Volcanoes
Why do shield volcanoes have gentle slopes?
A. Pyroclastic ash material gradually flows outward from the crater and forms a broad slope
B. The low viscosity of mafic lava allows for it to spread out during eruption
C. Caldera collapse causes inverted topography and decreases the relief
D. The high viscosity tends to pile up forming blister-shaped pockets
B. The low viscosity of mafic lava allows for it to spread out during eruption
Which of the following explains the coloration of an unaltered igneous rock?
A. The type of volcanic eruption and therefore the viscosity
B. The amount of ionic material found in the rock
C. The minerals found within the rock and therefore percentage of silica in the rock
D. The staining of the interior of the rock from chemical weathering
C. The minerals found within the rock and therefore percentage of silica in the rock
Why does magma become more felsic as it travels through continental crust?
A. Equilibrium crystallization and contamination by hot spots
B. EMORB vs. NMORB enrichment in incompatible (LILE and HFSE) ions
C. Fractional crystallization and contamination by continental material
D. Diapiric crystallization and contamination by sedimentary rocks
C. Fractional crystallization and contamination by continental material
Which mineral often found in coal is most responsible for acidification of water related to abandoned coal mines?
A. halite (salt)
B. pyrite
C. sugar
D. liquid petroleum
B. pyrite
Weathering refers to
A. Breakdown of only minerals but not rocks and only by laser ablation
B. Breakdown by a sick drum solo
C. Breakdown of material by physical or chemical processes like fracturing or dissolution
D. Collection of loose debris and lithification
C. Breakdown of material by physical or chemical processes like fracturing or dissolution
The dense collection of gas and particulate matter that rushes rapidly down the side of a stratovolcano during eruption is called:
A. lava flow
B. eruption column
C. pyroclastic flow
C. pyroclastic flow
What does the vesicular texture of scoria tell you about its formation?
A. There was likely not any gas present during the crystallization of the rock
B. There was likely a meteorite impact that blasted high velocity fragments through the magma as it cooled
C. A high amount of gas was probably venting through the magma as it cooled, preserving air pockets
D. The magma likely cooled partially at depth, then moved upwards
C. A high amount of gas was probably venting through the magma as it cooled, preserving air pockets
What style of eruption is formed in a mafic magma with a very high gas content?
A. lava fountain
B. lava dome
C. pyroclastic flow
D. lava flow
A. lava fountain
Minerals are all naturally occurring solid substances with a definable chemical composition. They must also possess ____________.
A. metallic luster
B. an ability to be synthesized in the laboratory as well as being found in nature
C. metallic elements, such as iron, calcium, or magnesium
D. a fixed, predictable crystalline structure (spatial arrangement of atoms and ions)
D. a fixed, predictable crystalline structure (spatial arrangement of atoms and ions)
Ionic, Covalent, and Metallic are types of atomic bonds. What does that mean?
A. These are different means by which atoms connect to form mineral structure. The type of bond also controls mineral properties
B. These describe the transition from the discontinuous to continuous side of Bowen's reaction series
C. These are different ways that minerals are attracted to each other. For example, calcite is attracted to pyrite
A. These are different means by which atoms connect to form mineral structure. The type of bond also controls mineral properties
Krakatoa and Mt Tambora, the two most powerful and deadly eruptions in recorded history were what types of volcano?
A. Lava fountain
B. Composite volcano
C. Lava dome
D. Lateral blast
B. Composite volcano
What two features of igneous rocks are used for classification purposes?
A. Precision and speed
B. Discontinuous reactions and continuous reactions
C. Size and shape
D. Texture and color
D. Texture and color
Large igneous provinces (huge volumes of mafic magma) are called ___________, which can flow tens to hundreds of kilometers like the Siberian Traps.
A. magma bursts
B. sills
C. super-duper plumes
D. flood basalts
D. flood basalts
Why is a synthetic solid grown in a lab NOT a mineral?
A. Minerals must form by natural Earth processes
B. Minerals must be crystalline and crystalline materials can't be grown in a lab
C. Because labs are weird
D. Minerals must be defined by chemistry and chemistry doesn't work in a lab
A. Minerals must form by natural Earth processes
Which type of magma has the greatest silica content, being made of mostly feldspar and quartz?
A. felsic
B. ultramafic
C. mafic
D. intermediate
A. felsic
Volcanoes like Hawaii that do NOT occur along or near present or probable future plate boundaries are associated with ____________.
A. subduction zones
B. hot spots
C. continental rifts
D. mid-ocean ridges
B. hot spots
Which of the following statements is true regarding preserved texture in an igneous rock?
A. Finely-crystalline rocks cool slowly and coarsely-crystalline rocks cool relatively quickly
B. Finely-crystalline rocks cool rapidly and coarsely-crystalline rocks cool relatively slowly
C. Finely-crystalline rocks cool only with a high silica content
D. Finely-crystalline rocks cool only with a low silica content
B. Finely-crystalline rocks cool rapidly and coarsely-crystalline rocks cool relatively slowly
If a body of magma becomes more felsic, its viscosity will
A. evaporate
B. decrease
C. increase
D. stay the same
C. increase
Bowen's reaction series is useful for what reason(s)?
A. It predicts the crystallization order and formation temperature of minerals in a cooling magma
B. It predicts the crystallization rate for different depths
C. It predicts the weather
D. It predicts the energy required to move atoms
A. It predicts the crystallization order and formation temperature of minerals in a cooling magma
The two most abundant elements in the crust are
A. Silicon and Tetrahedron
B. Aluminum and Magnesium
C. Silicon and Oxygen
D. Iron and Magnesium
C. Silicon and Oxygen
Coarse-grained granite is most similar in mineral composition to fine-grained ____________. (associated with explosive volcanoes)
Rhyolite
Which of the following statements regarding igneous rock texture is true?
A. The texture indicates the specific temperature at which the rock cooled
B. The texture indicates the chemical composition of an igneous rock
C. The texture indicates the original flavor of the magma prior to crystallization
D. The texture provides information regarding the cooling rate or cooling history of an igneous rock
D. The texture provides information regarding the cooling rate or cooling history of an igneous rock
The formation of magma within Earth is NOT caused by which of the following processes?
A. increase of heat from friction or transfer of heat from adjacent magma (like a hot spot)
B. loss of water to the atmosphere
C. decompression (drop in pressure)
D. addition of water
B. loss of water to the atmosphere
Which mineral property refers to a material's resistance to being scratched?
A. color
B. hardness
C. elasticity
D. cleavage
B. hardness
The movement of clastic material is called ____________.
A. detritus
B. erosion
C. weathering
D. deposition
B. erosion