CARBONIFEROUS UNDIVIDED. 387 



Yellowstone National Park, was kindly supplied by Mr. Arnold Hague, geologist in charge of 

 the Yellowstone National Park survey: 



Quadrant quartzite. 



Madison limestone. Feet. 



32. FoTir strata of light-gray, more or less cherty limestone 655 



31. Gray banded limestone, with abundant fossils 400 



30. Massive light-gray limestone 65 



29. Light-gray and brown, very finely crystalline or granular limestone 85 



28. Limestone, crystalline, light gray, and generally massive 200 



27. Limestone, dark gray and buff, very argillaceous, thick and thin bedded 50 



26. 15 feet of quite pure and 60 feet of thin-bedded argillaceous limestone, both containing 



fossils 75 



25. Coarsely crystalline dark-gray limestone 80 



24. Limestone, finely crystalline and massive below, cherty in its upper portion 60 



Three Forks limestone. 



1,670 



All the evidence available seems to indicate that the Madison limestone is faunally a unit 

 and can not be subdivided on the basis of its contained fossils. 



Having given a table showing the range of species in the Madison limestone 

 and having discussed certain diagnostic species, Girty ^'^* concludes : 



(1) The fauna of the Madison limestone can be referred wholly and without question to 

 Carboniferous time; (2) it has a marked Kinderhook facies; (3) it is essentially the same 

 fauna as that described by White, by Hall and Whitfield, and by Meek, and by them referred 

 to the Kinderhook or Waverly; (4) the fauna is not separable into independent units but must 

 be regarded as a whole. 



These views regarding the position of the Madison were reaffirmed by Girty ^'^^^ 

 in 1905: 



The fauna of the Madison limestone, which has so wide a distribution in the West, is 

 * * * closely related to the typical Mississippian faunas. Ip my earlier work I correlated 

 the Madison limestone with the Kinderhook, Burlington, and Keokuk groups of the Mississippi 

 Valley and have seen no reason since to change my views. Nevertheless, it seems to be almost 

 unquestionable that in some areas these western faunas, in their later developments, take on 

 the aspect characteristic of the St. Louis epoch. Nowhere in the West, however, have any 

 Kaskaskia faunas been discovered. One of three hypotheses seems necessary to explain this 

 fact, which is no less striking, even should local areas of Kaskaskia rocks subsequently be dis- 

 covered. Either no strata equivalent to the Kaskaskia have ever been deposited in this region; 

 or, though deposited, they have since been removed; or else contemporaneously formed sedi- 

 ments supported a fauna which was so unlike the Kaskaskia that its equivalence has failed of 

 recognition. Of these three hypotheses it is probable that the second is the correct one. Unmis- 

 takable evidence of unconformity between the Madison limestone (and its correlates^ and the 

 overlying beds has been found in so many points in the West that a period of erosion previous 

 to the Pennsylvanian sediments can be hypothetized for all this western country, a generaliza- 

 tion which is all the more safe from the widespread evidence of a similar occurrence in the 

 central and eastern United States, and indeed in other parts of the world. 



Girty " states that we now have reason to beUeve that the Quadrant, from which 

 no fossils were known when the foregoing was written and which was generally 

 supposed to be equivalent to the Weber quartzite (Pennsylvanian), maybe in part 

 of upper Mississippian or Kaskaskian age in some areas. 



"• Comment on manuscript. 



