Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
94 Cards in this Set
- Front
- Back
Molton rock ON surface
|
Lava
|
|
Molton rock BELOW surface
|
Magma
|
|
4 Heat sources for melting rock
|
Temperature increase with depth, frictional heat from plates moving, decay of radioactive minerals, mantle plumes
|
|
Does increasing pressure cause melting temperature to increase or decrease?
|
Increase
|
|
What does water make the melting temperature do?
|
Decrease
|
|
What is the primary constituent of magma?
|
Silica
|
|
Felsic Magma
|
high in silica, thick and pasty, doesnt flow and is very explosive
|
|
Where does Felsic magma form?
|
Convergent PB
|
|
Mafic Magma
|
silica poor, high in Fe/Mg and flows easily
|
|
Where does Mafic Magma form?
|
subduction zones
|
|
What controls magma/ viscosity?
|
silica content and temperature
|
|
Intermediate magma forms where?
|
convergent pb and subduction zones
|
|
Where are ferromagnesian silicates located?
|
the discontinuous side
|
|
Where are plagioclase silicates located?
|
the continuous side
|
|
Which side does one mineral change to another at a specific temperature?
|
discontinuous side
|
|
Which side does basic feldspar crystal remain the same?
|
continuous side
|
|
Crystal Settling
|
FeMg minerals fall to the bottom of the magma chamber
|
|
Assimilation
|
melting the country rock
|
|
Enchanted Rock
|
Batholith
|
|
intrudes parallel to sedimentary rock layers
|
sill
|
|
cuts across sedimentary rock layers
|
dike
|
|
Devil's Tower and Shiprock
|
volcanic neck
|
|
intrudes in a mushroom-like shape between sedimentary layers
|
laccolith
|
|
What determins magmas ability to erupt?
|
viscosity and gas content
|
|
Which type of magma rises and erupts at the surface?
|
Mafic magma
|
|
Whcih type of magma cools underground to form plutonic rocks?
|
Felsic magma
|
|
Most abundant gas relased and blows magma apart
|
water vapor
|
|
first gas to fizz out of magma
|
carbon dioxide
|
|
Pahoehoe
|
lava flow with a ropy surface
|
|
Aa
|
lava flows as rough, jagged blocks
|
|
Columnar joining
|
laval flow cools and shrinks forming hexagonal columns
|
|
Nuee Ardente
|
pyroclastic flow that rushed down slope at hurricane speeds in an incandescent flowing cloud
|
|
Where is a Nuee Ardente common?
|
Composite Cones
|
|
Lahar
|
mudflow that is the deadliest hazard
|
|
Shield Volcano
|
low, rounded profile and mafic lava erupts quietly
|
|
cinder cones
|
formed by pyroclastics falling around the vent
|
|
Composite Volcanoes/Stratovolcanos
|
MOST COMMON, both pyroclastic and laval flows, forms at convergent pb and subduction zones
|
|
Crater
|
bowl shaped pit centered over the vent at the top of a volcano
|
|
Lava domes
|
formed by silica lava that is to thick to flow and extrudes out over the vent
|
|
Caldera
|
depression formed by the collapse of "cone" into the empty magma chamber below
|
|
What does the most catastrophic event on earth form?
|
A caldera
|
|
Resurgent Caldera
|
formed by renewed surges of magmat into a caldera
|
|
3 examples of a resurgent caldera
|
yellowstone
long valley, CA Valle Grande, NM |
|
Fissure Eruptions
|
type of eruption that flows out of a long crack
|
|
Example of a fissure eruption
|
Columbia River Plateau
|
|
Last Gas to fizz out of magma
|
water vapor
|
|
Welded tuff
|
Name of the ash flow deposits that erupted from fissures during caldera formation
|
|
4 ways to predict an eruption
|
Plate tectonic locations, harmonic tremor, physical and chemical changes, eruptive history
|
|
Circum-Pacific Belt
|
ring of fire
where most the the volcanoes in the world are located |
|
Weathering
|
involves the physical breakdown and alteration at/near the surface
|
|
Erosion
|
involves transportation by wind, water, glaciers, etc.
|
|
Differential weathering
|
non homogenous rocks weather into bizarre sandstone forms
|
|
Mecahnical weathering
|
rocks decomposed by alteration of parent rock (rock change)
|
|
Name mechanical weathering processes
|
1) frost action
2)preserve release 3) thermal expansion and contraction 4) root wedging 5) activities of organisms |
|
Exfoliation domes
|
formed when batholiths undergo pressure relase
(large rounded areas) |
|
Dissolution
|
a part of chemical weathering where water removes ions from rocks and carries them in solution
|
|
Carbonic acid
|
formed by water and carbon dioxide
|
|
Oxidation
|
when Fe and Mg silicates are chemically altered. FeMg silicates combine with oxygen to form an acid.
If water is present - Limonite |
|
Hydrolysis
|
Weathers potassium feldspar. The end result is 1) clay
2)silica 3) potassium in solution |
|
Bowen's Reaction series least and most stable
|
Least- Olivine
Most - Quartz |
|
Spheroidal weathering
|
edges and corners of angular rocks weather into rounded boulders
|
|
Soil regions
|
climate is the most important factor of formation
|
|
Major Soil Types
|
1) pedalfers - Fe and Al oxides present, good agricultural soil
2) Pedocals - arid, evaporating waters enrich in CaCO3 3) Laterites - tropical, only deep red A horizon, slash & burn |
|
Lithification
|
Changes sediment into rock by two processes
1) compaction - weight of overlying rock 2) Cementation - minerals precipitated in pore spaces binding particles together |
|
Most common clastic rock
|
Quartz sandstone
|
|
Most common chemical rock
|
Limestone & dolostone
|
|
Transression
|
Sea level rising
Sequence: limestone-shale-sandstone |
|
Regression
|
sea level falling
Sequence: sandstone-shale-limestone |
|
When are sedimentary structures formed?
|
at the time of deposition
|
|
What do sand dunes in deserts show?
|
Cross bedding
|
|
Symmetrical ripple marks
|
waves going back and forth
Know the picture |
|
asymmetrical ripple marks
|
currents in one direction
know the picture |
|
Mudcracks
|
formed by drying out and shrinkage of clay
|
|
Where are fossils found?
|
Sedimentary Rocks
|
|
What is coal composed mainly of?
|
Carbon
|
|
Steps in forming coal
|
1) swams rich in plant life
2) plants accumulate slowly and form peat 3) decompose in an oxygen poor environment 4) undergo heat and pressure |
|
What is hydrocarbon composed of?
|
Hydrogen and Oxygen
|
|
List steps for hydro carbon formation
|
Accumulation of algae and microorganisms in shallow seas
burried quickly by silt/mud oxygen deficient envoronment so doesn't rot heat and pressure forms |
|
Vesuvius, Italy
|
79 AD
Destroyed Pompeii and Herculaneum Subduction of African plate under European plate |
|
Krakotoa, Indonesia
|
loudest noise recorded in history
Tsunami killed 36,000 Located in Circum-Pacific Belt |
|
Tambora, Indonesia
|
Larges and deadliest eruption
"year without a summer" Gloomy weather set mood for frankenstein Located in Circum-Pacific Belt |
|
Paricutin, Mexico
|
Cornfield volcano
studied birth to death cindercone Subduction of Cocos plate under N. American plate |
|
Mount Pelee, Martinque
|
St. Pierre - town wherenuee ardente killed 28,000 villagers
Killed voters Subduction of N. American plate under caribbean plate |
|
Heimaey, Iceland
|
Control lava flow - saved town & port
Divergent plate motion along Mid-Atlantic ridge |
|
Lake Nyos, Cameroon, Africa
|
cloud of carbon dioxide killed villagers and cattle
|
|
Cascades
|
active and sit above subduction zone
-Erupt andesite -Subduction of Juan de Fuca plate under N. American plate |
|
Mt. Rainer, Washington
|
Most dangeroud volcano in U.S.
-Lahars will reach populated areas of Pugent Sound |
|
Mt. St. Helens
|
erupted in 1980
millions of trees blown down spirit lake changes Hazards- Nuee Ardente, ash, lahar, and avalanche |
|
Mt. Shasta, Cal.
|
Largest volcanoe
|
|
Crater Lake, Oregon
|
Mt. Mazama - volcano that erupted
Formed a caldera |
|
Valle Grande, NM
|
Resurgent caldera
Resurgent caldera on w. side of Rio Grande rift Anasazi carved homes Bandelier tuff |
|
Long Valley, Cal.
|
Resurgent caldera
Most likely to have major eruption and most active volcanic area Warning signs - dome swelling, fumaroles and hot springs, earthquakes, carbon dioxide kills trees |
|
Yellowstone, Wyo.
|
resrugent caldera
Sits above a hotspot erupted 3 times Warning signs - mud pots, geysers, carbon dioxide kills forest and animals uplift/subsidence of ground, earthqueakes |
|
Alaska
|
2nd most active area in the world
Subduction of Pacific plate under NA plate |