MRI: Acquisition of a Superconducting Rock Magnetometer System for Earth Sciences Research

Dartmouth College, Hanover NH

Investigators

Abstract

This Major Research Instrumentation (MRI) Program grant supports acquisition of a superconducting rock magnetometer (SRM) equipped with in-line rock magnetic coils and automated sample handling system (RAPID system) and required ancillary equipment. The SRM will support research and research training in the Department of Earth Sciences at Dartmouth College. The SRM will support research on the development and evolution of the geomagnetic field, continental paleogeography, and deep-time environmental magnetism. The SRM will also support postdoctoral scientist, graduate, and undergraduate student research. The investigator plans local K-12 outreach through laboratory tours and summer research internships. The instrument will also support regional collaborations and faculty and student use from institutions in the New England region and likely beyond. Magnetic study of minerals, sediments, and rocks can inform us about past conditions on Earth’s surface—from the development and evolution of the geomagnetic field to the geographic position of continents to the timing of key events in Earth (and human) history to tracking changes in climate and environmental conditions—which in turn can inform our projections of Earth’s future. Research at Dartmouth will focus on novel magnetic applications and techniques such as “deep-time” environmental magnetism with absolute timing of magnetic mineral formation and development of a quick, non-destructive technique for identifying magnetic iron sulfides present in low-abundance. The SRM-RAPID system and thermal demagnetizer will provide an on-campus resource for measurements of thermal demagnetization and paleointensity. These protocols require large sample numbers and high-resolution steps that can result in tens of thousands of measurements per study. The instrumentation will also support automated alternating field demagnetization and rock magnetic experiments involving magnetic susceptibility, anhysteretic remanent magnetization, and isothermal remanent magnetization. Remanence magnetic measurements made by the SRM-RAPID system can be used for efficiently characterizing the magnetic mineralogy of samples, as well as analyzing ancient recorded fields in geologic samples. The high-sensitivity of the SRM and the low magnetic moment of the RAPID system holder will allow researchers to push the frontiers of the field through analysis of weakly magnetized sediments, heavily remagnetized volcanics, and very small samples such as biological specimens, filtered particulate, chemical residues, and pure mineral phases. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.