Pectinids from drill cores and outcrops document non-truly polar conditions in the Neogene of the Ross Sea region, Antarctica

Category Other
Group GSI.IR
Location International Geological Congress,oslo 2008
Author Taviani, Marco۱; Ceregato, Alessandro۱; Harwood, David M.۲; Florindo, Fabio۳
Holding Date 08 October 2008

Pectinid bivalves bear significant ecobiostratigraphic and paleoenvironmental information on the Neogene of Antarctica helping to shed light on the climate regimes at this crucial time. In the Ross Sea region their record is quite fragmentary and limited to a few outcrop occurrences (such as the Prospect Mesa Gravels in Wright Valley, McMurdo Sound) and boreholes recently drilled by the frame of the Cape Roberts and ANDRILL projects. Pectinid data from the Ross Sea region document the persistence of true non-polar (absence of extreme subfreezing) conditions in the McMurdo Sound from the Oligocene to at least the ?early Pliocene. Costate pectinids (Austrochlamys spp.) testify that paleoclimatic conditions comparable to present-day sub-Antarctica, are present in the Miocene sediments of the CRP-1 and AND-2A drill cores, as well as in the Pliocene fjord-like deposits of the Wright Valley (i.e. Austrochlamys tuftensis). Smooth Adamussium alanbeui pectinids occur in the Oligocene-Miocene sediments of this same region, and are equally interpreted to represent non-extreme polar conditions, i.e. seawater temperatures well above the present subfreezing 0/ -1.8°C range.
The authors acknowledge that the results of the SMS Project reported herein reflect the collective and dedicated efforts of the SMS Project Science Team, Drilling Team and ANDRILL camp members. The names and affiliations of those scientists can be found at the Web site: http://www.andrill.org/support/SMS_on-ice_phase.html.