Collaborative Research: Identification of magnetic sources in the upper mantle

合作研究：识别上地幔磁源

• 批准号: 1345071
• 负责人: Joshua Feinberg
• 金额: $ 4.5万
• 依托单位: University of Minnesota-Twin Cities
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2014
• 资助国家: 美国
• 起止时间: 2014-01-01 至 2015-12-31
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1345071&HistoricalAwards=false
• 关键词: Collaborative; Research; Identification; magnetic; sources

The view that the upper mantle is universally non-magnetic because it lacks ferromagnetic minerals and would be too hot to carry a magnetic remanence needs to be revisited because converging evidence suggests that some magnetic sources reside at mantle depths. This situation occurs in cold geotherm settings. We propose to carefully measure the magnetic properties of mantle xenoliths using new collections of fresh mantle rocks. The magnetic measurements will be supported by thorough petrologic investigations and by experiments in piston cylinders replicating the rapid ascent of mantle rocks to the Earth surface. The results these investigations will most likely transform the interpretation of data returned by the Swarm mission, deployed in November 2013, which will provide an unprecedented resolution of the lithospheric magnetic field.Our understanding of the internal structure of the Earth relies on geophysical approaches including for example seismology, gravimetry and magnetism. The magnetic field at the Earth's surface informs us about temperature at depth because below the Curie depth, minerals become too hot to be magnetic. Up to now, we thought that mantle rocks, at depths of about 30 kilometers, did not carry any magnetic minerals, an assumption based on measurements made in the 1980?s. The proposed research will re-evaluate this non-magnetic mantle concept and provide a far more accurate knowledge base to interpret magnetic satellite data. The information deduced from magnetic satellites provides vital information on regions of the globe where tectonic plates collide and create abundant seismicity.

由于缺少铁磁矿物质，因此上衣是普遍非磁性的，并且需要重新审视磁性雷诺，因为融合的证据表明某些磁源驻留在地幔深度处，因此需要重新审视磁性恢复。这种情况发生在冷地热设置中。我们建议使用新鲜地幔岩石的新集合仔细测量地幔异义石的磁性。磁性测量将由彻底的岩石学研究和活塞缸中的实验来支持，从而将地幔岩石快速上升到地球表面。结果这些研究很可能会改变2013年11月部署的Swarm Mission返回的数据的解释，该数据将提供岩石圈磁场的前所未有的解决方案。您对地球内部结构的理解依赖于地球物理学方法，包括诸如癫痫学，重学，重学和磁性。地球表面的磁场向我们告知了深度温度，因为在库里深度以下，矿物质变得太热而无法磁性。到目前为止，我们认为地幔岩石在约30公里的深处没有携带任何磁性矿物质，这是基于1980年代的测量值的假设。拟议的研究将重新评估这种非磁性地幔概念，并为解释磁性卫星数据提供更准确的知识库。从磁性卫星推导的信息提供了有关构造板碰撞并产生丰富地震性的地球区域区域的重要信息。