S. Korsun et M. Hald, MODERN BENTHIC FORAMINIFERA OFF NOVAYA-ZEMLYA TIDEWATER GLACIERS, RUSSIAN ARCTIC, Arctic and alpine research, 30(1), 1998, pp. 61-77
Living and dead foraminifera have been investigated along three transe
cts away from tidewater glaciers of northern Novaya Zemlya. There are
three glacier-proximal dominant foraminiferal taxa: Allogromiina (unid
entified species), Elphidium excavatum f. clavata, and Cassidulina ren
iforme. In this environment the sediment consists of ice-front diamict
on (0.17 km from the terminus) and massive glaciomarine clay (0.2 to 7
km). Allogromiids dominate the low-diverse fauna closest to the glaci
er outlet, followed by E. e. clavata. Diagenetic decay of the allogrom
iid tests will result in the preservation of an E. e. clavata dominate
d fossil assemblage. The occurrence of C. reniforme increases with nut
rient enrichment reflected in phytoplankton abundance and sediment C-o
rg content. The C. reniforme/E. e. clavatum-ratio exceeds 50% in locat
ions where glacial impact is moderate as marked by the absence of glac
ial-cooled surface water and low concentrations of suspended sediment.
The presence of Quinqueloculina stalkeri is specific to the glaciomar
ine clay. Islandiella norcrossi is abundant in distal stations (7 to 2
2 km from the glacier termini) in distal glaciomarine sediments enrich
ed with ice rafted debris and in marine mud. A Nonionellina labradoric
a peak is also characteristic of glacial-distal habitats. The frequenc
y of Cibicides lobatulus and other attached forms correlates with the
abundance of clasts and shows no relation to water depth as the hard s
ubstrate is primarily ice rafted. Larger foraminifera (Saccorhiza ramo
sa and others) occur only in the marine mud. Numbers of living foramin
ifera and macrofauna biomass vary likewise, and remain unexplained by
the measured physical parameters. Dissolution of calcareous tests, ubi
quitous on the adjacent shelf, occurs only in distal, oxidized sedimen
ts.