Science GTS Notes

Periods

Eras are subdivided into units of geologic time

Era

Geologists divided the time between Precambrian Time and the preset, into three long units of time

What are three eras from Precambrian Time?

Paleozoic Era, the Mesozoic Era, and the Cenozoic Era

What time did GTS first begin? And how wide did it cover Earth?

Precambrian Time and it covered 88% of Earth

When did Precambrian Time end? What happened to the fossils?

Precambrian Time began 542 million years ago, very few fossils from this time survived

How was the GTS first developed?

The GTS was first developed by studying rock layers and index fossils worldwide

What is the Geologic Time Scale used for?

The Geologic Time Scale show geologists Earth's history.

How do scientists name these different eras and periods?

The names of many geologic periods come from places around the world where geologists first described the rocks and fossils of that period

What are three periods from Precambrian Time?

Triassic Period, Jurassic Period, Cretaceous Period

Geologic Time Scale

a record of the geologic events and the evolution of life forms as shown in the fossil record.