| Samples 69A Dt 146, 148 #1, 148 #2, 149A, and 149B of this shipment from the Carter Creek area, are probably barren as no microfossils were found during examination of washed material. Also sample 69A Dt 153 from the Marsh Creek Tertiary ? section is seemingly barren, as appears to be sample 69A Dt 157 from the West Katakturuk River. Three samples from the Carter Creek are given below, however, yielded Foraminifera and ostracodes. The latter have been given to Joe Hazel for study. It should be kept in mind that the only published material on Tertiary Foraminifera from northern Alaska is the fauna from two samples collected by Robert Morris in 1953 (see P.P. 294-F by Ruth Todd). Unfortunately Todd did not describe nor illustrate the entire fauna; her illustrations are poor and she compared much of the identified material to warm water forms. Her designated age of late Miocene to early Pliocene is based largely on the conclusions from MacNeil’s work on the megafossils (Chlamys nuwokensis zone). Actually the Foraminifera seem more closely related to Pleistoncen and Recent forms than to Miocene-Pliocene material. Pleistocene Foraminifera from northern Alaska have not been described although they are common in the Gubik Formation. In the following identifications Todd’s names are used in part or are assigned to other genera, or questioned. Todd’s PP 294-F (Foraminifera from Carter Creek northeastern Alaska) can be used as basic reference but the fauna was inadequately described and compared. The following identifications should be noted as differing from Todd’s. Elphidiella ? brunescens Todd cannot be an Elphidiella and is more likely a Nonion, but for the present is herein left as she described it. Nonion erucopsis Todd specimens are all umbillicate and are berein placed under Melonis (an umbillicate form) because Nonion is always umbonate. Angulogerina fluens Todd should be under the genus Trifarina as indicated above. Buliminella curta Cushman of Todd is neither of that genus nor species. It is herein listed only as Bulimina sp. Todd’s Bolivina sp. Is definitely a Cassidella. Todd’s Nonion labridoricum (Dawson) specimens are not much like the types nor others assigned to that species as the Carter Creek forms all have long lobes on each side that extend to the initial part of the test unlike Dawson’s species. I have shown it in the lists above as Nonion sp. With comparison to N. labridoricum to indicate its relationship in the Todd fauna. I cannot find a described form like it. Some of the specimens which Todd may have included under Miliolinella circularis (Bornemann) are quinqueloculine and are better assigned to the genus Scutuloris because of this chamber arrangement and type of aperture. Scutuloris was described by Loeblich and Tappan from the Recent Arctic and I know of no other species presently assigned to it. The Carter Creek specimen which I list as Scutuloris ? are not quite the same as those from the Recent dredgings off Point Barrow. Even Todd’s identification of Elphidium discoidale (D’Orbigny) might be questioned as most specimens do not closely resemble this species which was described from the warm waters near Cuba. Age: Based on the above comments and current study which is not a thorough investigation of the fauna, I would tentatively consider the Carter Creek Foraminifera to be no older than late Pliocene and possibly Pleistocene in age. This may not be at all in keeping with the conclusions drawn from MacNeil’s study so I suggest you might get an evaluation of the latter’s Nuwork studies from Addicott. I do not know whether or not the microfossil samples studied came from the same beds designated the Chalmy nuwokensis zone by MacNeil. |