Open AccessThe last deglaciation of the Franz Victoria Trough, northern Barents Sea
Author(s) -
LUBINSKI DAVID J.,
KORSUN SERGEY,
POLYAK LEONID,
FORMAN STEVEN L.,
LEHMAN SCOTT J.,
HERLIHY FRANCES A.,
MILLER GIFFORD H.
Publication year - 1996
Publication title -
boreas
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.95
H-Index - 74
eISSN - 1502-3885
pISSN - 0300-9483
DOI - 10.1111/j.1502-3885.1996.tb00838.x
Subject(s) - geology , deglaciation , ice sheet , oceanography , trough (economics) , foraminifera , ice stream , paleontology , sea ice , holocene , cryosphere , benthic zone , economics , macroeconomics
A study of two piston cores and a 3.5 kHz seismic profile from the Franz Victoria Trough provides new stratigraphic, stable isotopic and foraminiferal AMS 14 C data that help constrain the timing of ice‐sheet retreat in the northern Barents Sea and the nature of the deglacial marine environment. Silty diamicton at the base of each core, interpreted as till or ice‐marginal debris flow, suggests that the Barents ice sheet was grounded at the core sites (470 m water depth). Eight AMS 14 C dates on sediment overlying the diamicton indicate that the ice sheet retreated from both core sites by 12.9 ka and that postglacial sedimentation began 10 ka ago. These dates, combined with a recently published 14 C date from a nearby core, suggest that the Franz Victoria Trough may not have been deglaciated until c . 13 ka, 2000 years later than modeled ice‐sheet reconstructions indicate. In the trough, oxygen isotopic ratios in planktonic foraminifera N . pachyderma (sinistral) were 0.5–0.750, lower during deglaciation than after, probably as a result of ice‐sheet and/or iceberg melting. Foraminiferal assemblages suggest that Atlantic‐derived intermediate water may have begun to penetrate the trough c . 13 ka ago.