Unit 4 review 8th grade

Front

How old is Earth thought to be?

Back

4.6 billion years

Front

Paleontologists study ______.

Back

fossils

Front

Which of the following is the oldest? Layer L, Intrusion D, Intrusion H, Layer E

Back

Layer E

Front

Once rock forms, it never changes. True or False?

Back

False

Front

____________ is undisturbed even rock layers with the oldest rocks at the bottom and youngest rocks at the top.

Back

Superposition

Front

What is the principle of superposition?

Back

In an undisturbed sequence of sedimentary rocks, the oldest layers are at the bottom and the youngest are at the top.

Front

What do fossils tell us about Earth's history?

Back

Fossils provide evidence of past life and the environments in which organisms lived.

Front

What is the difference between an intrusion and a layer in geology?

Back

An intrusion is a body of igneous rock that has melted and pushed through existing rock layers, while a layer is a sedimentary deposit.

Front

What is the law of original horizontality?

Back

Layers of sediment are originally deposited horizontally under the action of gravity.

Front

What does lateral continuity refer to in geology?

Back

Layers of sediment initially extend laterally in all directions; they may be interrupted by erosion or other geological processes.