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The geologic time scale (GTS) is a system of chronological dating that relates geological strata (stratigraphy) to time. It is used by geologists, paleontologists, and other Earth
Earth
scientists to describe the timing and relationships of events that have occurred during Earth's history. The tables of geologic time spans, presented here, agree with the nomenclature, dates and standard color codes set forth by the International Commission on Stratigraphy
Stratigraphy
(ICS).

Contents

1 Terminology 2 Rationale 3 History
History
and nomenclature of the time scale

3.1 Early history 3.2 Establishment of primary principles 3.3 Formulation of geologic time scale 3.4 Naming of geologic periods, eras and epochs 3.5 Dating of time scales 3.6 The Anthropocene

4 Table of geologic time

4.1 Proposed Precambrian
Precambrian
timeline

5 See also 6 Notes 7 References 8 Further reading 9 External links

Terminology[edit] The primary defined divisions of time are eons, in sequence the Hadean, the Archean, the Proterozoic
Proterozoic
and the Phanerozoic. The first three of these can be referred to collectively as the Precambrian supereon. Eons are divided into eras, which are in turn divided into periods, epochs and ages. The following four timelines show the geologic time scale. The first shows the entire time from the formation of the Earth
Earth
to the present, but this gives little space for the most recent eon. Therefore, the second timeline shows an expanded view of the most recent eon. In a similar way, the most recent era is expanded in the third timeline, and the most recent period is expanded in the fourth timeline.

Millions of Years

Corresponding to eons, eras, periods, epochs and ages, the terms "eonothem", "erathem", "system", "series", "stage" are used to refer to the layers of rock that belong to these stretches of geologic time in Earth's history. Geologists qualify these units as "early", "mid", and "late" when referring to time, and "lower", "middle", and "upper" when referring to the corresponding rocks. For example, the lower Jurassic
Jurassic
Series in chronostratigraphy corresponds to the early Jurassic
Jurassic
Epoch in geochronology.[2] The adjectives are capitalized when the subdivision is formally recognized, and lower case when not; thus "early Miocene" but "Early Jurassic." Rationale[edit] Evidence from radiometric dating indicates that Earth
Earth
is about 4.54 billion years old.[3][4] The geology or deep time of Earth's past has been organized into various units according to events which took place. Different spans of time on the GTS are usually marked by corresponding changes in the composition of strata which indicate major geological or paleontological events, such as mass extinctions. For example, the boundary between the Cretaceous
Cretaceous
period and the Paleogene period is defined by the Cretaceous– Paleogene extinction event, which marked the demise of the non-avian dinosaurs and many other groups of life. Older time spans, which predate the reliable fossil record (before the Proterozoic
Proterozoic
eon), are defined by their absolute age. Geologic units from the same time but different parts of the world often look different and contain different fossils, so the same time-span was historically given different names in different locales. For example, in North America, the Lower Cambrian
Cambrian
is called the Waucoban series that is then subdivided into zones based on succession of trilobites. In East Asia
East Asia
and Siberia, the same unit is split into Alexian, Atdabanian, and Botomian stages. A key aspect of the work of the International Commission on Stratigraphy
Stratigraphy
is to reconcile this conflicting terminology and define universal horizons that can be used around the world.[5] Some other planets and moons in the Solar System
Solar System
have sufficiently rigid structures to have preserved records of their own histories, for example, Venus, Mars and the Earth's Moon. Dominantly fluid planets, such as the gas giants, do not preserve their history in a comparable manner. Apart from the Late Heavy Bombardment, events on other planets probably had little direct influence on the Earth, and events on Earth had correspondingly little effect on those planets. Construction of a time scale that links the planets is, therefore, of only limited relevance to the Earth's time scale, except in a Solar System
Solar System
context. The existence, timing, and terrestrial effects of the Late Heavy Bombardment is still debated.[a] History
History
and nomenclature of the time scale[edit]

Life
Life
timeline

view • discuss • edit

-4500 — – -4000 — – -3500 — – -3000 — – -2500 — – -2000 — – -1500 — – -1000 — – -500 — – 0 —

water

Single-celled life

photosynthesis

Eukaryotes

Multicellular life

Land life

Dinosaurs    

Mammals

Flowers

 

Earliest Earth
Earth
(−4540)

Earliest water

Earliest life

LHB meteorites

Earliest oxygen

Atmospheric oxygen

Oxygen
Oxygen
crisis

Earliest sexual reproduction

Ediacara biota

Cambrian
Cambrian
explosion

Earliest humans

P h a n e r o z o i c

P r o t e r o z o i c

A r c h e a n

H a d e a n

Pongola

Huronian

Cryogenian

Andean

Karoo

Quaternary

Axis scale: million years Orange labels: ice ages. Also see: Human
Human
timeline and Nature timeline

Main articles: History of geology
History of geology
and History
History
of paleontology

Graphical representation of Earth's history as a spiral

Early history[edit] In Ancient Greece, Aristotle
Aristotle
(384-322 BCE) observed that fossils of seashells in rocks resembled those found on beaches – he inferred that the fossils in rocks were formed by living animals, and he reasoned that the positions of land and sea had changed over long periods of time. Leonardo da Vinci
Leonardo da Vinci
(1452–1519) concurred with Aristotle's interpretation that fossils represented the remains of ancient life.[6] The 11th-century Persian geologist Avicenna
Avicenna
(Ibn Sina, died 1037) and the 13th-century Dominican bishop Albertus Magnus
Albertus Magnus
(died 1280) extended Aristotle's explanation into a theory of a petrifying fluid.[7] Avicenna
Avicenna
also first proposed one of the principles underlying geologic time scales, the law of superposition of strata, while discussing the origins of mountains in The Book of Healing
The Book of Healing
(1027).[8][9] The Chinese naturalist Shen Kuo
Shen Kuo
(1031–1095) also recognized the concept of "deep time".[10] Establishment of primary principles[edit] In the late 17th century Nicholas Steno
Nicholas Steno
(1638–1686) pronounced the principles underlying geologic (geological) time scales. Steno argued that rock layers (or strata) were laid down in succession, and that each represents a "slice" of time. He also formulated the law of superposition, which states that any given stratum is probably older than those above it and younger than those below it. While Steno's principles were simple, applying them proved challenging. Over the course of the 18th century geologists realized that:

Sequences of strata often become eroded, distorted, tilted, or even inverted after deposition Strata laid down at the same time in different areas could have entirely different appearances The strata of any given area represented only part of Earth's long history

The Neptunist
Neptunist
theories popular at this time (expounded by Abraham Werner (1749–1817) in the late 18th century) proposed that all rocks had precipitated out of a single enormous flood. A major shift in thinking came when James Hutton
James Hutton
presented his Theory of the Earth; or, an Investigation of the Laws Observable in the Composition, Dissolution, and Restoration of Land Upon the Globe[11] before the Royal Society of Edinburgh
Royal Society of Edinburgh
in March and April 1785. It has been said[by whom?] that "as things appear from the perspective of the 20th century, James Hutton
James Hutton
in those readings became the founder of modern geology".[12]:95-100 Hutton proposed that the interior of Earth
Earth
was hot, and that this heat was the engine which drove the creation of new rock: land was eroded by air and water and deposited as layers in the sea; heat then consolidated the sediment into stone, and uplifted it into new lands. This theory, known as "Plutonism", stood in contrast to the "Neptunist" flood-oriented theory. Formulation of geologic time scale[edit] The first serious attempts to formulate a geologic time scale that could be applied anywhere on Earth
Earth
were made in the late 18th century. The most influential of those early attempts (championed by Werner, among others) divided the rocks of Earth's crust into four types: Primary, Secondary, Tertiary, and Quaternary. Each type of rock, according to the theory, formed during a specific period in Earth history. It was thus possible to speak of a " Tertiary Period" as well as of " Tertiary Rocks." Indeed, "Tertiary" (now Paleogene and Neogene) remained in use as the name of a geological period well into the 20th century and "Quaternary" remains in formal use as the name of the current period. The identification of strata by the fossils they contained, pioneered by William Smith, Georges Cuvier, Jean d'Omalius d'Halloy, and Alexandre Brongniart
Alexandre Brongniart
in the early 19th century, enabled geologists to divide Earth
Earth
history more precisely. It also enabled them to correlate strata across national (or even continental) boundaries. If two strata (however distant in space or different in composition) contained the same fossils, chances were good that they had been laid down at the same time. Detailed studies between 1820 and 1850 of the strata and fossils of Europe produced the sequence of geologic periods still used today. Naming of geologic periods, eras and epochs[edit] Early work on developing the geologic time scale was dominated by British geologists, and the names of the geologic periods reflect that dominance. The "Cambrian", (the classical name for Wales) and the "Ordovician", and "Silurian", named after ancient Welsh tribes, were periods defined using stratigraphic sequences from Wales.[12]:113–114 The "Devonian" was named for the English county of Devon, and the name "Carboniferous" was an adaptation of "the Coal Measures", the old British geologists’ term for the same set of strata. The "Permian" was named after Perm, Russia, because it was defined using strata in that region by Scottish geologist Roderick Murchison. However, some periods were defined by geologists from other countries. The "Triassic" was named in 1834 by a German geologist Friedrich Von Alberti
Friedrich Von Alberti
from the three distinct layers (Latin trias meaning triad)—red beds, capped by chalk, followed by black shales—that are found throughout Germany and Northwest Europe, called the ‘Trias’. The "Jurassic" was named by a French geologist Alexandre Brongniart
Alexandre Brongniart
for the extensive marine limestone exposures of the Jura Mountains. The "Cretaceous" (from Latin creta meaning ‘chalk’) as a separate period was first defined by Belgian geologist Jean d'Omalius d'Halloy in 1822, using strata in the Paris basin[13] and named for the extensive beds of chalk (calcium carbonate deposited by the shells of marine invertebrates) found in Western Europe. British geologists were also responsible for the grouping of periods into eras and the subdivision of the Tertiary and Quaternary
Quaternary
periods into epochs. In 1841 John Phillips published the first global geologic time scale based on the types of fossils found in each era. Phillips’ scale helped standardize the use of terms like Paleozoic ("old life") which he extended to cover a larger period than it had in previous usage, and Mesozoic
Mesozoic
("middle life") which he invented.[14] Dating of time scales[edit] Main article: Chronological dating When William Smith and Sir Charles Lyell
Sir Charles Lyell
first recognized that rock strata represented successive time periods, time scales could be estimated only very imprecisely since estimates of rates of change were uncertain. While creationists had been proposing dates of around six or seven thousand years for the age of Earth
Earth
based on the Bible, early geologists were suggesting millions of years for geologic periods, and some were even suggesting a virtually infinite age for Earth.[citation needed] Geologists and paleontologists constructed the geologic table based on the relative positions of different strata and fossils, and estimated the time scales based on studying rates of various kinds of weathering, erosion, sedimentation, and lithification. Until the discovery of radioactivity in 1896 and the development of its geological applications through radiometric dating during the first half of the 20th century, the ages of various rock strata and the age of Earth
Earth
were the subject of considerable debate. The first geologic time scale that included absolute dates was published in 1913 by the British geologist Arthur Holmes.[15] He greatly furthered the newly created discipline of geochronology and published the world-renowned book The Age of the Earth
Age of the Earth
in which he estimated Earth's age to be at least 1.6 billion years.[16] In 1977, the Global Commission on Stratigraphy
Stratigraphy
(now the International Commission on Stratigraphy) began to define global references known as GSSP (Global Boundary Stratotype Sections and Points) for geologic periods and faunal stages. The commission's most recent work is described in the 2004 geologic time scale of Gradstein et al.[17] A UML model for how the timescale is structured, relating it to the GSSP, is also available.[18][19] The Anthropocene[edit] The term "Anthropocene" is used informally by popular culture and a growing number of scientists to describe the current epoch in which we are living. The term was coined by Paul Crutzen and Eugene Stoermer in 2000 to describe the current time, in which humans have had an enormous impact on the environment. It has evolved to describe an "epoch" starting some time in the past and on the whole defined by anthropogenic carbon emissions and production and consumption of plastic goods that are left in the ground.[20] Critics of this term say that the term should not be used because it is difficult, if not nearly impossible, to define a specific time when humans started influencing the rock strata—defining the start of an epoch.[21] Others say that humans have not even started to leave their biggest impact on Earth, and therefore the Anthropocene
Anthropocene
has not even started yet. as of September 2015[update], the ICS has not officially approved the term.[22] The Anthropocene
Anthropocene
Working Group met in Oslo in April 2016 to consolidate evidence supporting the argument for the Anthropocene as a true geologic epoch.[23] Evidence was evaluated and the group voted to recommend "Anthropocene" as the new geological age in August 2016.[24] Should the International Commission on Stratigraphy
Stratigraphy
approve the recommendation, the proposal to adopt the term will have to be ratified by the International Union of Geological Sciences before its formal adoption as part of the geologic time scale.[25] Table of geologic time[edit] The following table summarizes the major events and characteristics of the periods of time making up the geologic time scale. This table is arranged with the most recent geologic periods at the top, and the most ancient at the bottom. The height of each table entry does not correspond to the duration of each subdivision of time. The content of the table is based on the current official geologic time scale of the International Commission on Stratigraphy,[1] with the epoch names altered to the early/late format from lower/upper as recommended by the ICS when dealing with chronostratigraphy.[2] A service providing a Resource Description Framework/Web Ontology Language representation of the timescale is available through the Commission for the Management and Application of Geoscience Information GeoSciML project as a service[26] and at a SPARQL end-point.[27][28]

Supereon Eon Era Period[b] Epoch Age[c] Major events Start, million years ago[c]

n/a[d] Phanerozoic Cenozoic[e] Quaternary Holocene

chrons: Subatlantic · Subboreal · Atlantic · Boreal · Preboreal

Quaternary
Quaternary
Ice Age recedes, and the current interglacial begins. Sahara
Sahara
forms from savannah. Rise of human civilization, beginning of agriculture. Stone Age
Stone Age
cultures give way to Bronze Age
Bronze Age
(3300 BC) and Iron Age
Iron Age
(1200 BC), giving rise to many pre-historic cultures throughout the world. Little Ice Age
Little Ice Age
(stadial) causes brief cooling in Northern Hemisphere
Northern Hemisphere
from 1400 to 1850. Following the Industrial Revolution, atmospheric CO2 levels rise from around 280 parts per million volume (ppmv) to the current level of 400[31] ppmv.[32][f] 0.0117[g]

Pleistocene Late (locally Tarantian · Tyrrhenian · Eemian · Sangamonian) Flourishing and then extinction of Pleistocene
Pleistocene
megafauna. Evolution
Evolution
of anatomically modern humans. Quaternary
Quaternary
Ice Age continues with glaciations and interstadials (and the accompanying fluctuations from 100 to 300 ppmv in atmospheric CO2 levels[32][f]), further intensification of Icehouse Earth
Earth
conditions, roughly 1.6 Ma. Last glacial maximum (30000 years ago), last glacial period (18000–15000 years ago). Dawn of human stone-age cultures, with increasing technical complexity relative to previous ice age cultures, such as engravings and clay statues (e.g. Venus of Lespugue), particularly in the Mediterranean and Europe. Lake Toba
Lake Toba
supervolcano erupts 75000 years before present, causing a volcanic winter that possibly pushes humanity to the brink of extinction. Pleistocene
Pleistocene
ends with Oldest Dryas, Older Dryas/Allerød and Younger Dryas
Younger Dryas
climate events, with Younger Dryas
Younger Dryas
forming the boundary with the Holocene. 0.126

Middle (formerly Ionian) 0.781

Calabrian 1.8*

Gelasian 2.58*

Neogene Pliocene Piacenzian Intensification of present Icehouse conditions, present (Quaternary) ice age begins roughly 2.58 Ma; cool and dry climate. Australopithecines, many of the existing genera of mammals, and recent mollusks appear. Homo habilis
Homo habilis
appears. 3.6*

Zanclean 5.333*

Miocene Messinian Moderate Icehouse climate, punctuated by ice ages; Orogeny
Orogeny
in Northern Hemisphere. Modern mammal and bird families become recognizable. Horses and mastodons diverse. Grasses become ubiquitous. First apes appear (for reference see the article: "Sahelanthropus tchadensis"). Kaikoura Orogeny
Orogeny
forms Southern Alps
Alps
in New Zealand, continues today. Orogeny
Orogeny
of the Alps
Alps
in Europe slows, but continues to this day. Carpathian orogeny forms Carpathian Mountains
Carpathian Mountains
in Central and Eastern Europe. Hellenic orogeny in Greece and Aegean Sea
Aegean Sea
slows, but continues to this day. Middle Miocene
Miocene
Disruption occurs. Widespread forests slowly draw in massive amounts of CO2, gradually lowering the level of atmospheric CO2 from 650 ppmv down to around 100 ppmv.[32][f] 7.246*

Tortonian 11.63*

Serravallian 13.82*

Langhian 15.97

Burdigalian 20.44

Aquitanian 23.03*

Paleogene Oligocene Chattian Warm but cooling climate, moving towards Icehouse; Rapid evolution and diversification of fauna, especially mammals. Major evolution and dispersal of modern types of flowering plants 28.1

Rupelian 33.9*

Eocene Priabonian Moderate, cooling climate. Archaic mammals (e.g. Creodonts, Condylarths, Uintatheres, etc.) flourish and continue to develop during the epoch. Appearance of several "modern" mammal families. Primitive whales diversify. First grasses. Reglaciation of Antarctica and formation of its ice cap; Azolla event
Azolla event
triggers ice age, and the Icehouse Earth
Earth
climate that would follow it to this day, from the settlement and decay of seafloor algae drawing in massive amounts of atmospheric carbon dioxide,[32][f] lowering it from 3800 ppmv down to 650 ppmv. End of Laramide and Sevier Orogenies of the Rocky Mountains in North America. Orogeny
Orogeny
of the Alps
Alps
in Europe begins. Hellenic Orogeny
Orogeny
begins in Greece and Aegean Sea. 37.8

Bartonian 41.2

Lutetian 47.8*

Ypresian 56*

Paleocene Thanetian Climate
Climate
tropical. Modern plants appear; Mammals diversify into a number of primitive lineages following the extinction of the non-avian dinosaurs. First large mammals (up to bear or small hippo size). Alpine orogeny
Alpine orogeny
in Europe and Asia begins. Indian Subcontinent
Indian Subcontinent
collides with Asia 55 Ma, Himalayan Orogeny
Orogeny
starts between 52 and 48 Ma. 59.2*

Selandian 61.6*

Danian 66*

Mesozoic Cretaceous Late Maastrichtian Flowering plants proliferate, along with new types of insects. More modern teleost fish begin to appear. Ammonoidea, belemnites, rudist bivalves, echinoids and sponges all common. Many new types of dinosaurs (e.g. Tyrannosaurs, Titanosaurs, duck bills, and horned dinosaurs) evolve on land, as do Eusuchia
Eusuchia
(modern crocodilians); and mosasaurs and modern sharks appear in the sea. Primitive birds gradually replace pterosaurs. Monotremes, marsupials and placental mammals appear. Break up of Gondwana. Beginning of Laramide and Sevier Orogenies of the Rocky Mountains. atmospheric CO2 close to present-day levels. 72.1 ± 0.2*

Campanian 83.6 ± 0.2

Santonian 86.3 ± 0.5*

Coniacian 89.8 ± 0.3

Turonian 93.9*

Cenomanian 100.5*

Early Albian ~113

Aptian ~125

Barremian ~129.4

Hauterivian ~132.9

Valanginian ~139.8

Berriasian ~145

Jurassic Late Tithonian Gymnosperms (especially conifers, Bennettitales
Bennettitales
and cycads) and ferns common. Many types of dinosaurs, such as sauropods, carnosaurs, and stegosaurs. Mammals common but small. First birds and lizards. Ichthyosaurs and plesiosaurs diverse. Bivalves, Ammonites and belemnites abundant. Sea urchins very common, along with crinoids, starfish, sponges, and terebratulid and rhynchonellid brachiopods. Breakup of Pangaea
Pangaea
into Gondwana
Gondwana
and Laurasia. Nevadan orogeny
Nevadan orogeny
in North America. Rangitata and Cimmerian orogenies taper off. Atmospheric CO2 levels 3–4 times the present day levels (1200–1500 ppmv, compared to today's 400 ppmv[32][f]). 152.1 ± 0.9

Kimmeridgian 157.3 ± 1.0

Oxfordian 163.5 ± 1.0

Middle Callovian 166.1 ± 1.2

Bathonian 168.3 ± 1.3*

Bajocian 170.3 ± 1.4*

Aalenian 174.1 ± 1.0*

Early Toarcian 182.7 ± 0.7*

Pliensbachian 190.8 ± 1.0*

Sinemurian 199.3 ± 0.3*

Hettangian 201.3 ± 0.2*

Triassic Late Rhaetian Archosaurs dominant on land as dinosaurs, in the oceans as Ichthyosaurs and nothosaurs, and in the air as pterosaurs. Cynodonts become smaller and more mammal-like, while first mammals and crocodilia appear. Dicroidiumflora common on land. Many large aquatic temnospondyl amphibians. Ceratitic ammonoids extremely common. Modern corals and teleost fish appear, as do many modern insect clades. Andean Orogeny
Orogeny
in South America. Cimmerian Orogeny
Orogeny
in Asia. Rangitata Orogeny
Orogeny
begins in New Zealand. Hunter-Bowen Orogeny
Orogeny
in Northern Australia, Queensland and New South Wales
Wales
ends, (c. 260–225 Ma) ~208.5

Norian ~227

Carnian ~237*

Middle Ladinian ~242*

Anisian 247.2

Early Olenekian 251.2

Induan 251.902 ± 0.06*

Paleozoic Permian Lopingian Changhsingian Landmasses unite into supercontinent Pangaea, creating the Appalachians. End of Permo- Carboniferous
Carboniferous
glaciation. Synapsid reptiles (pelycosaurs and therapsids) become plentiful, while parareptiles and temnospondyl amphibians remain common. In the mid-Permian, coal-age flora are replaced by cone-bearing gymnosperms (the first true seed plants) and by the first true mosses. Beetles
Beetles
and flies evolve. Marine life flourishes in warm shallow reefs; productid and spiriferid brachiopods, bivalves, forams, and ammonoids all abundant. Permian- Triassic
Triassic
extinction event occurs 251 Ma: 95% of life on Earth becomes extinct, including all trilobites, graptolites, and blastoids. Ouachita and Innuitian orogenies in North America. Uralian orogeny
Uralian orogeny
in Europe/Asia tapers off. Altaid orogeny in Asia. Hunter-Bowen Orogeny on Australian continent begins (c. 260–225 Ma), forming the MacDonnell Ranges. 254.14 ± 0.07*

Wuchiapingian 259.1 ± 0.4*

Guadalupian Capitanian 265.1 ± 0.4*

Wordian 268.8 ± 0.5*

Roadian 272.95 ± 0.5*

Cisuralian Kungurian 283.5 ± 0.6

Artinskian 290.1 ± 0.26

Sakmarian 295 ± 0.18

Asselian 298.9 ± 0.15*

Carbon- iferous[h] Pennsylvanian Gzhelian Winged insects radiate suddenly; some (esp. Protodonata
Protodonata
and Palaeodictyoptera) are quite large. Amphibians common and diverse. First reptiles and coal forests (scale trees, ferns, club trees, giant horsetails, Cordaites, etc.). Highest-ever atmospheric oxygen levels. Goniatites, brachiopods, bryozoa, bivalves, and corals plentiful in the seas and oceans. Testate forams proliferate. Uralian orogeny
Uralian orogeny
in Europe and Asia. Variscan orogeny
Variscan orogeny
occurs towards middle and late Mississippian Periods. 303.7 ± 0.1

Kasimovian 307 ± 0.1

Moscovian 315.2 ± 0.2

Bashkirian 323.2 ± 0.4*

Mississippian Serpukhovian Large primitive trees, first land vertebrates, and amphibious sea-scorpions live amid coal-forming coastal swamps. Lobe-finned rhizodonts are dominant big fresh-water predators. In the oceans, early sharks are common and quite diverse; echinoderms (especially crinoids and blastoids) abundant. Corals, bryozoa, goniatites and brachiopods (Productida, Spiriferida, etc.) very common, but trilobites and nautiloids decline. Glaciation
Glaciation
in East Gondwana. Tuhua Orogeny
Orogeny
in New Zealand tapers off. 330.9 ± 0.2

Viséan 346.7 ± 0.4*

Tournaisian 358.9 ± 0.4*

Devonian Late Famennian First clubmosses, horsetails and ferns appear, as do the first seed-bearing plants (progymnosperms), first trees (the progymnosperm Archaeopteris), and first (wingless) insects. Strophomenid and atrypid brachiopods, rugose and tabulate corals, and crinoids are all abundant in the oceans. Goniatite
Goniatite
ammonoids are plentiful, while squid-like coleoids arise. Trilobites and armoured agnaths decline, while jawed fishes (placoderms, lobe-finned and ray-finned fish, and early sharks) rule the seas. First amphibians still aquatic. "Old Red Continent" of Euramerica. Beginning of Acadian Orogeny
Orogeny
for Anti- Atlas Mountains
Atlas Mountains
of North Africa, and Appalachian Mountains
Appalachian Mountains
of North America, also the Antler, Variscan, and Tuhua Orogeny
Orogeny
in New Zealand. 372.2 ± 1.6*

Frasnian 382.7 ± 1.6*

Middle Givetian 387.7 ± 0.8*

Eifelian 393.3 ± 1.2*

Early Emsian 407.6 ± 2.6*

Pragian 410.8 ± 2.8*

Lochkovian 419.2 ± 3.2*

Silurian Pridoli First vascular plants (the rhyniophytes and their relatives), first millipedes and arthropleurids on land. First jawed fishes, as well as many armoured jawless fish, populate the seas. Sea-scorpions reach large size. Tabulate and rugose corals, brachiopods (Pentamerida, Rhynchonellida, etc.), and crinoids all abundant. Trilobites and mollusks diverse; graptolites not as varied. Beginning of Caledonian Orogeny
Orogeny
for hills in England, Ireland, Wales, Scotland, and the Scandinavian Mountains. Also continued into Devonian
Devonian
period as the Acadian Orogeny, above. Taconic Orogeny
Orogeny
tapers off. Lachlan Orogeny
Orogeny
on Australian continent tapers off. 423 ± 2.3*

Ludlow Ludfordian 425.6 ± 0.9*

Gorstian 427.4 ± 0.5*

Wenlock Homerian 430.5 ± 0.7*

Sheinwoodian 433.4 ± 0.8*

Llandovery Telychian 438.5 ± 1.1*

Aeronian 440.8 ± 1.2*

Rhuddanian 443.8 ± 1.5*

Ordovician Late Hirnantian Invertebrates diversify into many new types (e.g., long straight-shelled cephalopods). Early corals, articulate brachiopods (Orthida, Strophomenida, etc.), bivalves, nautiloids, trilobites, ostracods, bryozoa, many types of echinoderms (crinoids, cystoids, starfish, etc.), branched graptolites, and other taxa all common. Conodonts (early planktonic vertebrates) appear. First green plants and fungi on land. Ice age
Ice age
at end of period. 445.2 ± 1.4*

Katian 453 ± 0.7*

Sandbian 458.4 ± 0.9*

Middle Darriwilian 467.3 ± 1.1*

Dapingian 470 ± 1.4*

Early Floian (formerly Arenig) 477.7 ± 1.4*

Tremadocian 485.4 ± 1.9*

Cambrian Furongian Stage 10 Major diversification of life in the Cambrian
Cambrian
Explosion. Numerous fossils; most modern animal phyla appear. First chordates appear, along with a number of extinct, problematic phyla. Reef-building Archaeocyatha
Archaeocyatha
abundant; then vanish. Trilobites, priapulid worms, sponges, inarticulate brachiopods (unhinged lampshells), and numerous other animals. Anomalocarids are giant predators, while many Ediacaran fauna die out. Prokaryotes, protists (e.g., forams), fungi and algae continue to present day. Gondwana
Gondwana
emerges. Petermann Orogeny
Orogeny
on the Australian continent tapers off (550–535 Ma). Ross Orogeny
Orogeny
in Antarctica. Adelaide Geosyncline (Delamerian Orogeny), majority of orogenic activity from 514–500 Ma. Lachlan Orogeny
Orogeny
on Australian continent, c. 540–440 Ma. Atmospheric CO2 content roughly 15 times present-day (Holocene) levels (6000 ppmv compared to today's 400 ppmv)[32][f] ~489.5

Jiangshanian ~494*

Paibian ~497*

Series 3 Guzhangian ~500.5*

Drumian ~504.5*

Stage 5 ~509

Series 2 Stage 4 ~514

Stage 3 ~521

Terreneuvian Stage 2 ~529

Fortunian ~541 ± 1.0*

Precambrian[i] Proterozoic[j] Neoproterozoic[j] Ediacaran Good fossils of the first multi-celled animals. Ediacaran
Ediacaran
biota flourish worldwide in seas. Simple trace fossils of possible worm-like Trichophycus, etc. First sponges and trilobitomorphs. Enigmatic forms include many soft-jellied creatures shaped like bags, disks, or quilts (like Dickinsonia). Taconic Orogeny
Orogeny
in North America. Aravalli Range orogeny in Indian Subcontinent. Beginning of Petermann Orogeny
Orogeny
on Australian continent. Beardmore Orogeny
Orogeny
in Antarctica, 633–620 Ma. ~635*

Cryogenian Possible "Snowball Earth" period. Fossils
Fossils
still rare. Rodinia
Rodinia
landmass begins to break up. Late Ruker / Nimrod Orogeny
Orogeny
in Antarctica tapers off. ~720[k]

Tonian Rodinia
Rodinia
supercontinent persists. Sveconorwegian orogeny
Sveconorwegian orogeny
ends. Trace fossils of simple multi-celled eukaryotes. First radiation of dinoflagellate-like acritarchs. Grenville Orogeny
Orogeny
tapers off in North America. Pan-African orogeny
Pan-African orogeny
in Africa. Lake Ruker / Nimrod Orogeny
Orogeny
in Antarctica, 1,000 ± 150 Ma. Edmundian Orogeny
Orogeny
(c. 920 – 850 Ma), Gascoyne Complex, Western Australia. Adelaide Geosyncline laid down on Australian continent, beginning of Adelaide Geosyncline (Delamerian Orogeny) in Australia. 1000[k]

Mesoproterozoic[j] Stenian Narrow highly metamorphic belts due to orogeny as Rodinia
Rodinia
forms. Sveconorwegian orogeny
Sveconorwegian orogeny
starts. Late Ruker / Nimrod Orogeny
Orogeny
in Antarctica possibly begins. Musgrave Orogeny
Orogeny
(c. 1,080 Ma), Musgrave Block, Central Australia. 1200[k]

Ectasian Platform covers continue to expand. Green algae
Green algae
colonies in the seas. Grenville Orogeny
Orogeny
in North America. 1400[k]

Calymmian Platform covers expand. Barramundi Orogeny, McArthur Basin, Northern Australia, and Isan Orogeny, c.1,600 Ma, Mount Isa Block, Queensland 1600[k]

Paleoproterozoic[j] Statherian First complex single-celled life: protists with nuclei. Columbia is the primordial supercontinent. Kimban Orogeny
Orogeny
in Australian continent ends. Yapungku Orogeny
Orogeny
on Yilgarn craton, in Western Australia. Mangaroon Orogeny, 1,680–1,620 Ma, on the Gascoyne Complex in Western Australia. Kararan Orogeny
Orogeny
(1,650 Ma), Gawler Craton, South Australia. 1800[k]

Orosirian The atmosphere becomes oxygenic. Vredefort and Sudbury Basin
Sudbury Basin
asteroid impacts. Much orogeny. Penokean and Trans-Hudsonian Orogenies in North America. Early Ruker Orogeny
Orogeny
in Antarctica, 2,000–1,700 Ma. Glenburgh Orogeny, Glenburgh Terrane, Australian continent c. 2,005–1,920 Ma. Kimban Orogeny, Gawler craton
Gawler craton
in Australian continent begins. 2050[k]

Rhyacian Bushveld Igneous Complex
Bushveld Igneous Complex
forms. Huronian glaciation. 2300[k]

Siderian Oxygen
Oxygen
catastrophe: banded iron formations forms. Sleaford Orogeny
Orogeny
on Australian continent, Gawler Craton
Gawler Craton
2,440–2,420 Ma. 2500[k]

Archean[j] Neoarchean[j] Stabilization of most modern cratons; possible mantle overturn event. Insell Orogeny, 2,650 ± 150 Ma. Abitibi greenstone belt
Abitibi greenstone belt
in present-day Ontario
Ontario
and Quebec
Quebec
begins to form, stabilizes by 2,600 Ma. 2800[k]

Mesoarchean[j] First stromatolites (probably colonial cyanobacteria). Oldest macrofossils. Humboldt Orogeny
Orogeny
in Antarctica. Blake River Megacaldera Complex begins to form in present-day Ontario
Ontario
and Quebec, ends by roughly 2,696 Ma. 3200[k]

Paleoarchean[j] First known oxygen-producing bacteria. Oldest definitive microfossils. Oldest cratons on Earth
Earth
(such as the Canadian Shield
Canadian Shield
and the Pilbara Craton) may have formed during this period.[l] Rayner Orogeny
Orogeny
in Antarctica. 3600[k]

Eoarchean[j] Simple single-celled life (probably bacteria and archaea). Oldest probable microfossils. The first life forms and self-replicating RNA molecules evolve around 4,000 Ma, after the Late Heavy Bombardment ends on Earth. Napier Orogeny
Orogeny
in Antarctica, 4,000 ± 200 Ma. ~4000

Hadean[j][m] Early Imbrian
Early Imbrian
(Neohadean) (unofficial)[j][n] Indirect photosynthetic evidence (e.g., kerogen) of primordial life. This era overlaps the beginning of the Late Heavy Bombardment
Late Heavy Bombardment
of the Inner Solar System, produced possibly by the planetary migration of Neptune
Neptune
into the Kuiper belt
Kuiper belt
as a result of orbital resonances between Jupiter
Jupiter
and Saturn. Oldest known rock (4,031 to 3,580 Ma).[34] 4130[35]

Nectarian (Mesohadean) (unofficial)[j][n] Possible first appearance of plate tectonics. This unit gets its name from the lunar geologic timescale when the Nectaris Basin
Nectaris Basin
and other greater lunar basins form by big impact events. Earliest evidence for life based on unusually high amounts of light isotopes of carbon, a common sign of life. 4280[35]

Basin Groups (Paleohadean) (unofficial)[j][n] End of the Early Bombardment Phase. Oldest known mineral (Zircon, 4,404 ± 8 Ma). Asteroids and comets bring water to Earth.[36] 4533[35]

Cryptic (Eohadean) (unofficial)[j][n] Formation of Moon
Moon
(4,533 to 4,527 Ma), probably from giant impact, since the end of this era. Formation of Earth
Earth
(4,570 to 4,567.17 Ma), Early Bombardment Phase begins. Formation of Sun
Sun
(4,680 to 4,630 Ma) . 4600

Proposed Precambrian
Precambrian
timeline[edit] The ICS's Geologic Time
Time
Scale 2012 book which includes the new approved time scale also displays a proposal to substantially revise the Precambrian
Precambrian
time scale to reflect important events such as the formation of the Earth
Earth
or the Great Oxidation Event, among others, while at the same time maintaining most of the previous chronostratigraphic nomenclature for the pertinent time span.[37] (See also Period (geology)#Structure.)

Hadean
Hadean
Eon – 4600–4031 MYA[contradictory]

Chaotian Era – 4600–4404 MYA – the name alluding both to the mythological Chaos and the chaotic phase of planet formation[37][38][39][contradictory] Jack Hillsian
Jack Hillsian
or Zirconian
Zirconian
Era – 4404–4031 MYA – both names allude to the Jack Hills Greenstone Belt which provided the oldest mineral grains on Earth, zircons[37][38]

Archean
Archean
Eon – 4031–2420 MYA

Paleoarchean
Paleoarchean
Era – 4031–3490 MYA

Acastan
Acastan
Period – 4031–3810 MYA – named after the Acasta Gneiss[37][38] Isuan
Isuan
Period – 3810–3490 MYA – named after the Isua Greenstone Belt[37]

Mesoarchean Era – 3490–2780 MYA

Vaalbaran
Vaalbaran
Period – 3490–3020 MYA – a portmanteau based on the names of the Kapvaal (Southern Africa) and Pilbara (Western Australia) cratons[37] Pongolan
Pongolan
Period – 3020–2780 MYA – named after the Pongola Supergroup[37]

Neoarchean Era – 2780–2420 MYA

Methanian
Methanian
Period – 2780–2630 MYA – named for the inferred predominance of methanotrophic prokaryotes[37] Siderian
Siderian
Period – 2630–2420 MYA – named for the voluminous banded iron formations formed within its duration[37]

Proterozoic
Proterozoic
Eon – 2420–541 MYA

Paleoproterozoic Era – 2420–1780 MYA

Oxygenian
Oxygenian
Period – 2420–2250 MYA – named for displaying the first evidence for a global oxidizing atmosphere[37] Jatulian
Jatulian
or Eukaryian
Eukaryian
Period – 2250–2060 MYA – names are respectively for the Lomagundi–Jatuli δ13C isotopic excursion event spanning its duration, and for the (proposed)[40][41] first fossil appearance of eukaryotes[37] Columbian Period
Columbian Period
– 2060–1780 MYA – named after the supercontinent Columbia[37]

Mesoproterozoic Era – 1780–850 MYA

Rodinian
Rodinian
Period – 1780–850 MYA – named after the supercontinent Rodinia, stable environment[37]

Neoproterozoic Era – 850–541 MYA

Cryogenian Period – 850–630 MYA – named for the occurrence of several glaciations[37] Ediacaran
Ediacaran
Period – 630–541 MYA

Shown to scale:

Compare with the current official timeline, not shown to scale:

See also[edit]

Age of the Earth Bubnoff unit Cosmic calendar Deep time Evolutionary history of life Geological history of Earth Geology
Geology
of Mars/areology Geon Graphical timeline of the universe History
History
of the Earth History
History
of geology History
History
of paleontology List of fossil sites Logarithmic timeline Lunar geologic timescale Natural history New Zealand geologic time scale Prehistoric life Timeline
Timeline
of the Big Bang Timeline
Timeline
of evolution Timeline
Timeline
of the geologic history of the United States Timeline
Timeline
of human evolution Timeline
Timeline
of natural history Timeline
Timeline
of paleontology

Notes[edit]

^ Not enough is known about extra-solar planets for worthwhile speculation. ^ Paleontologists often refer to faunal stages rather than geologic (geological) periods. The stage nomenclature is quite complex. For a time-ordered list of faunal stages, see [29]. ^ a b Dates are slightly uncertain with differences of a few percent between various sources being common. This is largely due to uncertainties in radiometric dating and the problem that deposits suitable for radiometric dating seldom occur exactly at the places in the geologic column where they would be most useful. The dates and errors quoted above are according to the International Commission on Stratigraphy
Stratigraphy
2015 time scale except the Hadean
Hadean
eon. Where errors are not quoted, errors are less than the precision of the age given.

* indicates boundaries where a Global Boundary Stratotype Section and Point has been internationally agreed upon. ^ References to the "Post- Cambrian
Cambrian
Supereon" are not universally accepted, and therefore must be considered unofficial. ^ Historically, the Cenozoic
Cenozoic
has been divided up into the Quaternary and Tertiary sub-eras, as well as the Neogene
Neogene
and Paleogene periods. The 2009 version of the ICS time chart[30] recognizes a slightly extended Quaternary
Quaternary
as well as the Paleogene and a truncated Neogene, the Tertiary having been demoted to informal status. ^ a b c d e f For more information on this, see Atmosphere of Earth# Evolution
Evolution
of Earth's atmosphere, Carbon dioxide
Carbon dioxide
in the Earth's atmosphere, and Climate
Climate
change. Specific graphs of reconstructed CO2 levels over the past ~550, 65, and 5 million years can be seen at File: Phanerozoic
Phanerozoic
Carbon Dioxide.png, File:65 Myr Climate
Climate
Change.png, File:Five Myr Climate
Climate
Change.png, respectively. ^ The start time for the Holocene
Holocene
epoch is here given as 11,700 years ago. For further discussion of the dating of this epoch, see Holocene. ^ In North America, the Carboniferous
Carboniferous
is subdivided into Mississippian and Pennsylvanian Periods. ^ The Precambrian
Precambrian
is also known as Cryptozoic. ^ a b c d e f g h i j k l m n The Proterozoic, Archean
Archean
and Hadean
Hadean
are often collectively referred to as the Precambrian
Precambrian
Time
Time
or sometimes, also the Cryptozoic. ^ a b c d e f g h i j k l Defined by absolute age (Global Standard Stratigraphic Age). ^ The age of the oldest measurable craton, or continental crust, is dated to 3,600–3,800 Ma. ^ Though commonly used, the Hadean
Hadean
is not a formal eon[33] and no lower bound for the Archean
Archean
and Eoarchean
Eoarchean
have been agreed upon. The Hadean
Hadean
has also sometimes been called the Priscoan or the Azoic. Sometimes, the Hadean
Hadean
can be found to be subdivided according to the lunar geologic timescale. These eras include the Cryptic and Basin Groups (which are subdivisions of the Pre- Nectarian era), Nectarian, and Early Imbrian
Early Imbrian
units. ^ a b c d These unit names were taken from the lunar geologic timescale and refer to geologic events that did not occur on Earth. Their use for Earth
Earth
geology is unofficial. Note that their start times do not dovetail perfectly with the later, terrestrially defined boundaries.

References[edit]

^ a b "International Stratigraphic Chart". International Commission on Stratigraphy. Archived from the original on 30 May 2014.  ^ a b International Commission on Stratigraphy. "Chronostratigraphic Units". International Stratigraphic Guide. Archived from the original on 9 December 2009. Retrieved 14 December 2009.  ^ "Age of the Earth". U.S. Geological Survey. 1997. Archived from the original on 23 December 2005. Retrieved 2006-01-10.  ^ Dalrymple, G. Brent (2001). "The age of the Earth
Earth
in the twentieth century: a problem (mostly) solved". Special
Special
Publications, Geological Society of London. 190 (1): 205–221. Bibcode:2001GSLSP.190..205D. doi:10.1144/GSL.SP.2001.190.01.14.  ^ "Statutes of the International Commission on Stratigraphy". Retrieved 26 November 2009.  ^ Janke, Paul R. "Correlating Earth's History".  ^ Rudwick, M. J. S. (1985). The Meaning of Fossils: Episodes in the History
History
of Palaeontology. University of Chicago Press. p. 24. ISBN 0-226-73103-0.  ^ Fischer, Alfred G.; Garrison, Robert E. (2009). "The role of the Mediterranean region in the development of sedimentary geology: A historical overview". Sedimentology. 56: 3. Bibcode:2009Sedim..56....3F. doi:10.1111/j.1365-3091.2008.01009.x.  ^ "The contribution of Ibn Sina (Avicenna) to the development of the Earth
Earth
Sciences" (PDF).  ^ Sivin, Nathan (1995). Science in Ancient China: Researches and Reflections. Brookfield, Vermont: Ashgate Publishing Variorum series. III, 23–24.  ^ Hutton, James (1788). "Theory of the Earth; or an investigation of the laws observable in the composition, dissolution, and restoration of land upon the Globe". Transactions of the Royal Society of Edinburgh. 1 (2): 209–308. doi:10.1017/s0080456800029227. Retrieved 2016-09-06.  ^ a b McPhee, John (1981). Basin and Range. New York: Farrar, Straus and Giroux.  ^ Great Soviet Encyclopedia
Great Soviet Encyclopedia
(in Russian) (3rd ed.). Moscow: Sovetskaya Enciklopediya. 1974. vol. 16, p. 50.  ^ Rudwick, Martin (2008). Worlds Before Adam: The Reconstruction of Geohistory in the Age of Reform. pp. 539–545.  ^ "Geologic Time
Time
Scale".  ^ "How the discovery of geologic time changed our view of the world". Bristol University.  ^ Gradstein, Felix M.; Ogg, James G.; Smith, Alan G., eds. (2005). A Geologic Time
Time
Scale 2004. Cambridge University Press. ISBN 0-521-78673-8.  ^ Cox, Simon J. D.; Richard, Stephen M. (2005). "A formal model for the geologic time scale and global stratotype section and point, compatible with geospatial information transfer standards". Geosphere. The Geological Society of America. 1 (3): 119–137. Bibcode:2005Geosp...1..119C. doi:10.1130/GES00022.1. Retrieved 31 December 2012.  ^ "Official website". Archived from the original on 20 September 2005.  ^ "Anthropocene: Age of Man – Pictures, More From National Geographic Magazine". ngm.nationalgeographic.com. Retrieved 2015-09-22.  ^ Stromberg, Joseph. "What is the Anthropocene
Anthropocene
and Are We in It?". Retrieved 2015-09-22.  ^ "Subcomission on Quaternary
Quaternary
Stratigraphy, ICS » Working Groups". quaternary.stratigraphy.org. Retrieved 2015-09-22.  ^ "Subcommission on Quaternary
Quaternary
Stratigraphy
Stratigraphy
– Working Group on the 'Anthropocene'". International Commission on Stratigraphy. Retrieved 28 November 2015.  ^ Cite error: The named reference guardian was invoked but never defined (see the help page). ^ George Dvorsky. "New Evidence Suggests Human
Human
Beings Are a Geological Force of Nature". Gizmodo.com. Retrieved 2016-10-15.  ^ "Geologic Timescale Elements in the International Chronostratigraphic Chart". Retrieved 2014-08-03.  ^ Cox, Simon J. D. " SPARQL
SPARQL
endpoint for CGI timescale service". Archived from the original on 2014-08-06. Retrieved 2014-08-03.  ^ Cox, Simon J. D.; Richard, Stephen M. "A geologic timescale ontology and service". Earth
Earth
Science Informatics. 8: 5–19. doi:10.1007/s12145-014-0170-6.  ^ "The Paleobiology Database". Archived from the original on 11 February 2006. Retrieved 2006-03-19.  ^ "Archived copy" (PDF). Archived from the original (PDF) on 29 December 2009. Retrieved 23 December 2009.  ^ "NASA Scientists React to 400 ppm Carbon Milestone". NASA. Retrieved 15 January 2014.  ^ a b c d e f Royer, Dana L. (2006). "CO2-forced climate thresholds during the Phanerozoic" (PDF). Geochimica et Cosmochimica Acta. 70 (23): 5665–75. Bibcode:2006GeCoA..70.5665R. doi:10.1016/j.gca.2005.11.031.  ^ Ogg, J.G.; Ogg, G.; Gradstein, F.M. (2016). A Concise Geologic Time Scale: 2016. Elsevier. p. 20. ISBN 978-0-444-63771-0.  ^ Bowring, Samuel A.; Williams, Ian S. (1999). "Priscoan (4.00–4.03 Ga) orthogneisses from northwestern Canada". Contributions to Mineralogy and Petrology. 134 (1): 3. Bibcode:1999CoMP..134....3B. doi:10.1007/s004100050465.  The oldest rock on Earth
Earth
is the Acasta Gneiss, and it dates to 4.03 Ga, located in the Northwest Territories of Canada. ^ a b c "The Eons of Chaos and Hades" (PDF). Solid Earth. January 26, 2010.  ^ "Geology.wisc.edu" (PDF).  ^ a b c d e f g h i j k l m n Van Kranendonk, Martin J. (2012). "16: A Chronostratigraphic Division of the Precambrian: Possibilities and Challenges". In Felix M. Gradstein; James G. Ogg; Mark D. Schmitz; abi M. Ogg. The geologic time scale 2012 (1st ed.). Amsterdam: Elsevier. pp. 359–365. ISBN 978-0-44-459425-9.  ^ a b c Goldblatt, C.; Zahnle, K. J.; Sleep, N. H.; Nisbet, E. G. (2010). "The Eons of Chaos and Hades" (PDF). Solid Earth. Copernicus Publications on behalf of the European Geosciences Union. 1: 1–3. Bibcode:2010SolE....1....1G.  ^ Chambers, John E. (July 2004). "Planetary accretion in the inner Solar System" (PDF). Earth
Earth
and Planetary Science Letters. 223 (3–4): 241–252. Bibcode:2004E&PSL.223..241C. doi:10.1016/j.epsl.2004.04.031.  ^ El Albani, Abderrazak; Bengtson, Stefan; Canfield, Donald E.; Riboulleau, Armelle; Rollion Bard, Claire; Macchiarelli, Roberto; et al. (2014). "The 2.1 Ga Old Francevillian Biota: Biogenicity, Taphonomy and Biodiversity". PLoS ONE. 9 (6): e99438. Bibcode:2014PLoSO...999438E. doi:10.1371/journal.pone.0099438. PMC 4070892 . PMID 24963687.  ^ El Albani, Abderrazak; Bengtson, Stefan; Canfield, Donald E.; Bekker, Andrey; Macchiarelli, Roberto; Mazurier, Arnaud; Hammarlund, Emma U.; et al. (2010). "Large colonial organisms with coordinated growth in oxygenated environments 2.1 Gyr ago" (PDF). Nature. 466 (7302): 100–104. Bibcode:2010Natur.466..100A. doi:10.1038/nature09166. PMID 20596019. 

Further reading[edit]

Aubry, Marie-Pierre; Van Couvering, John A.; Christie-Blick, Nicholas; Landing, Ed; Pratt, Brian R.; Owen, Donald E.; Ferrusquia-Villafranca, Ismael (2009). "Terminology of geological time: Establishment of a community standard" (PDF). Stratigraphy. 6 (2): 100–105. Retrieved 18 November 2011.  Gradstein, F. M.; Ogg, J. G. (2004). A Geologic Time
Time
scale 2004 – Why, How and Where Next! (PDF). Retrieved 18 November 2011.  Gradstein, Felix M.; Ogg, James G.; Smith, Alan G. (2004). A Geologic Time
Time
Scale 2004. New York; Cambridge, UK: Cambridge University Press. ISBN 0-521-78142-6. Retrieved 18 November 2011 Paperback ISBN 0-521-78673-8  Gradstein, Felix M.; Ogg, James G.; Smith, Alan G.; Bleeker, Wouter; Laurens, Lucas, J. (June 2004). "A new Geologic Time
Time
Scale, with special reference to Precambrian
Precambrian
and Neogene" (PDF). Episodes. 27 (2): 83–100. Retrieved 18 November 2011.  Ialenti, Vincent. "Embracing 'Deep Time' Thinking."". NPR Cosmos & Culture.  Ialenti, Vincent. "Pondering 'Deep Time' Could Inspire New Ways To View Climate
Climate
Change". NPR Cosmos & Culture.  Knoll, Andrew H.; Walter, Malcolm R.; Narbonne, Guy M.; Christie-Blick, Nicholas (30 July 2004). "A New Period for the Geologic Time
Time
Scale" (PDF). Science. 305 (5684): 621–622. doi:10.1126/science.1098803. PMID 15286353. Retrieved 18 November 2011.  Levin, Harold L. (2010). " Time
Time
and Geology". The Earth
Earth
Through Time. Hoboken, New Jersey: John Wiley & Sons. ISBN 978-0-470-38774-0. Retrieved 18 November 2011.  Montenari, Michael (2016). Stratigraphy
Stratigraphy
and Timescales (1st ed.). Amsterdam: Academic Press (Elsevier). ISBN 978-0-12-811549-7. 

External links[edit]

Wikimedia Commons has media related to Geologic time scale.

The Wikibook Historical Geology
Geology
has a page on the topic of: Geological column

NASA: Geologic Time GSA: Geologic Time
Time
Scale British Geological Survey: Geological Timechart GeoWhen Database International Commission on Stratigraphy
Stratigraphy
Time
Time
Scale Chronos.org National Museum of Natural History
History
– Geologic Time SeeGrid: Geological Time
Time
Systems Information model for the geologic time scale Exploring Time
Time
from Planck Time
Time
to the lifespan of the universe Episodes, Gradstein, Felix M. et al. (2004) A new Geologic Time
Time
Scale, with special reference to Precambrian
Precambrian
and Neogene, Episodes, Vol. 27, no. 2 June 2004 (pdf) Lane, Alfred C, and Marble, John Putman 1937. Report of the Committee on the measurement of geologic time Lessons for Children on Geologic Time Deep Time
Time
– A History
History
of the Earth : Interactive Infographic

v t e

Geologic history of Earth

Cenozoic
Cenozoic
era¹ (present–66.0 Mya)

Quaternary
Quaternary
(present–2.588 Mya)

Holocene
Holocene
(present–11.784 kya) Pleistocene
Pleistocene
(11.784 kya–2.588 Mya)

Neogene
Neogene
(2.588–23.03 Mya)

Pliocene
Pliocene
(2.588–5.333 Mya) Miocene
Miocene
(5.333–23.03 Mya)

Paleogene (23.03–66.0 Mya)

Oligocene
Oligocene
(23.03–33.9 Mya) Eocene
Eocene
(33.9–56.0 Mya) Paleocene
Paleocene
(56.0–66.0 Mya)

Mesozoic
Mesozoic
era¹ (66.0–251.902 Mya)

Cretaceous
Cretaceous
(66.0–145.0 Mya)

Late (66.0–100.5 Mya) Early (100.5–145.0 Mya)

Jurassic
Jurassic
(145.0–201.3 Mya)

Late (145.0–163.5 Mya) Middle (163.5–174.1 Mya) Early (174.1–201.3 Mya)

Triassic
Triassic
(201.3–251.902 Mya)

Late (201.3–237 Mya) Middle (237–247.2 Mya) Early (247.2–251.902 Mya)

Paleozoic
Paleozoic
era¹ (251.902–541.0 Mya)

Permian
Permian
(251.902–298.9 Mya)

Lopingian
Lopingian
(251.902–259.8 Mya) Guadalupian
Guadalupian
(259.8–272.3 Mya) Cisuralian
Cisuralian
(272.3–298.9 Mya)

Carboniferous
Carboniferous
(298.9–358.9 Mya)

Pennsylvanian (298.9–323.2 Mya) Mississippian (323.2–358.9 Mya)

Devonian
Devonian
(358.9–419.2 Mya)

Late (358.9–382.7 Mya) Middle (382.7–393.3 Mya) Early (393.3–419.2 Mya)

Silurian
Silurian
(419.2–443.8 Mya)

Pridoli (419.2–423.0 Mya) Ludlow (423.0–427.4 Mya) Wenlock (427.4–433.4 Mya) Llandovery (433.4–443.8 Mya)

Ordovician
Ordovician
(443.8–485.4 Mya)

Late (443.8–458.4 Mya) Middle (458.4–470.0 Mya) Early (470.0–485.4 Mya)

Cambrian
Cambrian
(485.4–541.0 Mya)

Furongian (485.4–497 Mya) Series 3 (497–509 Mya) Series 2 (509–521 Mya) Terreneuvian
Terreneuvian
(521–541.0 Mya)

Proterozoic
Proterozoic
eon² (541.0 Mya–2.5 Gya)

Neoproterozoic era (541.0 Mya–1 Gya)

Ediacaran
Ediacaran
(541.0-~635 Mya) Cryogenian (~635-~720 Mya) Tonian (~720 Mya-1 Gya)

Mesoproterozoic era (1–1.6 Gya)

Stenian (1-1.2 Gya) Ectasian (1.2-1.4 Gya) Calymmian (1.4-1.6 Gya)

Paleoproterozoic era (1.6–2.5 Gya)

Statherian (1.6-1.8 Gya) Orosirian
Orosirian
(1.8-2.05 Gya) Rhyacian (2.05-2.3 Gya) Siderian
Siderian
(2.3-2.5 Gya)

Archean
Archean
eon² (2.5–4 Gya)

Eras

Neoarchean (2.5–2.8 Gya) Mesoarchean (2.8–3.2 Gya) Paleoarchean
Paleoarchean
(3.2–3.6 Gya) Eoarchean
Eoarchean
(3.6–4 Gya)

Hadean
Hadean
eon² (4–4.6 Gya)

 

 

kya = thousands years ago. Mya = millions years ago. Gya = billions years ago.¹ = Phanerozoic
Phanerozoic
eon. ² = Precambrian
Precambrian
supereon. Source: (2017/02). International Commission on Stratigraphy. Retrieved 13 July 2015. Divisions of Geologic Time—Major Chronostratigraphic and Geochronologic Units USGS Retrieved 10 March 2013.

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Time

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Past

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Measurement and standards

Chronometry

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Religion Mythology

Dreamtime Kāla Kalachakra Prophecy Time
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Philosophy of time

A-series and B-series B-theory of time Causality Duration Endurantism Eternal return Eternalism Event Multiple time dimensions Perdurantism Presentism Static interpretation of time Temporal finitism Temporal parts The Unreality of Time

Human
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Specious present

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Time
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Horology

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Big History

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Eight thresholds

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Chronology

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Geologic time

Concepts

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Methods

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Age of the Earth Evolutionary history of life Faint young Sun
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Day Global warming Human
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