Geological Time Table:Geological Time Scale[Looking back 4.8 billion years]

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In the course of time, the age of the earth today is about 4.6 billion years. How many epochs have passed in 460 crore years!

(According to Wikipedia, 454 million years)

So, this article is basically about all the epochs of that 460 crore years and all its classifications which will be a little helpful to understand the times and eras mentioned in the discussion of the ancient world. Basically, I have highlighted the time scales, along with a brief description of the eras. I have followed the latest timetable (2014) of the International Commission on Stratigraphy (ICS) here. So, let's get started-

(ICS) Internationally recognized time serial is-

SuperEon> Eon> Era>

Period> Epoch> Ages

Here,

The words Super Eon, Eon, Era, Period, Epoch, Ages, respectively

Used as Great Age, Age, Era, Period, Epoch, Ages. (There are a lot of synonyms for these words in Bengali, so there is a bit of controversy over the translated meaning, so I have kept the rest in English except Mahayug).

In order to keep the discussion short, I have excluded Epoch and Ages.

(For more details, see the image in the comments or the link.)

https://stratigraphy.org/timescale/

Pre-Cambrian Super Eon:

[480 to 541 million years]

Duration:

Started 460 crore years ago - ended 54.1 crore years ago.

The period from the creation of the earth to the present is divided into two major epochs in the geological time table -

1. Pre-Cambrian Super Eon: -

This great age began about 470 million years ago with the creation of the earth

And this era ended 541 million years ago.

This is the only Super Eon for the Earth. This means that there is no Super Eon in the history of the world. However, there are some eons.

2. Phanerozoic Eon: -

This epoch begins with the end of the great pre-Cambrian epoch. That's how it started

Its scope extends from 54.1 million years ago and even today. Many geologists call this epoch the Post-Cambrian Super Eon.

This pre-Cambrian epoch is further divided into 3 epochs -

I) Hadean Eon

II) Archean Eon

III) Proterozoic epoch

(Proterozoic Eon)

Therefore, these three epochs together spend about 4 billion years. Again, these three epochs are part of another great epoch, the pre-Cambrian epoch.

I) Hadean Eon:

Duration: 480 crore - 400 crore years

'Hedian' is the oldest epoch in the geological history of the world. The conditions of the earth in this great age were as hot as hell, so this great age is named after the Greek underworld god Hades. This epoch is also called Pre-Archean.

The major events of the Hedian era are - the creation of the earth, the formation of the moon, the origin of the oldest rocks, the arrival of water on Earth, evidence of indirect photosynthesis of ancient life (for example - kerosene), etc.

II) Archean epoch:

Duration: 400 crore - 250 crore years

The Archean epoch began after the Hedian epoch.

The Archean epoch is further divided into 4 Era -

1. Eo-Archean Era (Eoarchean)

2. Paleo-Archean Era (Paleoarchean)

3. Meso-Archean Era

(Mesoarchean)

4. Neo-Archean Era (Neoarchean)

The second pre-Cambrian epoch is the Archean epoch. The name Archean comes from the ancient Greek word ‘Arkhe’, which means - Beginning; Origin. The term Archean was first used in 182, the oldest geological epoch.

1. Yo-Archean Era:

Duration:

400 crore - 360 crore years

The main events of this Era are - the emergence of normal unicellular life (bacteria and archaea); The earliest possible fossil molecule is the emergence of the first self-plating RNA molecule,

The formation of the Napier Mountains in Antarctica, etc.

2. Paleo-Archean Era:

Duration:

360 crore - 320 crore

The main events of this Era are - the emergence of the first oxygen-producing bacteria; Origin of the oldest molecular fossils;

3. Meso-Archean Era:

Duration: 320 crore - 260 crore years

4. Neo-Archean Era:

Duration: 2608 250 crore years

III) Proterozoic era:

Duration: 250 crore - 54.1 crore years

The third and end of the pre-Cambrian Super Eon is the Proterozoic Era.

The name Proterozoic comes from the two Greek words ‘Protero’ = Earlier; Former and ‘Zoic’ = Animal or Living Being.

The Proterozoic epoch is divided into 3 Era -

1) Paleo Proterozoic Era

2) Meso Proterozoic Era

3) Neo Proterozoic Era

1) Paleo Proterozoic Era:

Duration:

250 crore - 160 crore years

The term ‘Paleo’ is used here to refer to the oldest geological period of the Proterozoic era.

The Paleo Proterozoic Era is further divided into 4 Periods:

a) Siderian Period

b) Rhyacian Period

c) Orosian Period

d) Statherian Period

a. Cedarian Period:

Duration:

250 crore - 230 crore years

The main events of this period are - the oxygen crisis on Earth; Layered iron structure; The formation of the Slyford Mountains on the continent of Australia; Structure of Gauler Craton etc.

b. Reese Period:

Duration: 230 crore - 205 crore years

The major events of this era were the formation of the Bushveld volcanic complex; Huronian ice age (the oldest and longest ice age) etc.

c. Orosian Period:

Duration:

205 crore - 160 crore years

The main events of this period are - oxygen main atmosphere; The Vredefort and Sudbury Basin asteroid ratios; A. Panocian and Trans-Hudsonian mountain formations in America

Statherian Period:

Duration:

160 crore - 160 crore years

2. Meso Proterozoic Era:

Duration: 160 crores -

100 million years

The Meso-Proterozoic Era is further divided into 3 Periods:

a) Calymmaian Period

b) Ectasian Period:

c) Stenian Period

This is the second era of the Proterozoic era.

The name Meso Proterozoic comes from two Greek words ‘Meso’ = Middle and ‘Proterozoic’ = Earlier / Former Living Being. The term Meso is used here to refer to the geological period between the Proterozoic Ages.

a) Kalimmian Period:

Duration: 160 crore years -

140 crore years

Ectasian Period:

Duration:

140 crore — 120 crore years

c. Stenian Period:

Duration:

120 crore - 100 crore years

3. Neo-Proterozoic Era:

Duration:

100 crore - 54.1 crore years

Neo Proterozoic Era -

The Neo Proterozoic Era can be further divided into 3 Periods -

a) Tonian Period

b) Cryogenian Period:

c) Ediacaran Period

a) Tonian Period:

Duration:

100 crore - 75 crore years

b) Cryogenic Period:

Duration:

65 crore - 63.5 crore years

c) Adiakaran Period:

Duration:

63.5 crore - 54.1 crore years

(End of the Great Pre-Cambrian Era)

Phanerozoic epoch:

Duration:

Start: 54.1

End: Still running

The pre-Cambrian post-geological period is known as the Phanerozoic Era.

The name Phanerozoic comes from the two Greek words ‘Phaneros’ = Visible and ‘Zoic’ = Life. This epoch has been given such a name because it is in this great age that most of the species originated and developed.

The Phanerozoic epoch is divided into 3 Era -

I) Paleozoic Era

II) Mesozoic Era

III) Cenozoic Era

I) Paleozoic Era:

Duration:

54.1 crore - 25.1902 crore years

Paleozoic

The Era is further divided into 6 Periods -

1) Cambrian Period

2) Ordovician Period

3) Silurian (Silurian Period)

4) Devonian Period

5) Carboniferous Period

6) Permian (Permian Period)

It is the oldest Era of the Phanerozoic era.

The name Paleozoic comes from two Greek words ‘Palaios’ = Old and ‘Zoic’ = Life. The word Paleozoic means - Ancient Life.

1. Cambrian Period:

Duration:

54.1 crore - 48.54 crore years

This is the oldest period of the Paleozoic Era.

The main events of the Cambrian Period are - the origin of the first phylum; Origin of the first vertebrates; The emergence of a super continent called Gondwana; The formation of Mount Peterman on the Australian continent is completed; Ross mountain formation in Antarctica; Atmospheric carbon dioxide levels are 6,000 ppmv (20-35 times higher than the current 365 ppmv), etc.

2. Ordovician Period:

Duration: 47.54 crore - 44.36 crore years

This is the second period of the Paleozoic Era.

The name Ordovician comes from the name of the Celtic tribe called ‘Ordovice’.

The major events of the Ordovician Period are - the diverse emergence of different types of invertebrates; Predominance of early corals, trollobites, bryozoa, etc .; Origin of Conodont animals; The emergence of the first green plants and fungi on land; The beginning of the ice age at the end of this period.

3. Silurian Period:

Duration: 44.38 crore - 41.92 crore years

- This is the third period of the Paleozoic Era.

The name Silurian comes from the name of the Celtic tribe ‘Silures’.

The major events of the Silurian Period are - the emergence of the first vascular plant; The emergence of the first Millipedas and Arthropleurids on land; Emergence of the first jawed fish; Sea-scorpion gains maximum shape; Increase the diversity of trollobites and molasses; Caledonian mountain formation; The creation of the Scandinavian mountains; Acadian mountain formation; Takonic and Lachlan mountain formation completed etc.

4. Devonian Period:

Duration:

41.92 crore - 35.89 crore years

- This is the fourth period of the Paleozoic Era.

The name Devonian comes from the name Devon County in England. This period is named after the first rock study in Devon County, England. This period is also called ‘Age Of Fish’.

The major events of the Devonian Period are - the emergence of the first Clubmosses, Horsetails and ferns; Origin of the first seeded plants; The origin of the first trees and insects; Kingdom of jaw-bearing fish in the sea; The first amphibian species still exists as an aquatic species; Acadian mountain formation in Africa; Variskan and Tuhua mountain formations etc.

5. Carboniferous Period:

Term: 35.89 Crores -

29.89 crore years

- This is the fifth period of the Paleozoic Era.

The name Carboniferous comes from two Latin words ‘Carbo’ = Coal and ‘Fero’ = I Carry / I Bear. Carboniferous = Coal-Bearing.

This period is also called "Age Of Coal".

The major events of the Carboniferous Period are -

Rapid emergence of winged insects; Emergence and development of amphibians; The origin of the first reptiles and coal-forests; The level of oxygen in the atmosphere is at an all-time high; Abundance of corals, bivalves, goniatites, etc .; Formation of the Ural Mountains in Eurasia; Variskan mountain formation in Europe and North America; Origin of the first terrestrial vertebrates; The predominance of ancient sharks in the sea; Refrigeration begins in eastern Gondwana; The formation of the Tuhua Mountains in New Zealand has been completed.

6. Permian Period:

Duration:

29.89 crore - 25.217 crore years

- This is the sixth and last period of Paleozoic Era. The main events of the Permian Period were: the landmass merged to form the super continent called Pangea; Appalachian mountain formation; Permo - the end of the Carboniferous ice age; The origin of the first real moss; Evolution of beetles and flies; Triassic extinction (95% of the world's extinction);

Ural mountain formation in Eurasia completed; A. The formation of the Kwachita and Inunisian mountains in America; Altai mountain formation in Asia, etc.

II) Mesozoic Era:

Duration:

25.1902 crore - 7.6 crore years

The Mesozoic Era is further divided into 3 Periods -

Triassic Period

Jurassic Period

Cretaceous Period

-This is the second Era of the Phanerozoic era.

The name Mesozoic comes from two Greek words ‘Meso’ = Middle; Between and ‘Zoic’ = Life. The word Mesozoic means - Middle Life. The Mesozoic Era is also known as ‘Age of Reptiles’ or ‘Age of Reptiles’ and ‘Age Of Conifers’ or ‘Age of Conifers’.

1. Triassic Period:

Duration:

25.1902 crore -

20.13 crore years

-This is the oldest period of the Mesozoic Era.

The name Triassic comes from the German word ‘Trias’ = three meaning three layers (three layers between Permian and Jurassic - Red Beds, Limestone & Mud - Sandstone; found throughout Germany and Northeast Europe).

The major events of the Triassic Period are - the predominance of Archosaurs on land and Ichthyosaurs, Nothosaurs and Pterosaurs in the sea; Origin of the first mammal and crocodile species; Abundance of Dicroidium Flora on land; The advent of modern coral and teleost fish; Origin of dinosaurs); The formation of the Andes Mountains in South America.

2. Jurassic Period:

Duration:

20.13 crore —14.5 crore years ago

This is the second period of the Mesozoic Era.

The name Jurassic comes from the name of the Jura Mountains in Europe (the word Jura is Celtic word Jor> Latin word Juria = Forest or Forest; Jura Mountains = Forest Mountains).

The major events of the Jurassic Period are - the abundance of gymnosperms and ferns, the development of dinosaurs on land (Sauropods, Carnosaurs, etc.); Spread of mammals (albeit small in size); The origin of the first birds and lizards; Abundance of sea urchin, starfish, sponge, etc. in the sea; Emergence of Gondwana and Laurasia by breaking up Pangea; Sea level rise etc.

3. Cretaceous Period:

Duration:

14.5 crore - 6.6 crore years

This is the third and final period of the Mesozoic Era.

The name Cretaceous comes from the Latin word ‘Creta’ = Chalk. This period has been so named because of the origin of chalk rock in different parts of the world.

The major events of the Cretaceous Period are - the advent of the more modern Teleost fish; Rapid proliferation of flowering plants; Origin of various insects; Abundance of Ammonnoids, Belemnoids, Sea Urchins, Sponge, etc .; Emergence and development of various species of dinosaurs in the first half (Tyrannosaurs, Titanosaurs, etc.); Extinction of dinosaurs in the last half; The advent of modern sharks and crocodiles at sea; Gondwana breakdown; The level of carbon dioxide in the atmosphere was the same as at present; Creation of delta islands by rivers; Increase in the size of deciduous forests etc.

III) Cenozoic Era:

Duration:

6.6 crore - current time

The Cenozoic Era is further divided into 3 Periods -

1. Paleogene Period

2. Neogene Period

3. Quaternary Period

- This is the third and last Era of the Phanerozoic era.

The name Cenozoic comes from the two Greek words ‘Ceno’ / ‘Kaino’ = New and ‘Zoic’ = Life. The word Cenozoic means - New Life. The Cenozoic Era is also known as ‘Age Of Mammals’ and ‘Age Of Birds’.

1. Paleogene Period:

Duration:

6.8 crore - 2.303 crore years

- This is the oldest period of the Cenozoic Era. The name Paleogene comes from two Greek words ‘Paleo’ = Old and ‘Gene’ = Life. This period is also known as Lower Tertiary Period.

2. Neogene Period:

Duration: 2.303 crore - 25.7 lakh years

This is the second period of the Cenozoic Era. The name Neogene comes from the two Greek words ‘Neo’ = New; Youth and ‘Gene’ = Life. This period is also known as the Upper Tertiary Period.

3. Quaternary Period:

Duration: 25.7 million years - current time

- This is the third and final period of the Cenozoic Era.

The name Quaternary comes from the Latin word ‘Quaternarius’ = Containing Of Four. In 1829, Jules Dejnovers used the name Quaternary after seeing the sedimentary deposits of the Seine Basin in France (which was younger than the Tertiary era).

Since the last period, its other lower time divisions are also highlighted-

The Quaternary Period is divided into two Epoch-

1. Pleistocene Epoch

2. Holocene Epoch

a) Pleistocene Epoch:

Duration: 25 lakhs - 11.6 thousand years

b) Holocene Epoch:

Duration: 11.6 thousand - present

The Holocene Epoch has three ages:

1.Greenlandian (Original Holocene-Greenlandian):

Duration: 11.6 thousand - 6.2 thousand

2.Northgrippian (Middle Holocene - -Nortgrippian):

Duration:

6.2 thousand - 4.2 thousand

3.Meghalayan (last Holocene-Meghalayaan):

Duration:

4.2 thousand - present

The main events of the Holocene Epoch are - the retreat of the Quaternary ice age; The beginning of the current intermittent period; The emergence and development of human civilization; The creation of the Sahara Desert from Savannah; The emergence of farming methods; Industrial revolution; The evolution of the Bronze and Iron Age from the Stone Age to human history; Increased levels of carbon dioxide in the atmosphere (260 ppmv to 400 ppmv), etc.

According to some, there is a third epoch called Anthropocene which started in the 18th century.

So what happened?

We -

In the Phanerozoic Eon> Cenozoic Era> in the Quaternary Period> in the Holocene Epoch>

I am living in Meghalaya Age.

Also among these are Stone Age> Bronze Age> Iron Age>

> Classical Era (800 BC-500AD), Classical Era (500 AD-1500AD) /

Middle Ages, present age (1500-present)

References:

https://en.wikipedia.org/wiki/Geologic_time_scale

Latest PDF file of the time scale provided by ICS:

https://web.archive.org/web/20140528015101/http://www.stratigraphy.org/ICSchart/ChronostratChart2014-02.pdf