Determining Ancient Field Intensities from Chemical Remanent Magnetisations in Rocks and Meteorites

该研究项目的重点是如何测量太阳系和地磁场的古代场强（古强度）。岩石和陨石记录磁场的一种方法是通过获得晶粒生长化学还原磁化（CRM），其中外部磁场随着磁性晶体的尺寸增长而被记录。在这个研究项目中，我将开发一种基于Preisach的方法，只使用室温测量来确定由晶粒生长CRM记录的古强度。该方法将进行经验测试，使用合成样品诱导与CRM，和历史样本从夏威夷，以前确定为携带颗粒生长CRM的地磁感应场是已知的。一旦开发，该方法将被应用于陨石，在磁剩磁在南极陨石，已经经历了化学变化，因此携带CRM。这使得研究早期太阳系的过程中使用的限制放置的古代磁场强度确定的过程。

This research project is focused on how we can measure the ancient field intensity (palaeointensity) of the Solar System and geomagnetic fields. One way in which rocks and meteorites record the magnetic field is by acquiring a grain-growth chemical remanent magnetisation (CRM), where an external magnetic field is recorded as magnetic crystals grow in size. During this research project I will develop a Preisach-based method using only room-temperature measurements to determine the palaeointensity recorded by a grain-growth CRM. The method will be empirically tested using both synthetic samples induced with a CRM, and historical samples from Hawaii, previously identified as carrying a grain-growth CRM where the geomagnetic inducing field is known.Once developed, the method will be applied to meteorites, looking at magnetic remanence in chondritic meteorites, which have undergone chemical alteration and therefore carry a CRM. This allows investigation into early Solar System processes by using constraints on processes placed by the ancient magnetic field strengths determined.