Magnetic Petrology of the Lower Crust: Record from Mafic Xenoliths

磁性岩石学的目标是将磁性研究与岩石学研究相结合，以了解岩石磁化的发展和变化。首席研究员将开始对下大陆地壳的磁性岩石学进行长期研究。作为该计划的初始阶段，本建议侧重于辐合弧边缘和大陆裂谷带的地壳捕虏体。除了采用标准岩石磁化技术外，还将采用岩石显微探针方法分析(1)阿留申弧、(2)日本、(3)里约热内卢大裂谷和(4)南极洲火山中心的基性捕虏体。该结果有望为Magsat和区域航磁调查揭示的长波磁异常提供候选源材料的约束。它们还应提供有关下地壳岩石磁化行为的岩石学控制的基本信息。

Magnetic petrology has as its goal the integration of magnetic property studies with petrologic studies for the purpose of understand the development and modification of magnetization in rocks. The principal investigator will initiate a long-term study of the magnetic petrology of the lower continental crust. As the initial phase of this program, this proposal focuses on crustal xenoliths from convergent arc margins and continental rift zones. Mafic xenoliths from volcanic centers in the (1) Aleutian arc, (2) Japan, (3) Rio Grande Rift and (4) Antarctica will be analyzed by petrographic-microprobe methods in addition to standard rock magnetization techniques. The results are expected to provide constraints on candidate source materials for the long-wavelength magnetic anomalies revealed by Magsat and regional aeromagnetic surveys. They should also provide basic information on petrologic controls responsible for the magnetization behavior of lower crustal rocks.