A Trip Through Earth's History - Recap

A Trip Through Earth's History - Recap

By Courtney Hazelip

Multiple Choice

Velociraptors lived during the ____________ era.

• mesozoic

• cenozoic

• precambrian

Multiple Choice

What does the principle of uniformitarianism state?

• Organisms that lived in the past can be preserved

• processes that operate today also operated in the past

• there are no gaps in the geologic record

• Earth's eras occurred during uniform time spans

Multiple Choice

The geologic time scale is divided by several different spans of time. Which of the following divisions of time are all eras?

• Cretaceous, Jurassic, Triassic

• Paleocene, Eocene, Oligocene

• Cenozoic, Mesozoic, Paleozoic

• Precambrian, Cambrian, Devonian

Multiple Choice

What is the main criterion that scientists use to decide where to place the boundaries between the major divisions of the geologic time scale?

• major changes in the structure of Earth's layers

• major changes that occur in the solar system

• major changes that are recorded in the fossil record

• major changes in the arrangement of the continents

Multiple Choice

Earth's earliest atmosphere lacked which gas that is necessary for life as we know it to exist today?

• nitrogen

• carbon dioxide

• argon

• oxygen

Multiple Choice

The time it takes for half of the radioactive atoms in a sample of a radioactive element to decay is the element's ________

• relative age

• potassium-argon date

• absolute age

• half-life

Multiple Choice

Geologists use radioactive dating to _________

• determine the relative ages of rock layers

• tell the difference between molds and casts

• tell where one soil horizon ends and the next one begins

• determine the absolute ages of rocks

Multiple Choice

Potassium-40 is useful for dating very old rocks because it has a(n) __________ of 1.3 billion years.

• shelf-life

• half-life

• thickness

• relative date

Multiple Choice

If the graph represents the decay of strontium-90 in an igneous rock, what event occurred at 0 years on the horizontal axis?

• the rock was destroyed

• the formation of the rock, or when the magma or lava first hardened to become rock

• this is when fossils were created in the igneous rock

• this is when the rock subducted beneath the oceanic plate

Multiple Choice

What is the half-life of the crystal isotope?

• 10,000 years

• 15,000 years

• 20,000 years

• 25,000 years

Multiple Choice

How many half-lives have gone by?

• 1

• 2

• 3

• 4

Multiple Choice

What is the age of the sample?

• 20,000 years

• 30,000 years

• 50,000 years

• 60,000 years

Multiple Choice

A(n) __________ fossil forms when dissolved minerals replace the remains of an organism and then harden to form rock.

• amber

• frozen

• asphalt

• petrified

Multiple Choice

Fossils usually occur in in metamorphic rocks.

• True

• False

Multiple Choice

Fossils are the preserved remains or traces of plants and animals that have lived on Earth throughout Earth's history. How does the fossil record of animals compare to animals that exist today?

• Animals in the fossil record are the same as animals that exist today.

• Animals in the fossil record are ancestors of animals that exist today.

• Animals in the fossil record have no similarities to animals that exist today.

• Animals in the fossil record are more complex than animals that exist today.

Multiple Choice

The relative age of a rock is ____________

• its age compared with the ages of other rocks

• less than the age of the fossil the rock contains

• the number of years since the rock formed

• its age based on how much carbon-14 the rock contains

Multiple Choice

A(n) ______________ is a gap in the geologic record where some rock layers have been lost because of erosion.

• layer

• relative age

• unconformity

Multiple Choice

The law of superposition helps geologists determine the absolute age of a rock layer.

• true

• false

Multiple Choice

If rock layers between B and D have eroded away, what is the boundary between B and D called?

• an unconformity

• a boundary line

• a fault

• a fossil

Multiple Choice

Layer F is an igneous extrusion. How could a geologist use layer F to infer the age of layer A?

• the geologist could use relative dating to determine the absolute age of F; then by the law of crosscutting, A must be at least as old as F, which lies above A.

• the geologist could use radioactive dating to determine the absolute age of F; then by the law of superposition, A must must be at least as old as F, which lies above A.

• The geologist could use relative dating to determine the relative age of F; then by the law of superposition, F must be at least as old as all the other layers.

• The geologist could use radioactive dating to determine the relative age of A; then by the law of unconformity, A must be at least older than F, which lies above A.