U.S.-France Cooperative Research: Oxygen and Hydrogen Isotope Geochemistry of Laterites

这个为期两年的奖项支持由凯斯西储大学的萨缪尔·萨文和让-皮埃尔·吉拉德以及艾克斯-马赛第三大学的丹尼尔·纳洪参与的美法合作研究。研究人员建议将同位素技术应用于红土的研究，红土是一种热带土壤，覆盖了地球的很大一部分。他们合作的目标包括分析在巴西发现的特征良好的活性红土中矿物的氧和氢比例。Drs。Savin和Girard带来了他们在低温地质材料中粘土和相关矿物稳定同位素研究方面的丰富经验。法国调查员在土壤成因和红土风化地球化学问题方面的专业知识补充了这一点。他们将共同收集在巴西亚马逊盆地发现的红土样本，并进行实验室分析。红土提供了获得有关古代气候信息的最佳前景之一。利用稳定同位素研究，研究人员建议确定红土矿物含量中记录的古温度和古代降雨的同位素值。这一结果对利用稳定同位素进行古气候重建的研究具有重要意义。了解这些古老的气候因素，特别是热带地区的降雨，将促进我们对赤道降雨模式变化与全球气候变化之间联系的理解。

This two-year award supports U.S.-France cooperative research involving Samuel Savin and Jean-Pierre Girard of Case Western Reserve and Daniel Nahon of the University of Aix-Marseille III. The investigators propose to apply isotopic techniques to the study of laterites, which are tropical soils that cover a substantial portion of the earth. The objectives of their cooperation involve analyzing oxygen and hydrogen ratios of minerals in well-characterized, active laterites found in Brazil. Drs. Savin and Girard bring to the collaboration their extensive experience in stable isotope studies of clays and related minerals in geologic materials of low temperature origin. This is complemented by the French investigator's expertise in problems of soil genesis and geochemistry of laterite weathering. They will jointly collect laterite samples found in the Amazon Basin in Brazil and conduct laboratory analysis. Laterites offer one of the best prospects to obtain information about ancient climates. Using stable isotopes studies, the investigators propose to determine both paleotemperatures and isotopic values of ancient rainfall as recorded in the mineral content of the laterites. The results will be important to research into the use of stable isotopes for paleoclimatic reconstructions. Knowledge about these ancient climatic factors particularly rainfall in tropical regions will advance our understanding of the link between change in equatorial rainfall patterns and global climate change.