Final Flashcards
(100 cards)
1
Q
Two geologic theories
A
Catastrophism and Uniformitarianism
2
Q
Earth’s major parts/spheres
A
Geosphere, Hydrosphere, Atmosphere, Biosphere
3
Q
Rock cycle?
A
Magma –> cooling/crystalization –> igneous –> weatering/transport/deposit –> sediment –> lithification (compaction/cementation) –> sedimentary rock –> metamorphism –> metamorphic rock –> melting –> …
4
Q
Layers of Earth
A
Lithosphere, Asthenosphere, Mesosphere, Core
5
Q
What is a mineral?
A
Naturally occurring inorganic solid possessing definite structure… most rocks are made of 2 or more minerals
6
Q
What are elements?
A
building blocks of minerals. atoms are the smallest
7
Q
Properties of minerals?
A
crystal form, luster, color, streak, hardness, cleavage, fracture, density
8
Q
Two most common elements
A
Silicate and Oxygen
9
Q
Extrusive vs. Intrusive Igneous rocks
A
Extrusive - result when lava cools at surface, Intrusive - result when magma solidifies at depth
10
Q
What size crystals form when magma cools slowly?
A
Large crystals
11
Q
What size crystals form when magma cools quickly? Instantly?
A
Quickly =Small, intergrown crystals. Instant = glass
12
Q
How are igneous rocks classified?
A
Texture and mineral composition
13
Q
Texture?
A
overall appearance of rock based on size/ arrangement of interlocking crystals
14
Q
Texture: aphanitic
A
Super small crystals
15
Q
Texture: phaneritic
A
intergrown small crystals, but you can see
16
Q
Texture: porphyritic
A
large crystals
17
Q
Texture: phenocrysts
A
big and small crystals
18
Q
Light-colored silicate minerals
A
granite and rhyolite
19
Q
Dark-colored non-silicate’s
A
basalt and gabbro
20
Q
Factor’s that determine nature of volcanic eruptions
A
magma composition, temperature, amount of dissolved gasses
21
Q
Rhyolitic lava
A
high silica content, very viscous and forms short, thick flows
22
Q
Basaltic lava
A
low silica content, more runny - travels further before cooling
23
Q
Shield Volcanoes
A
broad, slightly domed, built of fluid, basaltic lava - DIVERGENT PB
24
Q
Composite Volcanoes
A
most violent volcanic activity - CONVERGENT PB
25
Mass wasting
transfer of rock down slope by gravity
26
Erosion
removal of material by wind, water, ice
27
Rates of weathering depend on...
particle size, mineral makeup, climate (temp and moisture)
28
Types of sedimentary rocks
detrital and chemical
29
Detrital sedimentary rocks?
transported sediment as solid particles - mainly clay and quartz
30
Chemical sedimentary rocks?
chemicals that were once in solution but are now recrystallized
31
What is digenesis?
all physical, chemical, biological changes that occur after sediments are deposited and during or after the time they turn into sedimentary rock
32
Processes that form sedimentary rocks
weathering/erosion, transportation, deposition, lithification (compaction and cementation)
33
Characteristics of sedimentary rocks
layers (strata), ripple marks, mud cracks, cross-bedding, graded bedding, fossils
34
How does metamorphism happen?
heat, pressure (stress), chemically active fluids
35
What is foliation? What are examples?
platy, elongated crystals are aligned... examples are slate, phylite, schist, and gneiss
36
Examples of nonfoliated rocks
marble, quartzite
37
Environments where geologic environments forms
contact/thermal metamorphism, hydrothermal metamorphism, burial/ subduction zone metamorphism, regional metamorphism
38
Contact/ thermal metamorphism
rocks in contact with igneous body
39
Hydrothermal metamorphism
where hot, ion-rick fluids circulate through rock and cause chemical alteration - along ocean ridge system
40
Regional metamorphism
at considerable depths over extensive area and is associated with mountain building
41
Important triggers of mass wasting
saturation of material with water, over-steepening of slopes, removal of anchoring vegetation, ground vibrations from earthquakes
42
Mass wasting is classified by...
type of material that moves, type of movement, velocity of movement
43
Types of mass wasting
mudflows/earthflows, slumps, slides, galls, creep (expansion by freezing/contraction during thawing)
44
How do streams erode?
abrasion, solution, hydraulic action
45
How do rivers transport sediment?
suspension, solution, bed load
46
Different aspects of a streams load
dissolved load, suspended load, bed load
47
Capacity vs. Competence
capacity = max load a stream can transport, competence = max particle size a stream can transport. competence determined by stream's velocity
48
Types of stream channels
bedrock and alluvial
49
Distribution of groundwater
(top to bottom) zone of aeration, water table, zone of saturation
50
Factors that influence storage and movement of groundwater
porosity, permeability, aquitard (impermeable - hinders water movement), aquifer (permeable - transmits groundwater freely)
51
Springs are...
where water intersects with ground
52
How much of earth's water is in glaciers?
slightly more than 2%
53
How do glaciers move?
basal sliding, internal plastic flow - top is zone of fracture
54
How do glaciers erode?
abrasion and plucking
55
Land forms created by alpine glaciers (erosion)
glacial trough's, hanging valleys, cirques, horns, fjords
56
What is a cirque?
headwalls at beginning of glacial valleys
57
What is a fjord?
glaciers erode land into the water
58
Land forms created by glaciers (deposition)
glacial till, glacial flour, moraines
59
Types of deserts
low-latitude deserts (30 degrees from equator) and mid-latitude deserts (rain shadow deserts - by mountain ranges)
60
Two important mechanisms of wind erosion
deflationa and abrasion
61
How is desert pavement formed?
deflation removes finest particle, gradually just leaving the hardest, most course particles
62
Oscillation waves
circular movement, with circles getting smaller and smaller as you get further under water
63
When wave base intersects with sea bed...
height increases, wavelength shortens, velocity decreases, oscillations deformed
64
Spits are formed by...
beach drift
65
What is a tombolo?
when there is an island a little way out from shoreline, sediment piles up and extends from shoreline to island
66
Structures that control shorelines
breakwaters, groins, jetties, seawalls
67
Breakwaters
built entirely in water, energy of waves deflected by wall, so on other side, water is calmer
68
Groins
a wall built attached to the ground on one end perpendicular to shoreline that extends into open water
69
Jetties
built to prevent deposition in channels, maintains passageway to bay/ harbor/ river
70
Seawalls
built on land, shields keeping land safe from waves
71
What is the earthquakes source called? What is right above the focus?
the source is called the focus, the epicenter is on ground right above it
72
How is epicenter found?
determining differences in velocity of P/S waves - (triangulation)
73
What are the two types of seismic waves?
Surface waves and body waves
74
What are the two types of body waves?
Primary Waves (P) and Secondary Waves (S)
75
Describe P-Waves
Push and Pull rocks direction wave is traveling through everything. move faster than S-Waves
76
Describe S-Waves
Shakes particles in rock at right angles to their direction of travel - travels only through solids
77
What are the ways to measure/ describe size of an earthquake?
Intensity and Magnitude
78
Intensity
measure of degree of ground shaking at given location based on damage - Modified Mercalli Intensity Scale
79
Magnitude
seismic records, estimates amount of energy released from at source of earthquake - Richter Scale
80
Structural damage from earthquakes depends on
wave amplitudes, duration of vibrations, nature of material upon which structure rests, design of structure
81
Divergent vs. Convergent vs. Transform boundaried
Divergent
Convergent --> <--
Transform - slide past each other
82
Plate tectonics supported by...
Paleomagnetism, global distribution of earthquakes/ association with plate boundaries, ages of sediments form ocean floors, existence of island groups that form over hotspots
83
Three Major units of the ocean floor
Continental margins, Deep-Ocean basins, Oceanic Ridges
84
3 parts of Continental margins
continental shelf, continental slope, continental rise
85
What determines how rocks deform?
environment (temperature and pressure), composition, length of time stress is maintained
86
What is ductile deformation?
solid-state flow results in change in size/shape of rock without fracturing. This occurs in high-temp/ high-pressure environments
87
Describe folds
folds are flat-laying sedimentary and volcanic rock bent into a series of wavelike undulations... Anticlines - arching, Synclines - down folds. Most folds are result of compressional stresses
88
Dip-slip faults
when movement is primarily vertical... Normal and reverse faults.. Thrust faults are at low-angles. Normal faults indicate tensional stresses that pull crust apart
89
Strike-slip faults
horizontal displacement parallel to fault surface (small transform faults)
90
Isostasy
Earth's less dense crust floats on top of mantle like wooden blocks in water. The thicker, the high up it goes, but also the further down it goes...
91
Types of dates used to interpret Earth history
Relative dates and numerical dates
92
How are relative dates established?
law of superposition, original horizontality, cross-cutting relationships, inclusions
93
What are uniformities?
gaps in rock record
94
What special conditions favor preservation of fossils?
rapid burial and possession of hard parts such a s bones, shells, teeth
95
How to tell numerical age?
Half-lifes. If half-life of isotope is known and parent/ daughter ratio can be measured, age of sample can be calculate
96
Geologic time scale
Precambrian (until about 540 million years ago, Phanerozoi (visible life - includes Paleozoic "ancient," mesozoic "middle," and cenozoic "recent"
97
Precambrian period
88% of Earth's history - beginning with formation of Earth 4.5 billion years ago until 540 million years ago. Not very well understood
98
Paleozoic period
marked by first appearance of life forms with hard parts such as shells. started with life in the seas, but organisms diversified dramatically
99
Mesozoic period
the "Age of Reptiles" - started with much land above sea level, but that changed... drier climate - reptiles, dinosaurs - many large reptiles, including dinosaurs became extinct at end
100
Cenozoic period
the "Age of Mammals" - mammals replaced reptiles as dominant land life - Marsupials and Placentals. Could also be known as the "Age of Flowering Plants" - plants strongly influenced evolution of both birds and herbivorous mammals throughout the era.
