pealkJ GEOLOGY FORT UNION OR GREAT LIGNITIC GROUP. 141 



Fort Union or Great Lignite group. 



Localty. 



At Fort Union, Fort 

 Clark, and under 

 the White River 

 beds, on the North 

 Fork of the Platte 

 Kiver, above Fort 

 Laramie, and west 

 of Wind Kiver 

 Mountains. 



Upper Missouri re- 

 gion. 



Extension into Brit- 

 ish America. 



Porcupine Creek, 

 Missouri Coteau, 

 West Souris. Kiver, 

 and other parts of 

 British America. 



Milk Kiver 



Tongue River 



Eastern base of Black 

 Hills. 



Grand River, Ne- 

 braska, (now Da- 

 kota. ) 



Lignite of Long 

 Lake, Nebraska , 

 (now Dakota.) 



Lignite of Big Horn 

 Mountains, and at 

 mouth of Big Horn 

 Kiver. 



Beds beneath White 

 River beds, south 

 of Fort Fetterman. 



North Platto Kiver 

 and La Prele Creek. 



Description of strata. 



Beds of clay and 

 sand, with round 

 ferruginous con- 

 cretions and nu- 

 merous beds and 

 seams and local 

 deposits of lignite. 



Age. 



Eocene Tertiary . . 









den. 



Miocene Tertiary. 

 Lower Tertiary. .. 

 Lower Tertiary... 



...do 



....do 



Hay den 











Tertiary 



Hay den 









Newberry 



Hayden 



Tertiary 











Lower Eocene 



Lesquereux. .. 



Eocene .... 



G. M. Dawson. 



Cretaceous 



J.J.Stevenson 



Eocene 



Lower Eocene . .. 

 Lignitic Tertiary 



.do 

 .do 



Cretaceous. 



...do 



...do 



Lignite (Tertiary) 



Eocene. 



Authority. 



Hayden. 



G. M. Dawson 



...do... 

 Hayden. 



.do 

 .do 



Cope. 



.do 



.do 



Hayden . 



.do 



Reference. 



Exploration of Yel- 

 lowstone and Mis- 

 souri Rivers, under 

 Capt, W. F. Ray- 

 nolds, 1859-'60 ; 

 Geol. Report of F. 

 V. Hayden, p. -29. 



Proceedings Acad. 

 Nat. Sci., Philadel- 

 phia, 1856, p. 63. 



Do., p. 225. 



Do., p. 113. 



Transactions Amer. 

 Philosophical Soc, 

 1860. 



Do. 



Exploration of Smoky 

 Hill Railroad route, 

 1868, p. 65. 



American Journal of 

 Sciences and Arts, 

 1868, p. 204. 



Transactions Ameri- 

 can Philosophical 

 Soc, 1869. 



Annals Lyceum Nat- 

 History of city of 

 New York, vol. ix, 

 1868. 



ReportU.S. Geol. Sur- 

 vey of Ter., 1867- 

 '68-'69, p. 57. 



ReportU.S. Geol. Sur- 

 vey of Ter., 1*70, 

 pp. 95, 96. 



Report United States 

 Geol. Survey, 1873, 

 p. 433. 



Report U. S. Geol. 

 Survey, 1872, pp. 

 410-417. 



Canadian Naturalist, 

 vol. vii, April, 1874, 

 p. 252. 



"TheGeological Rela- 

 tions of the Lignitic 

 Groups," read be- 

 fore the American 

 Philosop. Soc , June 

 18, 1875. 



Report of British 

 American Boundary 

 Survey of Forty- 

 ninth Parallel, pp. 

 6, 8, 18, 19, 86, 93, 97, 

 103, 152. 



Do., p. 186. 



ReportU.S Geol. Sur- 

 vey of Ter., 1867- 

 '68-'69, p. 72. 



Do., p. 73. 



Do., p. 73. 



Report U.S. Geol. Sur- 

 vey of Ter., 1873, 

 p. 446. 



Do., pp. 453-4. 



Do., pp. 453-'4. 



Report U.S. Geol. Sur- 

 vey of Ter., 1870, 

 p. 10. 



Do., p. 22. 



