Seismic and chronostratigraphic results from SHALDRIL II, northwestern Weddell Sea

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