HR: 11:50h
AN: PP32A-07    [Abstracts]
TI: Extending the High-Resolution Global Climate Record in Santa Barbara Basin: Developing the Predictive 3D Model for Core Site Locations
AU: * Nicholson, C
EM: nicholson@msi.ucsb.edu
AF: Marine Science Institute and Department of Geological Sciences, University of California, Santa Barbara, CA 93106-6150 United States
AU: Sorlien, C C
PP32A-07 AF: Marine Science Institute and Department of Geological Sciences, University of California, Santa Barbara, CA 93106-6150 United States
AU: Hopkins, S E
PP32A-07 AF: Marine Science Institute and Department of Geological Sciences, University of California, Santa Barbara, CA 93106-6150 United States
AU: Kennett, J P
PP32A-07 AF: Marine Science Institute and Department of Geological Sciences, University of California, Santa Barbara, CA 93106-6150 United States
AU: Normark, W R
PP32A-07 AF: U.S. Geological Survey, MS999, 345 Middlefield Rd, Menlo Park, CA 94025 United States
AU: Sliter, R W
PP32A-07 AF: U.S. Geological Survey, MS999, 345 Middlefield Rd, Menlo Park, CA 94025 United States
AU: Kooker, L
PP32A-07 AF: U.S. Geological Survey, MS999, 345 Middlefield Rd, Menlo Park, CA 94025 United States
AB: ODP Site 893 in Santa Barbara Basin recovered high-resolution global climate data extending back to ~160 ka at 200 m sub-seafloor. Safety concerns though have prevented deeper drilling at this site. Santa Barbara Basin is, however, tectonically active. As a result, continuous late-Quaternary strata deposited in the deep paleo-bathymetric basin were uplifted and folded across the Mid-Channel Trend, and strata as old as ~500 ka are exposed at the seafloor where they are now accessible to piston coring. This project tested the accessibility along the anticline of these older stratigraphic sequences through detailed basin correlation of high-resolution seismic stratigraphy, and subsequent piston coring and deep-towed chirp surveying using the R/V Melville in August 2005. Grids of high-resolution MMS analog, industry multichannel, and 2D USGS high-resolution seismic reflection data were used to correlate dated reference horizons at ~110 ka, ~160 ka and ~1 Ma along with several intervening seismic sequence boundaries across the Mid-Channel Trend. Results provided the initial basis for modeling the structure and stratigraphy in 3D, and to precisely locate coring sites. As coring and chirp operations progressed, core locations were selected interactively based on the chirp data integrated into our 3D model in near real-time, and results from each previous recovered core. Suites of overlapping cores were acquired across dipping strata to provide a more continuous, composite geologic record. Preliminary core analyses verified our predicted outcrop pattern and basin-wide sequence stratigraphic interpretation. Recovered cores exhibit alternating laminated (interglacial) and massive (glacial) character of deep basin sediments remarkably similar to the high-resolution sequences found in ODP-893. The recovered core material is thus likely to provide critical high-resolution windows into global climate history for these older late-Quaternary periods, in addition to helping document the local interaction between tectonics, climate, and sea-level change.
DE: 1635 Oceans (1616, 3305, 4215, 4513)
DE: 3022 Marine sediments: processes and transport
DE: 3025 Marine seismics (0935, 7294)
DE: 4900 PALEOCEANOGRAPHY (0473, 3344)
DE: 8005 Folds and folding
SC: Paleoceanography and Paleoclimatology [PP]
MN: Fall Meeting 2005