EXPLORATION IN ALASKA IN I907 — GILMORE II 



posed mostly of fine light-colored, unstratified silts. Some sixty feet 

 down from the top is a layer of coarse gravel conformable with the 

 silt, which may represent the Palisade conglomerate of Spurr. 1 



This terrace at irregular intervals has been dissected somewhat by 

 the drainage from above (see pi. in) . In many places along the 

 cut banks of the stream the silt was underlaid by a stratum of rather 

 fine reddish-colored gravel. A section of these flood-plain deposits, 

 when no complications occur, presents the following divisions in 

 their natural order and approximate thickness : 



Layer of peat 18 inches to 2 feet 



Layer of fine silt ' 8 feet to 10 feet 



Fine reddish gravel 4 feet to — 



DalF noted the occurrence of a similar fine reddish gravel in the 

 deposits of Eschscholtz Bay. 



A few scattered bones were collected on the bars below the depos- 

 its of elevated silts just described, but although continued search 

 was made for two days upstream from this point, no fossils were 

 found. Even though no indication of vertebrate remains were seen 

 in the silts, the writer is inclined to the opinion that the few frag- 

 mentary specimens picked up on the bars below may have been 

 washed out of these bluffs and carried downstream by the river dur- 

 ing a flood stage. This idea is strengthened somewhat from the 

 fact that no mammal remains were found in the lower cut banks or 

 alluvial deposits of either this stream or the Nowitna, although 

 persistent and continued search was made, and from our own 

 experience and that of others we do know they occur in the elevated 

 lacustral phase of the silts. 



The absence of fossil evidence on the last two days of our ascent 

 and the fact that little had been found previously showed that this 

 stream did not cut an extensive deposit of Pleistocene mammal 

 remains, and it appeared to be a waste of time to continue our 

 search : so we returned by the same route we had ascended, reaching 

 the Yukon on July 30. 



A short distance above Louden we met Air. R. A. Motschman, 

 who. being thoroughly familiar with the region, told us of several 

 localities where fossils had been found. The most important of 

 these was an exposure on the Klalishkakat River, a locality visited 

 by Air. Arthur J. Collier, of the V. S. Geological Survey, some five 

 years previous. At the time of Mr. Collier's visit a large tusk was 



1 Spurr. J. E. : iSth Ann. Rept. U. S. Geological Survey. 1896-97, p. 199. 

 "' 17th Ann. Rept. U. S. Geological Survey, pt. t, 1895-96, p. 852. 



