68 



LARAMIE FLORA OF THE DENVER BASIN. 



In 1906 A. K. Schultz ^» continued the fiold 

 work directly north of the area covered by 

 V'oatch in the report just considered, but his 

 report was not pubhshed until 1914. When 

 the field study was made the area covered by 

 Schultz was in the northern part of Uinta 

 County, but subsequently (1912) this area was 

 included in Lincoln County. In the main the 

 geolojijic formations present in the southern 

 area were carried northward into Lincoln 

 County, though with some notable changes in 

 the thickness of the beds. The Adaville forma- 

 tion showed a decrease in thickness from a 

 maximum of 4,000 to 2,800 feet, and the 

 Evanston an increase from 1,600 to over 

 9,500 feet. Both these formations were de- 

 scribed in much the same terms as were used 

 by N'eatch; in fact, full quotations were made 

 from his report. No stratigraphic or paleon- 

 tologic evidence was procured or recorded con- 

 cerning them that would tend to change their 

 age assignments as recorded by Veatch, yet in 

 the stratigraphic column given on page 29 of 

 Schultz's report striking modifications ap- 

 peared. Thus the Adaville was placed entirely 

 in the Montana, and the designation "Lower 

 Laramie" had disappeared, while the Evanston, 

 before called "l^pper Laramie" and made the 

 basal member of the Eocene, was here placed 

 under the designation "Cretaceous or Ter- 

 tiary," and the Almy formation became the 

 lowest accepted Eocene. 



COALVILLE, UTAH, AND VICINITY. 



The geology in the vicinity of Coalville, 

 Utah, is somewhat complicated, and extensive 

 diff'erences of opinion on it have prevailed 

 among geologists. The following brief his- 

 torical account of it is given by T. W. Stanton:" 



The coal-bearing Cretaceous beds exposed at Coahille, 

 Utah, and on Bear River, near the mouth of Sulphur 

 Creek, Wyo., have been the subject of considerable dis- 

 cussion, and various opinions concerning their precise age 

 have been piiblished by several geologists and paleontolo- 

 gists who have visited the localities or examined collec- 

 tions from them. They were referred to the Cretaceous 

 by Messrs. Meek and Engehnann in 1S60 and were com- 

 pared with certain Cretaceous beds at the mouth of Judith 

 River, then regarded as belonging to No. 1 (Dakota) but 

 afterward proved to lie of Fox Hills age. When Capt. 



*" Schultr, A. R., Geolopy and geography of a portion of Lincoln 

 County, Wyo.; U. S. Gcol. .Survey Bull. .MS, 1914. 



*• The Colorado formation and its invertebrate fauna: U. S. Geol. 

 Survey Bull. 106, pp. 37, 38, 1893 118941. 



Simpson's report was published in 1876 Mr. Engelmann 

 again expressed the opinion that these beds are probably 

 "Lower Cretaceous'' [Dakota]. 



They were at first regarded as Tertiary by Messrs. Hay- 

 den and liBsquereux. In 1870 Messrs. Meek and Hayden 

 adopted the view that the Coalville beds are Cretaceous 

 but that they "occupy a higher horizon in the Cretaceous 

 than even the Fox Hills beds of the Upper Missouri Creta- 

 ceous series." 



Mr. Meek visited Coalville in 1872, and after making 

 larger collections and studj-ing the stratigraphy he decided 

 that the entire upper Missouri Cretaceous section, with 

 perhaps some older beds, is represented here. The 

 detailed section that he published shows correctly the 

 essential features of the stratigraphy. The opinions that 

 he then expressed concerning the correlation of these lieds 

 were repeated in subsequent publications. 



Messrs. King and Emmons assigned the Cretaceous 

 strata at Coalville to the Colorado, Fox Hills, and Laramie 

 formations and so mapped them in the atlas accompanying 

 their report. The principal (lower) coal bed is included 

 in the Colorado formation and the upper one in the Fox 

 Hills, the line Ijetween these two formations being drawn 

 in the second ridge above the lower coal bed. Jt should 

 l)e remembered that the Colorado formation was then made 

 to include the P'ort Pierre division. 



Dr. C. A. Wliite studied the section in 1877, and after 

 discussing the fossils collected in it, he states that it is 

 impracticable to refer the strata to any one or more of the 

 established Cretaceous groups with certainty, but he 

 thinks there is no reason to doubt that the greater part of 

 the series at least is referable to the Fox Hills. 



Stanton presented a detailed section, which 

 shows the presence of about 6,000 feet of strata 

 below the recognized Tertiary. Of this column 

 about 1,700 feet was assigned to the Colorado, 

 about 2,800 feet tentatively to the Montana, 

 and approximately 1,500 feet of unfossiliferous 

 strata were said to include the Laramie if it is 

 present. 



None of the investigators prior to Stanton 

 had noticed the presence of plants, but he found 

 a fairly rich deposit nearly 1,000 feet above the 

 base of the Montana, overlain by fully 1,800 

 feet of richly fossiliferous marine Cretaceous, 

 representing the upper portion of the Montana. 



These plants were studied by me, and a brief 

 report on them is printed on page 42 of Stanton's 

 bulletin. In this report it was stated that the 

 most important of the species "belong clearly 

 to the Laramie group," but it should be re- 

 membered that this statement was in accord 

 with the current conception of the Laramie 

 when the flora from Point of Rocks was re- 

 garded as typical. The subject was reviewed 

 and the plants from Coalville properly re- 



