This award supports a collaborative research Project between Caltech (EAR-0004069) and Vanderbilt University to develop an Ultra High Resolution Scanning Superconducting Quantum Interference Device (SQUID) Microscope (UHRSSM) for Paleomagnetic and Rock Studies. The instrument will be based on a small superconducting pickup coil coupled to a SQUID sensor housed in the vacuum space of a cyrostat, suspended behind a thin sapphire window less than 50mm above a room temperature sample. Scanning the sample allows us to map the z-component of the magnetic field above the sample with spatial resolutions as small as 100mm (limited mainly by the pickup coil diameter). The close spacing between sample and pickup coil results in an increase in sensitivity by four orders of magnitude compared to commercial SQUID moment magnetometers. The new instruments will allow for new classes of paleomagnetic analyses: (1) Conglomerate, baked contact, and fold tests on extremely small spatial scales, vastly expanding the utility of of these critical geological field tests of magnetic stability, (2) a suite of rock-magnetic and paleomagnetic experiments on standard petrographic thin sections, allowing the observed magnetic components to be matched with the minerals that are present, (3) Thellier-Thellier paleointensity analyses on individual mineral grains and at very high rates, (4) high resolution magnetic stratigraphy, and (5) spatial correlation of rock magnetic data with SEM, microprobe and other data on thin sections, at submillimeter scales.
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