528 E. M. Kindle— Section at Cape Thompson, Alaska. 



zon in question at Cape Thompson is above all the Carboniferous 

 faunas and offers no stratigraphic difficulties in its reference to 

 the Triassic." 



The fossils in Collier's collection alluded to above as having 

 been included in the Carboniferous fauna appear in the lists 

 published by him as faunnles composed exclusively of lamelli- 

 branchs and with one exception showing no associated species 

 which would point definitely to their Carboniferous age. This 

 exception is the faunule of station 4 A C 16,* and it includes 

 in addition to Aviculopecten f sp., Productella sp., Peticularia 

 sp., Proetus sp., etc. Examination of these fossils shows that 

 the Aviculopecten of this faunule is an entirely different shell 

 from the " Aviculopectens " of the other faunules, which con- 

 tain only " Aviculopectens" It does not, therefore, . connect 

 the faunules composed almost exclusively of the latter with an 

 undoubted Carboniferous fauna, as Messrs. Collier and Wash- 

 burne, who collected the fossils, supposed it did. With refer- 

 ence to the stratigraphic evidence of the superposition of Car- 

 boniferous limestone above the beds containing " Aviculopec- 

 ten " {P seudomonotis subcircularis) in the Cape Lisbnrne 

 region, it may be remarked that the region is one in which 

 faulting is a common and characteristic feature, and one, 

 therefore, in which present superposition might not represent 

 the original relations of the beds. 



The beds containing P seudomonotis subcircularis at Cape 

 Thompson and the 500 feet or more of soft shales above them 

 lie nearly horizontal for about half a mile to the south of the 

 anticlinal arch known as Agate Rock. The belt of territory 

 underlaid by these softer horizontal beds is a valley region 

 broken up by ravines and bordered on each side by an elevated 

 limestone ridge and moderate-sized hills. If the shales were 

 followed by any thick limestone formation, its presence should 

 be manifested in the topography, but there is no such evidence 

 of any limestone series above the flat-lying shales. The soft, 

 black shale comprising the highest subdivision of this section 

 contained no fossils where examined by the writer, and we 

 are without definite evidence as to whether it should be 

 assigned to the Triassic or Jurassic. The resemblance of the 

 carbonaceous shales comprising it to portions of the Corwin 

 formation as described by Collierf near Cape Lisbnrne suggests 

 its provisional correlation with that formation. 



* Bull. U. S. Geol. Survey, No. 278, p. 23, 1906. 



\ Collier, A. J. , Geology and Coal Resources of the Cape Lisburne Kegion, 

 Alaska, Bull. U. S. Geol. Survey, No. 278, pp. 27-28, 1906. 



