International Research Fellowship Program: Elevation Change in the Andes Mountains between 35-321S Latitude

点击翻译按钮获取中文摘要

0601957HokeThe International Research Fellowship Program enables U.S. scientists and engineers to conduct nine to twenty-four months of research abroad. The program's awards provide opportunities for joint research, and the use of unique or complementary facilities, expertise and experimental conditions abroad.This award will support a twenty-four-month research fellowship by Dr. Gregory D. Hoke to work with Drs. Laura Giambiagi, Instituto Argentino de Nivilogia, Galciologia y Ciencias Ambientales, Victor A. Ramos, Universidad de Buenos Aires, and Carmala N. Garzione, University of Rochester. The main objective of this research is to determine when the Andes mountains between 32 degrees S and 35 degrees S attained elevations at or near those observed today. Constraining the elevation history of the Andes will provide insight into several fundamental geologic questions. Most geologists relate periods of rock deformation (i.e. faulting and folding) observed in mountain ranges to an increase in overall range elevation. Advances in our state of knowledge of how thrust belts evolve suggest that a one to one correlation between upper crustal deformation and rock uplift may, in fact, not be the case. Uplift of the mountain range may also be responsible for dramatic impacts on the local and even regional climate. Both climate and topography are primary influences on the creation, transport and accumulation of sediment in basins. The PI will use stable isotopes of O and C in preserved ancient soil (paleosol) carbonates to re-construct paleoelevation and paleoclimate of the Andes. Using stable isotope-based paleoaltimetry methods (d18O on soil carbonates) he hopes to elucidate the development of range crest topography. The coeval evolution of climate in the Andean foreland will be examined using d13C in soil carbonates. Combined, these complementary datasets should allow for an integrated view of how local climate evolves in response to the continued Miocene topographic uplift of the Andean Cordillera. These records can then be compared to the known histories of rock faulting and folding and deposition in sedimentary basins.The Argentina hosts, Drs. L. B. Giambiagi and V. A. Ramos, have intimate knowledge of the geology of this part of the Andes, and share a mutual interest in understanding the timing of relief development in the region. Equally important, the American host, C. N. Garzione is an expert on the interpretation of isotopic records of elevation change and environmental change and would be an ideal advisor in the laboratory component of the proposed research. This research will serve as a knowledge bridge between the USA and Argentine geoscience communities, while providing important and timely scientific results.