Collaborative Research: Initial Sedimentological Characterization of the Late Cretaceous-Early Cenozoic Drill Cores from Cape Roberts, Antarctica

点击翻译按钮获取中文摘要

Krissek OPP 9527008 Powell OPP 9527481 Abstract An international initiative to collect 1500 m of drill core from offshore of Cape Roberts, McMurdo Sound Antarctica, is intended to provide a better understanding of Antarctic history through the late Cretaceous and early Cenozoic. Events during this period, which extends from before the final breakup of Gondwana through the onset of Antarctic glaciation, are ill-defined by existing data. The Cape Roberts Project (CRP) aims to provide new data about the development of the West Antarctic rift system, the subsidence history of the Ross Sea, and ice sheet fluctuations on Antarctica through this critical time interval. These regional events must be documented better because they have ramifications of regional and global significance, including: 1) impacts on both regional and global climatic development, with its terrestrial and marine effects, and 2) impacts on the preservation of such climatic records through the regional and global influences of Gondwana tectonics. CRP is partly an extension of previous drilling efforts on the Antarctic continental margin, and is partly a new initiative to more completely document the developmental history of the Ross Sea sector of the Antarctic and southern Pacific region through the late Cretaceous - early Cenozoic. It will draw on the successes of previous drilling efforts to document regional and environmental development with good spatial and temporal resolution, and it will also draw upon newly compiled geophysical data bases. CRP is a collaborative endeavor and is currently being supported by six participating countries. This award supports the U.S. contribution to the stratigraphic logging and initial sedimentological characterization of the drill core. Pursuit of more specific research goals will be accomplished via proposals from individual scientists in the future. Tasks involved in the proposed work will include initial description and characterizatio n of the stratigraphic successions; these results will be used as the fundamental data base for other analyses. The stratigraphic sections will also be used as reference sections for modeling observed marine and geophysical events. Initial sedimentological characterization of the successions will allow the definition of facies, the construction of facies sequences, and the interpretation of depositional environments through time. The end result of the proposed work will be an Ocean Drilling Program-style initial report for each drilling season. These reports will include the stratigraphic log, initial facies and depositional system interpretations, sedimentary petrologic and petrogenetic analyses, and initial clay mineralogical analysis. Information provided by other specialists will also be included in the reports, including biostratigraphy, magnetostratigraphy, geophysical logs and geochemical interpretations. The initial interpretations of regional history will be presented in these reports, and the regional and global ramifications of this history will be highlighted.