LOWER CRETACEOUS. 631 



A few fossil plants were collected from the coal-bearing beds of Goat Creek, [among] which 



* * * Prof. Penhallow [identified] * * * GleicJiemia giliert-thompsoni Fontaine. Along 

 the international boundary line, on the Skagit Rirer, * * * Daly obtained the same species 

 [which is thought to indicate a Lower Cretaceous age]. 



N-O 4. ALASKA PENINSULA. 



The IMesozoic area in the Alaska Peninsula includes Cretaceous as well as 

 earlier IMesozoic rocks. Stanton and IVlartin summed up their general conclusions 

 as quoted on page 574, Chapter XIII. Their statement in regard to the Creta- 

 ceous^'^ is as follows: 



The presence of the Russian type of Lower Cretaceous on the Alaska Peninsula is sug- 

 gested by the occurrence of Aucella related to A. crassicoUis at Port MoUer and Herendeen Bay, 

 where Jurassic types of Aucella also occur in other beds, but the details of the stratigraphy are 

 unknown. These beds, with Aucella cf. crassicoUis, comparable with the Upper KJuoxville 

 beds of California, are widespread in Alaska, though we found no indication of them at any 

 localities studied by us. The species was obtained by Mendenhall on Bubb Creek, a branch 

 of the Taxlina, in the Matanuska series; by Spurr in the Oklune series on the Kanektok near the 

 mouth of the Kuskokwim; by Schrader in the Koyukuk and Anaktuvuk series in northern 

 Alaska, and by Wright on Admiralty Island, southeast Alaska, where Aucella piocM, another 

 Lower Cretaceous species, was found at a neighboring locality. It also occurs in the Mission 

 Creek series on the Yukon. The geographic distribution of these Cretaceous Aucella beds is 

 thus seen to differ radically from the distribution of the Naknek formation with its Jurassic 

 AuceUse, and this is regarded as evidence of a probable unconformity between them. 



On Chignik Bay Upper Cretaceous rocks, closely associated with plant-bearing Kenai beds, 

 occur on the lagoon 1 to 2 miles northeast of the Alaska Packers Association cannery and on 

 Whalers Creek, 5 miles west of the same place, where they apparently include a workable coal 

 bed. The exposures at the first locality consist of several hundred feet of shales and sand- 

 stones with some thick beds of coarse conglomerate in the middle portion. The beds beneath 

 the conglomerate contain great numbers of fossil plants, a collection of which yielded * * * 

 Upper Cretaceous species identified by Dr. Knowlton." * * * 



The shales above the conglomerates yielded * * * fossUs [which] indicate correlation 

 with a horizon in the Chico as developed in California and Vancouver Island, which includes 

 practically aU of the Upper Cretaceous, but the beds at Chignik are probably not older than 

 basal Senonian. 



Beds of possibly the same age occur on the north shore of the small bay north of Aievak or 

 Douglas vUlage, where there is a series of shales and sandstones with an estimated thickness of 

 2,000 feet. * * * 



The Cretaceous beds at Chignik may be directly correlated with those on the Yukon near 

 Nulato, and less certainly with those on the Anaktuvuk, in northern Alaska, which are the only 

 occurrences of Upper Cretaceous hitherto reported in the Territory. 



It is probable that more detailed study wiU reveal considerable areas of Upper Cretaceous 

 rocks on the Alaska Peninsula, but their recognition in rapid reconnaissance is made difficult 

 by the fact that Hthologically they resemble the Eocene Kenai beds of the same region, which, 

 like the Upper Cretaceous, are coal-bearing and contain fossU plants of similar general types. 



* * * There are doubtless unconformities both below and above the Upper Cretaceous of this 

 region, since aU of the Lower Cretaceous is lacking at most localities, and at some places the 

 Kenai rests directly on the Jurassic. 



o For list of species see the work cited. — B. W. 



