Definitions Flashcards
(189 cards)
1
Q
Andesite:
A
An extrusive intermediate igneous rock
2
Q
Asthenosphere:
A
The hot and weak part of the upper mantle, underlying the lithosphere, on which the tectonic plates slide.
3
Q
Batholith
A
A very large igneous intrusion.
4
Q
Clastic
A
A sediment or sedimentary rock which is made up of deposited particles, of whatever size or
material.
5
Q
Continental drift
A
The movement of the continents across the surface of the earth
6
Q
Convergent boundary
A
A zone where two tectonic plates are moving towards each other. These may be continent-continent, ocean-continent, or ocean-ocean
7
Q
Core
A
The centre of the Earth, made up mostly of iron, consisting of a solid inner core and a liquid
outer core.
8
Q
Crust
A
The rocky surface of the Earth
9
Q
Crystal
A
A uniform material in which atoms or molecules are arranged in a completely regular
structure.
10
Q
Divergent boundary
A
A zone where two tectonic plates are moving apart, sliding away from ridge formed by mantle convection
11
Q
Dyke
A
A mass of intrusive igneous rock that formed in a crack through the surrounding country rock.
12
Q
Extrusive
A
A kind of igneous rock that has cooled quickly at the ground surface, and so has small crystals
13
Q
Feldspar
A
A common mineral in igneous rocks
14
Q
Felsic
A
A composition of igneous rock that is rich in Feldspar and Silica (Quartz), and is usually light in colour. Low density, mp, high viscosity
15
Q
Igneous Rock
A
A rock which has formed by solidification of molten rock as it cools
16
Q
Intermediate
A
A composition of igneous rock that is intermediate between felsic and mafic
17
Q
Intrusion
A
A mass of igneous rock that has solidified underground, and so has large crystals
18
Q
Lava
A
Molten rock that erupts onto the ground surface from a volcano
19
Q
Intrusive
A
A kind of igneous rock that has cooled slowly underground, and so has large crystals.
20
Q
Lithosphere
A
The Earth’s crust and the top part of the mantle, divided into tectonic plates which
move around on the surface of the Asthenosphere.
21
Q
Mafic
A
A composition of igneous rock which is rich in magnesium and iron, and is usually dark in colour. fine grained
22
Q
Mantle
A
The bulk of the Earth (about 84%), between the outer core and the crust.
23
Q
Mineral
A
A material of specific chemical composition which is part of a rock, often as a crystal. Rocks
are in general made up entirely of minerals.
24
Q
Plate tectonics
A
The process by which tectonic plates move around.
25
Sediment
Material deposited on the Earth’s surface which may eventually form a sedimentary rock.
26
Sedimentary rock
Rock formed from sediments, principally either clastic or chemical/biochemical.
27
Sill
A sheet of intrusive igneous rock that formed by squeezing into the country rock on a bedding
plane.
28
Tectonic Plate
A section of the Earth’s lithosphere that moves around on the surface of the
asthenosphere as a single unit, and may contain both continental crust and oceanic crust.
29
Foliated
growth of a mineral crystal in 1 direction
30
non-foliated
rock has been evenly compressed
31
chemical
mineral constituents in solution which become supersaturated and precipitate
32
biogenic
when organisms use materials in air/ water to build their tissue
33
clastic
a sedimentary rock made up of deposited particles
34
stratigraphic column
a sequence of rock formation arranged chronologically
35
liquefaction
unconsolidated sediments transformed into a liquid-like substance
36
rock
a substance made up of a mixture of minerals
37
creep
slow downhill movement of loose weathered materials
38
slump
intermittent movement of rock debris
39
weathering
process by which a soil or rock increases its specific surface
40
erosion
carrying away of weathered soil, rock and other materials on the earth's surface
41
flux
flow over a given area per unit time
42
catchment
any area or land feature that captures and holds water, defined by local topography, acts as a funnel by collecting all water within the catchment basina nd channelling it to a single point
43
run off
increase in streamflow volume over the baseflow
44
groundwater
fills space between soil particles and fractures rock beneath Earth's surface
45
saturated zone
a region where pores and fractures of the ground are filled with water
46
water table
the upper surface of the zone of saturation
47
unsaturated zone
region of sediment above the water table
48
aquifer
an underground layer of water-bearing rock or unconsolidated material
49
deltas
layers of sediment deposited at openings due to a change in velocity
50
turbidity
caused by suspended materials and colloidal matter that obstructs light transmission through the water
51
limnology
study of lakes and other freshwater sources
52
fluvial
process associated with rivers and streams and the deposits and land-forms created by them
53
channel efficiency
a river's ability to transport bedload and flow
54
thalweg
a line drawn to join the deepest points along a river bed
55
static equilibrium
a beach which experiences neither sediment deposition or erosion
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dynamic equilibrium
occurs when sediments are eroded and deposited at equal rates
57
continental shelves
submerged edges of continental crust
58
seamount
an underground mountain formed by volcanic activity
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trenches
topographic depressions in seafloor
60
kettle hole
a lake formed by large bodies of melted ice
61
glacial till
unsorted material deposited directly by glacial ice
62
glacial striations
scars and scratches in a rocks' surface
63
varves
annual layers in sedimentary rock
64
moraine
mass of rock/sediment transported and deposited by a glacier
65
mantle plume
an upwelling of abnormally hot rock within the earth's mantle
66
pyroclastic flow
rapidly moving mass of lava, ash and volcanic gases that have been erupted from a volcano
67
tsunami
massive long, high ocean wave caused by earthquakes, submarine landslides or volcanic eruptions
68
acidic
=felsic >65% Si concentration
69
basic
=mafic <65% Si concentration
70
evaporites
minerals found in a sedimentary deposit of soluble salts that result from evaporation of water
71
dolomite
CaMg(CO3)2
72
Scree
broken rock fragments
73
sorted profile
contains a majority of geologic material within a small range of grain sizes
74
graded profile
distribution of geologic material over a wide range of grain sizes
75
esker
a long ridge of sand and gravel that deposited after a glacier has retreated
76
till
unsorted geologic material deposited via erosion bu movement of glacier.
77
scree
a collection of broken rock fragments along a mountain slope or at a mountain's base. Typically results from weathering process related to volcanic activity, landslides and/or rock falls
78
dendritic drainage pattern formed
on uniform ground
79
trellised drainage pattern
happens in strongly folded rock
80
esker
a long ridge of sand and gravel that is deposited, or left behind, after a glacier has retreated
81
till
unsorted geologic material deposited via erosion by movement of a glacier
82
boulder clay
largely composed of clay-sized particles but also contains many boulders and other rock fragments deposited by glaciers
83
basaltic lava
1000-1200 mafic; low silica content; 100km/h; 50km range
84
flood basalts
flat terrain- thin sheets pile up on top of each other
85
pahoehoe lava
lave with a thin elastic skin, quick fomation
86
aa lava
large angular boulders, low gas content, high viscosity
87
pillow lava
piles of rounded blocks about 1m in size, formed underwater
88
rhyolitic lava
800-1000, felsic, high viscosity
89
andesitic lava`
intermediate between rhyolitic and basaltic lava
90
central eruptions
lava from the central vent
91
fissure eruptions
lava from cracks in the rock
92
shield volcanoes
gentle slope formed by slow basaltic lava flow
93
volcanic domes
rounded,steep-sided volcanoes with plugged vents--> violent eruptions formed by felsic/viscous lava
94
cinder cones:
concave slopes built from pyroclasts
95
composite
built from pyroclasts and lava
96
craters
formed when lava sinks back into the vent (steep-inner sides result in instability)
97
calderas
form as a result of local collapse of surrounding rock
98
phreatic explosions
seawater mixes with magma causing violent eruptions
99
diatreme
explosive eruption empties vent which then sills with falling debris--> materials often formed at depths of 100km or more
100
lahars
any mudflow incorporating volcanic debris
101
edifice collapse
collapse of steepened face
102
tephra
all material thrown into air as a volcano explodes (some cools in flight)
103
cleavage
natural splitting of a mineral along parallel planes dictated by weaknesses in the atomic structure
104
mineral strength
function of hardness and lack of cleavage
105
clastic sediments
accumulation of clastic particles derived from the weathering of pre-existing rocks--> often dominated by quartz as it is hard and doesn't weather
106
stratification/ bedding
sediments are depostied in layers due to successsive episodes of depostion or changes in enviroment
107
cross bedding
cross-bedded layers on lee slope often found in dunes or sand bars
108
graded bedding
coarse at base reducing to fine at top as speed of current decreased with time
109
ripple
remain when sediment is lithified
110
bioturbation
remains of tubes from worms etc
111
bedding sequences
cycles of interbedded materials
112
subsidence
sedimentary basins, deep acculumlations of sediment and burial
113
compaction
squeezing out of water
114
cmentation
precipitation of new minerals or growth in size of existing particles
115
regional metamorphism
high pressure and temperatures at depth produce changes in the rock (water moves)
116
contact metamorphism
occurs at surface or at a shallow depth (low pressure but high temp due to igneous intrusion/extrusions)
117
dislocation metamorphism/cataclastic
high shear stress leads to formation of faults causing rock to be mechanically broken
118
hydrothermal
high temperatures associated witht hte presence of water leads to chemical reactions and solution and transportation of minerals
119
burial
occurs a low temperature and presssure as sedimentary tock undergoes an increase in pa
120
shock
due to meteorite impacts
121
METASOMATISM
hot water transports minerals into or out of rock
122
mechanical unloading
fissures open up orthogonal to the direction of loading (horizontal cracks open up on bedding plane)
123
mechanical loading
due to impact of sand, rain ,dust, gravel or boulders carried by flowing water or ice. results in material breaking away from surface of the rock
124
freezing
water expands by nearly 10%, causing rocks to crack and rock to disintegrate
125
laminar flow
slowly moving water in smooth channels (only fine particles are transported)
126
turbulent flow
fast-moving water which easily moves particles
127
slate
foliated
128
phyllite
foliated
129
schist
foliated
130
gneiss
foliated
131
hornfels
nonfoliated
132
quartzite
nonfoliated
133
marble
nonfoliated
134
amphibolite
nonfoliated
135
granulite
nonfoliated
136
lapis lazuli
nonfoliated
137
mica
widely distributed mineral that occurs in igneous, metamorphic and sedimentary rocks
138
muscovite
white mica
139
biotite
black mica
140
phlogopite
green mica`
141
gabbro
intrusive
142
diorite
intrusive
143
granodiorite
intrusive
144
granite
intrusive
145
basalt
extrusive
146
andesite
extrusive
147
dacite
extrusive
148
rhyolite
extrusive
149
limestone
chemical
150
dolostone
chemical
151
evaporites
chemical
152
conglomerate
clastic
153
breccia
clastic
154
sandstone
clastic
155
siltstone
clastic
156
mudstone
clastic
157
shale
clastic (makes up 70% of rock in Earth's crust)
158
coal
biogenic
159
chert
biogenic
160
peat
biogenic
161
spheroidal weathering
the peeling of layers off granite, associated with penetration and freezing of water
162
oolitic limestone
roughly spherical sand sized particles which have grown like hailstones as they settled through a calcium rich sea
163
karst
landscape underlain by limestone weathered and eroded by dissolution producing ridges, towers, fissures sinkholes, caved and other characteristic landforms
164
pyrite+water+oxygen
results in cracking in floors and weathering
high volume of gypsum crystal in pyritic shale caused the expansion of the rock
formation of sulfuric acid occurs
165
pyrite related engineering problems
volume expansion' concrete degradation; rust of steel rebar and piping; acid mine drainage; water quality
166
freshwater breakdown
2.5% of the total world water
0.3% of freshwater, lakes and rivers
30% groundwater
70% ice and snow cover in mountainous regions
80% of GW is used to irrigate farmland
167
flow rate/discharge equation
volume of water that passes through a given point per unit time
Q=VA
168
continuity equation
rate at which mass enters a system is equal to the rate at which mass leaves the system (VA=VA)
169
water budget method
quantifies how much water is within a system at a given time
| helps manage water supplies, predict water shortages, irrigation and well design
170
river
a body of water flowing along a natural channel
171
fluvial
processes associated with rivers and streams and the deposits and landforms created by them
172
hydromorphology
hydrological and geomorphological processes and attributes of rivers, lakes, estuaries and coastal waters
173
river flow
the velocity of river is the speed at which water flows along it (velocity depends on gradient, volume, shape and friction)
174
sedimentation
occurs when eroded material that is being transported by water settles out of the water column onto the bed, as the water flow slows
175
hydraulic radius
ration between the CSA of a stream channel and the length of the water channel at that cross-section (A:P)
176
stream orders
a measure of relative size of streams and rivers (smallest 1- largest 12)
177
meandering stream
helical flow erodes the outside of a river bend and deepens the pool
178
oxbow lake
crescent shaped lake formed on a river when a meander has been cut through and abandoned
179
floodplains
low lying plains on both sides of a river that has repeatedly overflowed its banks and flooded the surrounding areas . Once flooding has subsided, alluvium is deposited on the floodplain
180
retention time
time water is held in a reservoir before it is released. allows particles and silt to settle out
181
permeability
ability of a rock to transmit water through its interconnected voids or spaces between particles
182
aquiclude
impermeable rock with static water held in poorly connected voids
183
aquifuge
impermeable rock with no voids
184
aquitard
rock with low permeabiiity
185
perched aquifer
lies on an aquiclude above the regional water table
186
porosity
% volume of voids or pore spaces in a rock
187
specific yield
%volume of water that can drain freely from a rock
188
continental shelves
submerged edges of continental crust
189
hypoxic conditions
have diminished water quality
