Oxygen and Hydrogen Isotopes in Soils as Indicators of Continental Paleoclimates

关于进化的定量信息要少得多 和气候的历史比在深海中要复杂得多。 其中一个原因是缺乏量化的替代指标 大陆性气候的指标。 概述的工作是一项努力， 开发和应用氢氧利用技术 土壤剖面中矿物的同位素比值作为 土壤形成过程中的气候条件。 初始 研究阶段将包括一系列详细的研究， 在各种母质上发育的活跃风化剖面 材料在各种气候条件下。 风化剖面 本研究的目标包括亚马逊盆地的红土 弗吉尼亚皮埃蒙特的腐泥土， 在不同降雨量下夏威夷玄武岩上形成的剖面 政权。 该方法结合了仔细的现场描述， 岩石学和矿物学研究，土壤同位素分析 分离土壤矿物的水和同位素分析。 我们预计 这项对现代风化剖面的研究， 了解控制同位素的气候因素 土壤矿物的组成。 在项目的后期，我们 将把工作初期的成果应用于 古土壤研究 最重要的结果预期从 拟议的工作是开发新的工具， 大陆古气候 当这些工具广泛应用于 这项研究和以后的研究，所获得的信息将是有用的， 全球古气候重建和气候测试 模型

There is far less quantitative information about the evolution and history of climate on the continents than in the deep sea. Among the reasons for this is a scarcity of quantitative proxy indicators of continental climate. The work outlined is an effort to develop and apply techniques for using oxygen and hydrogen isotope ratios of minerals in soil profiles as indicators of climatic conditions during the soil-forming process. The initial stage of the research will consist of detailed studies of a series of active weathering profiles developed on a variety of parent materials in a variety of climatic regimes. Weathering profiles targeted for this study include lateritic soils in the Amazon Basin of Brazil, saprolites on the Virginia Piedmont, and weathering profiles developed on Hawaiian basalts under varying rainfall regimes. The approach combines careful field description, petrographic and mineralogical study, isotopic analysis of soil water and isotopic analysis of separated soil minerals. We expect this proposed study of modern weathering profiles to lead to an understanding of the climatic factors which control the isotopic compositions of soil minerals. In a later stage of the project we will apply the results of the initial stage of the work to the study of paleosols. The most important result expected from the proposed work is the development of new tools for the study of continental paleoclimates. When these tools are widely applied in this and later studies, the information obtained will be useful for global paleoclimatic reconstructions and the testing of climate models.