A Field-based Test of Remagnetization Hypothesis for the Ecstall Pluton, Coast Mountains Batholith, British Columbia

这项研究的重点是澄清不列颠哥伦比亚省海岸山脉内花岗岩类天体(ECstall Pluton)中记录的磁化的起源和时间。到目前为止的研究表明，该岩体很可能是被一种最近才认识到的过程磁化的，这种过程发生在特定的铁钛氧化物的混合过程中。混合过程需要在岩浆初始侵入后缓慢冷却或重新加热。埃克斯托尔岩体的磁性在地理上是不同的，因此很可能由于热剪切带而重新加热。这项研究更重要的是，磁性变化的起源将澄清一个悬而未决的问题，即北美西部大陆地壳的大部分是否像从该地区和该地区其他岩石单元的磁性所推断的那样，是从数千公里以外的大陆上吸积而来的。这项研究包括田野调查、地质年代学、岩石磁学和古地磁学，以及矿物学研究，包括电子显微镜和其他材料科学技术。

This research is focused on clarifying the origin and timing of magnetization recorded in a granitoid body (the Ecstall Pluton) within the Coast Mountains of British Columbia. Research to date has revealed that this pluton was likely magnetized by a process only recently recognized, which arises during unmixing of specific iron-titanium oxides. The unmixing process requires either slow cooling or reheating following the initial intrusion of the magma. The magnetism of the Ecstall pluton varies geographically in such a way that reheating due to a hot shear zone appears likely. The larger importance of this research is that the origin of the variation in magnetism will clarify the outstanding question of whether large portions of the western North American continental crust were accreted to the continent from thousand of kilometers away, as has been inferred from magnetism of this and other rock units in the region. The research entails fieldwork, geochronology, rock magnetism and paleomagnetism, and mineralogical studies including electron microscopy and other materials science techniques.