Question

on the basis of time the geological history of the earth has been divided in eras
a..2 eras
b..3 eras
c..4 eras
d..5 eras​

Answer 1

The geological history of the earth has been divided into more than 10 eras composing 4 eons.

Answer 2

Answer:

None of the answers in the option mentioned is correct.

Explanation:

Eon is the largest category in the geological time scale. The history of the earth is categorized into 4 eons:

1. Hadeon
2. Archean
3. Proterozoic
4. Phanerozoic

Hadeon is the earliest, while the Phanerozoic is the current eon.

Eons are classified into different eras. An era is the second longest unit of geological scale.

• Hadeon Eon is not divided into eras.
• Archean eon has 4 eras namely, Eoarchean, Paleoarchean, Mesoarchean and Neoarchean.
• Proterozoic eon is divided into 3 eras, Paleoproterozoic, Mesoproterozoic and Neoproterozoic.
• The current phanerozoic era is divided into 3 eras as of now, Paleozoic, Mesozoic, and Cenozoic.
• Cenozoic is the ongoing era.

According to the latest research, there are a total of 10 defined eras.

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