palaeomagnetischer

Palaeomagnetischer refers to the study of the Earth's past magnetic field, as recorded in rocks. This field, known as the geomagnetic field, originates from the motion of molten iron in the Earth's outer core. When certain rocks, particularly igneous rocks like basalt, cool and solidify, magnetic minerals within them align with the prevailing geomagnetic field at that time and location. This alignment is then locked in place as the rock solidifies, preserving a record of the Earth's magnetic field from millions or even billions of years ago.

By analyzing the direction and intensity of the remanent magnetization in these rocks, scientists can reconstruct past magnetic field orientations. This palaeomagnetic data has been crucial for understanding plate tectonics. As tectonic plates move, the rocks they carry also move, carrying their palaeomagnetic signatures with them. Comparing the palaeomagnetic orientations of rocks from different continents has revealed that continents have drifted significantly over geological time, a phenomenon known as continental drift.

Furthermore, the Earth's magnetic field has experienced reversals throughout its history, where the magnetic north and south poles have swapped places. These reversals are recorded in the sequence of magnetic orientations in layered rocks, such as sedimentary rocks or successive lava flows. The pattern of these reversals, known as the geomagnetic polarity timescale, provides a powerful tool for dating rocks and correlating geological strata across vast distances. Palaeomagnetic studies also provide insights into the history of the Earth's core and its processes.