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This work assessed the geologic history of the currently defined eons and eras of the pre-Cambrian, [note 2] and the proposals in the "Geological Time Scale" books 2004, [74] 2012, [5] and 2020. [75] Their recommend revisions [ 4 ] of the pre-Cryogenian geologic time scale were (changes from the current scale [v2023/09] are italicised):
This is a list of such named time periods as defined in various fields of study. ... Geologic Time – Period prior to humans. 4.6 billion to 3 million years ago ...
The geologic record is the strata (layers) of rock in the planet's crust and the science of geology is much concerned with the age and origin of all rocks to determine the history and formation of Earth and to understand the forces that have acted upon it.
The Phanerozoic Eon (Greek: period of well-displayed life) marks the appearance in the fossil record of abundant, shell-forming and/or trace-making organisms. It is subdivided into three eras, the Paleozoic, Mesozoic and Cenozoic, with major mass extinctions at division points.
The Paleozoic era spanned roughly (Ma) [39] and is subdivided into six geologic periods: from oldest to youngest, they are the Cambrian, Ordovician, Silurian, Devonian, Carboniferous and Permian. Geologically, the Paleozoic starts shortly after the breakup of a supercontinent called Pannotia and at the end of a global ice age.
Petermann Orogeny – Neoproterozoic mountain building event – Central Australia, late Neoproterozoic Era to Cambrian Period (c. 630–520 Ma) Delamerian Orogeny – Major geological province in central South Australia – South Australia and Victoria, Ordovician Period, (c. 514–510 Ma)
This is a list of the main divisions by continent and region. Dating also varies considerably and those given are broad approximations across wide areas. The three-age system has been used in many areas, referring to the prehistorical and historical periods identified by tool manufacture and use, of Stone Age , Bronze Age and Iron Age .
The succeeding eon is the Phanerozoic, divided into three eras: the Palaeozoic, an era of arthropods, fishes, and the first life on land; the Mesozoic, which spanned the rise, reign, and climactic extinction of the non-avian dinosaurs; and the Cenozoic, which saw the rise of mammals. Recognizable humans emerged at most 2 million years ago, a ...