Collaborative Research: Magnetic Ocean Crust: High-Fidelity Geomagnetic Field Recorder and Sensitive Indicator of Magmatic, Tectonic, and Alteration Processes

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Intellectual Merit: This research uses classical, state-of-the-art, and new techniques to investigate the magnetic, petrologic, and geochemical characteristics of iron oxide minerals from Ocean Drilling Program drill cores to determine the nature and genesis of seafloor magnetic anomalies. It will also determine which minerals are faithful recorders of Earth's geomagnetic field and at what depths in the crust they minerals occur and/or alter. The research also examines the impact of mineral composition, grain size, and alteration state on the magnetic signal of seafloor volcanic rocks. The measured properties will be used to understand the magmatic, tectonic, and alteration history of the ocean crust, as well as changes in Earth's geomagnetic field strength and direction. Cores that penetrate nearly an entire section of ocean crust will be analyzed and magnetic properties will be determined using natural and induced remnence magnetizations, as well as hysteresis properties; susceptibilities; moments; and FORC distributions at high, low, and room temperatures. Composition, oxidation state, and mineral characteristics of the iron oxides will be determined from reflected light microscopy, electron microprobe, and scanning electron microscopy. Paleointensities will be estimated using Thellier-type methods, along with recently published modifications and two new exploratory methods. Broader Impacts: Broader impacts of the work include development of new methods for paleomagnetic studies; collaboration between institutions, one of which is in an EPSCoR state; and support of a PI from a minority under-represented in science and engineering. The work also supports undergraduate training and has a component of public outreach through a university Open House.