PART 1 Rock Texture And Metamorphism – Geology
This lesson covers Rock Texture And Metamorphism – Geology.
What are the three major rock types defined in the rock cycle?
sedimentary, igneous, and metamorphic
The principle of _______ states that physical, chemical, and biological processes at work shaping the earth today have also operated in the geological past.
uniformitarianism
The protolith of quartzite is:
sandstone
The two most common elements in the Earth’s crust are:
oxygen and silicon
An igneous pluton will have what type of texture?
phaneritic
A large depression due to volcanic eruption followed by subsidence of the land surface as the magma chamber is emptied is called a ________ ?
caldera
A _______ is a mixture of volcanic debris and water that moves rapidly down the slopes of volcanoes, generally following stream channels.
lahar
If an atom of carbon has a mass number of 13 and an atomic number of 6, how many neutrons are located nucleus?
7
Which of the following locations is an example of intraplate volcanism?
Yellow Stone National Park in the central U.S.
A(n) ________ is a tentative explanation, whereas a(n) _______ has survived scrutiny over many years.
hypothesis; theory
Which of the following forces creates a foliated texture in metamorphic rocks?
compressive stress, tectonic forces, differential stress, shear stress
Which of the following common, rock forming minerals is a silicate?
potassium feldspar
Which of the following diagrams properly labels the Earth’s layers and the physical state of those layers?
the one that says inner core (solid), outer core (liquid), mantle (solid), crust (solid)
According to Bowen’s Reaction Series, the first mineral the melt in granite would be….
quartz
What type of igneous rock texture is due to tiny gas bubbles de-gassing as lava cools?
vesicular
Which of the following is NOT part of the definition of minerals
organic
Which of the following rocks would most likely be found at a divergent plate boundary?
basalt
The earth is ________ years old.
4,550,000,000
What is the definition of the geosphere?
the solid earth
The mantle is characterized by what rock type?
peridotite
The correct sequence of rocks that are formed when shale undergoes metamorphism is:
slate, phyllite, schist, gneiss
Which of the following processes can occur at divergent plate boundaries?
decompression melting
This type of metamorphism is due to relatively lower temperatures and pressures as sediment is deposited in basins.
burial
Name the era and eon in which we currently live.
we live in the cenozoic era of the phanerozoic eon
Which of the following statements about Mt. St. Helens is FALSE?
the volcano is an example of a cinder cone
Which of the following statements about a single silicate tetrahedron is FALSE?
a silicate tetrahedron has four silicon atoms
What is the name of a rock composed of fine-grained pyroclasts (dust and ash) that are cemented together?
tuff
Andesite and diorite:
-crystalized from magma/lava with the same silica content
-cooled at different rates
-have the same mineral composition
-have different textures
Which of the following diagrams shows how foliation could develop in a rock due to compression (the compression is shown with arrows)?
the one with the arrows point towards the block from directly above and below
Covalent bonding involves the _____ of valence electrons between atoms, and an example of a mineral with this type of bonding is ______.
sharing; diamond
Mafic magmas tend to produce less violent eruptions than felsic magmas because of:
lower magma viscosity
In which type of silicate structures are four oxygen atoms shared among silicate tetrahedra?
framework
A rock that has undergone metamorphism and partial melting is called a _________.
migmatite
Which of the following events occurred first and lead to the formation of planet earth?
rapid expansion of stellar matter (mostly H and He)
Which of the following rocks has a foliated texture?
slate
You observe a mineral sample that has smooth, planar sides. What could the smooth sides be caused by?
-cleavage
-crystal form
An aphanitic igneous rock with a felsic composition is called ________.
Rhyolite
Shield volcanoes have the following characteristics EXCEPT:
magma and lava that are felsic in composition
If increasing hear and pressure change basalt into hornfels, the rock has changed from a(n) _______ rock into a(n) _______ rock.
igneous, metamorphic
How are igneous rocks formed?
cooling and crystallization of molten rock
Cinder cones form due to the accumulation of ejected pyroclasts.
True
Science is a collection of facts.
False
Most volcanism occurs away from plate tectonic boundaries, in the cratons of plates.
False
Magma forms throughout the mantle because temperatures are sufficiently high to melt solid rock.
False
During metamorphism rock is melted.
False
The three agents of metamorphism include heat, pressure, and reactive fluids.
True
Quartz is a felsic rock.
False
Polymorphs are minerals that have identical chemical composition, but different mineral structures.
True
The three types of plate boundaries are divergent, convergent, and transform.
True
Partial melting of the mantle produces mafic magma.
True
What type of rock can be found at Yellowstone National Park and provides evidence that a supervolcano erupted violently in the past?
tuff
Gabbro and basalt:
-formed from magma with the same silica content
-formed at different depths within the earth
-have the same minerals
-have different textures
An intrusive igneous rock with a silica content greater than 65% is called:
granite
If an atom of carbon has a mass number of 13 and an atomic number of 6, how many neutrons are located in the nucleus?
7
Which of the following is NOT part of the definition of minerals?
organic
Which is NOT true of a single silicate tetrahedron?
a silicate tetrahedron has four silicon atoms
During the Cretacceous when dinosaurs were living, evaporite rocks were deposited in what is now southwest Arkansas and these rocks form part of the ___________ geologic division in Arkansas.
Gulf Coastal Plain
In order of decreasing grain size (largest listed first), sedimentary grain sizes include:
gravel, sand, silt, clay
This type of metamorphism occurs due to relatively high temperatures and lower pressures, without the addition of ions from an external source of water:
contact
The most common end product of the chemical weathering of feldspar is:
clay minerals
Plutonic rocks that cool slowly at depth typically have a(n) ________texture.
phaneritic
Which acid forms naturally due to rain water picking up carbon dioxide (CO2) from the atmosphere and soil zone?
Carbonic
Which of the following ions or molecules is NOT a common end product of chemical weathering?
Nitrogen (N)
All of the following are true regarding Mount St. Helens, EXCEPT:
There has not been any igneous activity at the volacno since 1980
The correct sequence of rocks that are formed when shale undergoes prograde metamorphism is:
slate, phyllite, schist, gneiss
All of the following are examples of sedimentary rocks where minerals have precipitated out of an aqueous solution, EXCEPT:
shale
The temperature and pressure at the Earth’s surface is relatively lower than at depth within the crust or mantle. Which mineral is most stable at the Earth’s surface?
Quartz
The relative violence of volcanic eruptions are controlled by:
–Si content of the magma
-the amount of gasses in the magma and the relative ease of escaping
-temperature of the magma
-magma viscosity
All of the following rocks have a non-foliated texture EXCEPT:
gneiss
Which of the following common, rock-forming minerals is a silicate?
muscovite
Which statement is true regarding the formation of magma in the mantle?
Decompression melting forms magma due to a decrease in pressure.
All of the following are true about compaction and cementation, EXCEPT:
Occur at temperatures and pressures similar to the formation of igneous rocks
If increasing heat and pressure changes subbituminous coal into anathracite, the rock has changed from a(n) _______ rock into a(n) _______rock.
sedimentary; metamorphic
The primary cause of fatalities related to volcanic eruptions is:
pyroclastic flows/surges
All minerals are crystalline, but not all mineral samples are cyrstals.
True
Mechanical weathering breaks down rocks into smaller pieces without affecting the composition of the minerals.
True
When minerals and rocks are removed from the environment in which they formed, they remain stable and are not broken down into new materials.
False
The magma beneath Yellowstone National Park continues to affect the park, causing changes in the land surface elevation and earthquakes.
True
Isotopes of the same element have the same number of neutrons.
False
Covalent bonding involves the sharing of valence electrons between atoms.
True
The Earths external heat engine is the primary driver of plate tectonics.
False
Volcanism occurs most frequently away from plate tectonic boundaries at plate interiors.
False
The three types of sedimentary rocks are chemical, detrital, and organic.
True
Most rock-forming minerals are oxides, such as hematite.
False
Which of the following is true concerning Bowen’s reaction series? As temperature and pressure decrease:
silicate structure becomes more complex
This mineral is an example of which type of silicate structure?
single-chain silicate structure
What is the correct mineral?
Amphibole
If this mineral has a high Ca content (as opposed to a high Na content), what is the correct term for its composition?
Mafic
The settling and/or accumulation of sediments and/or organic material.
deposition
The movement of sediment away from its source.
transportation
The physical picking up of sediment by water, wind, or ice.
erosion
Process by which sediment grains are separated according to grain size.
sorting
Processes that change the physical and chemical character of rocks at the Earth’s surface.
weathering
Process of magma evolution where Fe and Mg rich minerals separate from the magma through crystal settling.
differentiation
Process of magma evolution where minerals with higher Si content are the first to melt from rocks.
partial melting
Process of magma evolution where two magmas of different compositions combine
magma mixing
Process of magma formation due to the addition of volatiles (such as water).
flux melting
Process of magma evolution where hot magma incorporates melted country rock into the magma body.
assimilation
A(n) ________ is a tentative explanation, whereas a(n) ________ has survived extensive scrutiny over many years.
hypothesis; theory
Which process below is driven by Earth’s solar energy?
ocean circulation
The layers of Earth are based on what two sets of characteristics?
chemical composition and physical properties
The upper mantle can be divided into the athenosphere and lithosphere based on what physical properties?
The athenosphere is solid, but mobile, while the lithosphere is solid and relatively rigid.
What are the two types of crust?
Oceanic and Continental
What is the category name for the largest division of time used on the geologic time scale?
Eon
Why is the geologic time scale more detailed in the Phanerozoic than in previous eons?
The Phanerozoic Eon is more detailed because of the presence of organisms with hard parts and the rapid increase in biodiversity
The Jurassic Period lies in the _____ Era, which was dominated by large terrestrial vertebrates, or ________.
Mesozoic; dinosaurs
Name the epoch, period, era, and eon in which we currently live.
We live in the Holocene Epoch of the Quaternary Period, which is part of the Cenozoic Era and Phanerozoic Eon
What are the two most abundant elements in Earth’s crust?
Oxygen and Silicon
What minerals make up half of Earth’s crust?
Feldspars
What is an accurate description of the silicon-oxygen tetrahedron?
The silicon-oxygen tetrahedron is a four-sided figure with a silicon atom in the middle bonded to four neighboring oxygen atoms
The micas (biotite and muscovite) exhibit what type of silicate structure?
sheet
Crystalization can occur _______.
-from solutions in water
-with temperature changes
-from biological processes
Which of these are minerals?
–Ruby
-gold nugget
-quartz
Igneous rocks are formed by:
The cooling and crystallization of molten rock
What is required to generate an igneous rock with a fine-grained texture?
a fine grained texture is the product of rapid cooling and crystallization of lava
A phaneritic texture is characteristic of a(n) ________ igneous rock that cooled _________.
intrusive; below the surface
What does it mean if an igneous rock has an aphanitic texture?
The igneous rock exhibits mineral crystals too small to see with the naked eye.
Which of the following is an aphanitic rock?
rhyolite
The partial melting of _____ will yield mafic (basaltic) magma.
Peridotite
How can magma be generated from solid rock?
-by an addition of volatiles
-by a decrease in pressure
-by an increase in temperature
Why are shield volcanoes wider than composite volcanoes?
The lava that flows out of shield volcanoes is more fluid than the lava that flows out of composite volcanoes
Basaltic magmas have a _____ viscosity, whereas rhyolitic magmas have a _______ viscosity.
low;high
Shiel volcanoes produce lava that is primarily ______ in composition.
mafic
What is rock texture?
the way a rock looks
How will minerals orient when a rock is put under normal stress?
perpendicular to the direction of the greatest stress
How will minerals grow when a rock is put under normal stress?
perpendicular to the direction of the greatest stress
How will minerals orient when a rock is put under shear stress?
Parallel to the direction of the shear stress
Why do bands of minerals form when rocks are put under normal stress?
Minerals dissolve, atoms migrate to new locations, and minerals reform
Why are mineral bands in metamorphic rocks light and dark colored?
dark minerals rich in iron and magnesium separate from light minerals rich in silica and aluminum
Shale subject to high grade metamorphism will change into____.
gneiss
Where does Earth’s internal heat come from?
-radioactive decay
-energy from earths formation
-magma
In confining pressure, forces are applied ______.
equally in all directions
What type of volcano is Cerro Negro?
cinder cone
Slate is a ______ grade metamorphic rock.
low
Peridotite is the main constituent of which part of the Earth?
upper mantle
The principle of _______ states that the physical, chemical , and biological processes at work shaping the Earth today have also operated in the geologic past.
unifromitatianism
Polymorphs are minerals that will have two identical mineral structures, but different chemical compositions
false
A(n) _______ is a silicate structure where no silica tetrahedra share any oxygen ions.
independent
What mineral has a sheet silicate structure?
Muscovite
If the temperature in the Earth generally increases with depth, how is it possible that the Inner Core is a solid?
The pressures in the core are immense ad keep it in a solid state in spite of the temperature
What was the rate of cooling and the environment of formation for an extrusive igneous rock?
fast because it was erupted from a volcano
Metamorphism ends when the rock begins to melt.
True
The lithosphere is the layer in the interior of the Earth that is just below the crust.
False
What is the extrusive equivalent of the intrusive igneous rock Gabbro?
Basalt
Which mineral on the Bowen’s Reaction Series will be the first to melt if an igneous rock is heated?
quartz
The more silica in magma, the lower the viscosity.
False
What kind of lava is most closely associated with composite cones?
andesite
Generally speaking, how is the chemical composition of most metamorphic rocks going to compare to that of the parent rock?
chemical compositions will be nearly the same
What agent is always required in all metamorphic processes on Earth?
heat
The stable interior of a continent is called a _____.
shield
Which mineral class makes up most igneous rocks?
silicates
What are the three types of plate boundaries?
convergent, divergent, and transform
Which of these is NOT part of the definition of minerals?
liquid
All of the following rocks have a non0foliated texture EXCEPT:
phyllite
Which of the these common, rock forming minerals is a silicate?
pyroxene
Which statement is true concerning Bowen’s reaction series? As temperature and pressure decease:
mineral composition changes from mafic to felsic
This type of metamorphism occurs dues to relatively high temperatures and lower pressures, without the addition of ions from an external source of water:
contact
Ionic bonding involves the _____ of valence electrons between atoms, and an example of a mineral with this type of bonding is ______.
transfer; halite
The primary cause of fatalities related to volcanic eruptions is:
pyroclastic flows/ surges
If an atom of oxygen has a mass number of 18 and an atomic number of 8, how many neutrons are located in the nucleus?
10
Which of the following diagrams shows how floiation could develop in a rock due to shearing?
the image of the block with the arrows on both the top and the bottom going opposite directions from each other
Which of the following forces creates a folliated texture in metamorphic rocks?
-compressive stress
-tectonic force
-differential stress
-shear stress
Which statement is TRUE regarding magma formation
adding water can lower the melting point of rocks to form magma
Which of the following statements about Mt. St. Helens is FALSE
there has not been any igneous activity at the volcano since 1980
gabbro and basalt:
-crystallized from magma with the same silica content
-cooled at different rates
-have the same mineral composition
-have different textures
A large depression due to volcanic eruption followed by a subsidence of the land surface as the magma chamber is emptied is called a _______?
Caldera
Index minerals can be sued to understand the temperature and pressure conditions during metamorphism.
True