faunichron

Geochronology is the scientific study of Earth's rocks and rock assemblages to determine their age and history. It involves examining the distribution and succession of rock layers, known as strata, and the characteristics of fossil organisms preserved within them to understand past geologic events.1

A faunizone is a stratigraphic unit defined by the presence of a specific fauna that holds significance for a particular time or environment. The corresponding unit of geologic time is called a faunichron. Correlation, a key technique in geochronology, uses similar fossil content to establish the time equivalence of separated rock outcrops, based on the principle of faunal succession. This principle, first observed by William Smith around 1800, states that different rock layers are characterized by distinct fossil assemblages, indicating a specific order of succession in animal life throughout geologic history.23

Geochronometry specifically refers to the measurement of past time using geochronological methods, particularly those involving radioactive minerals or elements. Radiometric dating is a crucial method within geochronology, utilizing the constant decay rates of radioactive atoms into daughter atoms to determine ages.41