GEOLOGICAL REPORT. 



lately — fossil turtles and the bones of various mammals. Traveling in forced u 

 we were unluckily prevented from collecting much. 801110 of the hones we 

 mitted to the eminent osteologist, Prof. Joseph Leidy, of Philadelphia, who 

 volunteered in examining them. He recognizes them as belonging to DeimsHi 

 a large carnivorous animal related to the weasel, and to some ruminant pad 

 perhaps Oreodon, which both, like the turtles, occur also in the Miocene forma 

 the bad lands of White River. The lithological character of these strata seen 

 wise, to be similar, and indications are strong that both formations arc ot the sa 

 and have perhaps been deposited in the same basin. 



In the banks of a ravine, in the lowest strata of the above section, the bo 

 huge animal have been found. A Mr. AV. "\V. Wright, of Minnesota, diseoveiv 

 and brought to Fort Laramie two leg bones, nearly complete, each over 3< 



some excavations to be made at the same spot, and we obtained a large shoulde 

 some vertebra?, ribs, fragments of the ivory of a large task, &C. Infortiina 

 bones are in a friable condition, or else probably a large portion ot the skelete 

 have been secured. Although their state ot preservation ditlers trom that ot the 

 of the smaller animals, which are siliciried, the former are apparently ot the sa 

 or rather slightly older. 



The fossiliferous strata are among the lowest of this series. The next < 

 which I observed on the river present a different character. 



If we compare again the above-mentioned section of Dr. Ilayden with tin 

 tion which we have just described, we find that, j 1 " 

 still they show a marked resemblance. The strata 

 correspond to his turtle and Oreodon beds, B; the next higher one to his C, with the 

 difference, that we find the calcareous matter more concentrated in a few beds; and D 

 is represented by the upper portion of the Chimney Rock section. Dr. Ilayden esti- 

 mated the thickness of B, C, and D at 480 to 580 feet. On Platte River the thickness 

 of this formation is much greater, but then we may have there his bed E, which is 

 between 180 and 200 feet thick, replaced by more finely-grained deposits. It that is 

 not the case, then F must be wanting on the Platte, while farther southwest, on Pole 

 Creek, it is again considerably developed. Dr. Ilayden's extensive collections have 

 led to the conclusion that all these beds are probably of Miocene-Tertiary age, and the 

 stratigraphical evidence, which alone I can adduce, does not conflict with this opinion. 



FROM ABOVE SCOTT S BUFFS TO FORT LARAMIE. 



Above Scott's Bluffs still lower strata gradually rise to the surface. They present 

 a decidedly different appearance, but were only seen 111 scattered outcrops, niostly ot 

 no great extent. They are made up of a series of variegated, green, gray, butt, whitish, 

 and reddish argillaceous and i 

 few limestones; and their age 1 

 probably the same formation ^ 

 above Fort Laramie, and may 

 den's section, which he provis 



^ I'.In 



m bed, No. A of Dr. Ha 



Future investigation c 



