Final Flashcards
(164 cards)
1
Q
relative dating
A
sequence of geologic events in a region
2
Q
Law of superposition
A
older layer is on bottom; Works best for sedimentary rocks
3
Q
Principle of original horizontality
A
sediments are originally deposited as horizontal beds; Use for tilted/bent layers
4
Q
What causes rocks to bend?
A
plate collisions or temperature
5
Q
Folding happens after…
A
rocks were deposited
6
Q
Law of cross cutting
A
An igneous intrusion/fault is younger than the rock layers that it cuts across
7
Q
Law of inclusions
A
The inclusion is older than the rock it is in
8
Q
Angular unconformities
A
folding
9
Q
nonconformity
A
younger sedimentary rock on top of older igneous rocks
10
Q
disconformity
A
missing sedimentary rock layers
11
Q
How MI basin formed?
A
Deposited as Sea dried up; Forms circular patterns; oldest rocks on edges of basin
12
Q
Relative dating
A
a sequence of geologic events
13
Q
Absolute
A
the exact age of a rock
14
Q
Radiometric dating
A
divide parent isotope by 2 until reach amount left; count # times you divided by 2
15
Q
Divergent
A
moving apart; Mid-ocean ridge; Tensional stress
16
Q
Example of Divergent boundary
A
Mid-ocean ridge; East African Rift
17
Q
Convergent
A
Moving together; Compressional Stress; Trenches
18
Q
ocean-ocean convergence
A
Formes deepest trenches; Volcanoes form on ocean floor off continental coast; Island Archs + earthquakes; Andesite
19
Q
Ocean-Ocean example
A
Japan; Caribbean Islands
20
Q
Ocean-Continental Convergence
A
Trenches (not as deep); ocean subducts b/c more dense; Composite volcanoes; Pumice + rhyolite
21
Q
Examples of Ocean-COntinental
A
Mt. St. Helens; Rings of Fire
22
Q
Transform
A
Plates sliding past each other; Shearing stress; Shallow earthquakes
23
Q
Example of transform
A
San Andreas Fault
24
Q
How do plates move?
A
Convection currents + slab/pull
25
Convection currents
Hot magma rises and cold magama sinks creating a current
26
Slab pull
Plates pull themselves down at subductive zones due to gravity
27
How did Wegner change science of geology?
Continental Drift theory
28
How do magnetic reversals support plate tectonics?
Zebra stripes on ocean floor had to form together
29
Formation of Himalayas
Convergence of Australian-Indian plate w/ Eurasian palte
30
San Andreas Fault
Transform fault between North American and Pacific Plate
31
Andes mountains
Convergent of nazca and South American plates
32
Mt. St Helens
Convergent of Juan De Fuca and North American plates
33
Mid Atlantic Ridge
Divergent of North American and Eurasian plates
34
Red Sea
Divergent of Arabia and African plates
35
Mariana Trench
Ocean-Ocean Convergence of Pacific and Phillipine Plates
36
Iceland
Ocean Divergent of North American and Eurasian Plates
37
How a spit formed...
Ridges of sand tht extends into mouth of an adjacent bay; Created by longshore currents + beach drift; Depositional
38
How tombolo formed...
Ridge of sand that conects an island to the mainland; Created by longshore currents; Depositional
39
How baymouth bar formed...
Sandbar that corsses a bay; Sections off bay from open ocean; Depositional
40
Sea arch
when sides of headlands are attacks by wave refraction; Erosional
41
Wave cut platfrom
Created from cutting action of surf against rock of coastal land, gradually over hanging rocks erosed; Erosional
42
Emergent coast
Developed due to an area experiences uplift or result of drop in sea level
43
Submergent shorline
created when sea level rises or land adjacent to land subsides underwater
44
Longshore current
Pushes the sand
45
Ocean sand
Well rounded, well sorted, and usually mainly quartz
46
Desert sand
angular
47
Great Lakes sand
Variety of minerals because glaciers
48
Problems with groins
current erodes sand from beach on leeward side of groin
49
Problem with seawalls
seaward side of beach experience significant erosion; Eventually wall falls due to reduced width of beach and increased pounding of water
50
pacific Coastlines
rocksy, tectonically active, beach sand supply from rivers
51
Atlantic coastlines
subject to hurricans, has barrier islands
52
Barrier islands
sand deposits
53
How Morains formed
depsoited along edge of glacier dueing melting
54
sediment of morians
till
55
Esker
Curving ridges of stratified drift; deposited by melt water streams;
56
Sediment of esker
outwash
57
Kame formation
depsoited at end of meltwater streams (delta); Mined for gravel
58
Kame sediment
outwash
59
Kettle lake formation
made from ice blocks
60
Kettle lake sediment
till
61
Outwash plain formation
lake meltwater; Formed next to moraines
62
Drumlin formation
Hills of sediment deposited by glacier
63
Drumlin sediment
till
64
How glaciers formed Great Lakes
1. each of Great Lakes started as rivers; 2. glaciers carved v-shaped valleys into u-shaped valleys as climate cooled; 3. As climate warmed; glaviers began to melt and retreat; 4. freshwayer from melting glaciers filled in u-shaped valleys
65
Oldest GL
Erie
66
Youngest GL
Supieriour
67
3 pieves of evidence to support glaciers in MI
1. MI covered in till; 2. Morain deposits follow outline of GL; 3. Erratics; 4. Striations/grooves
68
Plesiocene glaciers (When/Where)
2 mya; As far as Ohio/Illinois
69
Till
unsorted, deposited by ice
70
Outwash
meltwater
71
Cirques
bowl shaped depression located where glacier begins to form
72
Fjord
long, deep narrow salt water valley; Glaciers carved u-shaped valley
73
Horn
a pointedrock peak left at top of mtn
74
Arete
spins/ridges of rock that seperate glacial valleys
75
Isostatic rebound
land uplifts, once the weight of glacier is taken off to original elevation
76
Eccentricity
Variations in shape of Erath's orbit about the Sun
77
Obliquity
Changes in the angle that the axis makes with the plane of Earth's orbit
78
Precession
The wobbling of Earth's axis
79
Bedload
along bottom; Most erosive
80
Suspension load
silt/clay; Make water cloudy; Gives water color
81
Dissolved load
dissolved minerals/pollutants in solution; Creates foam
82
Early stream
Deep; high gradient (steep); High downcutting (v-shaped valley); High velocity (rapids, waterfalls); Narrow; Lots of eroision; Low deposition; Low sidecutting
83
Late stream
Shallow; Low gradient (flat); Low downcutting (flat); Low velocity; Wide; Differential erosion (low); lots of deposition (large deltas); High sidecutting
84
Flood plains
Sand/gravels originally as Point Bar by meanders, shifting laterally across valley floor
85
levees
Successive flooding over years; Increase in elevation
86
deltas
Due to drop in velocity as stream enters still water
87
oxbow lakes
due to buildup. plugs with silt and clay
88
point bars
deposited that occurs inside "point" of the bend as water travels around bend
89
Undercut slope
Cut bank; water hitting the meander, loosens the material, which travels downstream which is then deposited on point bar
90
Yazoo streams
due to flooding on floodpain and runs parallel to river
91
V shaped valleys
forms by downcutting
92
Stream Gradient
Rise/ Run
93
Rule of V's
opposite direction of v's is direction of stream flow
94
Base Level
The lowest point a stream can erode its channel to; The way it flows
95
Flowing Artesian Well
Water must be confined between impermeable layers; Must be below recharge zone/ water table
96
Nonflowing water table
located where the pressure surface is below ground level
97
Zone of aeration
above water table
98
Zone of saturation
below water table
99
Best place to bury toxic waste
Sand
100
Hardwater
Ca + Mg ions from Limestone; Leaves sa white film, scale in hot water; no suds
101
Calculate permeability
ML/SEC
102
Low permeablity rock
Clay
103
High permeability rock
Gravel
104
How a septic tank works
Bacteria and filters allow for liquid to move through but not effluent, and solids settle out; Sand filters out solid in effluent; Clean water returns to water table
105
Caves
Dissolution of Limestone; Lowering of water table
106
Sinkholes
bedrock erodes which causes overburden to fall and then soil faills as well
107
Subsidence
Slow sinking of ground due to groundwater withdrawl
108
karst topography
acid water dissolves Limeston; Series of Sinkholes
109
lead
Sources from pipes; causes brain damage
110
Aresenic
Source: naturally in shale/SS and pesticieds; Problems: aresenocosis and cancer
111
Flint water crisis
Found high levels of lead, iron, and bacteria in drinking water when switched To Flint River water and didn't add phosphate
112
Contour interval
Change in Elevation b/w index contours / # of space between
113
Land Survey Method
Smallest to largest; SE 1/4, NE 1/4, Sec 14, Township (T) 25, R3W
114
Latiude
North and South
115
Longitude
East and West
116
'
Minutes
117
"
Seconds
118
Depressions
Circles with tick marks around them
119
Hills
Circle within circle
120
Flat lands
Flatter = farther apart the lines
121
Elevation of hills and pits
Give range
122
Large intervals
Steep
123
Fractional Scale
1 Inch to ... Miles
124
RF scale
1inch to 62,500 inches
125
Verbal Scale
1 inch : 45 miles
126
Normal fault
tensional stress; Divergent boundaries
127
Reverse fault
Compressional stress; Convergent boundaries; Usually highest magnitue earthquake; Tsunamis
128
Strike slip
Shearing stress; transform boundary
129
Calculating Richter magnitude from seismograph readings
Find difference from S/P wave -- divide S wave from P wave; Find distance on graph, plot distance and amplitude found in first graph
130
Amplitude
highest wave
131
Determine location of epicenter
1. determine lage time b/w P and S waves; 2. go to graph to find distance b/w epicenter and seismograph; 3. plot circles with distance radius; 4. intersect of circles = epicenter (triangualte)
132
What do the circles represent?
The distance the seismograph and the epicenter
133
Mercalli scale
Measures intensity; Depends on population and building type
134
Primary Waves
Compressional; Travels through liquids and solids; Travels through outer core and mantle; fastest
135
Secondary Wave
up/down motion; Ground moves up and down; Travels through solids; Travels through mantle
136
Raleigh wave
Rolling motion (like water); Very damaging; Slowest
137
Love waves
Horizontal shifting of surface; Very damaging; Slowest
138
Intraplate earthquake
Thought to be from ancient falts or the astehnosphere causing vertical movements
139
Mantle
Solid that flows; P+S waves
140
Outer core
Liquid; P waves
141
Inncer core
Solid; P waves
142
Moment magnitude scale
For bigger earthquakes; x32
143
Epicenter
Directly above focus (Earthquake source)
144
Formation of tsunami
Displacemnt of water due to power and enegy gained from subduction
145
Evidence supporting contiental drift...
1. shapes of continents fit together; 2. Identical fossils seperated by oceans; 3. Same rock layers match actoss continents; 4. Glacial evidence in today's tropical climates
146
Why continental drift theory was not widely excepted?
Wegner didn't know what moved the plates; couldn't descire how continets plow through oceans b/c no ocean data
147
Slab pull
plates pull themselves down at subduction zones due to gravity
148
How are continetal shelves related to plate tectonics?
Not related at all
149
Post wegner Evidence
ocean floor is not flat; zebra stripes; ocean crust is young compared to continets; Pattern of earthquakes
150
What is a plate?
Lithosphere and upper asthenosphere
151
Moho
the boudary b/w crust and mantle
152
Older rocks at...
Edge of MI basin
153
Amplitdue
10x
154
Magnitude
32x; Energy released
155
Prediction of earthquake
loaction can be predicted by when it will occur is not easily determined
156
A tsunami is created from
an underwater reverse falt
157
San Andreas fault type...
strike-slip
158
Most of what we know about Earth's interior
comes from seismic waves
159
Location closest to epicenter
has largest waves
160
Watertable is highest in...
Spring
161
Trench plate boundary
Ocean-Ocean
162
Composite plate boundary
Ocean- Continetal
163
Divergent volcano
Fissure
164
Hotspot volcano
shield
