136 
GEOLOGICAL REPORT- 
-THIRTY-FIFTH PARALLEL. 
a un gres calcaire jaunatre, avec nombreuses 
concretions calcaires cle la grosseur d’une 
noisette on d’une pomme, a peu pres 30 pieds. 
Puis au-dessus on a une couche de conglomerate 
tres-calcaire, les cailloux sont de silex, quartz, 
jaspe, gneiss, fer ; la pate calcaire est rose. 
Dans deux cailloux, l’un est de fer avec beau- 
coup d’empreintes de petites bivalves indeter- 
minables et deux petites Turritella. Jepense 
que ce morceau de fer vient du carbonifere. 
Plus un morceau de calcaire jaune rougeatre, 
renfermant une lumachelle que je crois etre 
d ’ Ostrea Aquila Americana. Deux pieds au- 
dessus on a un demi-pied de calcaire blanc, 
tres-compacte, a cassure concboide avec petites 
geodes de cristaux de carbonate of lime. Puis 
suit un calcaire, tantot un peu grisatre, le plus 
souvent tres-blanc, friable un peu crayeux, qui 
tacbe les doigts et qui vu au-loin ressemble a 
la craie, 15 a 20 pieds. Au-dessus il n’y a pas 
de diluvium de meme espece, mais la terre 
vegetale. Je pense que cette Llano formation 
est cretace superieur. 
18 Septembre. —Le Llano Estacado est de 
la terre, provenant de la decomposition du 
limestone cretace; pas d’alluvion d’aucune 
espece. An Camp No. 46, on a la section sui- 
vante. 
half-way up the hill of Barrancas; then we 
found, for about thirty feet, a yellowish calca¬ 
reous sandstone containing numerous calcare¬ 
ous concretions of the size of a hazel-nut or an 
apple. Still above we found a bed of a very 
calcareous conglomerate; the pebbles are of 
silex, quartz, jasper, gneiss, and iron-ore, and 
the calcareous cement is rose-colored. Of two 
of these pebbles, one is ferruginous, with many 
casts and imprints of small undeterminable 
bivalves and two little Turritellas; I think that 
this ferruginous mass is of carboniferous age. 
Another mass of limestone, of a reddish yellow 
color, contains a lumachelle, which I consider 
to be of Ostrea aquila Americana. Two feet 
above we have a thickness of half a foot of 
white limestone, very compact, breaking with 
a conchoidal fracture and containing small 
geodes of crystals of carbonate of lime. Then 
follows fifteen or twenty feet of limestone; a 
little greyish, but mostly very white; it is fria¬ 
ble and somewhat chalky, soiling the fingers, 
and when seen from a distance resembles chalk. 
Above it there is no diluvium of any kind, but 
the earth is vegetable mould. I think that 
this Llano is the superior cretaceous. 
September 18.—The surface of the Llano 
Estacado is of earth, proceeding from the de¬ 
composition of the cretaceous limestone. No 
alluvium of any kind. At Camp No. 46, we 
i have the following section: 
a. Limestone resemblant au foret marbre.. 10 pieds. 
b. Red sandy marl ) 
c. Sandstone, violet >- 150 “ 
d. Red marl ) 
e. Grey sandstone, quelques fois violet-100 “ 
Le sandstone du Rocky Delaware creek ou 
Agua Piedra est gres blanchatre, quelques 
assises schisteuses sont rosatres, denudation 
profonde et bizarre, hieroglyplies des Pueblo 
Indians. [Drawings of some of these hierogly¬ 
phics accompany this note.] 
Au-dessus on a des marnes rouges et grisatres, 
avec teintes vertes et quelque assises de gres 
а. Limestone resembling forest marble. . 10 feet. 
б. Red sandy marl ) 
c. Violet sandstone [---150 “ 
d. Red marl ) 
e. Gray sandstone, sometimes violet... 100 “ 
The sandstone of the Rocky Delaware creek, 
or Agua Piedra, is whitish-grey, with some 
shales of a rosy hue. The denudation is deep 
and peculiar. Some singular hieroglyphics, 
made by the Pueblo Indians, were seen here. 
Above the sandstone we have one hundred 
and fifty feet of red and greyish marls, with 
green tints, and some heds of shaly sandstone 
