Geology Flashcards
(131 cards)
1
Q
Mohorovicic Discontinuity
A
boundary between crust and mantle
2
Q
Where does Earth’s heat come from?
A
Collisions from early Earth days, radioactive decay and rocks are just poor conductors of heat
3
Q
How do we know Earth has a large collision in it’s past?
A
Increased spin
Tilted axis
Moon rocks have similar composition to Earth rocks
4
Q
What are the chemical layers of the Earth?
A
Crust
Mantle
Core
5
Q
What are the 3 most common elements in the Earth?
A
Iron, oxygen, and silicon
6
Q
What are the 3 most common elements in the CRUST?
A
Oxygen, silicon, and aluminum
7
Q
What is the core mainly made of?
A
Iron
8
Q
T or F: The mantle is liquid
A
false
9
Q
what type of crust is thicker?
A
continental crust
10
Q
what type of crust is denser?
A
oceanic
11
Q
how do plate tectonics move?
A
convection in the mantle
12
Q
how does convection work?
A
as material heats up, it sinks while the material that’s cooler will rise
13
Q
what is uniformitarianism
A
the idea that the processes we see occuring today, most likely occurred in Earth’s ancient past
14
Q
What was the theory of continental drift missing that plate tectonic theory is not?
A
a way to explain the plates moving
15
Q
what do we find at the top of Mt. Everest
A
seashells
16
Q
What fossils were found on the east coast of South America and the west coast of Africa that support the theory of Plate Tectonics?
A
mesosaurus
17
Q
what’s the difference between a rock and a mineral
A
a mineral makes up rocks
18
Q
3 different rock types
A
igneous, sedimentary, metamorphic
19
Q
what makes a mineral a mineral?
A
Naturally occurring
Specific chemical composition
Relatively inorganic
Natural, crystalline substances
20
Q
what are the mineral properties we test
A
hardness, luster/color, streak, cleavage, magnetic, reacts to acid
21
Q
is synthetic diamond a mineral?
A
no, it is not naturally occuring
22
Q
is ice a mineral
A
yes
23
Q
is coal a mineral
A
no, it comes from organic material
24
Q
is quartz a mineral
A
yes
25
what is the atomic number
the number of protons
26
what is the atomic mass
proton and neutrons
27
what are isotopes of
atoms of the same element with differing numbers of neutrons
28
is a cation positively or negatively charged
positive
29
is an anion positive or negative
negative
30
which chemical bond is stronger
covalent bonding
31
what are the two main types of bonding
ionic and covalent
32
how does covalent bonding work
electrons are shared
33
which are larger - cations or anions
anions
34
an atom that has gained electrons is called..
anion
35
Large, well defined crystals suggest what about it's growth and space?
steady growth and lots of space
36
Small, poorly formed crystals suggest what about it's growth and space?
smaller space and rapid cooling
37
The process of turning a liquid into a solid with crystals in it is called...
crystallization
38
What happens when we apply pressure to a mineral?
becomes denser, melting temp. increases, changes crystal structure
39
What do we call minerals made of the same thing but produced under different conditions? (Ex. Graphite and diamond)
polymorphs
40
what is the most common of the mineral groups?
silicates
41
what mineral class would calcite be (CaCO3)
carbonate
42
What mineral class would pyrite be (FeS2)
sulfides
43
what mineral class would hematite be (Fe2O3)
oxide
44
what mineral class would gypsum be (CaSO4)
sulfates
45
why do we use gypsum for drywall
it contains water, a natural flame retardant
46
what mineral class does gold fall into? (Au)
native element
47
what is the name of the scale we use to measure hardness
mohs scale
48
what is the softest mineral on the mohls scale
talc
49
what is the hardest mineral on the mohs scale
diamond
50
what is it called when a mineral breaks irregularly
fracture
51
what is luster
how a mineral reflects light
52
how do igneous rocks form
it forms from cooling and crystallizing of magma or lava
53
slow cooling means what for igneous rocks?
smaller crystals
54
which suggests faster cooling? extrusive or intrusive?
extrusive
55
what is weathering
breakdown of rock
56
what is erosion
process of sediments being carried away from their original location
57
what are the two types of sediments
clastic and (bio)chemical
58
what is lithification
process of making rock
59
what are the two processes of lithification
compaction and cementation
60
what is compaction
the process that presses sediments together
61
what is cementation
the process in which dissolved mineral crystallize and glue particles of sediments together
62
how do metamorphic rocks form
alteration of preexisting rock due to high T and P
63
what are the 2 types of metamorphism
contact and regional
64
how do the two types of metamorphism differ
contact - smaller areas, mainly high temperature
regional - large areas, mainly high pressure
65
with what type of metamorphism do we get foliation
regional
66
what rock types can be igneous?
sedimentary, metamorphic, and igneous rocks
67
what type of rocks can become metamorphic
sedimentary, metamorphic, igneous
68
which of these are extrusive? gabbro, basalt, granite, rhyolite
basalt and rhyolite
69
which of these are intrusive? gabbro, basalt, granite, rhyolite
gabbro and granite
70
which of these are felsic? gabbro, basalt, granite, rhyolite
granite and rhyolite
71
which of these are mafic? gabbro, basalt, granite, rhyolite
gabbro and basalt
72
how do we melt the mantle
add water
increase temperature
decrease pressure
73
what causes the mantle to melt at the ocean-continent subduction zones
adding water
74
what causes the mantle to melt at divergent boundaries
decrease pressure
75
How do we know there are magma chambers beneath the surface? Or how big they are?
seismic waves, s-waves cannot travel through liquid
76
how much of the mantle do we need to melt to form magma?
a little bit, <5%
77
Magma/lava coming from the mantle tends to be mafic, felsic, or intermediate?
Mafic
78
Which magma/lava type has the highest silica content?
Felsic
79
which magma/lava type has the lowest silica content?
mafic
80
what is fractional crystallization
crystallization of part of a magma, leaving behind melted rock with a different composition from the original magma
81
highest to lowest silica content. andesite, basalt, granite
granite, andesite, basalt
82
if we melt the mantle, what type of magma do we get
mafic
83
what are the large intrusive magmatic bodies called
batholiths
84
do sills cut across rocks or travel along the rock layers
along
85
What are the two requirements to create foliation?
directed pressure and platy minerals
86
what is the term used for a not-foliated metamorphic rock
granoblastic
87
geothermal gradient
increasing in temperature with depth
88
do we get a higher or lower geothermal gradient with a thinner plate
higher
89
what is a geothermometer
mineral that tells you the temperature at which the rock was formed
90
what is geobarometer
mineral that tells you the pressure at which the rock was formed
91
metasomatism
hydrothermal fluid metamorphism that can alter minerology
92
what are the two types of metamorphism
regional and contact
93
what is regional metamorphism and where does it occur
metamorphism altering rocks due to temperature and pressure. Happens at convergent boundaries, forming large-scale linear belt regions.
94
what is contact metamorphism and where does it occur
Metamorphism due to high temperature. Happens when magma or lava comes into direct contact with surrounding country rock. This can occur around magma chambers and lava flows.
95
what type of metamorphism do we get at subduction zones (ocean-continent)
regional metamorphism with high pressure and low temperature
96
example of platy minerals
mica, chlorite, biotite
97
burial metamorphism
progressive burial of sediments (low-grade metamorphism). Example: Shale to Slate
98
shock metamorphism
metamorphism due to ultra-high pressure (meteorite)
99
foliation
rock that is sheeted. due to directed pressure. must have platy mineral
100
directed pressure
pressure coming from one direction. example: convergent boundary
101
confining pressure
pressure coming from all directions equally
102
banding gneiss
present in high-grade metamorphic rocks. Minerals have separated into alternating layers. because of very high temperatures and pressures. Example: Gneiss
103
what is the parent rock (protolith) to slate
shale
104
what is the parent rock (protolith) to marble
limestone
105
why do we get granoblastic (non-foliated) rocks
from a lack of deformation and lack of platy minerals
106
example of a granoblastic rock
quartzite and marble
107
what is the parent rock of quartzite
quartz sandstone
108
slate
low grade metamorphic rock, minerals not visible
109
phyllite
low grade metamorphic. glossy. mica and chlorite crystals are larger
110
schist
mid-grade metamorphic. platy minerals large enough to see (mica and chlorite). Bands start separating. Wavy foliation
111
gneiss
high-grade metamorphic rock. coarse. banding present. poor foliation
112
migmatite
high grade metamorphic rock. almost igneous again
113
sedimentary cycle
1) Weathering
2) Erosion
3) Transportation
4) Deposition
5) Burial
6) Diagenesis
114
two categories of sedimentary rocks
clastic and biochemical
115
clastic sedimentary rock
forms from physical weathering. mineralogy varies according to parent rock
116
two categories of sedimentary rocks
clastic and biochemical
117
clastic sedimentary rock
forms from physical weathering. mineralogy varies according to parent rock
118
biochemical sedimentary rock
precipitation of dissolved products of weathering. Made up of remains of organisms as well as precipitation via biological processes
119
continental environments
alluvial (rivers), desert, lake, glacial
120
shoreline environments
deltas, tidal flats, beach
121
marine environments
continental-shelf, organic reef, continental margin, deep sea
122
lithification
making sediments into rock
123
diagnesis
physical and chemical changes due to mild temp and pressure
124
cementation
chemical diagnosis, minerals, precipitate in pore spaces, minerals bind clastic sediments together.
125
compaction
physical trait. compression due to pressure
126
coarse-grained sedimentary rocks
gravel, conglomerate
127
medium grained sedimentary rocks
sandstone
128
fine-grained sedimentary rock
siltstone, mudstone, shale, clay
129
carbonates (sedimentary rocks)
derived from shells and organic structure
130
low to high grade metamorphism
slate, phyllite, schist, gneiss, migmatite
131
