THE BASIN PROVINCE 163 



quartzite, whose fauna is almost unknown, seems to show considerable modifica- 

 tion in the Idaho sections. 



"In notable contrast to the Weber formation, the beds above the Park City 

 formation show striking persistence in their main lithologic and paleontologic 

 characters. These are the 'Permo-Carboniferous' beds of the King Survey and 

 were divided by Boutwell in the Park City district into the Woodside, Thaynes, 

 and Ankareh formations. It seems all but certain that the ' Permian ' of Walcott's 

 section in Kanab Canyon, in southern Utah; the 'Permo-Carboniferous' of the 

 Wasatch Mountains, in northern Utah; and, in part, the 'lower Triassic' of 

 southeastern Idaho are one and the same seiies. The Woodside, Thaynes, and 

 Ankareh do not, perhaps, maintain precise boundaries throughout all this terri- 

 tory, and in Idaho the first occurrence of Triassic ammonites (Meekoceras beds) 

 is conventionally taken as the base of the Thaynes. * * *" 



"The Triassic age of at least the major portion of the ' Permo-Carboniferous' 

 (Thaynes and Ankareh) seems to be shown by fairly satisfactory evidence — the 

 presence of an extensive ammonite fauna of Triassic type and the practical 

 absence of any distinctive Carboniferous forms. In advance of a detailed study 

 of these faunas, however, it may be pointed out that above the Meekoceras beds 

 there are zones which contain great numbers of Rhynchonella closely related to the 

 Carboniferous Pugnax Utah and many specimens of apparently true Myalina, 

 not unlike Carboniferous species. 



"It is much less certain that the Woodside formation is not Paleozoic (Per- 

 mian?). A preliminary study of the fauna of the Woodside shows that, except 

 that it has yielded no ammonitic forms, it does not differ materially from the 

 fauna of the Thaynes and presents a strong contrast to the Carboniferous fauria 

 of the Park City. Lithologically also there is a well-marked division between 

 the Woodside and the Park City formation, and no lithologic boundary can be 

 traced between the Woodside and the Thaynes. That the Woodside, Thaynes, 

 and Ankareh form a natural group is indicated by the classification of these rocks 

 adopted by most geologists. If the Thaynes is Mesozoic, the obvious line between 

 the Mesozoic and the Paleozoic would seem to be the line between the Park City 

 and the Woodside. If, then, as may be tentatively concluded, the Woodside 

 does not represent the Permian, the natural question to follow is. Does not the 

 Park City formation belong in the Permian? A decisive judgment on this point 

 should wait upon a careful study of the faunas obtained from other members of 

 the Park City beds, as well as upon a study of other related faunas less certainly 

 appearing at the same horizon. Because of the close relationship or identity of 

 many species of these faunas with the Gschelian fauna of Russia, I am pro- 

 visionally holding that the Park City formation is older than the Permian. 



"Anyone at all familiar with the Carboniferous faunas of the Mississippi 

 Valley will at once recognize the fact that the forms found in the phosphate beds, 

 individually as well as collectively, are quite different from any others found in 

 that area. In fact, but few of the phosphate species have closely related forms 

 in the Pennsylvanian, and a correlation by paleontology with any definite portion 

 of the Pennsylvanian section is at present impossible. Even among western 

 faunas this has an extremely individual and novel facies, one which is known to 

 me as occurring only in a well-defined area. * * * 



"Though the phosphate fauna possesses a remarkable individuality of facies, 

 it is not altogether out of relationship with other formational faunas, for with 

 the aid of the fossils from the associated rocks it can be recognized as belonging 



