Paleomagnetism is the study of rock magnetism in order to determine the intensity and direction of Earth's magnetic field in the past.
it is paleomagnitism
The theory of plate tectonics links the theory of continental drift, which suggests that continents have moved over time, with the theory of seafloor spreading, which proposes that new oceanic crust is created at mid-ocean ridges. These two theories together explain how the Earth's lithosphere is divided into moving plates.