Question 27 options:    Make-up 75% of the Earth's crust

Question 27 options:

 Make-up 75% of the Earth's crust.

Are found at the surface over 75% of the Earth's continental areas.

Record the history of life on Earth.

Can be explained completely by Bowen's reaction series.

Both B and C above.

Question 28 (1 point)

 Probably the single, most common feature of ALL sedimentary rocks is that they:

Question 28 options:

Are found occurring in layers.

Form deep below the earth's surface.

Mostly contain silicate minerals.

Form according to Bowen's theory

Question 29 (1 point)

For Sedimentary Bowen's Reaction series:

Question 29 options:

explains why quartz is common a sedimentary mineral at the Earth's surface.           

explains why olivine is common a sedimentary mineral at the Earth's surface.

explains why olivine is unstable at the Earth's surface.

both A and C are true.

Question 30 (1 point)

All of the following are true about LIMESTONES except:

Question 30 options:

They are probably the most abundant non-clastic rock.

They form in oceans mostly and sometimes in lakes. 

They may form inorganically.

They sometimes contain abundant fossil remains.

No exceptions, all of the above are true of limestones.

Question 31 (1 point)

Clastic sedimentary rocks are classified primarily on the basis of:

Question 31 options:

Orthoclase vs. plagioclase content.

Foliated vs. non-foliated.

Intrusive vs. extrusive.           

Size of grains.

The origin of many metamorphic rocks is different than sedimentary or igneous rocks in that metamorphism often involves:

Question 39 options:

very high temperatures (>1200°C)

very-near-surface, low pressures

exposure to running water

high applied squeezing or shearing stresses

Question 40 (1 point)

Foliation in metamorphic rocks is expressed by all of the following features EXCEPT:

Question 40 options:

segregated mineral layers

aligned plate-like minerals

platy minerals which have grown parallel to the applied shear stress

blocky minerals which have completely resisted deformation by shear stress

Question 41 (1 point)

The fossil record shows that species on Earth have changed steadily and irreversibly through geologic time. This is a useful fact because...

Question 41 options:

It allows age correlation of widely separated rock exposures to assemble composite geologic histories of large regions.

It provides a history of life on Earth and a longer time perspective on biological evolution than is possible using only studies of currently living organisms.

It provides a history of environmental conditions on Earth through geologic time.

All of the above

Question 42 (1 point)

The events which cause mass extinctions on Earth potentially include...

Question 42 options:

Rapid climate change due to large volcanic eruptions

Large impacts from collisions with extraterrestrial objects (e.g. asteroids, comets, etc.)

Plate tectonics and changing continental configurations

All of the above

Question 43 (1 point)

Radiometric dating of rock material is possible because:

Question 43 options:

Rapid climate change due to large volcanic eruptions

Large impacts from collisions with extraterrestrial objects (e.g. asteroids, comets, etc.)

Plate tectonics and changing continental configurations

All of the above

None of the above

Question 44 (1 point)

Radiometric dating of rock material is possible because:

Question 44 options:

The decay characteristics and half lives of radioactive elements commonly found in igneous rocks are well understood thanks to advances in nuclear chemistry and physics.

The carbon cycle makes sure that radioactive carbon is distributed evenly through all rock material, which makes dating any rock relatively easy.

Radioactive elements are so rare that whenever we find them, we can be sure of the exact event which deposited them in the rock to start with.

Fossil preservation gives rise to radioactive decay in their shell material, which allows for direct dating of fossils and the rocks they are contained if they are older than 500,000 years in age.

Question 45 (1 point)

An igneous rock that originally had 8000 atoms of a certain radioactive material when it was formed is found to now have only 125 atoms of that material left. If the half-life of the radioactive material is 2 million years, how old is the igneous rock?

Question 45 options:

6 million years

12 million years

64 million years

128 million years