Palaeomagnetism is the study of the Earth’s magnetic field preserved in rocks, sediment, or archeological materials. Some minerals, at the time of their formation, can become magnetized parallel to the Earth’s magnetic field.
Palaeomagnetism has a range of applications. Paleomagnetic evidence, both reversals and polar wandering data, was instrumental in verifying the theories of continental drift and plate tectonics. Paleomagnetic evidence combined with geochronological methods are used in dating rocks and in reconstructing the deformational histories of the earth’s crust and to estimate the age of sites bearing fossils. Conversely, for a fossil of known age, the paleomagnetic data can fix the latitude at which the fossil was laid down.
Applied Physics Systems applied our knowledge of high performance, superconducting systems for magnetic measurements to palaeomagnetism to create the APS Superconducting Rock Magnetometer (SRM). We received contracts to build the first two systems from the University of California at Santa Barbara in 1981 (Prof. Mike Fuller), and from the California Institute of Technology in 1982 (Prof. Joe Kirschvink). We have since installed over 100 liquid helium cooled systems and are currently on our third production of liquid helium free systems.