HISTORICAL REVIEW OF THE LARAMIE PROBLEM. 



49 



Mountains has proved to be of much geologic 

 interest. A number of short reports and news- 

 paper and magazine articles regarding this 

 area had appeared prior to 1871, but they 

 were devoted mainly to descriptions of scenic 

 features and contained little or no geologic 

 information. In 1871 F. V. Hayden *' began 

 his investigations in the Yellowstone National 

 Park and incidentally described the geology 

 of the area between Fort Ellis and what is 

 now the north line of the park. He noted the 

 presence of both Cretaceous and Tertiary 

 rocks in the area. In the same report '° 

 Lesquereux described the fossil plants obtained 

 by the Hayden parties, referring those found 

 6 miles above Spring Canyon; on High Ridge, 

 about 10 miles west of Hot Springs; and at 

 Yellowstone Ijake, among basaltic rocks, to 

 the Eocene, while those from the mouth of 

 Spring Canyon were not definitely placed. 



In the following year the exploration of 

 the Yellowstone National Park was continued 

 by the Hayden Survey, and A. C. Peale '' 

 reported on the geology of the area between 

 Fort Ellis and the Yellowstone Valley and 

 thence up the Yellowstone to the park. He 

 also noted the presence of Cretaceous and 

 Eocene, the latter on the basis ot the deter- 

 minations of the fossil plants by Lesquereux. 



In 1878 liBsquereux" published his "Ter- 

 tiary flora." in which he brought together all 

 the species of plants — 329 in number — which 

 he then considered as belonging to the flora of 

 the "Lignitic." The beds at the localities 

 near Fort Ellis, above Spring Canyon, and at 

 Yellowstone Lake he referred to his so-called 

 "first group," which he considered as of 

 Eocene age. The species from the locality at 

 the mouth of Spring Canyon were not alluded 

 to, as they were, at least by inference, con- 

 sidered as Cretaceous. 



In 1886 the final report of the Tenth Census 

 of the United States relating to the mineral 

 resources, exclusive of the precious metals, was 

 published imder the general direction of 

 Raphael Pumpelly. It embraced reports by 

 Waldemar Lindgren" and George H. Eldn 



«9 U. S. Geol. Survey Terr. Fifth Ann. Rept., for 1871, pp. 1-165, 1872. 

 '» Idem, pp. 296-300. 



n U. S. Geol. Survey Terr. Sixth Ann. Rept., for 1872, pp. 108 et seq., 

 1873. 

 n Lesquereux, Leo, U. S. Geol. Survey Terr. Rept., vol. 7, 1878. 

 IS U. S. Tenth Census, vol. 15, pp. 743-746, 1SS6. 



ridge ''* on the geology and coal resources of 

 Montana, and each contained data bearing 

 more or less directly on the present problem. 

 Lindgren reported especially upon the section 

 from the Bull Mountains to Musselshell River 

 and referred the immense thickness of nearly 

 10,000 feet of beds above the Fox Hills to the 

 Laramie, which ho divided into a "Lower 

 Laramie" and an "Upper Laramie," the latter 

 being recognized as the Fort Union. 



The so-called Bozeman coal field was de- 

 scribed by Eldridge. He presented a section 

 of the rocks (LVI, fig. 2) through this field, 

 beginning with the Jurassic and including the 

 Dakota, Benton, and Niobrara and of course 

 the coal-bearing rocks. The coal-bearing rocks 

 were not definitely referred to the Laramie, 

 though they were obviously considered as be- 

 longing in it. As regards the stratigraphic rela- 

 tions of the coal measures. Eldridge wi'ote as 

 follows : 



There is another most important peculiarity in the be- 

 havior of the principal coal seams, noticed in the eastern 

 portion of the field. The surface of the ground on which 

 the coal bed was originally laid down is most irregular. 

 For a length of 2 miles at least, and for an undeteianined 

 width, but presumably covering quite an area altogether, 

 the surface was covered by gentle undulations in the form 

 of knolls, of varjdng and irregular dimensions, oftentimes 

 .extensive, oftentimes a few feet only either way, with no 

 definite arrangement of the axes. In the hollows of these, 

 overlapping some and only coming up on the sides of others, 

 the material subsequently to be converted into coal was 

 laid down, and finally came the roof of sandstone, capping 

 the whole. These irregularities have furthermore been 

 increased by disturbances in certain parts, which have 

 caused both rock and coal to be slickensided and rendered 

 it extremely friable. 



In the same year (1886) Lester F. Ward " 

 briefly alluded to the plants from the Hayden 

 locality known as "6 miles above Spring 

 Canyon, neaT Fort Ellis, Mont.," and from 

 several places in the Yellowstone Park. He 

 said: 



These plants are all classed by Mr. Lesquereux in his 

 fii'st or lowest group as true Laramie, but upon careful 

 investigation I am tolerably well satisfied that they belong 

 to the Fort LTnion deposits. 



In 1891 Walter H. Weed '" published a short 

 paper on "The Cinnabar and Bozeman coal 

 fields of Mont.ana," in which he described in 



"Idem, pp. 739-743. 



15 Synopsis of the flora of the Laramie group: U. S. Geol. Survey Sixth 

 Ann. Kept., p. 741, 1886. 



16 Geol. Soc. .\merica Bull., vol. 2, pp. 319-364, 1891. 



