GEOLOGICAL SURVEY OF THE TERRITORIES. 325 



the bluffs, and continue to do so as far as Fort Harker, thirty-three miles 

 farther west. They are " a coarse, brown sandstone, containing irregular 

 concretions of oxide of iron," and numerous mollusks of marine origin. 

 Near Fort Harker certain strata contain large quantities of the remains 

 (leaves chiefly) of dicotyledonous and other forms of land vegetation. 

 Near this point, according to the same authority, the sandstone beds 

 are covered with clay and limestone. These he does not identify, but 

 l)ortions of it from Bunker Hill, thirty-four miles west, have been iden- 

 tified by Dr. Hayden as belonging to the Benton or second group. The 

 specimen consisted of a block of dark bluish-gray clay rock, which bore 

 the remains of the fish Apsopelix sauriformis^ Cope. That the eastern 

 boundary of this bed is very sinuous is rendered probable by its occur- 

 rence at Brookville, eighteen miles to the eastward of Fort Harker, on 

 the railroad. In sinking a well at this point, the same soft, bluish clay 

 rock was traversed, and at a depth of about 30 feet the skeleton of a 

 saurian of the crocodilian order was encountered, the Ryposaurus Vehhii, 

 Cope. 



The boundary line or first appearance of the beds of the Niobrara 

 division has not been pointed out, but at Fort Hays, seventy miles west 

 of Fort Harker, its rocks form the bluffs and outcrops everywhere. 

 From Fort Hays to Fort Wallace, near the western boundary of the 

 State, one hundred and thirty-four miles beyond, the strata present a 

 tolerably uniform appearance. They consist of two portions — a lower 

 of dark bluish calcareo- argillaceous character, often thin-bedded 5 and a 

 superior, of yellow and whitish chalk, much more heavily bedded. Near 

 Fort Hays the best section may be seen at a point eighteen miles north, 

 on the Saline Eiver. Here the bluffs rise to a height of 200 feet, the 

 yellow strata constituting the upper half. No fossils were observed in 

 the blue bed ; but some moderate-sized Ostrew, frequently broken, were 

 not rare in the yellow. Halt- way between this point and the fort, my 

 friend N. Daniels, of Hays, guided me to a denuded tract covered with 

 the remains of huge shells described by Mr. Conrad, at the close of this 

 section, under the names of Haploscapha grandis and JI. eccentrica. 

 They may have affinities to the Budistes ; some of them are 27 inches in 

 diameter. They exhibited concentric obtuse ridges on the interior side, 

 and one species a large crest behind the hinge. Fragments of fish 

 vertebrae of the Anogmius type were also found here by Dr. Jane way. 

 These were exposed in the yellow bed. Several miles east of the post, 

 Dr. J. H. Janeway, post-surgeon, i^ointed out to me an immense accu- 

 mulation of Inoceramus problematicus in the blue stratum. This species 

 also occurred in abundance in the bluffs west of the fort, which were 

 composed of the blue bed, capped by a thinner layer of the yellow. 

 Large globular or compound globular argillaceous concretions coated 

 with gypsum were abundant at this point. 



Along the Smoky Hill Eiver, thirty miles east of Fort Wallace, the 

 south bank descends gradually, while the north bank is bluffy. This, 

 with other indications, points to a gentle dip of the strata to the north- 

 west. The yellow bed is thin or wanting on the north bank of the 

 Smoky, and is not observable on the north fork of that river for twenty 

 miles northward or to beyond Sheridan Station on the Kansas Pacific 

 Eailroad. Two isolated hills, " The Twin Buttes, '' at the latter point, 

 are composed of the blue beds, here very shaly, to their summits. Tliis 

 is the general character of the rock along and north of the railroad be- 

 tween this point and Fort Wallace. 



South of the river the yellow strata are more distinctly developed. 

 Butte Creek Valley, fitteen to eighteen miles to the south, is margined 



