ESH - Paleoclimatic Significance of the Wucheng Loess in China

地球系统史的三个重要因素是米兰科维奇强迫、西藏隆升和全球冰量。这三种元素相互作用的陆地记录可以在中国黄土高原的古气候记录中找到。然而，大多数对中国黄土和相关古土壤的研究只涉及这260万年序列的前三分之二。下三分之一，即武城组，具有非常不同的物理外观，现有数据表明，其成土性和磁性也与上三分之二不同。这些差异被认为反映了青藏高原隆升影响的增强，以及由以倾角和岁差为主的米兰科维奇强迫向以偏心率为主的米兰科维奇强迫的转变。提出支持开展武城组基础成土、沉积和矿物磁学研究，以解读武城组古气候历史。我们认为，这一研究将成为中国黄土/古土壤序列研究的重要对照，将显著提高我们对整个序列古气候记录的解释能力，将为海洋和陆地气候之间的耦合提供新的见解，并将为测试大气和海洋环流的计算机模型提供新的机会。

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.