What Are The 4 Eons?

What are the eons?

Eon, Long span of geologic time.

In formal usage, eons are the longest portions of geologic time (eras are the second-longest).

Three eons are recognized: the Phanerozoic Eon (dating from the present back to the beginning of the Cambrian Period), the Proterozoic Eon, and the Archean Eon..

Which EON has the most life?

Phanerozoic EonThe Phanerozoic Eon is the current geologic eon in the geologic time scale, and the one during which abundant animal and plant life has existed. It covers 541 million years to the present, and it began with the Cambrian Period when animals first developed hard shells preserved in the fossil record.

What are eons divided into?

Eons are divided into eras, which are in turn divided into periods, epochs and ages. … 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.

How old is the earth?

4.543 billion yearsEarth/Age

What era do we live in 2020?

Holocene eraThe present year, 2020, can be transformed into a Holocene year by adding the digit “1” before it, making it 12,020 HE. Years BC/BCE are converted by subtracting the BC/BCE year number from 10,001. Beginning of the Meghalayan age, the current and latest of the three stages in the Holocene era.

Which era do we live in?

CenozoicOur current era is the Cenozoic, which is itself broken down into three periods. We live in the most recent period, the Quaternary, which is then broken down into two epochs: the current Holocene, and the previous Pleistocene, which ended 11,700 years ago.

What’s bigger than an eon?

A supereon is longer than an eon.

What age are most of the Earth’s cratons?

2 billion yearsSome are over 2 billion years old. Cratons are generally found in the interiors of continents and are characteristically composed of ancient crystalline basement crust of lightweight felsic igneous rock such as granite. They have a thick crust and deep roots that extend into the mantle beneath to depths of 200 km.

What are Earth’s eons eras and periods?

To make geologic time easier to comprehend, geologists divided the 4.6 billion years of Earth’s history into units of time called eons. Then they further divided the eons into two or more eras, eras into two or more periods, periods into two or more epochs, and epochs into two or more ages.

How are time periods divided?

Geologists have divided Earth’s history into a series of time intervals. … Eons are divided into smaller time intervals known as eras. In the time scale above you can see that the Phanerozoic is divided into three eras: Cenozoic, Mesozoic and Paleozoic.

Is Hadean an eon?

Hadean Eon, informal division of Precambrian time occurring between about 4.6 billion and about 4.0 billion years ago. … Throughout part of the eon, impacts from extraterrestrial bodies released enormous amounts of heat that likely prevented much of the rock from solidifying at the surface.

What was the longest era?

PrecambrianThe longest geologic era was the Precambrian. It began with the formation of the earth about 4.53 billion years ago, and ended about 542 million years…

What was before Stone Age?

The Prehistoric Period—or when there was human life before records documented human activity—roughly dates from 2.5 million years ago to 1,200 B.C. It is generally categorized in three archaeological periods: the Stone Age, Bronze Age and Iron Age.