm 
and more or less arid climate, with a sparse 
vegetation. I picture this vegetation as of 
meager variety and as having been confined 
largely to the region of watercourses between 
which were larger areas of sand-hill or beach- 
dune country over which the dried leaves and 
fruits were blown, collecting in the hollows and 
becoming covered by wind-blown sands. The 
203 
clay lenses—for example, Cragin’s ‘‘ Lanphier 
beds’’—are waterlaid and might represent 
seasonal rainfall and flood-plain or playa de- 
posits or normal stream sedimentation, and 
it is possible that some of the sands had a like 
origin. 
There is no evidence of aridity in any of the 
Cretaceous floras with which the Cheyenne 
sandstone flora may be compared, whether such 
comparisons are made with the Patapsco and 
Fuson floras, on the one hand, or the Woodbine, 
Dakota, and Tuscaloosa floras, on the other.’ 
I believe, therefore, that the Cheyenne flora 
does not represent. general conditions but is 
purely an expression of the local environment 
and perhaps represents a wide sandy coastal 
plain or fluctuating beaches backed by dunes, 
and that farther inland a more varied and nor- 
mal flora probably existed throughout the 
period when the shallow sea was migrating 
back and forth across southern Kansas. 
A sample of the Cheyenne sandstone was 
submitted to Mr. Marcus I. Goldman, who has 
kindly furnished the appended observations: 
Macroscopic ‘examination.—A solid but friable fine- 
grained sandstone of a pale lavender-brown color charac- 
teristic of moderately carbonaceous sandstones. No 
lamination. Contains curled and wrinkled leaf impres- 
sions suggestive of deposition in a dry condition, hence in 
wind-blown sand. 
Mechanical analysis.—The rock could be easily rubbed 
down into its constituent grains. Onsieving these divided 
as follows: Fine sand through 60 on 100 mesh, 12.9 per cent, 
0.45-0.26 millimeter; very fine sand through 100 on 200 
mesh, 82.2 per cent, 0.26-0.04 millimeter; extra fine sand 
through 200 mesh, 4.9 per cent, less than 0.04 millimeter. 
Microscopic examination showed that the two finer parts 
contained thoroughly disintegrated grains. The coarsest, 
however, consisted largely of compound grains which 
yielded slowly to disintegration, so the following rough 
figures may be taken: Fine sand, 5 per cent; very fine 
sand, 90 per cent; extra fine sand, 5 per cent. In either 
case the great predominance of the very fine sand is obvious. 
This predominance of a single size at once suggests wind 
action, but comparison with dune sands (cf. my paper on 
the Catahoula sandstone, where several analyses are 
assembled) shows that the maximum is in the size next 
finest to that which forms the maximum in typical dune 
material. I have looked up the large collection of analyses 
given by Udden™ and find that in this character the 
sample resembles the finer sand carried by the wind out 
of other deposits. Thus it corresponds with only two of his 
dune sands—No. 219, which is the finest material gathered 
at the crest of a dune, and No. 248, from a blown field. 
144 Goldman, M. I., Petrographic evidence on the origin of the Catahoula: 
sandstone of Texas: Am. Jour. Sci., 4th ser., vol. 39, p. 269, 1915. 
15 Udden, J. A., Mechanical composition of clastic sediments: Geol. 
Soc. America Bull., vol. 25, pp. 655-744, 1915. 
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