Recent foraminifera from the Gulf of Alaska and southeastern Alaska

In each of these places numerous species were found in common Pamplona Searidge is a northeast-trending submarine ridge, about 30 miles off the coast in the Gulf of Alaska, near the outer edge of the continental shelf. It now rises from surrounding depths (of about 400 6athoms to within 68 fathoms of the surface and conceivably might have been what 18th century Spanish and Russian explorers reported to be the dangerous rocky shoal, "Pamplona Rock." Three samples dredged between 85 and 100 fathoms from near the top of Pamplona Searidge contain rich assemblages of Foraminifera dominated by Caesidfrlina oalifornica and C. tortt~osa. Two samples were dredged from the sides of the searidge between 133 and 205 fathoms. The fauna of the shallower one-that between 133 and 148 fathoms-is similar t o those on the summit, but the deewr sample is dominated by GoeseZ6a flintii. For comparison with the Foraminifera of the searidge, six samples from depths between 10 and 215 fathoms, dredged in the channels and bays of the fjordland of southeastern Alaska were also studied. These six samples reveal the faunal distinctiveness of the various fjordland localities a s contrasted with the comparative uniformity of the open environment of the searidge samples in the Gulf of Alaska. Only two of the fjordland samples have dominating species, namely EZpkidielZa groenlandioa and Cassidulina limbata a t Hxcursion Inlet and Rotalia colztmbiettsis a t Gambier Bay. Elsewhere, each assemblage contains a group of major constituents with supplementary minor ones. Some of these major constituents are Reopltur scorpitrruu, Haplopkragncoides planissimus, Cribrostomoides oraesimurgo, Snrn~otittm cassis, Garrdrvina arenaria, Eggerclla adecna, Qtrinqrreloctrlina akneriana, Globobuliw~ina artricctlata, Bolivina alata, Ucigerina peregrina, Sngulogerina fluens, Rosalilza ornatissirna, Buccella frigida, Elpkidittm clacatrtrn, E. frigidum, Cibicidcs Zobatulox, Florilus labradoriclta, Nonior~ella pzrlclrcllcr, I'sordonottio~~ artric~tl~rrt~, and Bstrononion gallowayi. Alteogether, 140 species are recordrd, and their distributioll and ubundance indicated, but about 8.5 of them constitute a clnantitatively negligible part of the \\.hole lmyul-ation of l'oraininifera. I"rom the total of 140 species, about 56 percent have previously been recoluled as inhabiting Arctic regions, and an additional S gerceiit :IS inliabiting .Intarctir regions. Only 36 percent have not been reported in either ])olar region. C'umlrarisoiis are made with Recent Foran~i i~ i f r ra assemblages fro111 elevated glacial sedin~eiit in ~ o u t h e a s t t ~ r i ~ Alaska, from dredged bottoin sediinent in sontliern British ('cdumbia, from the ilorthwrsterii IBac.itic., froin shallow shelf water along the Arctic coast of eastthrn S i b r i a , and fro111 off the coaslt of Chile. with the present assemblages. Comparisons were also made with three probably Pleistocene or Pliocene occurrences : a submarine beach deposit near Nome, Amchitka Island in the Aleutians, and Middleton Island in the Gulf of Alaska west of the searidge. Here, too, similarities were found with the present assemblages. Search for evidence that Pamplona Searidge had formerly been a t a higher elevation near sea level was fruitless, but a t the same time the Foraminifera showed nothing tha t would rule out such an inltterpretation.