522 GEOLOGICAL SURVEY OF THE TERRITORIES. 



Feet. In. 



11. Li gilt grayish sandstone, weatbering yellowish or red- 



dish, and varying much in hardness in different por- 

 tions, irregularly bedded, (estimated) 300 



12. Thin-bedded, hard, reddish sandstone 50 



The upper members of this section , from 1 to 5 inelusi ve, were given as the 

 beds, in their order, passed through in sinking an air-shaft, and were not 

 seen in phice by either of us. From an opening made near the railroad- 

 track, which penetrated a portion of these beds, a quantity of fragments 

 of a laminated, ashy-colored sandr tone were tlirown out, which were 

 quite full of impressions of leaves. These, with similar remains from 

 beds G and 8, w'ere all the fossds we obtained, though it was reported 

 to us that shells had been found in the beds underneath the main coal- 

 seam, No. 5. Number 10 of the section is nowhere well exposed, and the 

 thickness of these beds, as well as of those immediately below, could 

 only be estimated in a very general way. Number 11 forms the high 

 bluff of fantastically-weathered sandstone, which is to be seen on the 

 side of the railroad, a little west of the station, and which forms the 

 extremity of a ridge stretching away to the north and east. This ap- 

 pears to be the eastern edge of an anticlinal valley, as in the opposite 

 ridge, a mile or two distant, the beds seemed to have a reversed dip to 

 the west or west-northwest. 



Fort Steele Our next stopping-i>lace west. of Carbon was at Fort 



Steele, where we made some examinations of the strata in the exten- 

 sive exi^osures along the Platte Eiver, on the southern side of the rail- 

 road at this point. The cliff's on the northern side were not visited, as 

 they were merely the equivalents of the beds examined, and could only- 

 present local variations. Owing to a lack of time we also did not visit 

 the interesting localities on the railroad east of the station at the fort. 



Passing up the valley of the Platte from Fort Steele, the vicinity of 

 the post for the first mile, or a little more, is occupied by rounded hil- 

 locks of whitish clays, which probablj- fiorm the lowest of the beds 

 which are exj)osed by the rift of the anticlinal at this point. Beyond 

 that distance, however, there appears a series of ridges of harder sand- 

 stone rocks abutting immediately u]:)on the left bank of the river for 

 the distance of a mile or more. The hollows, or parallel valleys between 

 the ridges, are caused by the erosion of the less resistant intermediate 

 beds of shales or clays. The whole constitutes an immense series of 

 heavy-bedded grayish-buff' and drab sandstones of various degrees of 

 hardness, alternating to some extent with ashy and dark colored shales, 

 amounting altogether to several thousand feet. The sandstones pre- 

 sented a very well marked jointed structure, perpendicular to the lami- 

 nation, the sloping faces of some of the ridges, when viewed from a little 

 distance, appearing like the edges of vertical strata. The dip of the 

 ridges along the river was nearly due south-southeast, and the angle 

 in the lowest beds about 35°, then gradually increasing to over 40 or 45 

 in the middle of the series, and again decreasing to from 15 to 20 at the 

 upper limit of our examinations. Beyond" that point, the beds appear 

 nearly or quite horizontal. A little below the middle of the series we 

 found in a bed of light-colored shale a stratum of about 4 feet in 

 thickness, almost entirely made up of imperfect specimens of an Ostrea, 

 unidentifiable as to species; the only animal remains fouhd in the whole 

 thickness of sandstones and shales. In the upper part of the series we 

 observed various seams of dark carbonaceous shale approaching lignite, 

 and at least one small seam of coal, but without associated fossils, oth'Cr 

 than indistinct vegetable remains. In the heavy sandstone-beds we 



