What is the timeline created by geologists called?

• Biological timescale

• Astronomical timescale

• Paleontological timescale

• Geologic timescale

What do geologists look for in sedimentary rock layers to map out Earth's history?

• Mineral composition

• Fossil record

• None of the above

• Both A and B

What rule states that the layers at the bottom of sedimentary rocks are always older than the layers at the top?

• Law of Original Horizontality

• Law of Crosscutting Relationships

• Law of Lateral Continuity

• Law of Superposition

What rule helps geologists determine the relative ages of geologic features that intersect each other?

• Law of Lateral Continuity

• Law of Superposition

• Law of Crosscutting Relationships

• Law of Original Horizontality

What are fossils that are only found on a specific section of the geologic timescale called?

• Index fossils

• Specific fossils

• Exclusive fossils

• Unique fossils

What can help geologists figure out a rock's relative age if it contains evidence of the same geologic event as another rock layer?

• Geologic event

• Mineral composition

• Fossils

• None of the above

What did relative dating help geologists figure out about the evolution of life on Earth?

• The extinction of Stegosauruses

• The first single cellular life formed about 3.8 billion years ago

• The first multicellular life formed about 600 million years ago

• All of the above

When did modern humans first exist according to the geologic timescale?

• About 200,000 years ago

• About 4.6 billion years ago

• About 3.8 billion years ago

• About 600 million years ago

What is the main purpose of index fossils in determining the relative age of a rock?

• To provide evidence of ancient life forms

• To indicate the age of the rock

• To point to when on the geologic timescale a rock was formed

• To give directions on the geologic timescale

What is the process called that helps scientists determine the relative ages of rock layers and fossils?

• Radiometric dating

• Carbon dating

• Relative dating

• Absolute dating