Stratigraafilisi

Stratigraafilisi is the scientific study of stratification in rocks and soils, focusing on the arrangement, composition, and temporal relationships of layers. It aims to describe how rocks were deposited, how they relate to one another across space and time, and how to integrate them into a coherent record of geological history. The discipline provides the backbone of the geologic time scale and supports interpretations of past environments, climates, and processes.

Key principles include superposition (younger layers over older ones), original horizontality (sediments are deposited near horizontally), lateral continuity (layers extend laterally until they thin at edges), and cross-cutting relationships (intrusions or faults disrupt existing layers). The principle of faunal succession uses fossil content to correlate strata, while unconformities indicate gaps in the record.

Stratigraafilisi encompasses several subdisciplines: lithostratigraphy classifies rocks by lithology into units such as formations and members; biostratigraphy uses fossils to define biozones; chronostratigraphy aligns rock units with the geological time scale; sequence stratigraphy analyzes deposition in the context of sea-level changes. Other approaches include chemostratigraphy and magnetostratigraphy.

Methods involve field stratigraphy, measured sections, geological mapping, core and borehole data, and laboratory analyses. Dating combines radiometric methods with biostratigraphic correlation to establish relative and, where possible, absolute ages. Its outputs include stratigraphic columns, correlation charts, and seismic or borehole-based interpretations.

Applications span petroleum geology, groundwater and mineral exploration, environmental reconstructions, and archaeological dating. Stratigraafilisi has a long history, developing from foundational principles in the 17th–19th centuries to the present, with continual refinement through new dating techniques and imaging methods.