Science 9 Review for the Earth History

1. The smallest division of time on the geological scale______________. epoch

Are epochs found in every era? Why or why not? No. They are only found in the current era (cenozoic). More information, records, technology and more happening.

What is the Cambrian Explosion? A great number of different types of organisms evolved at the one time.

Beginning of the Paleozoic Era When did the cambrian explosion occur? Beginning of the Paleozoic Era

One of the GHG’s that is commonly found in fertilizer Nitrous oxide

Fault line and intrution What is younger the fault line or intrution or the layers of rock that they cut through? Fault line and intrution

Triassic, Jurassic, and Cretaceous What are the three periods of the Mesozoic Era? Triassic, Jurassic, and Cretaceous

Paleozoic Era Mesozoic Cenozoic Put the eras in the order in which they occurred from oldest to youngest. Paleozoic Era Mesozoic Cenozoic

States that the oldest rock is always the bottom layer What is the law of superposition? States that the oldest rock is always the bottom layer

If an organism is no longer on earth it is said to be _____________ extinct

Occurred at end of cretaceous period. Ended Mesozoic era. What is the K-T extinction? When did it occur? 65MYA Dinos extinct Occurred at end of cretaceous period. Ended Mesozoic era.

Largest extinction ever 250 MYA What is the Permian Extinction? When did it occur? Possible cause? Largest extinction ever 250 MYA Break up of pangaea, warming CO2 build up, Asteroid impact End of permian period (Paleozoic Era)

ice and glaciers cover earth no true mass extinction What is the Pleistocene Ice Age? When did it Occur? 9 MYA ice and glaciers cover earth no true mass extinction

Cambrian period – during the cambrian explosion When did invertebrates appear? Cambrian period – during the cambrian explosion

Animals that spent some of the time in water and some on land What are amphibians? Animals that spent some of the time in water and some on land

Animals without a backbone What are invertabrets? Animals without a backbone

Animals with a backbone What are vertebrates? Animals with a backbone

Evolved from amphibians to live on land What are reptiles? Evolved from amphibians to live on land

What are mammals? Warm blooded vertebrates that became abundant after the dinos became extinct

The age of rocks compared to other rocks What is the relative age of rocks? The age of rocks compared to other rocks

What are index fossils? Fossils of organisms that were widely distributed but only lived a short time

Why are index fossils important to geologists? Found in layers of rock. Help geologists tell the relative age of the rock. (when organism lived)

Know how groups of animals changed and developed over time From a fossil record geologists can do what? Know how groups of animals changed and developed over time

What happens in radioactive decay? Parent material breaks down into daughter material. ( one element turns into another element)

Way to find age of rock using radioactivity. (exact age) What is absolute dating? Way to find age of rock using radioactivity. (exact age)

Time it takes for half of the parent material to decay Half life

Radioactive or absolute dating works best on which type of rock? igneous

What type of rock must be used for relative dating? sedimentary

When did life on earth first appear? Precambrian Time

When did life on earth first appear? Precambrian Time

Why have a geological scale? Because earth’s history is so long it is the best way to keep events/organisms in order.

With the beginning (forming) on the earth How did Precambrian time begin? With the beginning (forming) on the earth

With the beginning (forming) on the earth How did Precambrian time begin? With the beginning (forming) on the earth