US-Mexico Cooperative Research: Geomagnetic Paleointensity Determinations on Historic Lava Flows

该奖项将支持霍斯特沃姆教授和苏比尔教授 明尼苏达大学的Banerjee教授与教授合作。 国立自治大学的Jaime Urrutia-Fucugauchi 墨西哥（墨西哥国立自治大学）。 研究人员打算研究磁记录 在历史上的熔岩流，并比较它与磁观测 数据 墨西哥是唯一适合这一目的的国家，因为它的积极 火山的历史提供了许多历史性的熔岩流， 成分和冷却历史。 同样重要的是，直接威慑-- 自1791年以来就有地磁场的测量。 拟议的研究将包括两个阶段。 一是 不同性质熔岩流中剩磁的变化 将从纵向和横向两个方面系统地研究这些特征， 数据区. 此外，磁性和矿石岩石学 特征将被确定。 研究第一阶段的结果将提供一个很好的 为系统的古强度方法研究奠定了基础。 热和非- 将评估热方法的适用性，准确性， 效能 自然反射磁化（NRM）将 在墨西哥国立自治大学的古地磁实验室进行了研究， 滞后、各向异性和其它测量以及详细的 强度测定工作将在 明尼苏达 此外，微探针和扫描电子显微镜 工作将涉及教授Negendank在德国，从而增加了一个多- 横向尺寸到这个项目。 拟议的工作将是 研究古强度记录的第一阶段， 二叠纪时代以来，墨西哥保留了一个几乎独特的 连续的火山记录

This award will support Professor Horst Worm and Professor Subir Banerjee of the University of Minnesota in collaboration with Prof. Jaime Urrutia-Fucugauchi of the Universidad Nacional Autonoma de Mexico (UNAM). The researchers intend to study the magnetic record in historic lava flows and to compare it with magnetic observatory data. Mexico is uniquely suited for this purpose because its active volcanic history has supplied numerous historic lava flows of varying composition and cooling history. Equally important, direct deter- minations of the geomagnetic field are available since 1791. The proposed research will consist of two phases. First, the variation of magnetic remanences in lava flows of different charac- teristics will be systematically studied in vertical and horizontal profiles. Additionally, magnetic properties and ore petrological characteristics will be determined. Results from the first phase of the study will provide an excellent basis for systematic paleointensity method studies. Thermal and non- thermal methods will be evaluated for their applicability, accuracy, and efficiency. Natural remanent magnetizations (NRM's) will be studied in the paleomagnetic laboratory at UNAM while magnetic hysteresis, anisotropy and other measurements as well as detailed intensity determinations will be performed at the University of Minnesota. In addition microprobe and scanning electron microscope work will involve Prof. Negendank in Germany, thus adding a multi- lateral dimension to this project. The proposed work will be the first stage in studying the paleointensity record all the way back to Permian times since when Mexico has retained an almost unique continuous volcanic record.