HR: 0800h
AN: PP51B-0478    [Abstracts]
TI: Revised stratigraphy, timing, and amplitude of the middle Miocene eustatic sea-level fall recorded on the Marion Plateau, Northeastern Australia (ODP Leg 194)
AU: * John, C M
EM: john@iodp.tamu.edu
AF: Integrated Ocean Drilling Program, 1000 Discovery Drive, College Station, TX 77845, United States
AU: Karner, G D
EM: garry@ldeo.columbia.edu
AF: ExxonMobil Upstream Research Company, 3120 Buffalo Speedway P.O. Box 2189, Houston, TX 77252, United States
AU: Mateo, Z
EM: mateo@iodp.tamu.edu
AF: Integrated Ocean Drilling Program, 1000 Discovery Drive, College Station, TX 77845, United States
AU: Leckie, M
EM: mleckie@geo.umass.edu
AF: University of Massachusetts, Department of Geosciences 611 N. Pleasant St, Amherst, MA 01003, United States
AU: Browning, E
EM: ebrown12@geo.umass.edu
AF: University of Massachusetts, Department of Geosciences 611 N. Pleasant St, Amherst, MA 01003, United States
AU: Schouten, S
EM: schouten@nioz.nl
AF: NIOZ, PO Box 59, Den Burg, Texel, 1790 AB, Netherlands
AB: Carbonate sequences of the Marion Plateau of northeast Australia (ODP Leg 194) have been critical in reconstructing the amplitude of the middle Miocene sea-level fall. Here, we present a revised stratigraphic framework for the Marion Plateau based on correlating drilling sites along the slope using core and downhole log data, and tying the platform to the slope sequences using recently published Sr isotope data. The new stratigraphic framework is significantly different from the shipboard results, which prompts us to reevaluate the estimate of the magnitude of the eustatic sea-level fall based on backstripping of the Marion Plateau sequences. Because correlation between the upper slope and distal slope sites is significantly improved, we can now use the relatively well-constrained age model of the distal slope to date critical sequences on the upper slope. Preliminary results show that the lowstand interval is characterized by condensed depositional facies, probably triggered by a reduction in the carbonate factory during eustatic lowstands. Furthermore, we show that the middle Miocene "lowstand" recorded by the Marion Plateau is a composite of several phases of successive sea-level falls, spanning the 13.5-11.7 Ma interval (oxygen isotope events Mi3, Mi4, and Mi5).
DE: 1641 Sea level change (1222, 1225, 4556)
DE: 3002 Continental shelf and slope processes (4219)
DE: 3022 Marine sediments: processes and transport
DE: 3036 Ocean drilling
DE: 4870 Stable isotopes (0454, 1041)
SC: Paleoceanography and Paleoclimatology [PP]
MN: 2007 Fall Meeting