Chapter 3
What are the two most important driving forces of metamorphism? Magma and lava Deposition and lithification Melting and crystallization High heat and pressure Weathering and accumulation
High heat, pressure
Where else might you expect to find metamorphic rocks like the Vishnu Schist of the Grand Canyon? In a mountain range. In a thick pile of lava flows. Deep beneath Earth's surface, where sedimentary layers have been buried. At the top of a pile of flat sedimentary layers.
In a mountain range. Deep beneath Earth's surface, where sedimentary layers have been buried.
How does magma differ from lava? Magma and lava differ in chemical composition. Magma and lava differ in physical properties. Lava is molten rock beneath Earth's surface; magma is molten rock at Earth's surface. Magma is molten rock beneath Earth's surface; lava is molten rock at Earth's surface. Lava is associated with explosive volcanic eruptions; magma is not associated with explosive volcanic eruptions
Magma is molten rock beneath Earth's surface; lava is molten rock at Earth's surface.
Contact metamorphism takes place when rocks _____. are rapidly melted come in contact with a magma body are quickly weathered are rapidly lithified are dragged down deep into Earth
come in contact with a magma body
What is the most abundant chemical sedimentary rock in Earth's crust? gypsum limestone chert rock salt flint
limestone
Generally a darker igneous rock is granite richer in silica lower in silica more mafic more felsic
lower in silica more mafic
Check all that apply. Bowen's Reaction Series says that as solid rock is heated the lower silica minerals melt first the higher silica minerals melt first the lower silica minerals melt last the higher silica minerals melt last
the higher silica minerals melt first the lower silica minerals melt last
Check all that apply. Bowen's Reaction Series says that as molten magma cools the lower silica minerals crystallize first ie at the higher temperatures the higher silica minerals crystallize first ie at the higher temperatures the lower silica minerals crystallize last ie at the cooler temperatures the higher silica minerals crystallize last ie at the cooler temperatures
the lower silica minerals crystallize first ie at the higher temperatures the higher silica minerals crystallize last ie at the cooler temperatures
As a result of partial melting, magma originates in __________. the crust and the inner core the atmosphere the outer core and the mantle the outer core and the inner core the mantle and crust
the mantle and crust
You find a sedimentary rock that has all its flat particles aligned in parallel. From this you can infer that _____. there is no quartz in the rock the particles have been compacted there are no fossils in the rock the particles have been cemented the particles have been melted
the particles have been compacted
A characteristic feature of sedimentary rocks is strata, or beds. true false
true
Clast (particle) size is the primary basis for naming detrital sedimentary rocks. true false
true
Glassy igneous rocks form when magma cools too fast for mineral grains to grow. true false
true
Metamorphism is commonly associated with mountain building. true false
true
What are the two important processes involved in lithification of sedimentary rocks? Transportation and accumulation Cooling and reorganization Crystallization and uplift Cementation and compaction
Cementation and compaction
Which of the following statements is related to chemical sedimentary rocks? Chemical sedimentary rocks are classified according to the particle size and shape. Chemical sedimentary rocks form from sediment derived from other rocks. Chemical sedimentary rocks are classified based on mineral color. Chemical sedimentary rocks form from the precipitation of minerals from dissolved substances.
Chemical sedimentary rocks form from the precipitation of minerals from dissolved substances.
When fine-grained tabular minerals in a rock at depth are subjected to differential stresses, they _________. melt rapidly align parallel to the plane in which the maximum compressive stress is applied weather quickly fracture align perpendicularly to the plane in which the maximum compressive stress is applied
align perpendicularly to the plane in which the maximum compressive stress is applied
Which of the following agents is capable of moving sediment from the site of formation to the site of deposition? ice waves wind All of the answers are correct. running water
all of the answers are correct
Metamorphism may result from ________. igneous rocks metamorphic rocks sedimentary rocks all of these
all of these
Pyroclastic debris from a volcanic eruption can include _____. cross-bedding coarse-grained crystals ash and cinders fossils very well-rounded particles
ash and cinders
When a sedimentary rock consists of angular, gravel-sized particles, it is called ________. conglomerate breccia sandstone shale siltstone
breccia
Check all that apply. As a magma body cools, metallic ores may be produced by hydrothermal fluids in layers by magmatic differentiation in vein deposits by hydrothermal fluids
by hydrothermal fluids in layers by magmatic differentiation in vein deposits by hydrothermal fluids
_____ igneous rocks are those that cool below the surface. Vesicular Volcanic Intrusive Extrusive Basaltic
intrusive
Which of the following best describes why the Vishnu Schist is visible at Earth's surface? The Vishnu Schist formed at Earth's surface. The Vishnu Schist erupted from a volcano on Earth's surface. The Vishnu Schist was exposed when sedimentary layers above it were eroded.
The Vishnu Schist was exposed when sedimentary layers above it were eroded.
Obsidian exhibits a ________ texture. coarse-grained porphyritic glassy fine-grained
glassy
Rhyolite is the fine-grained equivalent of this igneous rock. granite andesite diorite basalt
granite
An igneous rock that contains quartz and potassium feldspar would have a mineralogic content placing it in the range of __________. ultramafic rocks glassy rocks granitic or felsic rocks andesitic or intermediate rocks basaltic or mafic rocks
granitic or felsic rocks
Why does magma have a tendency to rise after its formation? It is denser than the surrounding rock. It contains significant amounts of volatile gases. The rocks below can't melt. It has less volume when it is a liquid. It is less dense than the surrounding rock.
It is less dense than the surrounding rock.
What is the difference between magma and lava? Magma is molten rock located above the surface; lava is molten rock below ground. Magma is generally granitic in composition; lava is dominantly basaltic in composition. Magma cools to produce extrusive igneous rocks; lava cools to produce intrusive igneous rocks. Magma is molten rock located below the surface; lava is molten rock erupted above ground. Magma is lower in temperature; lava is higher in temperature.
Magma is molten rock located below the surface; lava is molten rock erupted above ground.
An igneous rock becomes buried, is subject to high heat and pressure, and recrystallizes. This rock then is eroded, transported, deposited and subsequently lithified. Which rock types—in order—did the original igneous rock develop into? Metamorphic and sedimentary Metamorphic and igneous Igneous and sedimentary Sedimentary and metamorphic
Metamorphic and sedimentary
Metamorphic rocks can form when which of the following conditions are met? As pre-existing rocks undergo crystallization, the result is metamorphic rock. When pre-existing rocks melt, they are transformed into metamorphic rocks. Pre-existing rocks can undergo metamorphism when they are subjected to repeated freezing and thawing. Pre-existing rocks undergo metamorphism when they are subjected to heat and pressure without melting. The presence of fossils in pre-existing rocks leads to the development of metamorphic rocks.
Pre-existing rocks undergo metamorphism when they are subjected to heat and pressure without melting.
The formation of sedimentary rocks occurs under what conditions? If weathered particles are heated to the point where they melt, the result is sedimentary rock. Sedimentary rocks form during the assimilation of weathered particles into magma. When weathered particles are subjected to extreme heat and pressure, the result is sedimentary rock. When sediments are carried deep within Earth's crust, sedimentary rocks can form. Sedimentary rocks form when weathered particles are cemented and/or compacted
Sedimentary rocks form when weathered particles are cemented and/or compacted
How does cooling rate affect the crystal size of minerals in igneous rocks? Slow cooling produces smaller crystals; quick cooling produces larger crystals. Slow cooling produces larger crystals, but only in lava and not in magma. Slow cooling produces larger crystals; quick cooling produces smaller crystals. Quick cooling produces smaller crystals, but only in magma and not lava. Crystal size is independent of cooling rate.
Slow cooling produces larger crystals; quick cooling produces smaller crystals.
Most igneous rocks never reach the surface. However, igneous rocks other than those formed in volcanoes are found exposed on many parts of Earth. How do you account for this phenomenon? They formed at the surface and sank due to their greater density. They are the result of meteorite impact. They are composed of lava flows. They have been glaciated. They formed at depth and have been exposed by uplift and erosion.
They formed at depth and have been exposed by uplift and erosion.
While vacationing in Hawaii you notice that the sands on the beach are composed of black sediments. What inferences can you make about these sediments? You determine that the sediments were deposited by wind. You conclude that metamorphism has taken place. You note that cementation and compaction are taking place. The sediments formed deep within Earth. They were derived from the igneous rocks from which the islands were formed.
They were derived from the igneous rocks from which the islands were formed.
While working in the field, you discover an outcrop of metamorphic rocks. What can you conclude from this observation? You know that these rocks formed at great depth below the surface. You are certain that these rocks have undergone cementation and compaction. You determine that these rocks formed in a volcano. You conclude that these rocks were deposited in a glacial moraine. You know that these rocks formed near the surface of Earth.
You know that these rocks formed at great depth below the surface.
The geologic laboratory where you work received a sample for analysis that is composed of calcite that includes many microscopic fossils of marine organisms and reacts with acid. What name would identify this rock? chert rock salt chalk travertine gypsum
chalk
What are the agents of metamorphism? change in temperature change in pressure the presence of chemically active fluids the presence of running water
change in temperature change in pressure the presence of chemically active fluids
Sedimentary rocks that exhibit the intergrowth of crystal masses are generally formed from the products of _____. chemical weathering erosion melting mechanical weathering heat and pressure
chemical weathering
Which two minerals are most common in detrital sedimentary rocks? muscovite and biotite clay minerals and quartz olivine and pyroxene amphibole and quartz quartz and muscovite
clay minerals and quartz
Which of the following conditions are necessary to cause loose sediment to become sedimentary rock? elevated temperatures compaction cementation magma or lava hot fluids
compaction cementation
What is the classification of igneous rocks based on? the presence or absence of foliation grain size and texture porosity and permeability composition and texture color and composition
composition and texture
Working in the field, you find a rock that contains rounded fragments that are greater than 2 mm in diameter. What would you call this rock? basalt conglomerate sandstone shale limestone
conglomerate
Metamorphism that occurs because of close proximity to a mass of magma is called ________ metamorphism. contact pressure rifted regional
contact
What process forms igneous rocks? cooling and solidification of magma weathering and transport of magma alteration of sediments by heat and pressure compaction of sediments deposition of sediments
cooling and solidification of magma
What is a coarse-grained rock composed of intermediate plagioclase feldspar and pyroxene? peridotite granite andesite diorite gabbro
diorite
Rock salt and rock gypsum are common examples of a group of chemical sedimentary rocks called ________. glasses evaporites sandstones detritals
evaporites
When lava erupts at Earth's surface, what type of rock is produced? extrusive limestone metamorphic sedimentary intrusive
extrusive
When a metamorphic rock exhibits a layered or banded appearance, it is said to exhibit bedding planes fracture foliation luster
foliation
Which of the following textures is considered metamorphic? glassy texture strata foliation porphyritic texture vesicles
foliation
________ is a strong, parallel alignment of different mineral bands in a metamorphic rock. Rock cleavage Stress streaking Marbleizing Foliation
foliation
Intrusive rocks ________. are usually glassy are generally fine-grained are quite often vesicular form below Earth's surface form at Earth's surface
form below Earth's surface
This igneous texture is characterized by two distinctively different crystal sizes. coarse-grained glassy porphyritic fine-grained
porphyritic
In addition to temperature, which of the following agents increases with depth in Earth? cementation hardness weathering pressure erosion
pressure
What is a fine-grained igneous rock composed primarily of very small crystals of potassium feldspar and a few large crystals of quartz? rhyolite porphyry andesite porphyry basalt porphyry
rhyolite porphyry
Generally a paler igneous rock is basalt lower in silica richer in silica more mafic
richer in silica
Which is an example of a sedimentary rock composed of solid masses of intergrown crystals? basalt shale sandstone conglomerate rock salt
rock salt
Which of the following names describe common foliated metamorphic rocks? schist quartzite gneiss slate marble
schist gneiss slate
The formation of sedimentary rock requires _____. erosion of pre-existing rocks the melting of pre-existing rocks the application of heat and pressure to pre-existing rocks weathering and erosion of pre-existing rocks weathering of pre-existing rocks
weathering and erosion of pre-existing rocks
Which of the following agents move sediment from one place to another? wind rivers convection cells volcanoes glaciers
wind rivers glaciers