Earth's History

What is the concept of uniformitarianism?

• The idea that the laws of nature have changed over time

• The belief that only biological laws have remained constant

• The idea that physical, chemical, and biological laws that operate today also operated in the past

• The theory that geological processes are unpredictable

What method do geologists use to place rocks in chronological order?

• Absolute dating

• Radiocarbon dating

• Relative dating

• Fossil dating

What does the Law of Superposition state about sedimentary rock layers?

• Each bed is younger than the one above it and older than the one below it.

• Each bed is older than the one above it and younger than the one below it.

• Each bed is the same age as the one above it.

• Each bed is older than the one below it and younger than the one above it.

What does the Principle of Original Horizontality suggest about sediment layers?

• Layers are deposited vertically.

• Layers are deposited diagonally.

• Layers are deposited in a horizontal position.

• Layers are deposited randomly.

What does the principle of cross-cutting relationships state?

• Faults are older than the rock layers they cut through.

• Magma is always older than the rocks it intrudes.

• Faults or intrusions are younger than the rocks they affect.

• Rock layers are younger than the faults that cut through them.

What are fossils?

• Remains or traces of prehistoric life

• Modern animal bones

• Types of minerals

• Ancient tools

What are fossils important components of?

• Igneous rocks

• Sediment and sedimentary rocks

• Metamorphic rocks

• Volcanic ash

What determines the type of fossil that is formed?

• The size of the organism

• The color of the sediment

• The conditions under which an organism died and how it was buried

• The age of the rock

What is a common alteration that occurs to fossils over time?

• They become petrified or turned to stone.

• They dissolve completely.

• They turn into liquid.

• They evaporate.

Which remains of organisms may not have been altered over time?

• Teeth, bones, and shells

• Skin and hair

• Leaves and flowers

• Muscles and tendons