The first two samples at the base of the section (17J, 17M) indicate marginal marine to shallow marine environments similar to those existing in the Beaufort Sea today. The species are represented by a relatively large number of individuals. Samples 17H, 17I note a barren interval. Beginning with sample 17G, a marked change in the ostracodes is seen. RABILIMIS MIRABILIS occurs here. I am currently of the opinion that this species marks cold water condition. This is based on several intervals in Prudhoe Bay boreholes that contain R. MIRABILIS along with a number of foraminifers known to document cold waters. The number of individuals representing each species in sample 17G is dramatically reduced compared to 17J. Continuing through samples 17F-17D up the section, several new species occur indicating frigid, normal marine waters with no influence from land seen in the assemblage. Sample 17A contains only two species that occur in subfrigid to frigid climatic zones, and in waters ranging from marginal to shallow marine.

Samples 78 Ahp 15C-15J occur at the Drew Point exposure, Lat. 70 deg. 53 min. 6 sec.. long. 153 deg. 54 min. 00 sec. The exposure is a section of sand-sized sediments below Holocene thaw lake sediments.

Samples 15C to 15E at the base of the section represent a marginal marine to shallow nearshore marine conditions. The fauna is typical of the frigid climatic zone assemblages living off of the north coast today. Samples 15F, G contain no ostracodes. Sample 15H is probably marginal marine. Sample 15I near the top is wholly non-marine.

Cape Simpson Section - Samples are taken from the Flaxman Formation exposed in the second high bluff, 1.5km east of the Cape Simpson Dew Line Station. Latitude 71 deg. 1 min. 48 sec.; Longitude 154 deg. 36 min. 12 sec. A stratigraphic columnar section is on file with the Menlo P&S Branch. Analysis of samples is done in stratigraphic order from oldest to youngest.

Two foraminiferal faunas are present in the Cape Simpson samples. The older fauna (samples Mf 5511-5510) has a low species diversity (6 species per sample) and a large number of specimens (more than 1600 specimens per 100gm), whereas the younger fauna (samples Mf 5507-5501) has a somewhat greater diversity (8-12 species per sample) and a small population (less than 100 specimens per 100gm). A barren interval (Mf 5509-5508) separates the two faunas.

Age:

Three possible age interpretations exist for these Cape Simpson faunas.

(1) The lower fauna is Sangamon and the upper fauna represents reworked sediments (age of reworking unknown).

(2) both faunas are indicative of an interstadial in the Wisconsin.

(3) the lower fauna is Sangamon and the upper fauna represents the early Wisconsin or an interstadial within the Wisconsin.

Reworking is evident in most samples and easily identified by the worn appearance and orange coloration of the specimens. Only a fraction, usually less than 50 percent of the specimens in these faunas are reworked; thus the first interpretation is unlikely.

The second and third interpretations are supported by studies elswhere. Throughout, the USSR and northern Europe a auna with low diversity, low specimen number and a diagnostic fauna dominated by elphidiums is recongnized. Gudina (USSR, 1977) interprets this fauna as inter-Riss, middle Pleistocene. The Europeans, however, consider the fauna indicative of the Sandes Interstadial, early Weichselian (early Wisconsin). Earlier work by the Europeans gave the age of this fauna as Eemian (Sangamon). Both agree that the fauna can be no younger than Wisconsin because of the presence of ELPHIDIUM ASKLUNDI which became extinct during the last glacial (Wisconsin). Despite the various age interpretations the upper fauna and in some respects the lower fauna are this Sangamon/Wisconsin fauna of Europe and Russia and as suggested by the earlier workers indicative of cold, low salinity waters. The abundance of the lower fauna, however, suggests more normal inner neritic arctic marine conditions and probably represents the Sangamon.

Ecology:

The upper fauna is indicative of cold arctic faunas common to very shallow water, approximately 10m in depth. The lower fauna is indicative of similar conditions. The difference in population size is believed to be due to lower salinity conditions which restrict the population size of the upper fauna.

Drew Point Section - Samples are taken from the Flaxman Formation exposed in coastal bluffs at Drew Point. Alaska. Latitude 70 deg. 53 min. 6 sec.; Longitude 153 deg. 54 min. 00 sec. Stratigraphic columnar section is on file with Menlo P&S Branch. Analysis of samples is done in stratigraphic order from oldest to youngest.

Samples Mf 5440 to Mf 5443 are the low abundance, low diversity fauna of late Sangamon/early Wisconsin age. The absence or extremely low numbers of foraminifers and the poor preservation of the specimens suggests that the sediment sampled in the upper part of the section (Mf 5444 to Mf 5451) is non-marine, possibly a thaw lake deposit. Fresh water ostracods do occur in the upper part of the section.

The samples from the Drew Point Section collected by D. Carter (E&R Shipment number A-79-30M) are more abundant and from the upper part of the section. Specimens from Carter's samples are poorly preserved and have a "rusty" color. indicating probable reworking.

Mf 5452 and Mf 5453:

These samples are also from Drew Point exposure but are 300 meters from the samples considered previously.

As in the previous section, these faunas are poorly preserved and have "rusty" color. Sample Mf 5453 is believed to be reworked. Faunas are late Sangamon/early Wisconsin in age but reworking could have occured at any time after this.