Rubens coil in the Rock Magnetics Laboratory in Menlo Park, California

Rubens coil inside the Rock Magnetics Laboratory on the USGS Menlo Park campus. The function of the Rubens coil is to cancel the earth's magnetic field for thermal demagnetization of core samples. It is constructed of nonmagnetic materials and the control unit is place far enough away from the instrument to avoid interference from its metal components.

During the early 1960s, three of the key scientists working on the theory of magnetic reversals operated in the Rock Magnetics Laboratory that was housed in tarpaper shacks shacks. The Rock Magnetics Laboratory was designated a National Historic Landmark on October 12, 1994.

For more information, see the USGS film “Secrets in Stone” online.