FICKETT SERIES 243 



Age. — On the basis of Lower Carboniferous fossils found in the stream 

 gravels, and the lithologic resemblance of the fossil-bearing gravels to 

 the rocks contained in the series, and the relation of the series to the 

 limestone formation, which seems to be Devonian and to underlie it, the 

 Fickett series is provisionally assigned to Lower Carboniferous ; but as 

 the fossils are believed to occur near the base of the series, it probably 

 contains also rocks younger than the Lower Carboniferous. 



' The following are the principal forms collected by the writer and 

 identified by Mr Schuchert : 



Lithostrolion. Pinnatopora. 



Cystodidya nearest to C. lineata. Produdus scabriculvs Martin. 



Slreblotrypa near nicklesl Vine. Productus semireticulatus Martin. 



Rhombopora. Spirifer striatus Martin. 



Fenestel/a. Spirifer near S. neglectus Hall. 



Fenestella near F. cettricevsis Ulrich Spiriferina cristata Schlotheim 



Mr Schuchert states that — 



"The above localities represent one formation, in the upper portion of the 

 Lower Carboniferous. This fauna, however, is unlike that of the Mississippi val- 

 \ey, in that it does not have such characterizing fossils as the screw-like bryozoan 

 Archimedes and the blastoid genus Pentremites. 



"The only other Alaskan region with which this Arctic Lower Carboniferous 

 fauna can be compared is that found on Kuiu island, in southeastern Alaska." 



CORRELATION OF PALEOZOIC 



As lack of space forbids the correlation of each individual formation 

 or series, especially of those of the Paleozoics, with similar formations of 

 the same age in other parts of Alaska or the Arctic regions, it may here 

 be briefly stated that the present season's work, together with the evi- 

 dence previously collected to the eastward and that to the westward in 

 the Cape Lisburne region, seems to indicate beyond question the exten- 

 sion of a well developed belt of Paleozoic formations across northern 

 Alaska, along the Rocky mountains, from the 35th meridian near the 

 Mackenzie to the 66th meridian at cape Lisburne, a distance of nearly 

 1,000 miles. In the Cape Lisburne region, as noted, these rocks, having 

 a known width of 75 or more miles, terminate in abrupt sea cliffs. The 

 thickness of the section here is not known, but it must be considerable, 

 from which it seems safe to infer that as a submarine geologic axis the 

 Paleozoics probably extend far seaward, and, as this part of the ocean is 

 known in the main to be shallow, it is not unlikely that the same Paleo- 

 zoic axis may continue across and reappear to the westward on the 

 Siberian coast. It may be noted, however, that on the portions of this 



