Unit 1 review game

Which fossil makes the best index fossil?

• ammonite

• brachiopod

• trilobite

• shark

• all four are good index fossils

How does absolute age differ from relative age?

• only absolute dating indicates which rock is older than another
• only absolute dating finds the age in years
• only relative dating finds the age in years

States that younger rocks lie above older rocks if the layers have not been disturbed

• Law of crosscutting
• Law of superposition
• Relative Dating
• Unconformity

If scientists find an ice core from 30,000 years ago that contains chemicals radically different than the chemicals that are around today, they would likely conclude that...

• these chemicals are abundant today.

• the atmosphere 30,000 years ago was different than our atmosphere today.

• the number of layers they counted in the ice core was incorrect.

• the atmosphere never changes its composition.

When examining a rock sample, which of the following is the best method for determining its exact age?

• applying the law of superposition

• relative dating

• radiometric (radioactive) dating

• index fossil identification

*A geologist identifies the identical index fossil in rock layers from two different areas. Which conclusion is best supported by this discovery?*

• The deposition rate of two rock layers was identical.

• The fossil organism evolved independently in the two separate areas.

• The two rock layers were deposited at approximately the same time.

• The index fossil will also occur in sediment deposited on top of these rock layers.

Which statement best describes the Law of Superposition?

• Each sedimentary layer of rock represents 1,000 years of Earth’s age, much like the rings of a tree.

• In undisturbed layers of sedimentary rock, the upper rock layers are older than the lower rock layers.

• In undisturbed layers of sedimentary rock, the lowest layers contain the older rocks.

• Rocks that form near volcanoes are older than surrounding rock.

Uranium is a naturally occurring radioactive element contained in some rocks. Over time, the uranium radioactively decays to the element lead. The ratio of grams of uranium to grams of lead for four rock samples is shown. Assuming no lead was originally present in any of the rock samples, which rock sample is most likely the oldest?

• 4
• 1
• 2
• 3

Carbon 14 has a half life of 5,730 years. If a fossil sample has 25% of the original carbon 14 in it, how old is the fossil?

• 11,460 years old
• 5,730 years old
• 17,190 years old
• none of these

In what type of rock would a geologist MOST likely find evidence of ancient life?

• sedimentary
• foliated
• metamorphic
• volcanic