GEOLOGIC
TIME SCALE (GTS) - GEOGRAPHY
News:
Anthropocene epoch
declaration unlikely soon, but the idea lives on
What's
in the news?
●
Scientists recently proposed to formalise
an ‘Anthropocene Epoch’ on the geologic time scale, triggering several debates.
●
The earth’s geological history is divided
into multiple epochs depending on their natural evolution.
Key
takeaways:
●
The SQS-AWG
is a commission responsible for recognising time units within our most recent
period of geologic time.
Geological
Time Scale:
●
Geological Time Scale (GTS) is a way to divide Earth’s history into different time
intervals based on significant geological events and changes.
●
It allows scientists to study and
understand the Earth’s history and how it has evolved over time.
Eon:
●
The largest
time period of the GTS, represents billions
of years.
●
There are only four eons in Earth’s history: the Hadean, Archean,
Proterozoic, and Phanerozoic.
Era:
●
A division of an eon, representing tens to hundreds of millions of years.
●
The Phanerozoic eon, which began about 541
million years ago, is divided into three
eras: the Palaeozoic, Mesozoic, and Cenozoic.
Period:
●
A division of an era, representing
millions of years to tens of millions of
years.
●
For example, the Mesozoic era is divided
into three periods: the Triassic, Jurassic, and Cretaceous.
Epoch:
●
A division of a period, representing hundreds of thousands of years to tens of
millions of years.
●
The Cenozoic era is divided into three epochs: the Paleogene, Neogene,
and Quaternary.
It’s worth noting that
the boundaries between these subunits of the GTS are not always well-defined,
and may vary depending on the region being studied.