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How along did the solar system form?
4.5 billion years ago
According to the big bang, the universe was created about _________
14 billion years ago from a cosmic explosion that hurled matter and in all directions.
The models must fit 3 classes of constraints:
- (1) Motions: The observed spin and orbital motions of the planets, asteroids, and comets.
- (2) Compositions: The measured or inferred compositions of planets, asteroids (meteorites), and comets.
- (3) Ages: The measured ages of primitive meteorites.
Planets, asteroids, and most comets circle the Sun ______
The compositions of the planets vary with distance from the Sun:
- –The inner planets are dense and rocky/metal-rich.
- –The outer planets are primarily gas (H, He) and ices.
The solar nebula model
- 1. Previous generations of stars lived and died before our solar system was formed.
- 2. The solar system was born from an enormous cloud that collaspsed of hydrogen, helium, tiny amounts of heavier elements, and interstellar dust particles
- 3. mostt mass fell into the center and formed the sun and a smaller fraction formed the planets.
Inside a terrestrial planet
- -lower density
- -Continental: granitic
- -oceanic: basalt
- -medium density
- -iron-rich silicates
- - crust: iron and nickel
Composition of the earth and crust
- About 90% of Earth consists of only four elements:
- 1. iron,
- 2. oxygen,
- 3. silicon,
- 4. magnesium.
- -Iron makes up 35% of the Earth’s mass, but most sank to the core, little at the crust
- -lacked oceans
- -lacked atmosphere
- -heated up and was molten
- -target of many impacts
Multicelled creatures appear
1 billion years ago
Vertebrates appear about
500 million years ago
land plants appear about
human beings appear
2-4 milion years ago
modern human(homo sapiens) appear
What two properties uniquely define a particular mineral?
- 1. chemical composition
- 2. Crystal structure
What are two principal classes of sedimentary rocks?
- •4 Oxygen atoms held covalently to a single silicon atom.
- •The tetrahedra may then bond:
- –covalently with other tetrahedra (sharing Oxygens) or
- –ionically with other combinations.
- -the natural mineral form of lead(II) sulfide
- -It is the most important lead ore mineral.
- -contain significant amounts of silver
- - colorful mineral
- - found in hydrothermal veins
- - used as a flux in iron smelting
- -ceramic manufacturing
- -the most abundant group of minerals in the crust
- 1. Muscovite(white mica)
- 2. Biotite(black mica)
- used as drilling mud, in building materials, and as a soil modifier
- 1. Olivine – peridot (semiprecious gem)
- 2. Garnet – abrasives; semiprecious gems
- 3. Amphibole – industrial products
- - table salt
- - not a silicate
Types of rocks
- 1. igneous
- 2. sedimentary
- 3. Metamorphic
- -formed from hot, molten material
- -plutonic rocks: form if magma cools inside earth’s crust (does not flow onto surface); coarse crystals will grow
- -volcanic rocks: form if magma flows onto surface as lava; glass often forms
- Ex. Granite, Obsidian
- -produced by weathering of pre-existing rocks and minerals
- Ex. Limestone, Sandstone
- -layering caused by deformation
- 1. minerals form elongated/platy crystal
- 2. line up parallel to each other
- 3. examples:
- •Slate (low grade => lower temeprature and pressure
- •Schist (higher grade)
- •Gneiss “nice” (higher yet)
Some metamorphic rocks not foliated
- –Marble is metamorphosed limestone
- –Quartzite is metamorphosed quartz-rich sandstone
- 1. "Changed form" rock: formed from pre-existing rocks
- 2. Heat and pressure increase with depth and cause rock to change
- Ex. Slate, Schist, Gneiss
Evidence of Continental drift:
- 1. mid ocean ridge parallel to coastlines
- 2. precise locations of earthquakes and volcanoes
- 3. age of rocks on sea floor
- 4. pattern of glacial deposits on continents
How does the age of the oldestrocks compare with the age of the earth?
the earth is 1 billion older
Except at boundaries, ________occurs below th eplates in the mushy part of the mantle (“asthenosphere”).
Ocean ridges and magnetic stripes mark_______
places where plates spread apart
Deep trenches and volcanic arcs mark______
places where oneplate is pushed (subducted) under another.
- ex. san andreas fault
- - fault between offset segments of a spreading ridge
- -move horizontally in opposite directions
- Mid-ocean ridges do not form straight lines but are instead offset in many places by fracture zones
Divergent Plate boundaries
- – Lithospheric plates move apart; form oceanicridges
- – Upwelling of asthenosphere injects magmaforming oceanic ridges and new oceanic crust
- – New oceanic crust cools through Curie Pointand takes on present magnetic field direction
Convergent Plate Boundaries
- • Lithospheric plates move toward each other
- • Higher density oceanic crust overridden bylow density continental crust
- • Subduction zone forms and produces a trench
- •Subduction of older oceanic crust balancesthe spreading seafloor equation
- • Subduction zones are active geologic places
- oIsland arc formation
Conservative Plate Boundaries
- • Transform Boundaries
- – short segments ofa ridge
- – Transform faults offset ridge
- – Plates move parallel to boundary, so materialis neither accreted nor subducted
- – San Andreas Fault
- – transform fault undercontinental crust
How is the plate tectonic processrelated to environmental science?
- • Ocean circulation: open/closed passages
- • Air circulation: orographic affect, monsoon
- • Evolution: connection or separation ofspecies
- • Resources: petroleum and metalresources• Passive-active margins, deltas: ch 5
- • Data: info on past climates, evolution inocean sediments.
Coal: igneous, metamorphic, or sedimentary?
Why are the oceans salty?
The salt in our oceans is the result of millions of years of minerals leaching and dissolving from the solid earth
Occurs in regions where plates slide pasteach other horizontally. Example: SanFrancisco.
Occurs under tension, when two plates move away from each other. Generally results in weakest earthquakes. Example:Greece.
Occurs where two plates are pushed together. Generally results in strongest earthquakes. Example: Chile
Where would you expect liquefaction?
areas where the ground is very wet, near the coast
5-6 m offset caused by Nobi earthquake, m=8, in Honshu.Japan 1891. What kind of fault is it?
Types of seismic wave motion:
- 1. P-waves: involve compression, parallels the direction of propagation
- 2. S-waves: cause no change in volume
Factors that affect earthquake damage
- • Magnitude
- • Distance (including depth)
- • Soil type
- • Frequency of shaking and naturalfrequency of building
- • Focusing of seismic waves
Sediments act as “wave guide,” trappingwaves_____-
what adds to oceanic crust at spreading centers?
- 90% of Earth’s volcanism adds to oceanic crust at spreading centers
- -This occurs largely under the oceans
- Exception: Iceland
Volumes of volcanic eruptions
Toba and Mt St Helens
- Toba: 100km^3
- Mt St Helens: 1 km^3
Seafloor Spreading ridges
- Mostly under the oceans ‐ except at Iceland
- Generally, harmless fissure eruptions
Continental fissure eruptions
Pour out of cracks in lithosphere, often during continental break‐up“flood basalts”: India, Brazil, East Africa, Columbia Plateau (Washington)
Very large, flat, with abundant, far‐reaching flows; Hawaii (hotspot)Fluid magmas: basalt
- -Steep flanks
- -Short travel flows
- -More viscous magmas: intermediate to rhyolite
Volcano Types: dominantly effusive
- 1. Seafloor Spreading Ridges
- 2.Continental fissure eruptions
- 3. Shield volcanoes
- 4. Volcanic Domes
Few examples on-land: volcanoe
- - Erta Ale volcano
- - (East African Rift)
Shield volcanoes Example
- Example: Mauna Loa (Hawaii)
- -Tallest mountain on Earth
- -4 km above sea‐level,
- 9 km abovesea‐floor
- -Effusive basalt lava
- Example: 2005 “Whaleback” dome growing inside Mt St Helens craterExtremely viscous lava
- Over‐steepened flanks: can collapse and cause rockfalls andpyroclastic flows
Volcano types: Explosive
- 1. Cinder Cones
- 2. Composite "Stratovolcanoes"
- 3. Calderas
Cinder Cones: moderately explosive
- -Pyroclastics: ash, cinders, bombs, blocks
- -Size of pyroclastics range from ash (very fine), cinders, bombs, or blocks(very coarse)
- -cone shaped volcano; e.g. Pisgah crater near Barstow (California)
- -Mix of lavas and pyroclastics: tall volcano
- -Usually associated with subduction zones
- -Explosive: Mount St. Helens, Cascade Range
- -Collapse structures after explosive venting of magma
- -Wide range in size (km to 10’s of km)
- -Largest single eruptions on Earth
- -Long Valley (California), Yellowstone, Toba
What is the most common volcano type on earth's surface?
what type of magma cinder cones have?
- Explosive basaltic magma
- -Ballistic ejection of ash, lapilli, bombs and blocks (“fire fountaining”)
Where do stratovolcanoes occur?
Occur as volcanic chains in subduction zones
How do Calderas form?
-Form by collapse during explosive venting of magmaaccumulations
- – low in SiO2 (~50 %) but highin iron, and magnesium
- (andesite, dacite)
- –intermediate range of SiO2 (50‐65 %), iron, andmagnesium
- – high in SiO2 (up to 76 %)but low in iron, and magnesium
what will affect explosive characteristics of eruptions?
Amount of volatile gases (H2O, CO2) will affect explosive characteristics of eruptions
High SiO2 content means
Volcano: More water means
Magmas at divergent margins
- - Typically melted asthenosphere material
- - Low SiO2 and dry: less explosive
- - Asthenosphere is rich in ferromagnesian (ultramafic)
Magmas at convergent margins
- -The composition p of the subducted plate +overriding plate determines the composition of the lava
- - magma rises through lithosphere
- -explosive eruptions common
- - in contact with continental crust
How do hot spots produce magmas
by melting of asthenosphere(no water involved)
Hot‐spots underneath oceanic crust (mafic)produce mostly
- basaltic magma
- ex: hawaii
Hot‐spots underneath continental crust (felsic)generally will produce a
- rhyolitic lava (and often anexplosive one)
- Example: Yellowstone
- volcanic muddflows
- -ash and water
extremely fast and long range smoke
1815 Tambora eruption
Classification by activity
- Active: erupted in recent geologic history (<10,000 years)
- Dormant: no recent eruptions but not badly eroded
- Extinct: no recent eruptions and badly eroded
Assuming the same magma composition and heightof volcano summit, which eruption will cause morecooling?
A volcano at low (tropical) latitude?
A volcano at high (polar) latitude?
a volcano at low tropical latitude
Fast water carries
all water at or near the surface of the earth
a flowing water within a channel
a region from whic a stream draws water
the volume of water flowing past a given point/cross section in a specified length of time
the total quantity of material that a streamtransports by all methods (traction, saltation,suspended, and dissolved)
a measure of the total load of material astream can move
the steepness of the stream channel
the lowest elevation to which the stream can erode
a sketch of a stream’s elevationfrom source to mouth
Stream velocity impacts sediment sorting
- – Slow moving water only carries fine-grained sediments
- – Swift moving water carries a wider range of grain sizes
- a large, fan-shaped pile of sediment instill waters created by a stream
- Ex. mississippi
- a fan-shaped pile of sediment in alarger stream or a region between mountainsand a plain formed by a small tributary stream
- Ex. albuquerque, NM
- The evelation of water
- -stream exceeds the bank height
occurs in a small, localized,upper part of a basin
occurs in a larger, lowerpart of a drainage basin
- type of upstream flood
- -characterized by a rapid rise of stream stage
- - a plot of stream discharge at a point over time
- – Records fluctuations in discharge or streamheight over time
- – Useful tool to monitor stream behaviorremotely
similar to strategies applicable to reducing damage from seismic andother geologic hazards
trap some of the surface water runoff
comes into play as stream stage rises, and redirects some of the water flowinto other safe places
various modifications of the stream channel itself to increase the velocity of water flow, the volume of the channel, or both
raised banks along a stream channel
1971 Bohla Cyclone
- • 115 mph winds (Category 3)
- • Landfall at high tide
- • Up to 500,000 deaths
- • Led to violent opposition to government
- – Creation of Bangla Desh
- – George Harrison’s Concert for Bangla Desh
Coastal control that has worked
Polders (reclaimed land) in Zuider Zee, Netherlands. worked for 80 years
the level to which the water would rise if uncontained
- -Freezing water expansion
- – Break up of rocks and minerals without changing therock’s composition
- – Salt crystallization can wedge cracks
- – Blasting by humans
- – Dissolution of carbonates and some silicates
- – Accelerated by sulfuric, carbonic, and other acids
- – Biological activity: roots, burrowers
Dark soils tend
to be rich in organic matter
Light soils tend
to lack organic matter
iron rich soil formed from Hawaiian basalt
- - forms in tropical climates
- - Forests in tropical areas hold the nutrients,not the soil
- -extreme version of pedalfer
- -contains few soluble nutrients
- -difficult to farm or
- -rich in accumulated organic matter
- -privode vital habitats for birds and other organism
- -retain flood waters easily
- -serve as pollution traps
Earth materials essential to well being: kg/person year
– construction, metals: 10,000 kg/person year
rock in which a valuable or useful metal occurs to be economic to mine
chimney formed of precipitated solids onmid ocean ridge.
How much CO2 is emitted per person day in the US?
– 57 kg/person day
What is the average US consumption of petroleum, ingallons/person day?
– 3 gallons/person day
What is the ratio of total global resources to consumptionrate, in years?
- About 30 – 40 years
- are sedimentary rockscontaining a very thick, semi-solid, tarlikepetroleum.
- - Tar sand deposits mayrepresent very immature petroleumdeposits.
Ozone levels are typically highest in
the summer months
Photovoltaic solar cells convert solar energy
directly into electric energy
an outstanding example of the scientific method
What happened at the end of the last ice age?
- -Sea level rose about 120 m
Blob of hot material
Kimberlite: Igneous Rocks and Magmatic deposits
volcanic, named after Kimberly, a miner
Where is the black smoker found? and where is it active?
- - chimney found of precipitated on mid ocean ridge
- -active on spreading centers
age of the earth
4.5 billion years
age of oxygen atmosphere
2-3 billion years
age of last glacial max
age of end of last ice age
average age of fossil fuels
300 million years
US rate of petroleum consumption/person
US rate of rock andminerals, per person
C02 per person/day
The tendency of a mineral to break preferentially along planes in certain directions in the crystal structure
Parallel alignment of linear or platy minerals in a rock
an igneous rock crystallized well below the earth's surface; typically coarse-grained
- - partialy molten
- -weak zone within the upper mantle immediatedly below the lithosphere
seismic waves that pass through the earth's interior, include P waves and S waves
a volcanic rock rich in ferromagnesian minerals; low in silica
the hot fragments of rock emitted during an explosive volcanic eruption
a composite volcanoe cone built of interlayed lava flows and pyroclastic materials
a wedge-shaped sediment deposit left where a tributary flows into a more slowly flowing stream, or where a mountain stream flows into a desert
a fan-shaped deposit of sediment formed at a stream's mouth
the steepness of a stream channel along its length
a flat region surrounding a stream channel
a graph of stream stage or discharge against time
the total quantity of material transported by a stream
the curves or bends in a stream
old meanders now cut off or abandoned by a stream
a sedimentary feature built in a stream channel, on the inside of a meander or anywhere the water slows
steep stream bank being eroded by lateral migration of meanders
the average length of time between floods of a given size along a particular stream
a continental margin at which there is significant volcanic and earthquake activity, commonly a convergent plate margin
a body of water along a coastline that contains a mix of fresh and salt water
steplike surface cut in rock by wave action at sea or lake level
the deflection of waves as they approach shore
the loss of glacier ice by melting or evaporation
erosion by wind-transported sediment or by the scaping of rock fragments fozen in glacial ice
wind-deposited sediment composed of fine particles
landform made of till
parallel grooves in a rock surface cut when a glacier containing rock debris flows over that rock
rock of low permeability, through which water flows very slowly
cone of depression
a broadly conical depression of the water table or potentiometric surface caused by pumped groundwater withdrawal
potential energy of water above a given point
- terrain characterized by abundant formation of underground solution cavities and sinkholes;
- -commonly underlain by limestone
proportion of void space in rock, sediment, or soil
- -top zone in soil
- -mix of mineral and organic material
- -Soil layer found below the soil's A and E horizon
- -AKA zone of accumulation
- soil layer found directly below the soil's B horizon; -consists of coarsely broken bedrock
- an extreme variety of pedalfer soil that is highly leached;
- -common in tropical climates
the removal of elements or compounds by dissolution
banded iron formation
- a sedimentary rock consisting of alternating iron-rich and iron-poor bands,
- -found in precambrian rocks
a sedimentary mineral deposit formed when shallow or inland seas dry up
where are manganese nodules found?
on the sea floor
a very coarsely crystalline igneous rock
the ores concentrated by stream or wave action on the basis of mineral densities and/or resistance to weathering
piles of waste rock and soil left behind by surface mining, especially strip mining
the piles of crushed waste rock created as a by-product of mineral processing
deep aquifers under usually high pressure, exceeding normal hydrostatic pressure
The two most common elements in the earth's crust?
silicon and oxygen
the best known silicate
the most common volcanic rock
line of volcanic islands
Rank the importance of the following ways earthquakes cause damage: fault, displacement, fires, shaking, landslides.
- 1. Fault/ ground rupture
- 2. shaking
- 3. Landslides
- 4. Fire
How many magnitude 5 earthquakesoccur per year in California?
Which of the following was the largestknown volcanic eruption?
– Mt. Mazama, Oregon
– Mt. St. Helens, Washington
– Krakatoa, Indonesia
Volcancoes built up of layers of more than one kind of material
stratovolcanoes or composite volcanoes
- Graphs of stream stage or flow over time
- -Hydrographs show fluctuating water levels over differing time scales
What is a “hundred year flood”?
- the level of flood water expected to be equaled or exceeded every 100 years on average
- -it means that there is a one in one-hundred (or 1%) chance of such a flood occurring in a given year.
landform that is formed at the mouth of a river where that river flows into an ocean, sea, estuary, lake, reservoir, flat arid area, or another river
What happened 10,000 years ago?
when the last ice age ended
the rate of sea level rise overthe last 10,000 years
Where does beach sand come from?
- the sand on our beaches comes from the erosion of the land/rocks.
- -beaches rely on sand transported from the mountains by the rivers and from eroding cliffs near the shoreline.
Name some evaporite deposits
- 1. Halite - rock salt
- 2. Gypsum Calcium Sulfate
Name some magmatic ore deposits
- 1.Chromite Deposits,
- 2.Nickel-Copper Deposits
What fraction of earth’s total petroleumresources have been used already?