Interior of Rock Magnetics Laboratory in the Tarpaper Shack (room 40)

Interior of room 40 inside the tarpaper shacks on the USGS Menlo Park campus, circa 1965. 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 these 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.