Upgrading of a Superconducting Rock Magnetometer

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9727706 Coe This grant provides partial support to the University of Californa-Santa Cruz for the costs of upgrading superconducting rock magnetometer (SRM) and building an in-line alternating field (AF) demagnetizer. The current SRM at UC-Santa Cruz was purchased in 1985, the third SRM ever built by 2G enterprises. It suffers from repeated freezing blockages within the liquid helium plumbing lines, rapid liquid He boil-off rate and an order of magnitude lower sensitivity than currently available on state- of-the-art SRM's equipped with DC SQUIDs. 2-G Enterprises will refurbish this SRM with DC SQUIDs and with improvements in the plumbing and thermal design that will both reduce operating costs and increase safety. The AF demagnetizer will be built in-house. The increased sensitivity afforded paleomagnetic investigations through addition of DC SQUIDS will improve the reliability of paleomagnetic declinations and inclinations calculated for weakly magnetized rocks and sediments. Funded tectonic studies in southern Asia and the eastern California shear zone will immediately benefit from this upgrade. Furthermore, the capabilities of an in-line AF demagnetizer will enable elimination of secondary component magnetizations in samples that have been struck by lighting and will prove useful for paleointensity measurements made on Miocene flood basalts from Steens Mountain and early Cretaceous flood basalts from the Parana Basin in Brazil. These measurements are crucial for understanding past variations in the geomagnetic field. ***