Benthic Foraminiferal Assemblages From the Southern Kara Sea, a River-Influenced Arctic Marine Environment

Abstract

Calcareous foraminifers and hydrographic parameters in 113 bottom samples from the southern Kara Sea were examined to improve the usage of foraminifers as paleoenvironmental proxies for river-dominated high-latitude continental shelves. Foraminiferal taxa form a succession from near-estuarine to distal open-sea locations, characterized by a gradual increase in salinities. Foraminiferal assemblages are discriminated into three groups: riverproximal,-intermediate, and-distal. This succession appears to be controlled by a combination of feeding conditions and bottom salinities, and are related to riverine fluxes of freshwater, organic matter, and sediments. Morphological and behavioral adaptations of foraminifers to specific environments are discussed.

Severnaya Zemlya, Arctic Russia: a nucleation area for Kara Sea ice sheets during the Middle to Late Quaternary

“…Elphidium ustulatum is an extinct species (Gudina and Evzerov, 1973;Gudina and Levchuk 1989, as Toddinella lenticularis) and except for one occurrence in presumably Middle Weichselian deposits from northern Denmark (Lykke-Andersen, 1987), it is not found in deposits younger than Eemian in NW Europe. Although Islandiella inflata has been described from the present continental shelves of the northern seas and the Bering Sea (Gudina and Evzerov, 1973, as Cassandara inflata), it is not found in the area today (Polyak et al, 2002). In NW Europe its hitherto youngest appearance is in the Late Saalian (cf Seidenkrantz, 1993), although it was found by Lorange (1977) in Holocene sediments from the Barents Sea.…”

“…Other abundant species include Haynesina orbiculare, which are currently found in riverproximal environments in the Kara and Laptev Seas (Bude, 1997;Polyak et al, 2002) as well as the higher salinity demanding Islandiella norcrossi, Miliolina and Trifarina fluens. The upwards decrease in higher salinity demanding, deeper-water species and the increase in E. albiumbilicatum, Haynesina nivea and Astrononion gallowayi indicates a lowering of the water depth and an increased depositional energy, as also indicated by the increasing grain size (Fig.…”

“…In the lowermost part the fauna is particularly characterized by Islandiella islandica, Haynesina orbiculare and some Elphidium asklundi, the later two of which are today found in river-proximal regions of the Kara and Laptev Seas (Bude, 1997;Polyak et al, 2002) and thus indicating somewhat reduced salinities that can be due to the melting glaciers at the end of a glaciation/stadial. The low but significant presence of Stainforthia loeblichi may be ascribed to seasonal sea-ice cover (see Steinsund et al, 1994).…”

Modern Distribution of Benthic Foraminifera From Disko Bugt, West Greenland

“…In particular, such studies have provided contemporary analogues for paleoenvironmental reconstructions, increasing our understanding of the interaction between climate change and high-latitude environments (e.g., Osterman and Nelson, 1989;Bilodeau and others, 1994;Jennings and others, 1996;Polyak and Mikhailov, 1996;Jennings and others, 2002). There have, however, been few studies of foraminifera from the west Greenland margin.…”

Late Holocene paleoceanographic evidence of the influence of the Aleutian Low and North Pacific High on circulation in the Seymour-Belize Inlet Complex, British Columbia, Canada

“…Species of Lobatula are also found through this section. These epifaunal suspension feeders are most abundant in environments with good circulation, as the increased oxygen concentrations estimated for this interval suggest (Polyak et al, 2002).…”