HR: 1340h
AN: PP43C-1537    [Abstracts]
TI: Eirik Drift: Complexity Beneath the Surface
AU: * Mountain, G S
EM: gmtn@rci.rutgers.edu
AF: Rutgers the State University of New Jersey, Earth & Planetary Sciences - Wright Lab 610 Taylor Rd., Piscataway, NJ 08854, United States
AU: Earley, R J
EM: rearley@rci.rutgers.edu
AF: Rutgers the State University of New Jersey, Earth & Planetary Sciences - Wright Lab 610 Taylor Rd., Piscataway, NJ 08854, United States
AB: Eirik Drift stands as much as 1800 m above the surrounding seafloor and extends approximately 400 km SW from the southern tip of Greenland. It is largely composed of late Neogene-Recent muddy contourites, and due to high depositional rates it contains a valuable archive of global climate, changes in regional contributions to Northern Component Water (NCW), and local expression of the stratal evolution of giant, elongated drifts. We report on observations based on 1900 km of hi-res MCS profiles we collected across Eirik Drift in Aug-Sept 2002 during cruise Kn166-14. Our interpretations are based on correlations to piston and drill core records collected before, during, and since that cruise. The scarcity of modern mudwaves on the surface of Eirik Drift belies its long history of current-controlled deposition. NCW flowing south through the western Irminger Basin has minimized sedimentation along the SW flank of the Drift since at least the late Miocene, causing NW migration and upward growth of this deposit. SW progradation, often cited in the literature, is not obvious to us. Instead, sediment waves and locally enhanced deposition at the SW extremity of the Drift, near the modern 3400 m isobath, began at the same time as elsewhere in our survey area. The most rapid drift buildup occurred during the early to mid-Pliocene. Higher sedimentation rates and thicker accumulations towards the NE were due to sources providing sediment through channels cut into the Drift near the Greenland margin. Rugged basement topography and extensive sediment failures provided locally steep topography that focused the geostrophically balanced NCW. This led to localized sediment buildups and internally complex growth patterns now hidden beneath a more nearly uniform blanket of post-late Pliocene sediment.
DE: 3022 Marine sediments: processes and transport
DE: 3070 Submarine landslides
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting