Monday, November 15, 2010

Grade 8 Week 8: Geologic Time Scale

This week we take what we have learned about fossils, relative and absolute age, of earthquakes and volcanoes, and all changes to the Earth to describe Earth's history in what we call the Geologic Time Scale.

How are fossils and other evidence used to describe the geologic time scale?
What trends do we see over the whole geologic time scale?




This week's contract asks you to continue the construction of our class Geologic Time Scale.

13 comments:

Giese said...

why were there animals back then when there was less or more oxegen why could the live in that and we couldn't

Stephanie said...

The main thing about the geological time scale is that it is seperated into different time periods or era's. The cause of these seperations is past mass extiction, and speciation. Over time there were many chages between the types of species(speciatation), and there were some mass extinstions like the Dinasours, which ended up leading to the end of the Cretaceous time period.

Stuart said...

Fossils and other evidence can be used to describe the geologic time scale by which layer of rock there under,how old they are,and the area in which the fossil was found. The trends we find troughout the the geolgic time scale is uniformation.

mag said...

Fossils and other evidence help to explain the geologic time scale. They provide explanations to life back then. Fossils show what types of animals lived at that point. From that fact, we can draw conclusions. For example, if an animal fossil is found, then conclusions can be drawn as to what gases and plants were present. If scientists know one fact, then they can make connections. Also, by figuring out what was present, scientists can guess as to what time earth events occurred and what might have followed.

Cara Bardon said...

The geolocic time scale is separated into different periods.Some animals adapt to the changed environment, and some become extinct.

Charlie said...

Fossils can show what types of plants and animals lived in the area. They also show what that place was like a long time ago, like if it had a lot of vegitation or not. The time scale shows that as time goes on the animals change and the earth gets more land from when it used to be all water.

josh lienau said...

does the time scale go on till the earth is ingulped by the sun

Kate Sommerfeld said...

Ryan: I think that the animals back then were adapted to the air back then, but after time the oxygen level went down. And then we came!

Moses said...

How can they know about how old the Earth is if there wasn't any fossils when the earth was created?

Unknown said...

after animals go exstinked how can more life forms just appear on earth

Unknown said...

after animals go exstinked how can more life forms just appear on earth?

Kassi said...

half-life is when a radioactive element has decayed half-way

Anonymous said...

By looking at the Geologic Time Scale, we can determine the Earth's past and the different events that took place there. Uniformitarianism is the evidence that the Earth is always changing. Uniformitarianism is the idea the Earth is always changing and the same forces of change of work of today were the same in the past. The geologic time scale also divides the Earth's history into intervals of time.