Geologic Time Exam

Which concept states that most sediments are deposited in layers that are flat and parallel to Earth's surface?

• principle of superposition

• cross-cutting relationship

• dynamic equilibrium

• original horizontality

Sedimentary rock layers A through D in the cross section below have not been overturned. Which rock layer is the oldest?

• A) A

• B) B

• C) C

• D) D

Which radioactive element would a scientist most likely have used to date the age of a fossil that is 10,000 years old?

• potassium-40

• carbon-14

• uranium-238

• rubidium-87

Approximately how long ago did the first dinosaurs appear on Earth?

• 66 million years ago

• 187 million years ago

• 230 million years ago

• 374 million years ago

The absolute age of an igneous rock can best be determined by

• A) comparing the amounts of decayed and undecayed radioactive isotopes in the rock

• B) comparing the sizes of the crystals found in the upper and lower parts of the rock

• C) examining the rock's relative position in a rock outcrop

• D) examining the environment in which the rock is found

One reason why carbon-14 was used to determine the age of the woolly rhinoceros tooth was because carbon-14

• A) never completely decays

• B) has a very long half-life

• C) can be found in most organic remains

• D) is easily identified in Carboniferous bedrock

When did the earliest humans appear on Earth?

• before the earliest dinosaurs

• before the earliest flowering plants

• during the Pleistocene Epoch

• during the Late Triassic Epoch

Geologic Time is broken down into smaller parts called eons, ____, periods, and epochs.

• eras

• decades

• lightyears

• points

Tags

NGSS.MS-ESS1-4