Organization and Divisions Within the Geologic Time Scale As a System
Geochronology is a universal scale for measuring geological events that have occurred in the history of the Earth. It is not a scale equally divided into millions and billions of years (Vermeesch, 2018). In this line, the marks are not numbers but events of a planetary scale: the origin of life, the appearance of animals on land, the beginning of the split of lithospheric plates and the drift of continents, the extinction of dinosaurs, the appearance of intelligent man (Vweneesch, 2018). A set of sediment characteristics is formed that tells about geological events that took place on Earth in a specific time interval and at a certain point on the planetary scale. The key milestones of geological history, depending on their significance, serve as markers of different levels (O’Hara, 2018). These milestones form the geochronological scale, which comprises the main events of geological history.
Determining Rock Age
A radiological method will be used to determine the age of the volcanic rock sample, which has an average size. Only relative dating was available before its appearance (Losiak et al., 2020). It is a reference to specific geological eras, periods, epochs, and others, the period of which was not well known. Various radioisotope dating techniques use different isotopes of distinct minerals. It is based on the fact that the atomic nuclei of some unstable (radioactive) elements with a constant rate inherent in each of them, independent of external conditions, spontaneously decay, forming stable chemical elements. Each radioactive element has its own half-life, its own period during which a certain amount of radioactive substance is reduced by half, which will allow calculating the age of the rock (Losiak et al., 2020). Thus, the radiological method of research makes it possible to chronologically pinpoint specific periods of time in the history of the Earth’s crust.
References
Losiak, A., Jõeleht, A., Plado, J., Szyszka, M., Kirsimäe, K., Wild, E. M.,… & Helde, R. (2020). Determining the age and possibility for an extraterrestrial impact formation mechanism of the Ilumetsa structures (Estonia). Meteoritics & Planetary Science, 55(2), 274-293.
O’Hara, K. D. (2018). A Brief History of Geology. Cambridge University Press.
Vermeesch, P. (2018). IsoplotR: A free and open toolbox for geochronology. Geoscience Frontiers, 9(5), 1479-1493.