CHAPTER I. 



BRIEF HISTORY OF THE LIGNITIC GROUP ; FIRST STUDIED ON THE UPPER MISSOURI — 

 EARLY VIEWS ENTERTAINED BY MEEK, NEWBERRY, AND OTHER PALEONTOLO- 

 GISTS ON THE AGE OF THIS GROUP — THE LIGNITIC GROUP OF THE NORTHWEST 

 BELIEVED TO BE CONTINUOUS SOUTHWARD WITH THE COLORADO AND LARAMIE 

 BEDS. 



In this chapter, I desire to note, as briefly as possible, the progress of 

 the development of the Lignitic group of the Western Territories; and 

 in doing so I need not go back farther in the past than the commence- 

 ment of my own explorations on the Upper Missouri in 1854. Prior to 

 that time, the observations that had been made by various travelers in 

 regard to the existence of coal-beds in different parts of the West were 

 of so indefinite a character that they cannot be used as evidence, though 

 they may form a part of the early history of discovery. 



I have frequently stated in my former reports that I regarded this 

 group as, in many respects, the most important one in the West; that, 

 in its relations to the well defined Cretaceous group below it, it had a 

 more important bearing on the physical history of the growth of the 

 western portion of our continent than any other in the geological scale. 

 Although this formation has been studied with great zeal by several 

 parties within a few years, and most important additions to geology 

 have resulted therefrom, there is evidently much more work to be done 

 before all the problems will be solved with sufficient clearness for our 

 entire satisfaction. That the evidence is very conflicting is shown by 

 the wide differences of opinion that are entertained in regard to its age 

 by geologists and paleontologists whose views have great weight in the 

 scientific world. 



The assistant geologists connected with the survey under my charge 

 have been continually instructed to gather all the materials possible 

 bearing on the age of this group, while Messrs. Meek, Lesquereux, and 

 Cope have been urged to study the subject from their own peculiar 

 standpoints, regardless of unity of results. Many extremely valuable 

 and instructive memoirs have already appeared in the reports of the 

 Survey touching upon this group, and several more are in process of 

 preparation or publication. 



One fruitful source of difference of opinion has been in the misunder- 

 standing in regard to the different horizons of the coal-strata of the West. 

 That there are important coal-beds in rocks of well-defined Cretaceous 

 age cannot be disputed, and I have long since yielded that point. What 

 we wish to show more clearly is that there exists in the West a distinct 

 series of strata which we have called the Lignitic group, and that it is 

 entirely separate, paleontologically and geologically, from a great group 

 of strata in the Lower Cretaceous, and perhaps extending down into the 

 Jurassic, which contains a great number of thick and valuable beds of* 

 coal. It is not necessary to discuss the question whether the term 

 Lignitic shall be applied to the coal of either or both groups. I have 

 used the term Lignitic for the upper group without reference to the 



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