Geologic Time

How did scientists develop the Geologic Time Scale?

• By observing changes in the fossils going from oldest to youngest in sedimentary rocks.

• By looking at the night sky

• By using carbon-dating

• By using absolute and relative age

________ does not give a specific date.

• relative dating

• absolute dating

_______ dating is very specific with dates and gives the actual age in years.

• relative dating

• absolute dating

• carbon-dating

• isotopes

documenting changes of fossil layers relating to age is an example of:

• carbon-dating

• relative dating

• absolute dating

• archeology

radio-carbon dating is an example of....

• relative dating

• radioactive decay

• absolute dating

• fossilization

isotopes are used in radioactive decay to ....

• the age of a rock can be estimated by looking at the isotopes, and their half-life.

• help the rock decay faster

• To help develop the Geologic Time Scale

• To help find the relative age

how old is the Earth?

Which era/period are we currently living in?

• Paleozoic/Jurassic

• Mesozoic/Cambrian

• Cenozoic/ Quarternary

• Hadean/Precambrian Time

_______ is when a bunch of animals and living things die in a short period.

What causes mass extinction

• asteroids

• climate change (no food or water)

• volcanic eruptions

• the animals are tired