Week 3 Lectures Flashcards
(116 cards)
1
Q
What factors determine rock types?
A
Rocks are naturally occurring solid aggregates of minerals or, in some cases, non-mineral solid matter.
2
Q
How are rocks grouped based on their formation?
A
Rocks are grouped into three main types based on their formation: Igneous, Sedimentary, and Metamorphic.
3
Q
What factors determine rock types?
A
Rock types are determined by texture and composition.
4
Q
Define texture in the context of rocks.
A
Texture refers to the size, shape, and arrangement of grains and crystals in the rock.
5
Q
Why is homogeneity important in rock composition?
A
Homogeneity is important because it indicates the uniformity of composition within the rock.
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6
Q
Describe the formation process of igneous rocks.
A
Igneous rocks form from the cooling and solidification of molten magma or lava.
7
Q
How do sedimentary rocks form?
A
Sedimentary rocks form through the accumulation and lithification of sediments, often influenced by weathering processes such as rain.
8
Q
Explain the formation of metamorphic rocks.
A
Metamorphic rocks form due to changes in temperature and pressure, often occurring closer to the Earth’s core, causing existing rocks to transform into new forms.
9
Q
How are textures of igneous rocks described?
A
Textures of igneous rocks are described in terms of their degree of crystallinity, ranging from entirely crystalline to entirely glassy, and their granularity, which is determined by grain size.
10
Q
What influences the grain size of igneous rocks?
A
Grain sizes in igneous rocks are primarily determined by the cooling rate during the rock’s formation
11
Q
Why are igneous rocks significant?
A
Igneous rocks are the most common type of rock, constituting about 90% of the Earth’s crust, and they are also found on Venus and Mars. They are commonly encountered in everyday life, such as in countertops and curling rocks.
12
Q
Where do intrusive igneous rocks form?
A
Intrusive igneous rocks form in chambers beneath the Earth’s surface
13
Q
Where do extrusive igneous rocks form?
A
Extrusive igneous rocks form at the Earth’s surface.
14
Q
Provide examples of extrusive igneous rocks.
A
Examples of extrusive igneous rocks include andesite, basalt, dacite, obsidian, pumice, rhyolite, scoria, and tuff.
15
Q
Provide examples of intrusive igneous rocks.
A
Examples of intrusive igneous rocks include diabase, diorite, gabbro, granite, pegmatite, and peridotite.
16
Q
How can you distinguish between extrusive and intrusive igneous rocks?
A
Extrusive igneous rocks are formed at the Earth’s surface, while intrusive igneous rocks form beneath the surface. The distinction depends on the cooling rate during formation.
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17
Q
Describe Granite.
A
Granite is a coarse-grained, light-colored, intrusive igneous rock composed mainly of quartz, feldspar, and mica minerals. It often exhibits pink feldspar and has larger crystals due to slow cooling beneath the Earth’s surface.
18
Q
Describe Basalt.
A
Basalt is a dark-colored, fine-grained, extrusive igneous rock composed mainly of plagioclase and pyroxene minerals. It forms at the Earth’s surface, cooling down quickly, resulting in smaller crystals and a darker appearance.
19
Q
What are some common characteristics of both Granite and Basalt?
A
Both Granite and Basalt are among the most common types of rocks. Granite is intrusive, with larger crystals and a light color, while Basalt is extrusive, with smaller crystals and a dark color.
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20
Q
Describe Obsidian.
A
Obsidian is a dark-colored volcanic glass that forms from the very rapid cooling of molten rock material. It is not a mineral because it is glass-like in nature.
21
Q
Describe Pumice.
A
Pumice is a very porous, frothlike volcanic glass. It contains vesicles, which are gas bubbles trapped in the rock during the rapid cooling of a gas-rich frothy magma. Like Obsidian, Pumice is not considered a mineral due to its glassy composition.
22
Q
How does the formation of vesicles in Pumice occur?
A
Vesicles in Pumice form due to the presence of air mixed with the material during a volcanic eruption, creating a porous structure.
23
Q
How does Obsidian differ from Pumice in terms of texture?
A
Obsidian has a smooth texture with no visible holes, while Pumice has a porous texture with vesicles, giving it a frothy appearance.
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24
Q
How are sedimentary rocks formed?
A
Sedimentary rocks are formed on or near the Earth’s surface from pieces of other existing rocks or organic material.
25
What geological processes are associated with the formation of sedimentary rocks?
The formation of sedimentary rocks is related to processes such as erosion, weathering, dissolution, precipitation, and lithification.
26
Name the four different types of sedimentary rocks.
The four types of sedimentary rocks are clastic, chemical, biochemical, and organic.
27
What distinguishes sedimentary rocks from other rock types in terms of their formation location?
Sedimentary rocks are not erupted from the Earth's interior; instead, they form on the surface of the Earth. Notable examples include rock formations in the Grand Canyon.
28
Why are sedimentary rocks considered among the most interesting?
Sedimentary rocks are considered among the most interesting rocks because they often contain fossils, providing insights into past life forms and environmental conditions.
29
What is clastic sedimentary rock, and how does it differ from other types?
Clastic sedimentary rocks are composed of fragments or clasts of pre-existing rocks. They differ from other types due to their fragmentary nature.
30
How is the presence of fossils related to sedimentary rocks?
Sedimentary rocks, especially those of the bio and organic types, often contain fossils due to the preservation of remains in the rock layers.
31
How do clastic sedimentary rocks form?
Clastic sedimentary rocks form from the accumulation and lithification of mechanical weathering debris.
32
Provide examples of clastic sedimentary rocks.
Examples of clastic sedimentary rocks include breccia, conglomerate, sandstone, siltstone, and shale.
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33
Describe the composition of breccia.
Breccia is composed of large angular fragments, and the spaces between these fragments can be filled with a matrix of smaller particles.
34
Where does sandstone mainly originate, and what is its composition?
Sandstone is mainly made up of sand-size weathering debris and can originate from environments such as beaches, deserts, floodplains, and deltas.
35
What is shale made up of, and how does it typically break?
Shale is made up of clay-size weathering debris, and it typically breaks into thin flat pieces.
36
How do clastic sedimentary rocks differ based on grain size?
Clastic sedimentary rocks, such as breccia, sandstone, and shale, differ in grain size. For example, breccia has larger grain size, while shale has smaller grain size.
37
How do chemical sedimentary rocks form?
Chemical sedimentary rocks form when dissolved materials precipitate from a solution.
38
Provide examples of chemical sedimentary rocks.
Examples of chemical sedimentary rocks include chert, some dolomites, flint, iron ore, limestones, and rock salt.
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39
How does Iron Ore, a chemical sedimentary rock, form?
Iron Ore forms when iron and oxygen combine in solution and deposit as sediment. Examples include hematite (Fe2O3) and magnetite (Fe3O4).
40
What is the composition of chert?
Chert is composed of microcrystalline silicon dioxide (SiO2) and is known for making sharp tools. It can also produce sparks when struck, making it useful for fire starting.
41
What is limestone primarily composed of, and what is its chemical composition?
Limestone is a sedimentary rock composed primarily of calcite, a calcium carbonate mineral, with a chemical composition of CaCO3.
42
How can limestone dissolve in water?
Limestone, composed of calcium carbonate, can dissolve in water due to the solubility of calcium carbonate.
43
How is chert historically used by humans?
Chert has been historically used to make sharp tools and has been utilized for starting fires as it produces sparks when struck.
44
How do organic sedimentary rocks form?
Organic sedimentary rocks form from the accumulation of plant or animal debris.
45
What are biochemical sedimentary rocks, and how do they form?
Biochemical sedimentary rocks form from the shells and bodies of underwater organisms.
46
Provide examples of organic and biochemical sedimentary rocks.
Examples of organic and biochemical sedimentary rocks include chalk, coal, diatomite, some dolomites, and some limestones.
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47
What is chalk composed of, and what is its significance?
Chalk is a type of limestone made up of microscopic calcium carbonate shells of marine organisms. Porous, subsurface chalk units can serve as reservoirs for oil and natural gas.
48
How does coal, an organic sedimentary rock, form?
Coal forms mainly from plant debris, which accumulates in a swamp environment.
49
What makes chalk unique, and how is it used?
Chalk, with its microscopic calcium carbonate shells, is often used for writing on boards. Its porous subsurface units can also serve as reservoirs for oil and natural gas.
50
In what industry is coal commonly utilized?
Coal is commonly mined and utilized as a fossil fuel for various industrial purposes.
51
How are metamorphic rocks modified?
Metamorphic rocks are modified by heat, pressure, and chemical processes, which alter their mineralogy, texture, and chemical composition.
52
What characterizes metamorphic rocks?
Metamorphic rocks are rocks that have undergone significant changes in mineralogy, texture, and chemical composition due to the influence of heat, pressure, and chemical processes.
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53
What can cause metamorphism in rocks?
Metamorphism in rocks can be caused by processes such as heat, pressure, and chemical reactions.
54
How are metamorphic rocks related to plate boundaries?
Metamorphic rocks can be associated with plate boundaries, especially convergent boundaries, where plates come together. This process can lead to the formation of mountains and subduction zones.
55
What are some characteristics of metamorphic rocks that have undergone deformation?
Metamorphic rocks may exhibit wavy structures, indicating deformation and the effects of tectonic forces.
56
How are gemstones like emerald and ruby related to metamorphic rocks?
Gemstones, such as emerald and ruby, can be associated with metamorphic rocks. The formation of these gemstones often involves a combination of heat and pressure, resulting in the development of attractive and valuable stones.
57
What plate boundary features are indicative of possible metamorphic rock formation?
Features like convergent plate boundaries, where plates come together, can be indicative of metamorphic rock formation. Mountains and subduction zones formed at these boundaries may host metamorphic rocks.
58
What characterizes foliated metamorphic rocks?
Foliated metamorphic rocks have a layered or banded appearance, a result of exposure to heat and directed pressure during their formation.
59
Provide examples of foliated metamorphic rocks.
Examples of foliated metamorphic rocks include gneiss, phyllite, schist, and slate.
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60
Describe Muscovite Schist and its dominant mineral.
Muscovite Schist is a foliated metamorphic rock with muscovite mica as the dominant visible mineral. The platy grains of muscovite are aligned, allowing the rock to be easily split.
61
What is characteristic of Gneiss, and what minerals does it typically contain?
Gneiss is a foliated metamorphic rock with a banded appearance and granular mineral grains. It typically contains abundant quartz or feldspar minerals.
62
What is Garnet Gneiss, and what minerals compose it?
Garnet Gneiss is a coarse-grained gneiss composed mainly of hornblende (black), plagioclase (white), and garnet (red). An example comes from Norway.
63
How does the aligned orientation of minerals in Muscovite Schist affect its properties?
The aligned orientation of muscovite mica in Muscovite Schist allows the rock to be easily split.
64
What is notable about the banded appearance of Gneiss?
Gneiss has a banded appearance due to alternating layers of different mineral compositions, giving it a distinctive visual pattern.
65
What characterizes non-foliated metamorphic rocks?
Non-foliated metamorphic rocks do not have a layered or banded appearance.
66
Provide examples of non-foliated metamorphic rocks.
Examples of non-foliated metamorphic rocks include hornfels, marble, novaculite, quartzite, and skarn.
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67
How is Marble formed, and what is its composition?
Marble is a non-foliated metamorphic rock produced from the metamorphism of limestone or dolostone. It is primarily composed of calcium carbonate.
68
How does Quartzite form, and what is its typical composition?
Quartzite occurs naturally when sandstone or chert undergoes heat and high pressure. It is typically made of more than 90% quartz.
69
What is significant about the texture of foliated metamorphic rocks?
Foliated metamorphic rocks have a distinct texture characterized by the alignment of mineral grains, resulting in a layered or banded appearance.
70
Provide examples of foliated metamorphic rocks.
Examples of foliated metamorphic rocks include schists and gneiss.
71
What mineral is commonly found in some varieties of Gneiss, and what is its significance?
Some varieties of Gneiss may contain garnet, which is the birthstone for January.
72
What is a notable use for non-foliated metamorphic rock, Marble?
Marble is commonly used for statues and carving due to its soft texture and workability.
Marble reacts to acid due to its primary composition of calcium carbonate. The acid can cause chemical reactions, leading to effervescence or fizzing.
Quartzite is known for its hardness, making it a durable and resistant rock.
Quartzite is generally harder than Marble. Marble is softer and more easily carved, while Quartzite is known for its durability.
Due to its hardness, Quartzite is commonly used as a building material, including countertops and flooring.
73
Rocks
Igneous Rock:
Characteristic: Crystals
Example: Granite, Basalt
Sedimentary Rock:
Characteristic: Dinosaurs/Fossils indicator
Example: Limestone, Sandstone
Metamorphic Rock:
Characteristic: Formed by heat/pressure, layers (track geological map)
Example: Schist, Gneiss
74
What are the key characteristics of minerals?
Minerals are naturally occurring, inorganic, crystalline solids with a definite, but sometimes variable, chemical composition. They are formed in nature by geological processes and not produced by humans.
75
Define "naturally occurring" in the context of minerals.
"Naturally occurring" means that minerals are found in nature, whether on Earth, the Moon, Mars, or other celestial bodies.
76
What does it mean for a mineral to be "inorganic"?
Being "inorganic" implies that minerals are not formed through biological activities. For example, pearls, which are formed organically, are not considered minerals.
77
How can the appearance of a natural diamond differ from a synthetic one?
The appearance of a natural diamond may differ slightly from a synthetic one, and gemologists can often identify subtle differences between them.
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78
How are the atoms arranged in minerals?
The atoms that comprise minerals are arranged in an orderly, repeating, three-dimensional structure.
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79
What is necessary for a substance to be considered a mineral in terms of atomic arrangement?
To be considered a mineral, a substance must have an orderly repeating, three-dimensional structure, known as being crystalline.
80
Provide an example of a non-crystalline mineral.
Obsidian, a black glass, is an example of a mineral with a non-crystalline structure.
81
What are substances called that look like minerals but lack a crystalline structure?
Substances like opal, which lack a crystalline structure, are called mineraloids.
Opal is an example of a mineraloid; it looks like a mineral but does not have a crystalline structure.
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82
What is another example of a mineraloid?
Amber is another example of a mineraloid. It does not exhibit a crystalline structure and is formed by the random aggregation of organic material
Amber is considered a mineraloid because it lacks a repeating, three-dimensional crystalline structure. Its formation involves the random aggregation of organic material.
83
How can substances like impact glass be classified?
Substances like impact glass, which lack a repeating structure, are not classified as minerals but are rather referred to as mineraloids.
84
What is a key characteristic of the chemical composition of minerals?
The chemical composition of a mineral is either fixed or varies within defined limits.
Examples of minerals with very specific compositions include halite [NaCl] and quartz [SiO2].
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85
How is the chemical composition of olivine represented, and what does it indicate?
The chemical composition of olivine is represented as [(Mg,Fe)2SiO4], indicating that it can have a range of compositions with varying amounts of magnesium (Mg) and iron (Fe).
86
What does a fixed chemical composition indicate about a mineral?
A fixed chemical composition indicates that the mineral has a specific, constant ratio of elements in its structure.
87
How does the chemical composition of some minerals vary?
Some minerals exhibit a range of compositions, where the presence of different elements can vary within defined limits.
88
How can trace elements affect the appearance of minerals?
Trace elements can alter the appearance of minerals, influencing their color, transparency, and other physical properties.
89
What is the chemical composition of Beryl minerals?
Beryl minerals have a chemical composition represented as Be3Al2Si6O18, indicating the presence of beryllium, aluminum, and silicon.
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90
How is Emerald, a variety of Beryl, formed, and what elements contribute to its color?
Emerald is formed from Beryl and gains its green color from the presence of Chromium (Cr), Vanadium (V), and Iron (Fe) as trace elements.
91
How many known elements are there?
There are 118 known elements.
There are over 4,000 types of minerals on Earth.
There are over 140 types of gemstones.
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92
What are atoms?
Atoms are the smallest components of nature with the properties of a given substance.
The atomic number is the number of protons in the nucleus of an atom.
The atomic number is the number of protons in the nucleus of an atom.
93
Define isotopes.
Isotopes are atoms with differing numbers of neutrons, hence differing mass numbers, but a similar number of protons.
94
What is an anion?
An anion is a negatively charged atom.
A cation is a positively charged atom.
Static electricity is the result of an imbalance between negative and positive charges in an object. It occurs when objects build up an excess of electrons (negatively charged) or lose electrons (positively charged), creating an electrical charge.
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95
What is a compound?
A compound is a substance made of two or more elements chemically bonded to each other in a fixed ratio.
96
What characterizes the chemical bonds in compounds?
The chemical bonds between atoms of elements in compounds involve a transfer or sharing of valence electrons.
The chemical bonding in a compound gives it different properties from its constituent elements.
97
How is a compound represented, and what information does it provide?
A compound may be represented by a chemical formula that shows the element symbols of the atoms and their proportions, providing information about the composition of the compound.
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98
Ionic Bond
-strong bond
-high melting points
-vitreous lusters
-higher solubility
e.g. salt
99
Covalent Bond
-strong bonds
-hard minerals
-very high melting points
-vitreous – adamantine lusters
e.g. diamond
100
Metallic Bond
-weak bonds
-low to high melting points
- metallic lusters
-electrically conductive
e.g. gold
101
What is the significance of silicates in the Earth's crust and minerals?
Silicates comprise over 90% of Earth's crust and approximately one-third of all known minerals.
102
What is the basic building block of all silicate minerals?
The silicate tetrahedron is the basic building block of all silicate minerals.
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103
How are silicates often divided into two major groups?
Silicates are often divided into two major groups: ferromagnesian silicates and non-ferromagnesian silicates.
104
What characterizes ferromagnesian silicates, and what elements are typically present in them?
Ferromagnesian silicates contain iron or magnesium ions joined to the silicate structure. They are darker and heavier minerals, examples include olivine, pyroxene, hornblende, and biotite.
105
Provide examples of non-ferromagnesian silicates.
Non-ferromagnesian silicates include minerals like muscovite, feldspar, and quartz.
106
What is the building block of carbonates?
The carbonate ion (CO32-) is the building block of carbonates.
The carbonate ion is composed of a carbon atom covalently bonded to three oxygen atoms.
How are groups of carbonate ions arranged in carbonates?
107
How are sheets of carbonate ions linked together in carbonates?
Sheets of carbonate ions are linked together by layers of cations, such as Ca2+, Mg2+, Fe2+, and others.
108
What factors define whether weaknesses (cleavage planes) will form in carbonate minerals?
The chemical bond strength and the fixed arrangement of atoms in carbonate minerals define whether weaknesses, or cleavage planes, will form.
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109
How is oxygen typically bonded in oxides?
Oxygen is typically ionic bonded to atoms or cations of other elements in oxides.
Oxides are a principal source of metals.
An example related to oxides and gemstones is "pigeon blood" ruby, where oxides play a role in the coloration of the gemstone.
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110
What are sulfides composed of?
Sulfides are minerals composed of one or more metal cations combined with sulfur.
Many sulfides are economically important ores.
Pyrite, also known as "fool's gold," is an example of a sulfide mineral.
Real gold should be soft, and both have different melting point (pyrite doesn’t really melt)
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111
What characterizes minerals that belong to the sulfate group?
Sulfates are minerals that include SO4 anionic groups with alkali earth and metal cations.
Sulfates are minerals that include SO4 anionic groups with alkali earth and metal cations.
112
Where do sulfates commonly occur?
Sulfates are found in various geological settings, including evaporite deposits, hydrothermal veins, and sulfide deposits.
113
What characterizes minerals that belong to the phosphate group?
Phosphates are minerals with the PO43- ion.
The apatite group, such as hydroxyapatite, is a phosphate mineral that makes up the enamel of teeth.
Phosphates are used in the production of fertilizers.
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114
What characterizes minerals that belong to the halide group?
Halides consist of halogen elements ionic bonding with alkali elements.
Halides are commonly found in marine evaporite deposits.
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115
Star Wars: The Last Jedi Planet Crait
-maybe salt lake evaporated
116
What characterizes minerals that belong to the native elements group?
Native elements are minerals that are composed of a single element.
Examples of native elements include Gold (Au), Silver (Ag), Copper (Cu), Iron (Fe), Diamonds (C), Graphite (C), and Platinum (Pt).
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