magnetostratigrfia

Magnetostratigraphy is a branch of stratigraphy that uses the magnetic properties of sedimentary and volcanic rocks to establish a chronological record of Earth's magnetic field reversals. The Earth's magnetic field is not static; it has reversed its polarity many times throughout geological history. These reversals are recorded in the magnetic minerals within rocks as they form. When sediments are deposited, or lava cools, magnetic particles align themselves with the prevailing magnetic field at that time, effectively locking in a record of the field's direction and polarity.

By analyzing the magnetic orientation of rocks in a stratigraphic sequence, scientists can identify patterns of normal and reversed polarity. These patterns can then be correlated with a globally recognized magnetic polarity timescale, which has been established through the study of numerous volcanic and sedimentary sections. This correlation allows for the dating of rock layers that might otherwise be difficult to date. Magnetostratigraphy is particularly useful in Cenozoic and Mesozoic sequences where the magnetic polarity timescale is well-defined. It provides a high-resolution dating tool that can complement other dating methods like radiometric dating. The technique is applied in various fields, including paleoclimate studies, paleoceanography, and the dating of fossiliferous deposits.