Earth Science Mid Semester Revision

New oceanic crust is continually forming on Earth. Where does most of this crust form?

• subduction zones

• hot spots

• Mid-ocean ridges

• collision zones

Tick the correct types of evidence Wegener used to prove his continental drift theory.

• Fossils

• Seafloor spreading

• Rock Formations

• Fit of the continents

This image is a model of mid-ocean ridge. Which statement is true?

• Rocks in area Y are older than rocks in area X

• Rocks in area X are older than rocks in area Y

• Rocks in area X and Y are moving towards each other

• Rocks in area X and Y are moving away from each other

The end of which era is marked by the largest extinction event in Earth’s history?

• Cenozoic

• Mesozoic

• Paleozoic

• Precambrian

How long did the Guass epoch last?

• 100,000 years

• 1 million years

• 3 million years

• 5 million

The best device to measure these magnetic reversals is:

• Sonar

• Magnetometer

• Seismometer

• Thermometer

Scientists study the decay of radioactive isotopes in a material in order to determine:

• only the relative age of the material.

• the porosity of the rock layer containing the material.

• the thickness of the rock layer containing the material.

• the absolute age of the material.

Tick the correct answers for continental crust.

• Made mostly of Granite

• Older

• Thicker (30-50 km)

• Less dense

• Younger

Tick the correct answers for oceanic crust.

• Made mostly of basalt

• Younger

• Less in thickness

  (5-10km)

• More dense

• Less dense

The principle where the oldest rocks are on the bottom and younger layers are above it is called

• Superposition

• cross-cutting relationship

• inclusions