Question 1

Lava flows are typically finer grained than intrusive igneous rocks.Why?

Accepted Answer

A) Intrusive magma is cooler because it is well insulated by the surrounding rock. 
B) Intrusive magma flows onto the Earth's surface and cools very slowly, allowing many small mineral grains to grow. 
C) The extrusive magma cools quickly so the mineral grains do not have time to grow. 
D) The extrusive magma, because it is deep below the surface, cools very slowly producing very small mineral grains. 
A) Intrusive magma is cooler because it is well insulated by the surrounding rock. 
B) Intrusive magma flows onto the Earth's surface and cools very slowly, allowing many small mineral grains to grow. 
C) The extrusive magma cools quickly so the mineral grains do not have time to grow. 
D) The extrusive magma, because it is deep below the surface, cools very slowly producing very small mineral grains.

Question 2

Vesicles are ________.

Accepted Answer

A) cavities or bubble-shaped holes formed in lavas or pyroclastics by escaping gases during quenching 
B) empty pits where large crystals like phenocrysts weathered out during exposure 
C) holes that used to be full of hot liquid water when the rocks erupted 
D) the sex organs of fossilized creatures that once lived in the molten magma 
A) cavities or bubble-shaped holes formed in lavas or pyroclastics by escaping gases during quenching 
B) empty pits where large crystals like phenocrysts weathered out during exposure 
C) holes that used to be full of hot liquid water when the rocks erupted 
D) the sex organs of fossilized creatures that once lived in the molten magma

Question 3

Glassy rocks can form either from extremely rapid cooling or high viscosity due to high silica contents.

Accepted Answer

A) True 
 B)False

Question 4

Olivine is an important mineral in peridotites and other ultramafic rocks.

Accepted Answer

A) True 
 B)False

Question 5

What are vesicles?

Accepted Answer

A) open voids in an igneous rock left when phenocrysts dissolved away 
B) the larger mineral grains of a porphyritic texture 
C) the fragments comprising a volcanic breccia 
D) open spaces formed in the rock as the lava solidified around gas bubbles 
A) open voids in an igneous rock left when phenocrysts dissolved away 
B) the larger mineral grains of a porphyritic texture 
C) the fragments comprising a volcanic breccia 
D) open spaces formed in the rock as the lava solidified around gas bubbles

Question 6

Which of the following is the major dissolved volatile constituent in both magmas and volcanic gases?

Accepted Answer

A) carbon monoxide 
B) methane 
C) nitrous oxide 
D) water 
A) carbon monoxide 
B) methane 
C) nitrous oxide 
D) water

Question 7

The earliest formed crystals (phenocrysts)in a magma tend to be ________.

Accepted Answer

A) crowded and irregular in shape 
B) small and clouded with inclusions of everything that formed later on 
C) those that can form only at the lowest temperatures 
D) larger and well formed because they have space to grow and a ready supply of ions 
A) crowded and irregular in shape 
B) small and clouded with inclusions of everything that formed later on 
C) those that can form only at the lowest temperatures 
D) larger and well formed because they have space to grow and a ready supply of ions

Question 8

Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases.
-Choose the option that does not fit the pattern.

Accepted Answer

A) plutonic 
B) lava 
C) extrusive 
D) volcanic 
A) plutonic 
B) lava 
C) extrusive 
D) volcanic

Question 9

________ is the dominant feldspar in basalt.

Accepted Answer

A) Plagioclase 
B) Microcline 
C) Orthoclase 
D) Pyroxene 
A) Plagioclase 
B) Microcline 
C) Orthoclase 
D) Pyroxene

Question 10

Rocks that consist completely of disordered ions with no long range structures are called ________.

Accepted Answer

A) aphanitic 
B) glassy 
C) phaneritic 
D) porphyritic 
A) aphanitic 
B) glassy 
C) phaneritic 
D) porphyritic

Lava flows are typically finer grained than intrusive igneous rocks.Why?

Vesicles are ________.

Glassy rocks can form either from extremely rapid cooling or high viscosity due to high silica contents.

Olivine is an important mineral in peridotites and other ultramafic rocks.

What are vesicles?

Which of the following is the major dissolved volatile constituent in both magmas and volcanic gases?

The earliest formed crystals (phenocrysts)in a magma tend to be ________.

Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. -Choose the option that does not fit the pattern.

________ is the dominant feldspar in basalt.

Rocks that consist completely of disordered ions with no long range structures are called ________.

An Introduction to Geology and Plate Tectonics

Minerals: The Building Blocks of Rocks

Volcanoes and Volcanic Processes

Weathering and Soil

Sedimentary Rocks

Metamorphism and Metamorphic Rocks

Geologic Time

Crustal Deformation

Earthquakes and Earth's Interior

The Ocean Floor

Plate Tectonics: The Framework for Modern Geology

Mountain Building and Continental Frameworks

Mass Wasting: The Work of Gravity

Running Water

Groundwater

Glaciers and Glaciation

Deserts and Winds

Shorelines

Mineral and Energy Resources

Filters

Exam 3: Igneous Rocks

Lava flows are typically finer grained than intrusive igneous rocks.Why?

Vesicles are ________.

Glassy rocks can form either from extremely rapid cooling or high viscosity due to high silica contents.

Olivine is an important mineral in peridotites and other ultramafic rocks.

What are vesicles?

Which of the following is the major dissolved volatile constituent in both magmas and volcanic gases?

The earliest formed crystals (phenocrysts)in a magma tend to be ________.

Examine the words and/or phrases for each question below and determine the relationship among the majority of words/phrases. -Choose the option that does not fit the pattern.

________ is the dominant feldspar in basalt.

Rocks that consist completely of disordered ions with no long range structures are called ________.

An Introduction to Geology and Plate Tectonics

Minerals: The Building Blocks of Rocks

Volcanoes and Volcanic Processes

Weathering and Soil

Sedimentary Rocks

Metamorphism and Metamorphic Rocks

Geologic Time

Crustal Deformation

Earthquakes and Earth's Interior

The Ocean Floor

Plate Tectonics: The Framework for Modern Geology

Mountain Building and Continental Frameworks

Mass Wasting: The Work of Gravity

Running Water

Groundwater

Glaciers and Glaciation

Deserts and Winds

Shorelines

Mineral and Energy Resources

Filters