1
Q
Continental drift
A
The hypothesis that continents move slowly across Earth’s surface.
2
Q
Pangaea
A
The ancient supercontinent formed by all continents joined together.
3
Q
Bathymetry
A
The study and mapping of ocean floor depths and topography.
4
Q
Mid-ocean ridge
A
An elevated underwater mountain chain where new oceanic crust forms.
5
Q
Abyssal plain
A
Flat, deep ocean floor regions away from ridges.
6
Q
Deep-sea trench
A
Deep depressions where oceanic crust subducts.
7
Q
Fracture zone
A
Offsets in mid-ocean ridges, perpendicular to the ridge axis.
8
Q
Seafloor spreading
A
oceanic crust stretches apart and splits along the axis of a mid-ocean ridge, and that new oceanic crust forms from molten rock that rises and solidifies along the split. As it forms, new seafloor moves away from the ridge, so the ocean basin grows wider over time
9
Q
Heat flow
A
Higher at ridges due to rising hot mantle material.
10
Q
Seismic belt
A
Zones of frequent earthquakes outlining plate boundaries.
11
Q
Lithosphere
A
Rigid layer including crust and uppermost mantle; behaves rigidly.
12
Q
Asthenosphere
A
the layer that is right below the lithosphere, it is Ductile and warmer and can undergo plastic flow
13
Q
Rigid behavior
A
deformation that occurs without a change in the rock’s size or shape, meaning the entire rock mass moves as a single, solid unit. Rock breaks under stress without deforming.
14
Q
what undergoes plastic flow and what is it
A
asthenosphere can undergo plastic flow, meaning that even though it is solid, it can change shape and move slowly without breaking.
15
Q
what is a Plate?
A
earths lithosphere consists of seperate pieces that move relative to one another
16
Q
Lithospheric mantle
A
top part of the Upper mantle that is cool enough so that it cannot flow easily, so it forms part of the lithosphere.
17
Q
Continental margin
A
Edge of continent, between the continental and oceanic crust;
active (with subduction/volcanoes) vs. passive (stable, no tectonics).
18
Q
Passive-margin basin
A
Sediment that has settled on passive margins, linked to continental shelves.
19
Q
Plate tectonics
A
Theory explaining Earth’s surface features via moving plates.
20
Q
Divergent boundary
A
Plates pull apart; new crust forms.
21
Q
Convergent boundary
A
Plates collide; one is forced underneath the other.
22
Q
Transform boundary
A
Plates slide past each other horizontally. causes shallow earthquakes
23
Q
Subduction
A
Sinking of oceanic lithosphere into mantle.
24
Q
Subduction zone
A
Region of active subduction.
25
Accretionary prism
Scraped-off sediments piled at subduction zones.
26
Volcanic arc
Chain of volcanoes from subducting slab melting.
27
Continental arc
a chain of volcanoes and mountain ranges formed by subduction on continents (e.g., Andes).
28
Island arc
a chain of volcanoes formed by a oceanic plate sliding under another
29
Transform fault
type of plate boundary where tectonic plates slide horizontally past each other
30
Magma
Molten rock beneath surface.
31
Lava
Magma erupted at surface.
32
Earthquake
Ground shaking from fault slip.
33
Fault
Fracture where rocks slide.
34
Rift
Zone where continent stretches/thins. the crust cracks
35
Rifting
Process of continental extension, leading to splitting.
36
Continental Collision
crusts collide and form mountain ranges, suturing continents together. it destroys the subduction zone
37
Suture
a fault zone where 2 plates have collided and been joined together
38
Buoyancy force
Resistance to subduction by low-density crust.
39
Triple junction
Point where three boundaries meet.
40
Hot spot
an area of earths mantle that is super hot, plumes of magma rise from it leading to volcanic activity on earths crust.
41
Hot-spot track
Volcanic chain (e.g., Hawaiian Islands) from plate motion over hot spot.
42
Mantle plume
a column of hot magma rising to earths surface
| creates hot spots and causes volcanic activity
43
Paleomagnetism
Study of ancient magnetism in rocks.
44
Apparent polar-wander path
Apparent pole migration due to continental drift.
45
Magnetic reversal
process where earths magnetic north and south poles switch places
46
Marine magnetic anomaly
Seafloor stripes from reversals during spreading.
47
Magnetic pole
Field's north/south ends.
48
Dipole
Basic field like a bar magnet
49
Paleopole
Ancient pole position
50
Paleogeographic map
Reconstructed ancient geography
51
Polar Wander
Different paths per continent prove drift (poles fixed, continents move)
52
Magnetic Reversals
Not Earth flipping; dated via lava flows/cores
53
Symmetric anomaly stripes
a pattern of alternating magnetic polarities on the ocean floor
| Validates spreading
54
Core Theory
Plates move via boundaries, driven by mantle forces, reshaping Earth over time
55
Minerals
Naturally occurring, homogeneous crystalline solids formed by geologic processes
56
Crystals
Orderly arrangement of atoms, ions, or molecules in a specific pattern
57
Inorganic chemical
Non-carbon-based compounds
58
Geode
A hollow rock lined with crystals, often formed by mineral precipitation
59
Glass
An amorphous (non-crystalline) solid, unlike true minerals
60
Solidification of a Melt
Magma or lava cools, and atoms bond into crystals
61
Precipitation from a Water Solution
Minerals crystallize from supersaturated solutions
62
Diffusion through a Solid
Atoms migrate and recrystallize in existing rock under heat/pressure
63
Metabolism of Organisms
Biological processes produce minerals
64
Precipitation from a Gas
Rare, occurs in volcanic fumes
65
Crystal Growth Process
Crystals grow by atoms attaching to a nucleus in an orderly pattern
66
Euhedral crystals
Have well-formed faces (free growth)
67
Anhedral crystals
Irregular (confined by surroundings)
68
Color
Influenced by impurities; not always reliable
69
Streak
Color of powder when scratched on porcelain
70
Hardness
Resistance to scratching, measured on Mohs hardness scale (1-10)
71
Luster
How light reflects (e.g., metallic, vitreous)
72
Cleavage
Breaks along flat planes
73
Halite
A transparent, white mineral that dissolves in acid.
74
Gypsum
A transparent, white mineral softer than copper (Mohs <3).
75
Silicate minerals
The most common minerals on Earth, built from silicon-oxygen tetrahedron (SiO₄ units).
76
Carbonates
Minerals that contain carbonate ions, such as calcite (CaCO₃).
77
Sulfides
Minerals that contain sulfur, such as bornite (Cu₅FeS₄).
78
Oxides
Minerals that contain oxygen, such as hematite (Fe₂O₃).
79
Gemstones
Rare, beautiful mineral varieties that are cut and polished for sparkle.
80
Igneous rocks
Rocks formed from the cooling of molten material.
81
Sedimentary rocks
Rocks formed from the compaction of sediments.
82
Metamorphic rocks
Rocks formed from heat and pressure on existing rocks.
83
Clastic rock
Rocks made of fragments (clasts) cemented together, such as sandstone.
84
Crystalline rock
Rocks with intergrown crystals, such as granite.
85
Glassy rock
Rocks that have no crystals, such as obsidian.
86
Weathering
The process that breaks rocks into clasts for sedimentary rocks.
87
Erosion
The process of moving sediments from one location to another.
88
Outcrop
Exposed bedrock, such as cliffs or road cuts.
89
Rock cycle
The progressive transfer of atoms between rock types over geologic time.
90
Igneous activity
The formation, movement, and evolution of magma and volcanism.
91
Partial melting
When only a small proportion of a magma source melts.
92
Viscosity
A measure of a fluid's resistance to flow, higher in felsic magmas.
93
Volcanic gas
Volatiles such as water vapor, CO₂, and SO₂ that form bubbles in magma.
94
Vesicle
Gas bubbles trapped in solid igneous rock.
95
Volcanic eruption
The release of magma, gas, and debris at the surface.
96
Volcano
A vent or fissure where volcanic materials emerge.
97
Decompression melting
Occurs when pressure decreases, allowing rocks to melt without added heat.
98
Flux melting
Addition of volatiles (e.g., water) lowers the melting point of rocks, common in subduction zones.
99
Heat-transfer melting
Hot magma intrudes and heats surrounding cooler rock, causing it to melt.
100
Felsic
High silica (>65%), light-colored, high viscosity.
101
Intermediate
55-65% silica, moderate properties.
102
Mafic
Low silica (45-55%), dark-colored, low viscosity.
103
Ultramafic
Very low silica (<45%), rare at surface.
104
Fractional crystallization
Process where crystals separate from melt, changing composition.
105
Volcanic gas sources
Derived from volatiles dissolved in magma, released as bubbles near the surfaces.
106
Igneous rock
Any rock formed by the solidification of melt (magma or lava).
107
Intrusive igneous rock
Forms underground from cooled magma.
108
Extrusive igneous rock
Forms at the surface from lava or debris.
109
Magma migration
Magma rises due to buoyancy and pressure from overlying rock.
110
Cooling and solidification
Intrusive: Slow cooling (deep, large bodies) produces coarse grains; Extrusive: Fast cooling (surface, thin flows) produces fine grains.
111
Surface area-to-volume ratio
Smaller bodies (e.g., 1m cube) cool faster than larger ones (e.g., 2m cube).
112
Igneous intrusion
Underground body of solidified magma.
113
Tabular intrusion
Sheet-like; includes dikes (cross-cut bedding) and sills (parallel to bedding).
114
Nontabular intrusion (pluton)
Irregular shape, larger than tabular.
115
Batholith
Huge composite of many plutons (>100 km² exposure).
116
Lava flow
Stream of molten lava on the surface.
117
Pyroclastic debris
Fragmented material from explosive eruptions.
118
Ash
Fine particles (<2 mm).
119
Lapilli
2-64 mm fragments.
120
Blocks/Bombs
>64 mm; blocks angular, bombs rounded.
121
Pillow basalt
Submarine mafic flows forming rounded blobs.
122
Texture
Grain size/shape; composition: Mineral content.
123
Crystalline igneous rock
Interlocking crystals.
124
Fine-grained
Rapid cooling (e.g., basalt, rhyolite).
125
Coarse-grained
Slow cooling (e.g., gabbro, granite)
126
Porphyritic
Large crystals in fine matrix (two-stage cooling)
127
Glassy igneous rock
No crystals, rapid cooling (e.g., obsidian - sharp, felsic; scoria - vesicular, mafic)
128
Fragmental igneous rock
Welded/cemented pyroclastics (e.g., tuff)
129
Pumice
Felsic, vesicular glass that floats due to trapped gas
130
Obsidian
Non-vesicular glass, sharp for tools
131
Grain size
Inversely relates to cooling rate: Fine = fast (extrusive); coarse = slow (intrusive)
132
Effusive eruption
Dominated by lava flows/fountains, typically mafic
133
Explosive eruption
Blasts pyroclastics; triggered by decompression or water-magma interaction
134
Volcanic explosivity index (VEI)
Scale 0-8; VEI 8 (supervolcanic) >1,000 km³ debris
135
Volcanic edifice
The built-up structure of a volcano
136
Crater
Summit depression
137
Fissure
Elongate vent
138
Caldera
Large collapse depression post-eruption
139
Pyroclastic flow
Hot debris avalanche
140
Shield volcano
Broad, gentle slopes from mafic flows
141
Cinder cone
Steep hill of lapilli
142
Stratovolcano
Layered lava and debris
143
Black smoker
Hydrothermal vent at mid-ocean ridges
144
Flood basalt
Thick mafic flows from hotspots
145
Large igneous province (LIP)
Vast mafic volcanism from hotspots
146
Natural hazard
Geologic event causing harm
147
Lahar
Mudflow from ash + water
148
Active volcano
Recently erupted, potential future activity
149
Dormant volcano
Inactive but not eroded away
150
Extinct volcano
No future eruptions possible, heavily eroded
151
Recurrence interval
Time between eruptions
152
Volcanic-hazard map
Shows at-risk areas based on past eruptions
153
Who proposed the continental-drift hypothesis?
Alfred Wegener
## Footnote
This hypothesis suggests that continents were once joined in a supercontinent called Pangaea.
154
Define **continental drift**.
The hypothesis that continents move slowly across Earth's surface
## Footnote
This concept was initially rejected due to lack of a mechanism for movement.
155
What is **Pangaea**?
The ancient supercontinent formed by all continents joined together
## Footnote
It is a key concept in the continental drift hypothesis.
156
List three types of **evidence** Wegener used to support his hypothesis.
* Matching rock formations
* Jigsaw-like continental margins
* Similar fossils on separated continents
## Footnote
These observations came from geology, geography, and paleontology.
157
What technology enabled efficient mapping of **seafloor bathymetry**?
Sonar
## Footnote
This technology led to the development of the seafloor-spreading hypothesis.
158
Define **bathymetry**.
The study and mapping of ocean floor depths and topography
## Footnote
It is crucial for understanding seafloor features.
159
What is a **mid-ocean ridge**?
An elevated underwater mountain chain where new oceanic crust forms
## Footnote
It is a key feature in the process of seafloor spreading.
160
What does **seafloor spreading** refer to?
The process where new seafloor forms at ridge axes, spreads outward, and is recycled at trenches
## Footnote
This process is essential for understanding plate tectonics.
161
What is the **lithosphere**?
Rigid layer including crust and uppermost mantle; behaves rigidly
## Footnote
It is divided into tectonic plates.
162
Define **asthenosphere**.
Ductile, warmer mantle layer below lithosphere that flows plastically
## Footnote
This layer allows the lithosphere to float on it.
163
What are the three types of **plate boundaries**?
* Divergent boundary
* Convergent boundary
* Transform boundary
## Footnote
These boundaries drive most geological activity.
164
What is a **subduction zone**?
Region of active subduction
## Footnote
It is where one tectonic plate sinks beneath another.
165
What is a **triple junction**?
Point where three boundaries meet
## Footnote
This can lead to complex geological interactions.
166
Define **paleomagnetism**.
Study of ancient magnetism in rocks
## Footnote
It provides evidence for continental drift and plate tectonics.
167
What is the **rock cycle**?
The progressive transfer of atoms between rock types over geologic time
## Footnote
It illustrates how igneous, sedimentary, and metamorphic rocks are interrelated.
168
What is **subduction**?
Sinking of oceanic lithosphere into mantle
## Footnote
This process is crucial for recycling crustal material.
169
What is the difference between **magma** and **lava**?
* Magma: Molten rock beneath surface
* Lava: Magma erupted at surface
## Footnote
Understanding this distinction is important in geology.
170
What is the **Wadati-Benioff zone**?
Inclined earthquake band tracing subducting slab
## Footnote
It indicates the depth and angle of subduction.
171
What is the **ridge-push force**?
Gravity slides elevated ridge slabs away
## Footnote
It is one of the driving forces of plate motion.
172
What is **slab-pull force**?
Sinking cold slabs pull plates
## Footnote
This force is considered the dominant mechanism for plate movement.
173
What is **relative plate velocity**?
Speed between two plates
## Footnote
This measurement helps in understanding plate interactions.
174
Define **magnetic reversal**.
Earth's field polarity flips
## Footnote
This phenomenon is recorded in the ocean floor and supports the theory of plate tectonics.
175
What is a **geode**?
A hollow rock lined with crystals, often formed by mineral precipitation
## Footnote
Geodes are examples of mineral formation processes.
176
What is the **Mohs hardness scale**?
Scale measuring resistance to scratching (1-10)
## Footnote
It helps in identifying minerals based on hardness.
177
What is the difference between **euhedral** and **anhedral** crystals?
* Euhedral: Well-formed faces (free growth)
* Anhedral: Irregular (confined by surroundings)
## Footnote
This distinction is important in mineralogy.
178
What is an **outcrop**?
Exposed bedrock (e.g., cliffs, road cuts)
## Footnote
Outcrops provide visible geological features for study.
179
What are the **study tools** used for examining rocks?
* Hand specimens in field
* Thin sections under petrographic microscopes
* Photomicrographs
## Footnote
These tools help analyze rock textures and compositions.
180
The **rock cycle** involves the transfer of atoms between which rock types?
* Igneous
* Sedimentary
* Metamorphic
## Footnote
This cycle illustrates how rocks transform over geologic time.
181
What drives the **rock cycle**?
* Internal heat
* External energy (sun/weather)
* Gravity
* Life
## Footnote
These factors cause processes like melting, burial, uplift, and erosion.
182
Fill in the blank: **Magma** is __________.
Molten rock beneath the Earth's surface
## Footnote
Magma becomes lava when it reaches the Earth's surface.
183
What is **viscosity** in the context of magma?
A measure of a fluid's resistance to flow; higher in felsic magmas due to silica content
## Footnote
Viscosity affects how magma behaves during eruptions.
184
What are the **three main types of melting** that form magma?
* Decompression melting
* Flux melting
* Heat-transfer melting
## Footnote
Each type occurs under specific geological conditions.
185
What is **fractional crystallization**?
Process where crystals separate from melt, changing composition
## Footnote
This process enriches the remaining melt in silica.
186
Define **intrusive igneous rock**.
Forms underground from cooled magma
## Footnote
Examples include granite and gabbro.
187
What is a **tabular intrusion**?
Sheet-like intrusion; includes dikes and sills
## Footnote
Dikes cross-cut bedding, while sills are parallel to bedding.
188
What is the difference between **effusive** and **explosive eruptions**?
* Effusive: Dominated by lava flows/fountains
* Explosive: Blasts pyroclastics
## Footnote
Effusive eruptions are typically mafic, while explosive eruptions are often triggered by water-magma interaction.
189
What is a **lahar**?
Mudflow from ash + water
## Footnote
Lahars can be extremely dangerous during volcanic eruptions.
190
What does the **Volcanic Explosivity Index (VEI)** measure?
Scale 0-8 for volcanic eruption explosiveness
## Footnote
VEI 8 indicates supervolcanic eruptions with >1,000 km³ debris.
191
What is a **volcanic arc**?
Chain of volcanoes from subduction
## Footnote
Volcanic arcs are commonly found at convergent plate boundaries.
192
What is **partial melting**?
Only a small proportion of a magma source melts to become magma
## Footnote
This process is crucial for the formation of different magma types.
193
What is the **key takeaway** regarding volcanic hazards?
Hazards differ by location—effusive in Hawaii vs. explosive in Cascades
## Footnote
Monitoring and hazard maps are essential for risk reduction.
194
Which layer of the Earth’s interior is completely molten?
the outer core
195
what boundary dose the asteroid belt mark?
The asteroid belt marks the boundary between the rocky planets and the gas giants.
196
Which layer accounts for most of the volume of the Earth?
mantle
197
The leading hypothesis for the formation of our Moon
was formed by the collision of the Earth with a protoplanet.
198
The process by which the Earth developed its layered interior is called
differentiation
199
The geothermal gradient
refers to the rate of increase in temperature with increasing depth in the Earth.
easc 101
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