stratigráfián

Stratigráfia is the scientific study of rock layers and layering. It is a fundamental branch of geology that deals with the description and interpretation of stratified rocks, which are rocks deposited in successive layers. The primary goal of stratigraphy is to understand the history of the Earth as recorded in these rock layers.

The foundational principle of stratigraphy is the law of superposition, which states that in an undisturbed sequence of sedimentary rocks, the oldest layers are at the bottom and the youngest layers are at the top. Other key principles include the law of original horizontality, which suggests that sedimentary layers are deposited horizontally, and the law of lateral continuity, which posits that layers extend laterally in all directions until they thin out or encounter a barrier.

Stratigraphy employs various methods to study rock layers. Lithostratigraphy classifies and correlates rock units based on their lithological (rock type) characteristics. Biostratigraphy uses the fossil content of rock layers to determine their relative ages and correlate them across different locations. Chronostratigraphy aims to establish the absolute ages of rock layers. Magnetostratigraphy utilizes the magnetic properties of rocks to correlate and date them.

By analyzing these rock layers, geologists can reconstruct past environments, understand geological events such as mountain building and sea-level changes, and even identify potential sources of natural resources like oil, gas, and minerals. Stratigraphy is essential for geological mapping, resource exploration, and understanding the evolution of life on Earth.