HISTORICAL REVIEW OF THE LARAMIE PROBLEM. 



79< 



through faulty interpretation, mistaken strati- 

 graphic identification, and general looseness of 

 application, to have a somewhat varying and 

 vicarious usage. It was undoubtedly estab- 

 lished by King as a formational term, although, 

 owing to lack of definiteness in stratigraphic 

 nomenclature current then and later, it was 

 sometimes alluded to as the '"Laramie group," 

 the "Laramie series," etc. As an instance of 

 this latitude in the usage of the term, mention 

 may be made of a recent textbook of geology, 

 in which "Laramie series" is applied to all the 

 beds between the Montana and the Fort 

 Lhiion, while "Upper Laramie" and "Lower 

 Laramie" or "Laramie proper" are applied, 

 respectively, to the beds above and below the 

 unconformity first shown by Cross to exist in 

 the Denver Basin. It has been and indeed to 

 some extent still is the custom among vertebrate 

 paleontologists to employ Laramie as a group 

 term, applying it collectively to the beds con- 

 taining the well-known ceratopsian fauna, such 

 as the Arapahoe, Denver, and Lance. In the 

 Canadian provinces Laramie is used practically 

 as it was established by Dawson, Tyrrell, and 

 others, namely, as a group term including the 

 Eihnonton (lower) and Paskapoo formations. 

 The Edmonton is sometimes called ''Lower 

 Laramie," and the Paskapoo "Upper Laramie." 

 In the present work the usage established 

 in the United States Geological Survey is 

 followed. Laramie is considered as a forma- 

 tional term, and the Laramie formation is 

 defined in acconlance with the original defini- 

 tion of King, namely, as the uppermost member 

 of the conformal)le Ci-etaceous series al)0ve the 

 Fox Hills. This usage not only brings the 

 term into harmony with the original application 

 but places it in accord with most recent inter- 

 pretation and obviates the confusion and 

 looseness that must inevitably result from using 

 it as a group term. If, as has been recently 

 suggested, Laramie were to be employed as a 

 group term it would involve the anomalous 

 condition of embracing portions of tw< geologic 

 systems which are separated bj an uncon- 

 formity that is believed by many ic be one of 

 the most important in the whole Rocky 

 Mountain section. If a group term is needed 

 for the several recognized formations contain- 

 ing the Triceratops fauna, it has already been 



supplied by Cross,'* who has proposed for them 

 the term Shoshone group, wliich is " defined as 

 embracing the lacustrine, fluviatile, or ter- 

 restrial deposits, composed of detritus from 

 the rising land area of the Rocky Mountain 

 province, formed between the Laramie and 

 Fort L'nion epochs." 



IS THERE A TYPE SECTION FOR THE LARAMIE? 



In the refinement of modern geologic methods 

 it is considered essential that a type section be 

 designated when a new formational or other 

 stratigraphic unit is proposed, though it not 

 infrecjuently happens that subsequent study 

 discloses the fact that what was described as. 

 "typical" is a more or less incomplete expreS-' 

 sion of what the unit under consideration is 

 found ultimately to represent. Concerning 

 this point Ulrich '^ said: 



No local section contains within itself the data required 

 for anything approaching a final classification of its com- 

 ponent parts. This becomes possible only when exhaus- 

 tive comparisons with many other near and far sections 

 have been made. * * * The di\'isions are seldom 

 drawn with due regard to the organic and diastrophic 

 histories of the several beds. 



At the time of the early work in the Rocky 

 Mountain region, which resulted in the estab- 

 lishment of many of the stratigraphic units 

 that have since become so widely known, ap- 

 preciation was not so keen as to the necessity 

 of tying such units to a definite type section, 

 though even then the practice varied among 

 the several geologists who were prominent in 

 this field. The naming of the Laramie offers 

 a case in point. It appears that it was the 

 usual custom of King, who named and estab- 

 lished the Laramie, to designate more or less 

 definitely a type section or locality for each 

 stratigraphic unit that he established. For the 

 Laramie, however, he failed to do this specif- 

 ically, though there was not then nor is there 

 believed to be now any valid doubt as to just 

 what he had in mind. 



This state of aft'airs led Veatch ^^ some years 

 ago to make a critical historical study' of 



M Cross, Whitman, The Laramie formation and the Shoshone group: 

 Washington Acad. Sci. Proc, vol. H. pp. 27-45, 1909. 



»!■ Ulrich, E. O., Revision of the Paleozoic systems: Geol. See. America 

 Bull., vol. 22. p. 387, 1911. 



fs Veatch, A. C, On the origin and definition of the geologic term 

 "Laramie": Jour. Geology, vol. 15, pp. 526-549, 1907; abstract under 

 same title in Am. Jour. Sci., 4th scr., vol. 24, pp. 18-22, 1907. 



