SGER: Magnetic Inclusions in Diamonds

这是一项试点研究，利用金刚石中磁黄铁矿包裹体的存在：1）地球磁场强度的潜在记录器，2）测试基于高压下磁黄铁矿磁性的假设。PI的初步结果令人吃惊，因为这些钻石中的内含物具有强磁性，也许更令人惊讶的是，它们被稳定地磁化。研究人员希望验证这些磁化是由磁黄铁矿携带的假设。磁黄铁矿具有许多随温度变化的诊断磁性。除了将在FIU古地磁实验室进行的标准岩石磁性测量外，我们还将在明尼苏达大学岩石磁性研究所进行磁滞和温度相关测量。在进行这些非破坏性测量后，PI将抛光钻石以暴露夹杂物，并使用微探针分析来检查矿物学。这些实验将确定所观察到的磁化是否由磁黄铁矿或其他铁/镍硫化物携带。确定矿物（S）负责这些包裹体的强磁化可能打开了令人兴奋的可能性，使用钻石，以获得古强度数据从地球历史的关键间隔，并为这些矿物的磁性研究在高压下的钻石。在佛罗里达国际大学的paleomanetism程序一直涉及本科生和研究生在其正在进行的研究计划。佛罗里达国际大学是一所以西班牙裔为主的大学，对佛罗里达国际大学古地磁学项目的支持有助于使地球科学中代表性不足的群体参与进来。

This is a pilot study to take advantage of the presence of pyrrhotite inclusions in diamonds as: 1) a potential recorder of the strength of Earth's magnetic field and 2) to test hypotheses based on the magnetic properties of pyrrhotite at high pressure. The PI's initial results are startling in that the inclusions in these diamonds are strongly magnetic and, perhaps more surprising, that they are stably magnetized. The researchers hope to test the hypothesis that these magnetizations are carried by pyrrhotite. Pyrrhotite exhibits a number of diagnostic magnetic properties that vary with temperature. In addition to standard rock magnetic measurements that will be carried out in the FIU paleomagnetism laboratory, we will conduct hysteresis and temperature-dependent measurements at the Institute for Rock Magnetism at the University of Minnesota. After conducting these non-destructive measurements, the PI will polish the diamonds to expose the inclusions and examine the mineralogy using microprobe analyses. These experiments will determine whether the observed magnetizations are carried by pyrrhotite or by other iron/nickel sulfides. Identifying the mineral(s) responsible for the strong magnetizations of theseinclusions may open up exciting possibilities for using diamonds to obtain paleointensity data from critical intervals of Earth history, and for the study of the magnetic properties of these minerals at the high pressures within diamonds.The paleomanetism program at Florida International University has consistently involved both undergraduate and graduate students in its ongoing research programs. Florida International University is a predominantly Hispanic university, and support of the paleomagnetism program at FIU helps to involve under- represented groups in the Earth Sciences.