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Show 402 APPENDIX B.-^- GEOLOGY. The route from the Missouri westward shows a continuation of this limestone as far as the Big. Blue. m Herejt disappears, judging from* pe6iuieAs and remarks in the notes. It is soon succeeded by strata of cretaceous age, which, from the specimen? preserved, I havfe been able to recognise as extending for a considerable distance on the route between Turkey Greek and Big Sandy. ^ * ' Among the cretaceous fossils are a species of Phpladomya, and the Inoceramuty which is 60 common and abundant in numerous localities in this region. It is quite probable that these beds extend much farther^ but I find no specimens in the collection; and the notes indicate that there are heavy deposites of drift, which may have obscured the ejpopure of the formation below* This drift formation, ( judging from tfye descriptions given in the notes,) or the. debris from the immediate geological formation, appears to, haye covered the older stratified depositee, sibce no mention ft made of them till approaching the forks of Platte River 011 . the 25th June. At this point were collected some specimens of clays with small marine shells, too imperfect for determination; but from the general character, and from the occurrence of bones in tjie ' same place, it is presumed that they are of tertiary age. Above th$ forks of the Platte Bivpr similar bones and shells are noticed, and, ota the 1st of July, specimens of bones were collected. Numerous fragments of bones were; collected jm the 3d of July, tp- . pareiitry belonging to some mammalia of the herbivorous character. These bones are too imperfect for determination beyond. their general oharacter. From the description of the jnode of occurrence, and their being imbedded in a matrix of considerable hardness and tenacity, pne would be led to infer that they were of some tertiary deposite. Among these specimens is a single ramus of the lower, jaw, which apparently belonged to some carnivorous animal; but no teeth are preserved in it, nor were ai> y teeth of any kind found in * the collection. * v . . I From July 3d to llth, the notes give no evidence of any thing of special interest On the latter date, bones are men tipped as occurring in the locality examined, but no specimens having this date are preserved in the collection. It would appear that the, character of the country from near Fort Kearny to near Fort Laramie is. uniform, and that no d* |