Stratigraphy
Study of rock layers and their formation / From Wikipedia, the free encyclopedia
This article is about the branch of geology. For stratigraphy in archaeology, see Stratigraphy (archaeology).
Stratigraphy is a branch of geology concerned with the study of rock layers (strata) and layering (stratification). It is primarily used in the study of sedimentary and layered volcanic rocks. Stratigraphy has three related subfields: lithostratigraphy (lithologic stratigraphy), biostratigraphy (biologic stratigraphy), and chronostratigraphy (stratigraphy by age).