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The geologic time scale or geological time scale (GTS) is a representation of time based on the rock record of Earth. It is a system of chronological dating that uses chronostratigraphy (the process of relating strata to time) and geochronology (a scientific branch of geology that aims to determine the age of rocks).
The Geologic Calendar is a scale in which the geological timespan of the Earth is mapped onto a calendrical year; that is to say, the day one of the Earth took place on a geologic January 1 at precisely midnight, and today's date and time is December 31 at midnight. [1]
In sediments, the time scale available for degradation increases by orders of magnitude with the result that 90% of the organic carbon delivered is degraded and only 0.2 Pg C yr −1 is eventually buried and transferred from the biosphere to the geosphere. [26] More complex model with many interacting boxes.
The Phanerozoic [5] is the current and the latest of the four geologic eons in the Earth's geologic time scale, covering the time period from 538.8 million years ago to the present. [1]
The earliest Earth crust probably forms similarly out of similar material. On Earth the pluvial period starts, in which the Earth's crust cools enough to let oceans form. c. 4,404 Ma – First known mineral, found at Jack Hills in Western Australia. Detrital zircons show presence of a solid crust and liquid water.
Carbon storage in the biosphere is influenced by a number of processes on different time-scales: while carbon uptake through autotrophic respiration follows a diurnal and seasonal cycle, carbon can be stored in the terrestrial biosphere for up to several centuries, e.g. in wood or soil. Most carbon leaves the terrestrial biosphere through ...
Geologic time shown in a diagram called a geological clock, showing the relative lengths of the eons of Earth's history and noting major events The geological history of Earth follows the major geological events in Earth's past based on the geologic time scale , a system of chronological measurement based on the study of the planet's rock ...
Exposure dating uses the concentration of exotic nuclides (e.g. 10 Be, 26 Al, 36 Cl) produced by cosmic rays interacting with Earth materials as a proxy for the age at which a surface, such as an alluvial fan, was created. Burial dating uses the differential radioactive decay of 2 cosmogenic elements as a proxy for the age at which a sediment ...