Seismic and Stratigraphic Data Acquisition and Integration for Cenozoic Tectonic and Paleoenvironmental Analysis in McMurdo Sound

University Of Nebraska-Lincoln, Lincoln NE

Investigators

Abstract

0128782 Harwood This award, provided by the Office of Polar Programs, allows a US investigator to join a geological field team sponsored by Antarctica New Zealand (the New Zealand national Antarctic program) and the Institute of Geophysical and Nuclear Sciences of New Zealand to gather seismic data over regions that have potentially important sedimentary records of paleoenvironmental conditions and tectonic uplift of the adjacent mountains. The paucity of exposures of Cenozoic strata in Antarctica, due to the present ice cover, requires the collection of geological data from drill cores. Seismic data are necessary for proper site selection toward future drilling and provide a means of understanding the depositional context of the drill sites. Much has been learned over the last 20 years of drilling by the DSDP, ODP and via the fast-ice and on-land drilling of the DVDP, MSSTS, CIROS and Cape Roberts Project drill holes. A new international drilling initiative, ANDRILL, is in an early stage of development, with an initial focus in the McMurdo Sound area using the proven Cape Roberts Project drilling technology. This award provides support for site survey work in three ANDRIL target areas that will result in new seismic information to address tectonic, basin history, and paleoenvironmental questions. The Principal Investigators have been invited to collaborate with a New Zealand seismic team during the 2001-2002 austral field season, and join an international collaborative effort with the United Kingdom and New Zealand to collect and interpret seismic data from the sea-ice and ice shelf in the McMurdo Sound region. US participation would allow the seismic program to include areas with considerable US interest. Financial support to enable the acquisition of seismic data in three target areas is the responsibility of the United States for New Harbour (NH), of New Zealand for Windless Bight (WB), and of the United Kingdom for Southern McMurdo Ice Shelf (SMIS). This project began initially as a 2-year NZ and UK collaborative project for WB and SMIS. At the ANDRILL Workshop (4/2001 at Oxford University) it became apparent that drill holes proposed in the New Harbour area could be the initial targets of ANDRILL because the extant drilling system would require little modification and because scientific targets require relatively modest investments in new site survey data. An invitation for the US to join this collaborative effort was extended to enable the collection of data in New Harbour during the first year of this project. In addition to the requisite site survey work, the seismic data will help address current questions regarding: (1) the geometry of sedimentary sequences that will provide insight on competing theories regarding development of the Victoria Land Basin, as well as cause and uplift history of the adjacent Transantarctic Mountains; (2) the contrasting stratigraphic history recorded in the Ferrar and Taylor valleys; (3) the postulated stability of the Dry Valley landscape under a cold, polar climate for the last 20 million years. The new seismic information will also enable the extension of existing drill core data into a broader stratigraphic framework. The spirit of international collaboration developed through the Cape Roberts Project and continuing with ANDRILL will result in scientific exchange during the follow-up studies of all three target areas. The existence of 12 drill holes in the McMurdo Sound/Dry Valleys region, combined with new seismic data to be acquired by this project and from marine vessels, and future drill holes, will make this region a focus of future chronostratigraphic correlation on the Antarctic continental shelf.