Midterm - Feb. 28th Flashcards
(160 cards)
1
Q
The science that studies the relationships among geographic areas, natural systems, society, cultural activities, and the interdependence of all of these through space
A
Geography
2
Q
The nature and character of physical space, its measurement, and the distribution of things within it
A
Spatial
3
Q
Is specific and absolute; allows you to discuss places in absolute terms
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Location
4
Q
Is subjective; every one has a distinct group of physical features and can change over time
A
Place
5
Q
A group of places that have physical features or human characteristics (or both) in common
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Region
6
Q
Humans depend on, adapt to, and modify the earth around them. Humans and the environment are continually shaping each other
A
Human-earth relationships
7
Q
The science concerned with the spatial aspects and interacts of the physical elements and process systems that make up the environment
A
Physical geography
8
Q
Process systems that make up the environment
A
Energy, air, water, weather, climate, landforms, soils, animals, plants, microorganisms
9
Q
A set of actions and changes that occur in some special order
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Process
10
Q
The things that a physical geographer studies
A
Earth, human, physical, and spatial sciences
11
Q
What are the steps of the scientific method?
A
Observation, hypothesis, experiment, analyze, peer review, iteration/reporting
12
Q
What is constructed on the basis of several extensively tested hypotheses, and represents a broad general principle?
A
A scientific theory
13
Q
Any ordered, interrelated set of things and their attributes, linked by linked by flows of energy and matter, and distinct from the surrounding environment
A
A system
14
Q
What are the conservation laws of mass and energy?
A
Mass is neither destroyed nor created
Matter is mass that assumes a physical shape and occupies space
Energy is the capacity to do work on (or change) matter
Energy is neither destroyed nor created
Input - output = storage change
15
Q
A system where inputs of energy and matter flow into the system, outputs of energy and matter flow out of the system
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An open system, ex. rivers, forests, hurricanes
16
Q
A system that is shut off from the surrounding environment
A
A closed system - these are very rare in nature
17
Q
Non-living earth spheres
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Abiotic: atmosphere (air/gases), hydrosphere (water), and lithosphere (land)
18
Q
Living earth sphere
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Biotic: the biosphere (life)
19
Q
Outputs that return to various points in the system
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Feedback loops
20
Q
Feedback information discourages response in the system - self regulation, stable condition
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Negative feedback loop
21
Q
The feedback information increases response in the system - runaway condition, snowballing
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Positive feedback loop
22
Q
Occurs when the rates of inputs and outputs in the system are equal and the amounts of energy and matter in storage within the system are constant (or fluctuate around a stable average)
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Steady-state equilibrium, ex. a river channel that constantly adjusts its shape but overall remains in roughly the same area
23
Q
System in a condition that has increasing or decreasing trend
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Dynamic equilibrium, ex. a river that is continuously widening
24
Q
When a dynamic equilibrium system changes to a new operation level
A
Tipping point
25
How are systems encountered in nature at Earth’s surface, such as a forest, best described?
As open systems in terms of energy and matter
26
The science that determines Earth's shape and size
Geodesy
27
Is the earth a perfect sphere or a perfect ellipsoid?
No, earth has both an equatorial bulge and is asymmetrical (mountains and valleys)
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The unique, irregular shape of earth's surface
Geoid
29
What are coordinated grid systems used for
They are fundamental to geographical science and required to determine absolute location on earth
30
An angular distance north or south of the equator, measured from the centre of earth
Latitude
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Angular distances east or west of a point on earth’s surface measured from the centre of earth
Longitude
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A line connecting all points along the same longitude
Meridian
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Any circle drawn on a globe with its centre coinciding with the centre of the globe, an infinite number are possible
A great circle
34
On opposite side of prime meridian, approximately the 180th meridian, located at 180° E or 180° W (they are the same)
International date line
35
The north star very slowly changes location over time, as does the earth
Milankovitch cycle (precession of axis)
36
The time when the sun is at the highest point in the sky
Solar noon
37
A generalized view of an area, usually some portion of Earth’s surface, as seen from above at a greatly reduced size
Map
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A ratio of the image on a map to the real world
Map scale
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A map with a scale of 1:50,000 or less, shows a smaller area in more detail
Large-scale map
40
Systems that record wavelengths of energy radiated from a surface
Passive remote-sensing systems, ex. landsat satellites
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A map with a scale of 1:50,00-1:250,000
Intermediate-scale map
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A map with a scale of 1:250,000 or higher, shows a larger area in less detail
Small-scale map
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Systems that direct a beam of energy at a surface and analyze the energy reflected back
Active remote-sensing systems, ex. radar
44
The reduction of a spherical globe (earth) onto a flat surface (paper) in some orderly and systematic realignment of the latitude and longitude grid
Map projection
45
What are the four classes of map projection?
Cylindrical (mercator projection, straight lines), planar, conic (albers equal-area projection), and oval (rand-mcnally maps, keeps distortion to a minimum)
46
A handheld instrument that receives radio signals from satellites
GPS (Global Positioning System)
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A computer-based, data processing tool for gathering, manipulating, analyzing, and displaying geographic information
GIS (Geographic Information Systems)
48
What are the five themes of geographic science?
Location, place, region, movement, and human-earth relationships
49
What early evidence did geographers have for the Earth's sphericity?
Ships ‘sinking’ beyond the horizon, star positions and their angle to the earth, solar and lunar eclipses
50
The system that encompasses internal processes that produce flows of heat and material from deep below earth’s crust (tectonics, earthquakes, and volcanism), powered by radioactive decay
Endogenic system
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The system that involves external processes that set into motion air, water, and ice, powered by solar energy
Exogenic system
52
What are some geologic processes that occur over long timescales?
Mountain building, canyon incision, formation and breakup of supercontinents (plate tectonics), infilling of sedimentary basins, etc.
53
What are some geologic processes that occur over short timescales?
Volcanic eruptions, meteor impacts, landslides, etc
54
What is the geologic time scale?
It breaks down the past 4.6 billion years, boundaries between intervals are based on major events in Earth’s history
55
What are the four units of geologic time from largest to smallest?
Eon > Era > Period > Epoch
56
The science that analyzes the sequence, spacing, geophysical and geochemical properties, and spatial distribution of rock strata
Stratigraphy
57
What are Steno's 4 principles of stratigraphy?
1. Principle of superposition
2. Principle of original horizontality
3. Principle of lateral continuity
4. Principle of cross-cutting relationships
58
How old is the earth?
About 4.6 billion years
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Process that provides the numerical ages of materials
Absolute dating
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A method of dating materials by determining the relative proportions of particular radioactive isotopes present
Radiometric dating
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Principle that the same physical processes active in the environment today have been operating throughout the geologic time - “the present is the key to the past”
Applies to processes like earthquakes, volcanic eruptions, landslides, mountain-building
Principle of uniformitarianism
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How old is the universe?
About 13.7 billion years old
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Where are the oldest rocks on earth found?
Greenland, the Canadian Shield, and western Australia
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How did the earth form (in basic terms)
It condensed and congealed from a nebula (cloud) of dust, gas, and icy comets about 4.6 billion years ago
It was hot af so silica and iron were liquid but as temps decreased, earth solidified and gravity sorted materials by density
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Bursts of plasma from the sun interact with the earth’s magnetosphere
Aurora borealis (northern lights)
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What causes the earth's magnetic field?
Earth's fluid outer core generates electric currents because it is made of liquid molten metallic iron. As the earth spins the liquid outer core spins and sloshes around the solid inner core.
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Thick crust, mostly granite, originally derived from volcanic processes, has a lower density
Continental crust
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Thin crust, mostly basalt extruded from cracks in earth's crust, has a higher density
Oceanic crust
69
What is buoyancy?
It tells us that something is less dense (wood, ice) floats in something denser (eg water)
70
The state of gravitational equilibrium between the lithosphere and asthenosphere
Isostatic equilibrium (or isostasy)
71
What is the earth's entire crust in a constant state of?
Compensating adjustment or isostasy
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An inorganic (nonliving), naturally occurring, compound with a specific chemical formula and possessing a crystalline structure
Mineral
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A combination of minerals
Rock
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Rocks that solidify (crystallize) from a molten state
Igneous rocks
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Igneous rocks with high silica
Felsic
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Igneous rocks with low silica
Mafic
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What causes fine-grained igneous rocks?
Extrusive cooling - rapid cooling on surface of earth's crust
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What causes coarse-grained igneous rocks?
Intrusive cooling - slow cooling within earth's crust
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What are clastic sedimentary rocks?
Made through lithification (compaction, cementation, and hardening of sediments into sedimentary rock)
80
What are chemical sedimentary rocks?
Made from direct precipitation from a water solution
81
What are biochemical sedimentary rocks?
Made from accumulation of shell material or biological oozes
82
How are clastic sedimentary rocks classified?
Determined by depositional energy (coarse = high energy, medium = moderate energy, fine = low energy)
83
Any rock that has been transformed
Metamorphic rock
84
What is regional metamorphism
Occurs over broad areas of compression
High heat and high pressure
Results in layered/banded rocks
Includes shale, slate, phyllite, schist, gneiss
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What is contact metamorphism
Occurs in a localized area
Close to a magma body
High heat, but low pressure
Results in larger crystals due to recrystallization (eg. limestone transforms to marble)
86
What drives the hydrologic cycle?
Exogenic processes, and involves water on earth cycles among the atmosphere, hydrosphere, lithosphere and biosphere
87
What drives the rock cycle?
Endogenic and exogenic processes, and processes that form all three rock types operate so that each rock can enter the cycle and be turned into other rock types
88
What drives the tectonic cycle?
Endogenic processes, and earth’s plates diverge, collide, subduct, and slide past one another, changing the continents and ocean basins and causing earthquakes, volcanoes, and mountain building
89
What is the theory of continental drift?
All landmasses migrate, and that approximately 225 million years ago they formed one supercontinent Pangaea meaning “all earth”
90
What are the four lines of evidence for plate tectonics?
1. The obvious fit of continents (especially South America and Africa)
2. The same rocks can be seen on previously adjoining continents
3. Fossils of the same organisms are found on now widely separated southern continents
4. Past climate clues (paleoclimatology) like glacial striations
91
What is seafloor spreading?
Pulling apart the lithosphere causes fractures where magma then upwells, cools, and forms dikes which create new ocean crust
92
What are mid-ocean ridges?
MORs are common and occur at seafloor spreading centres, where magma has upwelled and cooled to form a ridge
93
The historic magnetic field of the earth recorded in the rocks
Paleomagnetism
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How did paleomagnetism help explain seafloor spreading?
Magnetic surveys across MORs reveal a pattern of positive and negative anomalies as mirror images on either side
95
How do earthquakes, volcanoes and hot spots support the theory of plate tectonics?
Because most earthquakes, volcanoes and hot spots occur at tectonic plate boundaries
96
What is a divergent plate boundary?
2 types: mid-ocean ridges (divergent plate boundary within oceanic crust) and continental rifts (divergent plate boundary within continental crust)
97
What is a convergent plate boundary?
They occur in areas of crustal collision and come in 3 types:
Ocean - Continent
Oceanic plate subducted beneath continental plate
Chain of volcanoes (continental volcanic arc)
Eg. pacific coast of the americas
Ocean - ocean
Densest (older = colder = lower) oceanic plate is subducted
Forms chain of volcanoes (island arc)
Eg. Japan
Continent - continent
Collision of 2 continental plates
Intense folding, thrusting, faulting and uplifting
Eg. Himalayas
98
What is a transform boundary?
Occur where two plates slide laterally past each other rather than colliding or separating
Most transform plate boundaries occur between two offset segments of a mid-ocean ridge (seafloor spreading centres) where crust produced at one ridge moves in the opposite direction from the crust produces at the opposing ridge
99
What is the modern tectonic plate configuration off the west coast of British Columbia?
A divergent plate boundary is pushing the Juan de fuca plate into the North American Plate → causes a subduction zone. That zone is the reason we have the coast mountains.
100
What is relief and its three orders?
Relief is elevation differences in a local landscape; an expression of local height differences between landforms. Low relief = flat High relief = not flat
First order of relief
The coarsest level (“zoomed out” level, largest area), like satellite view
Ex. continental landmasses and ocean basins
Second order of relief
Intermediate level
Ex. mountain ranges, plains, lowlands, mid-ocean ridges, oceanic trenches
Third order of relief
Most detailed level
Ex. individual mountains cliffs, valleys, hills
101
Are we going to crush this test?
Yes :)
102
Term for the undulations and other variations in the shape of Earth's surface (including its relief), like mountains, basins, plains, high tablelands, hills and low tablelands
Topography (from topos (place) and graphein (to write))
103
What are the six types of topographic regions?
1. Plains: local relief < 100m.
2. High Tablelands : Elevation > 1520m and local relief < 300m.
3. Hills and Low Tablelands: 100m < local relief < 600m.
4. Mountains: local relief > 600m.
5. Widely Spaced Mountains: isolated, local relief < 150m.
6. Depression: surrounded by mountains, hills or tablelands.
104
What is hypsometry?
The measurement of land elevation relative to sea level
105
What is the hypsographic curve?
It shows the distribution of earth’s surface by area and relative elevation to mean sea level
*most of earth’s surface is actually below sea level (because oceans cover 71% of earth)
106
How is earth's continental crust formed?
From tectonic activity (powered by endogenic or internal energy processes) combined with weathering and erosion (powered by the sun through motion of air, water and ice)
107
What is a craton
(Or heartland region) is an old and stable part of continental crust, usually in centre of continent, continental shields and platforms
108
What is a continental shield
A region with a craton that is exposed at the surface, as continental crust forms it is enlarged through accretion of dispersed terranes
109
What is a basement (or crystalline basement)
A region below a sedimentary platform or cove
110
What are the three steps in the formation of continental crust?
1. Material from the dense asthenosphere upwells along seafloor spreading centres
2. Basaltic ocean floor is subducted beneath lighter continental crust, where it melts, along with its cargo of sediments, water, and minerals
3. Melting generates magma, which makes its way up through the continental crust to form igneous intrusions and extrusive eruptions of volcanic material
111
What is a terrane and terrane accretion?
Terrane is a migrating piece of earth’s crust, transported a distance by processes of plate tectonics → these “exotic” terranes are distinct from the continents that accept them in terms of history, composition and structure
*the Canadian rockies formed this way
112
What are the three types of stress? (stress for rocks, not the extreme stress caused by this mf class)
1. Tension stress causes stretching strain
2. Compression stress causes thickening/shortening strain
3. Shear stress causes twisting laterally strain
113
What is strain?
Strain is how rocks respond to stress, results in rocks folding (bending) or faulting (breaking)
114
What are the four types of rock folds?
Anticline (arch-shaped fold)
Syncline (trough-shaped fold)
Dome (similar to anticline but more umbrella shaped, oldest rocks in centre when eroded)
Basin (uplifted rock layers in a concave-upward shaped circular pattern, youngest rocks in centre when eroded)
115
When does faulting occur?
When rocks on either side of a fracture shift relative to the other side
Hanging wall: the fault surface that would form a roof if you separated the fault blocks and stand under it, sits on top of footwall
Footwall: looks like a doorstop ⊿
116
What is a right-lateral fault?
A strike-slip fault (horizontal faulting) where the right-hand side moves toward you, looking along the fault
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What is a left-lateral fault?
A strike-slip fault (horizontal faulting) where the left-hand side moves toward you, looking along the fault
118
What is a normal fault?
A dip-slip fault (vertical faulting) that occurs with tension stress, and the footwall moves up above the hanging wall
119
What is a reverse fault?
A dip-slip fault (vertical faulting) that occurs with compression stress, and the footwall moves down below the hanging wall
120
What is a recurrence interval?
The average time between surface ruptures on a fault, used when evaluating the hazard risk of an active fault
121
What is orogenesis?
Orogenesis means mountain building: the process occurs when large-scale compression leads to deformation and uplift of the crust; literally, the birth of mountains
Orogeny: a mountain-building episode that occurs over millions of years
122
What are the six geological provinces of Canada?
Canadian shield
Grenville orogeny
Interior platform
Appalachian orogeny
Innuitian orogeny
Cordilleran orogeny
123
What is a sharp release of energy that occurs at the moment of movement along a fault, producing sesmic waves?
An earthquake
124
What is the point of emission of an earthquake?
The focus or source
125
What is the projection of the earthquake's focus on the surface of the Earth?
The epicentre, determined using the time intervals of seismic waves
126
What is the elastic rebound of rocks?
Crust at rest = no strain
Crust deformed = strain accumulates (elastic energy stored as strain)
Ruptured crust = rupture with elastic rebound (elastic energy is released, causes earthquake)
Fractured crust = strain released, rocks rebound (return to original state)
127
What is seismology?
The study of seismic (earthquake) waves
128
What is an instrument that records earthquakes
Seismometer
129
What is the record itself of seismic waves
Seismogram
130
What are the three main types of seismic waves?
Body waves: P waves (travel fast but cause less damage) and S waves (travel slower than P waves, also less damaging)
Surface waves: L waves (travel slowest, cause most damage, travel only across the earth’s uppermost surface)
131
Where does volcanism occur?
Convergent plate boundaries, subduction zones (continental/island arcs)
Divergent plate boundaries (continental rifts and mid-ocean ridges)
Hot spots
132
What is an effusive volcanic eruption?
Low viscosity, gases can easily escape so lavas flow rather than explode.
Less destructive, no ash clouds, no explosions
Lava has low Si content, high Fe and Mg (Mafic)
Common at divergent boundaries, rift zones, hot spots
Resulting volcano = shield volcano
Ex. Mauna Loa, Hawaii
133
What is an explosive volcanic eruption?
High viscosity lava, gases cannot easily escape so they erupt explosively
Lava/magma has high Si content, low Fe and Mg (Felsic)
Common at convergent boundaries
Resulting volcano = composite volcano (or stratovolcano)
Eg. mount st. helens, washington
134
What is a volcanic peak?
Mountains made by lava cooling:
Shield volcanoes (low relief isolated mountain)
Composite volcanoes (high relief isolated mountain)
Cinder cones (smaller volcanic peaks made of pyroclastic flow material, basalt, from moderately explosive eruptions, can form on flanks of larger composite volcano)
135
What is a caldera?
Depression at top of volcano
Forms when magma erupts, leaving a void within the earth
Void collapses inward after eruption, often later fills with water
New volcano can form in center of caldera
Ex. crater lake oregon
136
What is a volcanic neck?
Forms when a column of magma within a volcano’s conduit cools and hardens
Surrounding softer rock layers erode
Preserves volcanic conduit, turns into isolated tower of rock
Ex. devil’s tower, wyoming
137
What is a lava tube?
Associated with effusive eruptions
Conduits or tunnels that lava followed beneath a lava flow surface
Outer stream of the flow will harden, leaving hollow tubes/caves behind
138
What are some benefits of volcanoes?
Rich volcanic soils (rich in nutrients like iron, magnesium, good for plant growth)
Geothermal energy from the earth’s crust
Hot springs and geothermal heating
139
Is a landscape an open or closed system?
It is an open system
140
How is this test gonna go?
We will probably pass :)
141
What is the study of the origin, evolution, form, and spatial distribution of landforms?
Geomorphology
142
What is denudation?
Any process that is removing rock, wears away or rearranges landforms
143
What are the processes that affect weathering and erosion?
Endogenic processes build initial landscapes
Exogenic processes develop sequential landscapes of low relief, gradual change, and stability
144
What is weathering?
The process that breaks down rock at Earth’s surface and slightly below
145
What is differential weathering?
Different rates of weathering as a result of differences in resistances of rocks (or differences in intensity of weathering)
146
What is erosion?
Denudation by wind, water, or ice, which dislodges, dissolves, or removes surface material
147
What is partially weathered rock overlying bedrock?
Regolith - created by continual weathering of upper surface
148
What are the factors that influence weathering processes?
Rock composition
Rock structure (eg. jointing)
Surface and sub-surface water
Climatic conditions
Slope orientation
Vegetation
Time
149
What is frost action/frost wedging?
Physical weathering:
Water infiltrates into cracks, expands as it freezes
Force from expansion overcomes tensional strength of rock
Cracks widen, splitting rocks into smaller blocks
150
What is salt-crystal growth/salt weathering?
Physical weathering: In warm dry climates, evaporation removes moisture from rock surface
Previously dissolved salt minerals are left behind
Salt crystals accumulate and grow
Growth exerts force on rocks strong enough to separate grains, breaking the rocks into smaller pieces
151
What is pressure-release jointing?
Physical weathering: process where rock peels or slips off in sheets instead of breaking up into grains
Creates arch- and dome-shaped features on landscape
Formed as pressure is released from the removal of overlying rock
152
What is desiccation cracking?
Physical weathering: Clay-rich rocks and sediments expand when wet and contract when dry
153
What is spheroidal weathering?
The sharp edges and corners of rocks are rounded due to chemical weathering
154
What is hydration?
Chemical weathering: water is added to the structure of a mineral, changing its structure so that it has larger volume, creating stress which causes the disintegration of rock
Mineral is just changing, not being broken down
155
What is hydrolysis?
Chemical weathering: Decomposition of a chemical compound by reaction with water. Differs from hydration in that mineral is being chemically broken down
156
What is oxidation?
Chemical weathering: metallic elements (Fe, Al) combine with oxygen to form oxides → larger, softer, more erodible compounds are formed
This is rusting
157
What is carbonation?
Chemical weathering: Water vapour readily dissolves CO2, (present in atmosphere), producing acidic precipitation.
158
What is dissolution?
Chemical weathering: when a mineral dissolves into a solution
159
What are some examples of biological weathering processes?
Tree root wedging
Lichens
Burrowing
160
What is Karst Topography?
A limestone region with a specific landscape of pitted, bumpy surface topography, poor drainage, and well-developed solution channels underground, due to chemical weathering
Requirements:
Limestone must contain 80% or more calcite (calcium carbonate)
Limestone must be jointed to provide access to subsurface
Aerated zone must exist between ground surface and water table
Vegetation cover must exist, supplies organic acids to enhance dissolution process
Moist and temperate climate?
