GEOL 101
Covalent
Which type of chemical bonding holds the base structure of the silicate tetrahedron together?
Tuff, lapilli, ash, scoria, bombs, and pumice are specific __________.
types of pyroclastic materials
In the "Earth Revealed" geologic video documentary #14 on Igneous Rocks, the source region of magma was discussed during the early portion of the video. Question: What was the noted source region from which most magmas form inside the Earth?
upper mantle
They must be an organic substance
A mineral is strictly defined by the following criteria, EXCEPT for one. Which one is NOT part of that criteria?
What is mineral "cleavage"?
A physical property related to differences in bonding strength between atoms in a mineral, creating preferential planar weaknesses through the mineral's structure.
What are two physical differences between chert and limestone - two common chemical sedimentary rocks - using mineral identification field methods? Select the answer that shows the correct results for both the acid test and the hardness test on chert and limestone, based on their mineralogy.
Acid test: chert does not fizz; limestone does fizz! Hardness test: chert is hard; limestone is soft!
Dynamic metamorphism is most closely related to which of the following metamorphic agents of change?
Active fault zone movement
In the "Earth Revealed" geologic video documentary #13 on volcanism, the location of today's active volcanoes worldwide was discussed during the middle portion of the video.Question: What was the noted location of most of today's active sites of volcanism?
At or near tectonic plate boundaries
Partial melting (say 15%) of a peridotite (mantle) rock typically produces a magma of _________. Hint: It's the most common type of magma that occurs at mid-ocean ridges and hot spots.
Basaltic composition
What exactly is graded bedding in a sedimentary rock?
Beds with a progressive vertical change in grain size
High degree of hardness
Besides being relatively rare, beautiful, and valuable, what other physical property do virtually all gemstones have?
Consider Bowen's reaction series. Which mineral would you most likely expect to see as an EARLY- forming phenocryst in a granite?
Biotite
Most of the common mineral found in the biochemical sedimentary rocks is __________.
Calcite
Which of the following common minerals is NOT a silicate?
Calcite
Which of the following minerals reacts with an acid, like hydrochloric, causing the mineral to fizz (release carbon dioxide gas)? Hint: It's what limestone and most invertebrate shells are made of.
Calcite
Which major change occurs during metamorphism of limestone to marble?
Calcite grains recrystallize, typically growing larger - increasing in size.
Erosion has to do with what aspect of the sedimentary part of the rock cycle?
Chemical breakdown of rock
What is the primary factor that controls the composition of an igneous rock?
Chemical composition of the parent magma
Complete chemical weathering of a granitic or basaltic rock directly results in the formation of what new, abundant sedimentary mineral?
Clay
What is the most abundant sedimentary mineral on Earth? Hint: It's in the most abundant sedimentary rock on Earth.
Clay
The chemical weathering of igneous minerals (feldspars, micas, amphiboles, pyroxenes, and olivine), in rocks such as granite or basalt, will produce a large abundance of this altered, solid, weathering product. What is it? Hint: The most abundant detrital mineral in sedimentary rocks.
Clays
Which kind of volcano is considered the most highly explosive and most dangerous? Hint: Mainly found over subduction zones.
Composite or strato.
Which of these sedimentary rocks is most likely to have been derived by the deposition of sediments in the channel of a very swift flowing (very high energy) river? Hint: Only coarse-grained sediments settle out in high energy depositional environments.
Conglomerate
What is the primary factor that controls the texture of an igneous rock?
Cooling rate/history of the magma or lava
Which type of chemical bonding holds the base structure of the silicate tetrahedron together?
Covalent
What metamorphic agent of change causes metamorphic rocks to become foliated?
Directed, vise-like crustal stresses
5. The greatest volume of magma produced on Earth occurs at ______________. Hint: It's where the vast majority of new crust forms on Earth.
Divergent plate boundaries
What physical factor in a cooling lava causes it to undergo vesiculation?
Excessive dissolved gas content
The term "reserve" is given to those already identified deposits of minerals that can be _________.
Extracted profitably right now at current market value
What is the most common mineral in the Earth's crust? Hint: True for both continental and oceanic crust.
Feldspar
Which igneous compositional group (see columns in the igneous rock chart) is rich in Na-plagioclase, potassium feldspar, quartz, and biotite?
Felsic/Silicic
What is the most important textural aspect of metamorphic rocks when it comes to classification?
Foliation
What is the term for the preferred orientation of platy and elongated minerals in a metamorphic rock?
Foliation
What is the name of an igneous rock that has a Color Index of 65, and a phaneritic texture?
Gabbro
What rock characteristic primarily defines an igneous to be called an "Obsidian"?
Glassy Texture
Which of the following metamorphic rocks has characteristic dark and light mineral layering?
Gneiss
Silici-clastic sedimentary rocks are primarily classified (named) on what primary basis?
Grain sizes of the clastic particles
What is the name for a coarse-grained, crystalline rock with lots of quartz and orthoclase feldspar?
Granite
The following minerals are all phyllosilicates EXCEPT for one. Which of the following is NOT a phyllosilicate?
Gypsum
Which of these is an essential component of plasters and plasterboard (drywall) used in the construction industry? Hint: it's a sulfate and has a MOHS hardness of 2.
Gypsum
Which of the following is the MOST USEFUL diagnostic physical property for identifying minerals in hand-sample?
Hardness
The carbonate minerals (like calcite and dolomite) are easy to identify from the silicates by two easy-to-test-for physical properties.What are those two properties/tests?
Hardness and Reaction to acid
In the "Earth Revealed" geologic video documentary #18 on metamorphism and metamorphic rocks, the temperature of metamorphism was discussed in the video, and how temperature controls the physical characteristics of the resultant metamorphic rock. Question: What were the two noted physical characteristics of metamorphic rocks that vary according to the temperature of metamorphism?
Hardness and grain size
Besides being relatively rare, beautiful, and valuable, what other physical property do virtually all gemstones have?
High degree of hardness
Contact metamorphism is most closely related to which of the following metamorphic agents of change?
Intense direct vise-like crustal stresses
What is the MOHS scale?
It is a mineral hardness scale.
Which igneous compositional group (see columns in the igneous rock chart) is rich in Ca-plagioclase, pyroxene, olivine, and hornblende?
Mafic
Which physical property sets magnetite and hematite apart from all other common minerals?
Magnetic
Which of the following minerals is NOT part of the sulfide group?
Magnetite
Staurolite, kyanite, andalusite, sillimanite, epidote, and zoisite are commonly found in which rock type?
Metamorphic rocks
Why do magmas rise towards Earth's surface?
Most magmas have lower densities and viscosities than the surrounding country rock through which they travel
What is the most common protolith or parent rock of a slate?
Mudstone or shale
Which of the following common minerals is NOT considered a dark-colored silicate?
Muscovite
What is the primary difference between orthoclase and plagioclase feldspars?
One is rich in potassium, the other is rich in sodium and calcium
The silica tetrahedron consists of what elements in what proportions?
One part silicon, and four parts oxygen
What is the most abundant element in the Earth's crust? Hint: Its the most abundant element in the mineral Quartz.
Oxygen
Which of the following items is NOT part of criteria for what technically defines a mineral?
Part of earth's crust
In the "Earth Revealed" geologic video documentary #14 on Igneous Rocks, Bowen's continuous and discontinuous reaction series igneous minerals were discussed during the middle portion of the video. Question: Which mineral was showcased as a continuous reaction series mineral in a cooling magma?
Plagioclase feldspar
What does marble and quartzite have most in common with one another in terms of their physical characteristics?
Protolith/parent rock Texture
They lack cleavage.
Quartz and olivine are unique amongst most of the common silicate minerals, like the feldspars, amphiboles, pyroxenes, and micas. Why/how so?
Which listed group of minerals are silica/felsic-rich?
Quartz, sodium plagioclase, and potassium feldspar.
When you metamorphose a quartz sandstone, what do you typically get for a metamorphic rock?
Quartzite
What chemical components (elements) in the dark-colored silicate minerals (like olivine and pyroxene) makes them darker-colored and relatively high in density compared to the light-colored, lower density silicates (like quartz and feldspar)?
Relatively high amounts of iron and magnesium.
What chemical components (elements) in the light-colored silicate minerals (like quartz and feldspar) makes them lighter-colored and relatively lower in density, compared to the dark-colored, higher density silicates (like olivine and pyroxene)?
Relatively high amounts of silica, potassium and sodium.
Weathering and erosion are most closely tied to this grouping of rocks.
Sedimentary rocks
Tourmaline
San Diego is world-renowned for the mining of a certain gemstone. What is the name of that gemstone? Hint: There is a street in San Diego named after it.
What is the name of a rock that is dark-colored, aphanitic, and has lots of vesicles?
Scoria
Coal and rock gypsum are most closely associated with which part of the rock cycle?
Sedimentary
Which of these detrital sedimentary rocks most likely formed the furthest away from its sediment source area and/or in the most still/tranquil aqueous conditions?
Shale/Claystone
In the "Earth Revealed" geologic video documentary #14 on Igneous Rocks, which intrusive igneous batholith was showcased during the later portion of the video?
Sierra Nevada batholith
In the "Earth Revealed" geologic video documentary #13 on volcanism, the primary factors that control the explosive nature of volcanism was discussed about a third of the way into the video. Question: What are the three factors of a magma that mainly control the explosive behaviour of a volcanic eruption?
Silica content, temperature, and dissolved gas content.
Which class of minerals are the most abundant on Earth? Hint: Makes up the vast majority of most rocks.
Silicates
In the "Earth Revealed" geologic video documentary #17 on sedimentary processes and sedimentary rocks, sediment sorting was discussed in the video. Question: What were the two noted characteristics of sediment that controlled sediment sorting?
Size and weight of the sediment.
What global-scale magma-forming tectonic process created the Sierra Nevada and Peninsular Ranges granitic batholiths of California? Hint: Magmas form by partial melting of mantle caused by dewatering of oceanic crust in the mantle.
Subduction at or near a continental margin
Besides mineralogy (composition/color index,) the other primary criteria for naming and classifying an igneous rock is _________. Hint: It has to do with the magma's cooling history.
Texture
What do rhyolite and basalt have in common
Texture
Hardness and Reaction to acid
The carbonate minerals (like calcite and dolomite) are easy to identify from the silicates by two easy-to-test-for physical properties. What are those two properties/tests?
Which region on Earth has the greatest concentration of active volcanoes? Hint: Which region has the greatest length of subduction zones?
The circum-Pacific area
Gypsum
The following minerals are all phyllosilicates EXCEPT for one. Which of the following is NOT a phyllosilicate?
One part silicon, and four parts oxygen
The silica tetrahedron consists of what elements in what proportions?
What exactly does the Bowen's Reaction Series explain?
The sequence in which minerals crystallize from a given composition of magma
Extracted profitably right now at current market value
The term "reserve" is given to those already identified deposits of minerals that can be _________.
Quartz and olivine are unique amongst most of the common silicate minerals, like the feldspars, amphiboles, pyroxenes, and micas. Why/how so?
They lack cleavage.
A mineral is strictly defined by the following criteria, EXCEPT for one. Which one is NOT part of that criteria?
They must be an organic substance.
San Diego is world-renowned for the mining of a certain gemstone. What is the name of that gemstone? Hint: There is a street in San Diego named after it.
Tourmaline
True
True or False? Minerals are what make up rocks.
False
True or False? Quartz has a lower hardness than feldspar.
Which of the following igneous textures indicates that a lava was exsolving gasses (effervescing) as it solidified?
Vesicular
Ionic
Which type of chemical bonding holds the base structure of the HALIDE minerals together?
Calcite
Which of the following minerals reacts with an acid, like hydrochloric, causing the mineral to fizz (release carbon dioxide gas)? Hint: It's what limestone and most invertebrate shells are made of.
Gypsum
Which of these is an essential component of plasters and plasterboard (drywall) used in the construction industry? Hint: it's a sulfate and has a MOHS hardness of 2.
Relatively high amounts of iron and magnesium.
What chemical components (elements) in the dark-colored silicate minerals (like olivine and pyroxene) makes them darker-colored and relatively high in density compared to the light-colored, lower density silicates (like quartz and feldspar)?
Relatively high amounts of silica, potassium and sodium.
What chemical components (elements) in the light-colored silicate minerals (like quartz and feldspar) makes them lighter-colored and relatively lower in density, compared to the dark-colored, higher density silicates (like olivine and pyroxene)?
A physical property related to differences in bonding strength between atoms in a mineral, creating preferential planar weaknesses through the mineral's structure.
What is mineral "cleavage"?
It is a mineral hardness scale.
What is the MOHS scale?
Oxygen
What is the most abundant element in the Earth's crust? Hint: Its the most abundant element in the mineral Quartz.
Feldspar
What is the most common mineral in the Earth's crust? Hint: True for both continental and oceanic crust.
The color
What is the primary difference between biotite and muscovite micas?
One is rich in potassium, the other is rich in sodium and calcium
What is the primary difference between orthoclase and plagioclase feldspars?
Silicates
Which class of minerals are the most abundant on Earth? Hint: Makes up the vast majority of most rocks..
Quartz, sodium plagioclase, and potassium feldspar.
Which listed group of minerals are silica/felsic-rich?
Calcite
Which of the following common minerals is NOT a silicate?
Muscovite
Which of the following common minerals is NOT considered a dark-colored silicate?
Hardness
Which of the following is the MOST USEFUL diagnostic physical property for identifying minerals in hand-sample?
Part of earth's crust
Which of the following items is NOT part of criteria for what technically defines a mineral?
Magnetite
Which of the following minerals is NOT part of the sulfide group?
Magnetic
Which physical property sets magnetite and hematite apart from all other common minerals?
Lahar is another name for a _______.
a mixture of water and volcanic debris that forms a fast moving mudflow down and away from the volcano
The term pluton is the name used for _________.
a single, intrusive body of igneous rock.
Metamorphism in the Earth's crust mostly occurs ___________.
along plate boundaries
The average rock type of a typical shield volcano is ___________, whereas, the average rock type of a typical composite or strato-volcano is ____________.
basalt; andesite
True or False? Quartz has a lower hardness than feldspar.
false
Which of the following minerals is NOT a typical cement found in clastic sedimentary rocks?
feldspar
As a general rule, the further out away from the shoreline toward the deep ocean, the depositing sediment becomes _________.
finer grained
Which type of chemical bonding holds the base structure of the HALIDE minerals together?
ionic
Island arc lavas generally have _____________ compared to continental margin arc lavas. Hint: Compare the two arc types, in terms of the overlying plate crustal composition - oceanic versus continental (basaltic versus granitic).
less silica and more iron and magnesium
Which of the following is NOT a type of physical (mechanical) weathering?
oxidation
What is the primary difference between biotite and muscovite micas?
the color
Most of Earth's sedimentary rocks deposited in _________ as sediments, where they eventually turned into rock.
the ocean
True or False? Minerals are what make up rocks.
true