Acquisition of a DC-SQUID magnetometer

0647852

Banerjee

This grant supports acquisition of a superconducting quantum interference device (SQUID) rock magnetometer (SRM) configured to measure the remanent magnetization of both discrete specimens and continuous sediment cores or u-channels. The SQUID SRM would replace an existing radio frequency (RF) detection based SRM installed at the University of Minnesota in 1986 and would allow for detection of magnetic remanence up to three orders of magnitude lower than currently possible with the RF-SRM, allowing for characterization weakly magnetized sediments and rocks. Currently a wide range of specialized rock magnetic equipment is housed at the NSF supported Institute for Rock Magnetism (IRM) national multi-user facility (EAR- 0218384) at the University of Minnesota. This u-channel capable SQUID SRM will be a fundamental IRM tool used for the measurement of magnetic remanence at room-temperature and zero-field. Fundamental research in rock magnetism, environmental and paleomagnetism will be facilitated by this acquisition. Examples of specific in-house rock magnetic research includes: 1) precise characterization of interparticle magnetostatic interactions and their anisotropic effects on the properties of various remanent magnetizations to support study of rock fabrics; 2) detailed studies of the magnetic coercivity spectra of natural sediments to extract information on magnetic mineralogy and grain size from sedimentary and soil records; and 3) sensitive detection of the natural remanence of single-crystal silicate mineral specimens containing exsolved magnetic oxide inclusions to resolve the origin of magentic carrier phases. Studies in paleomagnetism, magnetostratigraphy and environmental magnetism will also be facilitated by the u-channel capability for continuous measurement of magnetic remanence in sediment cores. Such studies are important to understand the dynamics of the geomagnetic field and to unravel depositional paleoenvironmental conditions. The u-channel SQUID SRM will be freely available to the broader geoscience community through the IRM facility. The IRM supports rock magnetic and paleomagnetic research by a large number of U.S. and international scientists annually. Students and postdoctoral scholars may gain access to the instrument via IRM hosted travel support through their Visiting Fellows program. The PIs plan to develop and distribute a set of well-characterized standard materials and all magnetic data acquired will be made freely available through web-accessible rock magnetic databases.

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