Tuesday, 28 August 2007 - 10:10 AM
2.A.A-1
Seismic and chronostratigraphic results from SHALDRIL II, northwestern Weddell Sea
John B. Anderson1, Julia S. Wellner2, Sherwood Wise Jr.3, Steve Bohaty4, Patricia Manley5, Tyler Smith1, Fred Weaver1, and Denise Kulhanek3. (1) Earth Sciences, Rice University, Houston, TX, TX 77251-1892, (2) Geosciences, University of Houston, 312 Science & Research Building 1, Houston, TX, TX 77204-5007, (3) Geological Sciences, Florida State University, 108 Carraway Building, Tallahassee, FL 32306-4100, (4) Earth and Planetary Sciences, University of California-Santa Cruz, Santa Crus, CA, (5) Geology, Middleburry College, 427 McCardell Bicentennial Hall, Middleburry, VT 05735
Summary The 2006 SHALDRIL II cruise was conducted in the northwestern Weddell Sea, with primary drilling targets in the James Ross Basin. A site drilled along the northern edge of the James Ross Basin sampled either latest Eocene or earliest Oligocene deposits, providing a lower chronostratigraphic benchmark for our seismic stratigraphic age model. Severe sea ice conditions forced abandonment of several of the James Ross Basin sites. Three alternate sites were drilled along the southern flank of the Joinville Plateau. Seismic data from the area show a thick, southward dipping stratigraphic succession with no conspicuous gaps. Three drill sites sampled this succession and recovered Oligocene, middle Miocene, and early Pliocene strata overlain by a thin drape of Pleistocene deposits. The Pliocene-Miocene boundary appears to be represented by a disconformity within the cored interval. Otherwise, this is one of the most complete post-Eocene successions anywhere on Antarctica and its adjacent margins.