42 C. Schuchert — Russian Carboniferous and Permian. 



" Tlie stratigraphic divisions represent the four or five great 

 natural groups into which the Permian system of the Salt- 

 Range is readily divisible, on the basis of the paleontological, 

 lithological, and genetic characteristics." 



" Naturally of greatest importance are the two groups of the 

 upper marine division — the Ceratite beds and the Productus- 

 limestone — for if the age of either of them can be satisfacto- 

 rily determined, it follows that the age of the other is also fixed. 

 In a general way, the age of these two groups is already estab- 

 lished : The Productus-limestone, with its very remarkable 

 abundance of Paleozoic Brachiopoda, must belong in the Paleo- 

 zoic, while, the Ceratite beds having the Ammonites char- 

 acterized by Ceratite suture lines must be referred to the Tri- 

 assic. However, the Productus-limestone was regarded as 

 Carboniferous until the detailed description of the fauna by 

 Waagen taught that this view must be decidedly modified. 

 On my first trip to the Salt Range I noticed the gradual tran- 

 sition from the Productus-limestone into the Ceratite beds at 

 Chideru ; later I was able to extend this observation through 

 the profile in the Chuas ravine, near Yirgal ; here can be 

 plainly seen the individual lithologic members of the Produc- 

 tus-limestone and the Ceratite beds in most intimate succes- 

 sion. . . . Because of the indisputable succession at these two 

 places I argued as follows : Such an intimate connection of 

 Paleozoic and Triassic can only exist near the dividing line 

 between the Permian and Triassic ; if the Ceratite beds belong 

 in the Triassic, then the underlying Productus-limestone must 

 fall into the Permian, and accordingly, on account of" the indi- 

 viduality of its fauna, it must represent but a single division 

 of the Permian, but can not at the same time be the equiva- 

 lent of both the Zechstein and the Rothliegendes." 



The author then makes comparisons with other Indian Tri- 

 assic regions, and also discusses the possibility that the Pro- 

 ductus-limestone may be Upper Carboniferous. He concludes 

 that if the Ceratite beds of the Salt Range are not Triassic, 

 then the entire lower Trias is absent in the Himalaya. He 

 maintains that the possibility of the Triassic being transgres- 

 sive upon the Upper Carboniferous is excluded, because the 

 transgression would then fall in the middle of an undisturbed 

 sequence, i. e., in the Upper Productus-limestone. Further, 

 if these deductions are not correct, then no reliance can be 

 placed on the development of the suture lines of ammonites 

 for the determination of geologic age (see below for his con- 

 clusions resulting from his studies on Medlicottia). 



Noetling holds that there was a faunal transgression from 

 the Urals,' but that the time of its spreading was at about the 

 middle of the Permian. " While this fauna was expanding 

 radially, one can readily believe that the peripheral parts of 



