CHAPTER IV. 

 THE BASIN PROVINCE. 



A. THE UPPER PENNSYLVANIAN IN THE BASIN PROVINCE. 



Though the distinction between the Permo-Carboniferous red beds of 

 the Plains and Basin Provinces is clearly marked, there is strong evidence that 

 the Pennsylvanian limestone which forms their base is continuous at least 

 across the southern end of the barrier which divided them. (Fig. 4.) There 

 has been a very general consensus of opinion that the Hueco limestone of 

 the Guadalupe Mountains is equivalent to the Kaibab of the Grand Canyon 

 region and connects through that limestone with a series of deposits which 

 extend through the basin province as far north as Alaska and that the fauna 

 of the whole horizon places it as equivalent to the Russian Gschelian; but 

 for a recent expression of a different opinion see the summary of a paper by 

 Schuchert on page 152. Girty says:^ 



"The Hueconian fauna is widely distributed over the West, ranging indeed 

 into Alaska, while it is even recognizable in Asia and eastern Europe. Most of 

 the occurrences of Carboniferous in the West can be referred to this series, 

 although some of them present more or less distinctive facies. The more im- 

 portant of the facies provisionally referred to the Hueconian are these: that of 

 the Aubrey group of Arizona, rather widely distributed; that of the phosphate 

 beds of the Preuss formation [Park City formation], local in Utah, Idaho, and 

 Wyoming; the Spiriferina pulchra fauna with a considerable distribution in 

 Idaho, Wyoming, Utah, and Arizona; the fauna of the McCloud limestone of 

 California probably extending into Nevada; and that of the Nosoni formation 

 of California (in part of the 'McCloud shale'), apparendy recognizable to the 

 eastward and to the North and West, even into Alaska." A little further on in 

 the same paper Girty says that 'The Gschelian is clearly related to our Hue- 

 conian.'" 



Further remarks by Girty in the same paper^ make it apparent that he 

 is far from assuming a definite position with regard to the equivalency of 

 the Russian and American beds: 



"I am tentatively assuming, on the grounds noted above, that the Guada- 

 lupian is equivalent to the Permian or to the Permian and Artinskian, the one 

 representing a normal marine and the other an abnormal facies. It may prove, 

 however, that all or part of the Guadalupian is younger than the Permian. * * * 

 In view of the striking difference between the faunas of the Guadalupian and the 



' Girty, Geo. H., Outlines of Geologic History, p. 130, 1910. 

 ''■ hoc. cit., p. 133. 

 9 113 



