PROPOSED SITES
Sites GAB-01C, GAB-02B, and GAB-13B
Sites GAB-01C (southern Australian upper continental rise), GAB-02B (mid-upper slope), and alternate GAB-13B (middle continental rise) are paleoceanographic sites located to intersect pelagic sections that collectively span the entire Cenozoic succession and a substantial part of the Late Cretaceous section. These sites compose the deeper water component of the shelf-to-basin transect. The principal objective at these sites is to obtain a complete record of the Cenozoic section in a deep oceanic setting, with the principal aim of elucidating the evolution of the Circum-Antarctic Current within the evolving seaway between Australia and Antarctica. As the condensed section in the Jerboa-1 well contains early Oligocene faunas, there is a high probability that the intermediate and deep pelagic successions will together contain a more expanded record of this critically important time of Antarctic ice-cap evolution and Southern Ocean paleoceanographic development.
Sites GAB-03B and GAB-04B
Sites GAB-03B and GAB-04B are located to intersect the Eocene to
early middle Miocene section deposited in lobes on the upper
slope, coeval with deposition of the extensive carbonate platform
on the continental shelf. In addition, these sites will also
intersect an early Neogene succession poorly sampled at other
sites; a highly condensed late Neogene succession; and the upper
part of the marine Cenomanian section at Site GAB-04B. The
principal objective at these sites is to collect a detailed
record of Paleogene-early Neogene temperate to subtropical,
mid-latitude sedimentation in an upper slope environment and to
recover a record of marine flooding of the evolving rift basin in
the Cenomanian (Site GAB-04B).
Sites GAB-05B and GAB-06B
Sites GAB-05B and GAB-06B are located to intersect distal (Site
GAB-05B) and proximal (Site GAB-06B) parts of the Paleocene to
middle Eocene progradational siliciclastic wedge. In addition,
these sites will intersect a major portion of the overlying
Neogene succession (Seismic Sequences 2 to 4). The principal
objective at these sites is to recover a detailed record of
shelf-edge siliciclastic deposition to evaluate the sedimentary
response to Paleogene sea-level fluctuations and to evaluate the
complex interaction between sea-level variation, accommodation
space, and subsidence evident in stratal patterns.
Sites GAB-07A, GAB-08A, and GAB-09A
Sites GAB-07A, GAB-08A (alternate), and GAB-09A will intersect a
spectacular set of late Neogene (?Plio-Pleistocene) clinoforms
immediately seaward of the present-day shelf edge. Site GAB-07A
will intersect the lowest, more condensed portion of the
clinoform sequence, but will also have the best record of the
youngest clinoforms; Site GAB-08A will intersect a ?Pleistocene
Holocene biogenic mound immediately below the seafloor, together
with the best record of the middle part of the clinoform
sequence; and Site GAB-09A will intersect a buried biogenic mound
originally formed immediately below the paleoshelf edge, together
with the best record of the oldest part of the clinoform
sequence. The principal objective at these sites is to collect
detailed, high-resolution profiles through a late Neogene
shelf-edge (high energy) to upper slope (low energy) succession
deposited within a cool-water carbonate environment to determine
the response of such a depositional system to Plio-Pleistocene
sea-level fluctuations.