After World War II, geologists developed the paleomagnetic dating technique to measure the movements of the magnetic north pole over geologic time. In the early to mid 1960s, Dr. Robert Dubois introduced this new absolute dating technique to archaeology as archaeomagnetic dating.
Magnetism occurs whenever electrically charged particles are in motion.
The Earth's molten core has electric currents flowing through it. As the earth rotates, these electric currents produce a magnetic field that extends outward into space. This process, in which the rotation of a planet with an iron core produces a magnetic field, is called a dynamo effect. The Earth's magnetic core is generally inclined at an 11 degree angle from the Earth's axis of rotation. Therefore, the magnetic north pole is at approximately an 11 degree angle from the geographic north pole.