Magnetostratigrafía

Magnetostratigrafía is a chronostratigraphic technique that uses the reversals of Earth's magnetic field recorded in rocks to establish a relative age for geological strata. The Earth's magnetic field has reversed its polarity numerous times throughout geological history, creating a pattern of normal and reversed polarity zones. When rocks form, magnetic minerals within them align with the prevailing magnetic field, preserving a record of its orientation at that time. By measuring the magnetic polarity of rock layers in a sequence, geologists can create a magnetostratigraphic column. This column is then correlated with the globally recognized Geomagnetic Polarity Time Scale (GPTS), a timescale based on numerous independently dated sections worldwide. This correlation allows for the assignment of absolute ages to the rock layers. Magnetostratigraphy is particularly useful in sedimentary sequences where traditional dating methods might be difficult or impossible to apply. It provides a robust framework for understanding the timing of geological events, such as sediment accumulation, volcanic activity, and fossil occurrences. The resolution of magnetostratigraphy depends on the rate of sedimentation and the frequency of magnetic reversals.