Age of Earth

Why is the principle of superposition important to geologists who are trying to understand the evolution of Earth over time?

• A. It describes the evolution of rocks as they go through the rock cycle.

• B. It indicates the relative ages of rock layers and the fossils in them.

• C. It describes the evolution sequence as rocks are laid down side by side.

• D. It states that the composition of rock remains the same throughout the different geological periods.

Tags

NGSS.MS-ESS1-4

Which of these choices is the best definition of absolute dating?

• determining the age of a rock layer by studying the fossils present

• finding the age of an object compared to other objects

• measuring the age of an object in years using any method

• determining the amount of a radioactive isotope in an object

What is the approximate age of Earth?

• 4.6 billion years

• 4.6 million years

• 46,000 years

• 4600 years

Which of these statements describes a key characteristic of index fossils?

• They existed in a unique location.

• They are present in very small numbers.

• They existed for a short span of time.

• They are similar to other fossils.

What could you conclude if you discovered this fossil on top of a mountain?

• This organism is now extinct.

• This trace fossil is older than the mountaintop.

• The mountaintop is made of metamorphic rock.

• The rocks on this mountaintop were once at the bottom of an ocean.

Which of the following is the best conclusion that you could make from this fossil discovery?

• The climate was cooler than it is at present.

• The climate was warmer than it is at present.

• The climate has not changed since the fossil formed.

• The climate will continue to get colder in the near future.

If a scientist wants to figure out the relative age of a layer of sediment what would they use? (SC.7.E.6.3)

• Rate of weathering

• Law of Superposition

• Core Sample

• Radioactive Dating

Tags

NGSS.MS-ESS1-4

What does the Law of Superposition state about the layers of sediment found on the Earth’s surface? (SC.7.E.6.3)

• The oldest layer is at the top and the sediment gets younger as you go down

• All layers of sediment are the same age roughly 4.6 billion years old

• The youngest layer of sediment is at the top and the layers get older as you go down

• All layers of sediment are the same age because of weathering, erosion, and deposition

Leon wants to determine the age of igneous rock by comparing the amount of potassium-40 to the amount of argon-40 present in rock samples. What is the correct term for this method of determining the age of an object if Leon is looking for the absolute age? (SC.7.E.6.3)

• Law of superposition

• radioactive dating

• relative dating

• isotope dating

Which claim describes the law of superposition? (SC.7.E.6.3)

• The exact age of a sedimentary rock layer can be found using the layers above and below it, even if the layers are not in their original positions.

• Metamorphic rock is older than nearby sedimentary rock because sedimentary rock is deposited before metamorphic rock forms.

• A sedimentary rock layer in its original position is older than the layers above it and younger than the layers below it.

• Igneous rock is older than nearby sedimentary rock, which is older than nearby metamorphic rock.