A 36 Ky record of iceberg rafting and sedimentation from north-west Iceland

Article English OPEN
Geirsdóttir, Áslaug ; Andrews, John T. ; Ólafsdóttir, Saedís ; Helgadóttir, Gudrún ; Hardardóttir, Jórunn (2002)

Evidence from north-west Iceland's shelf and fjords is used to develop a scenario for environmental change during the last 36 cal Ky. The retreat history of the Iceland Ice Cap during the last deglaciation is delineated through lithofacies studies, carbon analyses and magnetic susceptibility, and studies of ice-rafted debris (IRD) in sediment cores. Sedimentological data from lake Efstadalsvatn, Vestfirdir peninsula, trace the glacier retreat on land. In two of the high resolution shelf cores we detect near continuous IRD accumulation from 36 to 11 cal Kya. However, IRD is absent in the cores from ca. 22 to 19 cal Kya, possibly indicating more extensive landfast sea ice conditions. All cores show intensified IRD during the Younger Dryas chronozone; the fjord cores show a continuous IRD record until 10 cal Kya. Magnetic susceptibility and carbon analyses from Efstadalsvatn reveal the disappearance of local ice in the basin just before 10.5 cal Kya. No IRD was detected in the sediment cores during 10 to Ø4 cal Kya. Some indication of cooling occurs between 4 and 3 cal Kya, with a fresh input of IRD in fjord cores after 1 cal Kya.
  • References (29)
    29 references, page 1 of 3

    Alley, R. B., Mayewski, P. A., Sowers, T., Stuiver, M., Taylor, K. C. & Clark, P. U. 1997: Holocene climate instability: a prominent, widespread event 8200 yr ago. Geology 25, 483–486.

    Andrews, J. T., Hardardóttir, J., Geirsdóttir, Á. & Helgadóttir, G. 2002: Late Quaternary ice extent and depositional history from the Djúpáll trough off VestÞrdir peninsula, north-west Iceland: a stacked 36 cal Ky environmental record. Polar Res. 21, 211–226 (this issue).

    Andrews, J. T., Geirsdóttir, Á., Hardardóttir, J., Principato, S., Kristjánsdóttir, G. B., Helgadóttir, G., Grönvold, K., Drexler, J. & Sveinbjörnsdóttir, Á. in press: Distribution, age, sediment magnetism, and geochemistry of the Saksunarvatn (10.18 ± cal ka) ash in marine, lake, and terrestrial sediments, NW Iceland. J. Quat. Sci.

    Andrews, J. T., Smith, L. M., Preston, R., Cooper, T. & Jennings, A. E. 1997. Spatial and temporal patterns of iceberg rafting (IRD) along the East Greenland margin, ca. 68° N, over the last 14 cal. ka. J. Quat. Sci. 12, 1–13.

    Bard, E., Fairbanks, R. G., Hamelin, B. & Zindler, A. 1990: Calibration of the 14C timescale over the past 30,000 years using mass spectrometric U–Th ages from Barbados corals. Nature 345, 405–410.

    Bourgeois, O., Dauteil, O. & van Viet-Lanoe, B. 2000: Geothermal control on ice stream formation: ßow patterns of the Icelandic Ice Sheet at the Last Glacial Maximum. Earth Surf. Process. Landf. 25, 59–76.

    Dickson, R. R., Meincke, J., Malmberg, S. & Lee, A. 1988: The “Great Salinity Anomaly” in the northern North Atlantic 1968–1982. Progr. Oceanogr. 20, 103–151.

    Dowdeswell, J. A., Whittington, R. J., Jennings, A. E., Andrews, J. T., Mackensen, A. & Marienfeld, P. 2000: An origin for laminated glacimarine sediments through seaice build-up and suppressed iceberg rafting. Sedimentology 47, 557–576.

    Geirsdóttir, Á., Hardardóttir, J. & Sveinbjörnsdóttir, Á. 2000: Glacial extent and catastrophic meltwater events during the deglaciation of southern Iceland. Quat. Sci. Rev. 19, 1749–1761.

    Grobe, H. 1987: A simple method for the determination of icerafted debris in sediment cores. Polarforschung 57, 123–126.

  • Similar Research Results (1)
  • Metrics
    No metrics available
Share - Bookmark