ESH - Paleoclimatic Significance of the Wucheng Loess in China

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9710051 Verosub Three important elements of Earth Systems History are Milankovitch forcing, Tibetan uplift and global ice volume. A terrestrial record of the interaction of these three elements can be found in the paleoclimatic record of the Chinese loess plateau. However, most studies of the Chinese loess and associated paleosols have dealt with the upper two-thirds of this 2.6 million year-long sequence. The lower one-third, known as the Wucheng Formation, has a very different physical appearance, and the data that are available suggest that its pedogenic and magnetic properties are also different from the upper two-thirds. These differences are believed to reflect the increasing influence of the Tibetan uplift as well as a shift from Milankovitch forcing dominated by obliquity and precession to one dominated by eccentricity. This proposal represents a request for support to undertake fundamental pedogenic, sedimentologic, and mineral magnetic investigations of the Wucheng Formation with the goal of deciphering its paleoclimatic history. We believe that such a study will serve as an important counterpoint to studies of the rest of the Chinese loess/paleosol sequence, that it will significantly improve our ability to interpret the paleoclimate record of the entire sequence, that it will provide new insights about the coupling between marine and terrestrial climate, and that it will lead to new opportunities to test computer models of atmospheric and oceanic circulation.