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UM / Science / MGS 103 / What is a volcano?

What is a volcano?

What is a volcano?

Description

• What is a volcano?


What is a volcano?



o Vent in the earth’s crust through which magma, gases, and ash erupt.

o There are 1300 active volcanoes today and over 1 million extinct  

• Where do volcanoes occur?

o At plate edges and hot spots  

• What comes out of a volcano?

o Lava, rock and gasses  

• Silicate and magma viscosity

o Magma is composed of silicate and metals but it also contains about .3% dissolved  gasses which are mostly water and carbon dioxide

▪ The viscosity is higher when there is more silicate, so in general basalt magmas  and volcanoes will be different from andesitic and rhyolotic magmas and  Don't forget about the age old question of psyc4050

volcanoes  


Where do non-explosive volcanoes occur?



▪ The lower the viscosity and when its basaltic magma it means they are non  explosive volcanoes, like Hawaiian volcanoes

▪ Andesitic and rhyolite do expode because they have higher visocity, they are  found in North America, they occur where subduction is occurring, formed over  continental hotspots  

• Pyroclasts and tephra

o Volcanoes eject these stuff, and glassy ash- malten rock that has been cooled down fast  enough

o Tephra: tiny mineral particles that volcanoes eject  

• Volcanic carbon dioxide and climate

o Gas comes out of volcanoes: and when you combine Carbon dioxide with rain water it  makes it very acid which creates chemical weathering, the carbon dioxide controls the  climate because with more carbon dioxide there is hotter climate  


What are the causes of earthquakes?



o Volcanoes and chemical weathering are the main controls of earth’s long term climate  and temperature is controlled by volcanoes  Don't forget about the age old question of dna replication exam

• Volcanic sulfur dioxide and climate

o Volcanoes emit large amounts of sulfur dioxide, which forms aerosols that can cause  short term changes in climate  

o These aersols are fine liquid particles that don’t get washed out of atmosphere easily  and make the earth’s climate cooler  

• Basalt and non-explosive eruptions

o Low viscocity and basalt create non explosive volcanoes called Hawaiian eruptions and  are found in Hawaii,  

o It’s a thin liquid with a lot of gas in it and if pressure is dropped then gas fizzes out but  the volcano pours down it doesn’t explode it goes inside volcano  

• Aa, pahoehoe, pillow basalts, vesicular basalt, lava tubes

o AA:  

▪ crumply stuff at top of volcano:

▪ very hot magma that as you heat something up it gets thinner and thinner and  its flowing pretty quickly it freezes quickly and drops down, however its very  spikey and rough and so you cant walk on it  

o Pahoehoe:  If you want to learn more check out laws2301 class notes

▪ Bottom smoother texture rock of the picture, its liquid that is flowing slow and  its like AA but it flows slower so you get more muddy rock that easier to walk on  ▪ Same rock but cools at different rates  

o Pillow basalts:  

▪ mid ocean ridges, basalt coming up to bottom of sea

▪ underwater you don’t get a flat rock but rather a bolbus kind of pillowy texture,  rounded blobs, you can make this only underwater  

o vesicular basalt  

▪ basalt that is cooled down, and there is gas trapped in it, so you get bubbles in  it  

▪ basalt with gas bubbles in it

o lava tubes

▪ basalt can form lava tubes, the top part of lava freezes and theres an inside area  that doesn’t cool so fast, so the outside part of liquid is frozen and inside I svery  hot fast lava flowing along lava cave  

• Where do non-explosive volcanoes occur?

o At oceanic hot spots, pacific ocean, Hawaii,  

• Andesite, rhyolite, and explosive volcanoes

Where do explosive volcanoes occur?

o Sticky magma has gasses inside but instead of fizzing out they get stuck because much  thicker pressure will keep building up and then they explode  Don't forget about the age old question of kristen miller uga

o High in silicate and high viscosity

o North American plate, also where subduction occurs, continental hotspots  • The Andesite Line

o Oceanic plate going down so ocean gets way deeper  

• Pumice

o Comes out of andesitic and rhyolite volcanoes, a lot of bubbles, very sticky, harder for  gas to get out, a much more coarse rock that floats  

• Three main types of volcanoes and how they form: cinder cone, shield, composite/stratovolcano o Cinder Cones: basalt lava flow spills out from base of cinder cone, and there is a cinder  cone eruptive vent  

▪ They are small, and they are none explosive Hawaii volcanoes,  Don't forget about the age old question of stats notes

▪ The lava fizzes up and magma is up in the air, it cools down quickly with gassy  dusty stuff that piles up and becomes spikey lose pile of bits of rocks, they  

erode and break down quickly, lots of holes and very coarse  

o Shield volcanoes

▪ It’s a sloping dome that’s built of thousands of high fluid, it has low viscocity,  and basaltic lava flows, such as the Hawaiian islands  

▪ Basalt piles up but not steeply, it’s a very wide volcano with shallow grains, and  it keeps pumping basalt for a long time that the pile gets very big, they are the  largest single volcanos

▪ Mauna Loa: volcano size of Miami dade county  

▪ Tamu: largest volcano on earth, extinct now  

o Stratovolcano

▪ Composite volcano, mountain size, they are explosive andesitic and rhyolite  volcanoes, they are found on edges of pacific  

▪ Figi in japan

▪ It explodes through pyroclastic stuff and makes piles of stuff, then the magma  starts flowing out but very thick and sticky so its not fast or far rather just down  the side of the volcanoes so it recollects and puts together stuff again and  We also discuss several other topics like hgmgm

another explosion occurs  

• Calderas

o All volcanoes have these, gigantic mountain size piece of rock underneath the blob of  magma, the magma goes on top of the mountain when the volcano erupts, and there is  not a lot of magma underneath so the mountain drops forming a caldera, a huge hole in  ground

• Large Igneous Provinces

o Bunch of volcanoes stuck all together: india, mile thick slap of basalt that’s huge and  covers most of India

• Volcanic hazards: lava, lateral blast, pyroclastic flow, poisonous gas, long-term tephra damage,  lahars, tsunamis  

o Pyroclastic flow: hot gas and ash flows down the side of a volcano and can cause  destruction like Pompeii

o Lava: flows that can destroy things

o Lateral blast: st helen eruption

o Long term damage from tephra

o Landslides and lahars  

Chapter 10: Earthquakes

• Causes of earthquakes: elastic rebound theory and stick-slip motion  

o Andrew Lawson: says that we know plate tectonics and we know of the large cracks  called faults but everyone at that time believed faults were caused by earthquakes  ▪ However, it’s the other way around, faults cause earthquakes  

▪ Rocks move around gigantic cracks and faults and this causes the earthquake  o Harry Reid: used lawsons observations to find out more  

▪ Elastic rebound: relative motion along the cracks in the ground and the faults,  but because on each side of the crack there is rock being pressed and pushed  together, there is no smooth sliding and so they stick and twist and build up  with a lot of stress and causes earthquake  

o Stick slip motion along faults causes earthquakes  

o Reverse thrust fault: faults moving together  

o Normal fault: faults moving apart  

o Stick slip: past each other  

• Epicenter and focus

o ??

• Seismometers and the Richter scale/moment magnitude scale

o Seismometers: instrument that records the earthquake motion:  

o Ritcher scale: says that a 5.0 earthquake has waves ten times larger than a 4.0 and  generates thirty times more energy  

▪ So if you go from 1,2,3,… everytime you go up one point the amount of energy  and motion in ground goes up by 30 times and ten times respectively  

▪ A 7 on ritcher scale is about 900 times worse than a 5

▪ Its magnitude scale no one uses anymore  

▪ Now we use a moment magnitude scale: its similar but its more general  • Body waves and surface waves  

o Body waves: they move through the body of earth  

▪ Split into p waves and s waves  

o Surface waves: move along the surface of the earth, slowly and dissipate quickly, they  aren’t a big deal  

• P-waves and s-waves

o P- waves: primary waves or pressure waves that move faster than s waves and pass  through solids, liquids, and gases

o S- waves: more squigglier, and move up and down, they move slower than p waves and  can only pass through solids  

o When talking P waves sound most because S waves don’t move through liquids

• Calculating the distance to an epicenter, and triangulating the position of an epicenter Where  earthquakes occur

o Calculating the distance to epicenter:

▪ Three seismometers can show where the epicenter was by triangulation

• Andrija Mohorovicic and the M-discontinuity

o Meteorologist who observed two sets of p and swaves during an earthquake in Croatia  o He sees that the same waves take different routes during the earthquake and come out  at different times, some where moving more directly through earth the others would hit  boundary and bend out. This shows that some waves travel faster through the denser  mantle, and that the stiffer the material is the faster the seismic waves move through it,  the ocean floor is made of basalt so high speeds of seismic waves, continental crust is  slower waves because its less dense  

• Using earthquake waves to map the Earth’ interior

o Earthquake waves are like light waves sound waves all similar  

o When light goes through one material to another the light changes direction, so we can  know whether each layer is liquid or salt based on the S and P waves  

o Whatever is inside planet the p waves will move through it  

o But S waves will stop when they hit a liquid  

o Lehmann used seismic data to see inner core of earth,  

• How do we know that parts of the Earth’s interior are liquid?

• Earthquake hazards: ground splitting and motion, landslides, liquefaction, fire, tsunamis  Earthquake prediction  

o Ground splitting and motion: the ground is shaking a lot it splits and you can fall over or  things can fall over  

o Landslides: slide down a hill

o Liquefaction: sediment can undergo this, sand is damp held together by capillary forces:  thin layer of water between two things sticks the two things together

▪ Sand with moisture, liquid will act as glue  

▪ Shake it grains will move apart and will have thicker layer of water acting as a  lupicrent: things can sick in  

o Fires and tsunamis  

o Check powerpoint for location of earthquakes  

Chapter 11:  

• Stress and strain

o Stress: force we apply to rock to cause it to bend

o Strain: rocks respond to stress with this by moving, bending or breaking. The more  stress we apply the more strain it undergoes

• Tensional, compressional, and shear stress

o Tensional stress: expands rock like a divergent boundary

o Compressional: the rock comes in towards eachother: converget boundary  o Shear stress: past eachother, twist rocks, transform boundary

• Elastic deformation, ductile deformation, fracture Faulting and folding

o Three things happen with stress  

o Elastic deformation: first you change the shape of the rock but when you let go of the  stress it has only moved a little so its able to go back to how it was before: temporary  o Ductile deformation: comes after elastic where it’s a permanent bend in the rock, you  

bend something and then it stays bent when you stop applying the stress, not  temporary

o Fracture faults: this comes next, you twist the rock around and it snaps, it’s a fracture,  your actually breaking the rock

• Factors influencing whether a rock will break or bend Brittle-ductile transitions in the crust and  mantle  

o Whether a rock will break or bend depends on temperature pressure composition and  the rate of deformation

o Temperature: something that breaks easily and warms up its going to break more  ▪ Temperature increases rock becomes more ductile  

▪ Surface rocks are cooler but the deeper you burry a rock more likely it is to be  bendable  

o Pressure: if you have a rock and you try to break it the higher pressure puts the atoms  together, they get stronger and stronger but pressure becomes so high so you cant  break the rock if you want to break something you need space and with high pressure  there is no space  

o Rate of deformation: the slower you apply stress to something the more likely it is to  bend

o As you keep going down to crust you go from ductile to brittle because the bottom of  the crust and top of mantle are made of different things, it’s the same temperature and  pressure because different material its breakable, but as you go down temperature  increases and it becomes brittle again, brittle ductile brittle ductile  

• Footwall blocks and hanging wall blocks

o

• Strike-slip, normal, and thrust/reverse faults

o Strike Slip: occur near transform boundaries

o Normal: divergent boundaries, two rocks move apart, and have a huge gap in ground  which slides down horizontal and vertical motion, the rocks move apart you get a sliding  vertical motion  

o Reverse fault: convergent boundaries, you get horizontal and vertical movement, if you  pile up rocks and the first and oldest rocks are in the bottom of stuff and the newest at  the top, older rocks on top of younger rocks do happen in reverse faults

▪ Keystone thrust in Nevada  

• Normal faults and fault scarps

o Fault scarp: step in the landscape, as they move apart hanging wall block slides down  foot wall block and theirs a scar that forms  

▪ When a normal fault exposes the footwall block it is formed  

• Horst and graben landscapes

o Us basin and Range Province is an example of horst and graben  

• Monoclines, synclines, and anticline

o When rock doesn’t fault it folds  

o Monocline: simplest type of fold,  

o Syncline: fold which dips in the middle  

o Anticline: up in the middle, fold which rises in the middle  

• Collisional uplift: volcanic arcs and crustal shortening Extensional uplift

o Collisoional uplift: two tectonic plates bang them together and some land goes up to  make a mountain

▪ Continental plate is at one or both sides of a convergent boundary  

▪ Volcanic arcs form in subduction zones because of collision

o Crustal Shortening: convergence between two continents causes this which makes the  crust thicker  

▪ Himalayas  

o Extensional uplift: where a plate is rifting or being stretched apart by upwelling magma  • Isostatic uplift

o Occurs over hot spots and areas of mantle convective upwelling  

• Delamination  

o When two continental plates collide, the dense mantle portion of the lithosphere can be  come delaminated  

▪ Under Himalayas  

• Erosion and young vs. old landscapes  

o Mountains tend to erode, fresh unweathered rock but weathers fast at top  o Mountains break apart very fast  

o Three stage cycle  

▪ If erosion happens faster than uplift you get flatter more sloping areas  

Chapter 12

• Stratified rock: sedimentary rock

• Relative vs. absolute dating

o Relative: the order in which these occurences happen  

o Absolute dating: specifc years, how many years old is the thing

• Original horizontality, superposition, original continuity

o Nicolas Steno proposed three laws to determine relative ages of rock layers o Original horizontality: sediments are laid down in horizontal layers  

o Superposition: younger sediments lays on top of older sediment  

o Original continuity: rocks were laterally continuous when they were deposited may end  against a boundary or thin and pinch out

• Fossil correlation, principle of fossil succession, index fossils Index fossils and geologic time o Fossil Correlation: species used for this are index species, they are usually abundant,  cosmopolitan and quickly evolving marine species with hard parts  

o Fossil succession: most periods are defined by index fossils that implies that geologic  time is arranged by changes in the ecosystem  

• Chemical correlation

o K-pg boundary is an example: all similar layers world wide are the same age  • Cross cutting

o Any geological event which cuts through rocks is more recent than those rocks  o Igneous rock will cut through sedimentary rocks  

• Unconformities

o Changes in sea level can cause gaps in the geological record  

• Faults and relative dating

o Faults can complicate relative dating  

o Rocks can break- fault but also fold bend,  

• Folding, overturned strata, and relative dating

o Overturned strata: rock layer that has been completely flipped over, mirror image is a  clue  

o Be able to relatively date rock layers (as in slide 24)  

Chapter 13

o Ussher’s attempt to calculate the age of the Earth

o Based on study of the bible and historical documents he placed the creation of the earth  at 6pm Oct 22, 4004 BC  

o Catastrophism, uniformitarianism, and evolution

o Catastrophism: if the earth is young than differences in layers are caused by  catastrophic events. Young earth and ecosystem gets wiped up, young earth with rapid  geological changes  

o Uniformitarianism: james hutton: theorized that igneous rock had been laid down by  volcanoes in the past and then tilted and eroded. Geology happens really slow. Present  is the key to the past, everything rocks do in the past has to do and be the same with  the rock processes today because geological processes are really slow, so earth must  be really old  

o Evolution: Darwinian: very gradual changes in generations of animals and plants, and  they add up to evolution of stuff, earth has to be old, things happen slowly  

o Kelvin’s calculation of the age of the Earth, and why it was wrong Dendrochronology, climate,  and wiggle matching

o Kelvin’s calculation of the age of the earth: estimated the time that it would take for the  earth to cool from a molten mass to current temperatures  

o Estimated 20-100 million years  

o Not enough time for uniformitarian to occur or for Darwinian so he neglected this,  however the opening of the atlantic ocean slowly gets bigger and bigger, and how fast  this is occurring is 120 million years, how thick sediment is at bottom of ocean and how  fast it piles up is 200 million years so kelvins estimate was wrong because he didn’t  know about radioactive decay, which produces heat at earths interior  

o Dendrochronology: how old a tree is by cutting it down and counting its rings, summer  you grow and make a new ring and winter you stop making rings, every summer adds a  ring  

o Climate and wiggle matching:  

o Ice cores

o Have annual layers, during winter no snow in antartica but dust settles into ice and  summer comes around warmer so you get snow, so summer snow, winter dust, count  layer of dust of snow, and its on year  

o Radiation and half lives

o Atoms are made of protons electrons and neutrons, but neutrons change the mass and  radioactive nature of the atom, so you add neutrons you change atom, the radioactive  properties change but chemistry is the same  

o Radiation; atom undergoes radioactive decay and it starts to fall into bits and change  into another atom or isotope, it ejects energy and subatomic stuff:  

o We are carbon base: carbon 14 is radioactive and unstable, the half life of carbon 14 is  around 6000 years and if you have a pile of c14 and wait 6000 years half of it will change  to nitrogen 14

o Everyday we lose c14 but we gain one, amount of C14 in living things is always the  same  

o Isotopes

o Everytime an atom of a radioactive parent isotope decays it changes into a daughter  isotope, so overtime you lose the parent you gain the daughter  

o Carbon dating (also called radiocarbon dating or C-14 dating)

o Why is there always the same amount of radiocarbon in the atmosphere? Why is there always  the same amount of radiocarbon in similar living things? Be able to do simple radiometric  calculations

o Why can’t we use radiocarbon dating on rocks?

o Because it will not tell you how old it is it will just tell you how long ago it was crystalized  out of liquid magma  

o Starting the radiometric clock on an igneous rock

o Magma crystalizes into igneous rock with specific chemical formulas, daughter isotopes  of decaying isotopes will contaminate those minerals  

o 20K and 10Ar: just add the numbers so 30K is original rock  

o Calculating the age of the Earth

Chapter 14

o Homogenous accretion and differentiation of the Earth

o It accretes from a cloud of gas that’s mostly hydrogen and dust  

o Accretion forms a large planetesimal, then homogenous protoplanet forms, and then  differentiation begins the separation of materials  

o The geologic timescale: Precambrian, Paleozoic, Mesozoic, Cenozoic (you do not need to  memorize any of these numbers)

o Precambrian: four billion years

▪ We only find rocks four billion years old on moon

▪ Most precrambian rocks on earth have cut off at four billion years  

▪ Acasta gneiss: oldest exposed surface rock in the world  

o Formation of the Moon

▪ The giant impact hypothesis: one planet and another planet crashes into our  planet, the earth and this other planet that’s the size of mars crashes into us all  things get mixed together and big chunk of it goes into space, all the stone stuff  congeals and forms the moon

o Late Heavy Bombardment

o Causes the cut off of rocks at around 4 billion years

o Asteroids collided with early terrestrial planets  

o Earth’s early atmosphere and where it comes from

o Volcanic activity released nitrogen, water, and carbon dioxide gases from rocks, forming  the earths early atmosphere  

o Some of earths water also came from comets and asteroids  

o Plate tectonics and liquid water

o Plate tectonics must have been operating, four billion year old granite like materials tell  us that plate tectonics were making continents  

o We find pillow basalts made of volcano and flows into water showing there was liquid  water after crust and earth forms  

o Isotopic evidence for early life

o 3.7 billion year old scraps of carbon implies that there was life on earth almost  immediately after the bombardment

o plants prefer carbon 12 so they take extra carbon 12 and less carbon 13 so the plant  has extra carbon 12 and in it there is less carbon 13 in the atmosphere, when they die,  carbon gets locked into fossilized rock  

o Fossil evidence for early life

o Stromatolies are earliest fossils of living things, films of slime on bottom of ocean, the  goo doesn’t need oxygen to stay alive, so doesn’t care but soon stuff starts to  photosynthesize and you start to oxygeniate earths atmosphere  

o Source of Earth’s atmospheric oxygen

o It initially lacks oxygen but when photosynthetic life appears that oxygen can begin to  build up

o Grenville orogeny, Rodinia, Pangea, and Wilson cycles

o Grenville orogeny: boundaries between cratons, remains of eroded mountain chains, the  Greenville ones run up east coast of US and are 1.6 billion years old

o Rodinia: 1.5 billion years ago all continents were stuck together and called Rodinia,  which existed before Pangea  

o Pangea: they break apart and make ocean and then crash again to make Pangea  o Wilson Cycle: the atlantic ocean basin opened and closed roughly every 500 million  years  

o Cambrian explosion

o The Paleozoic era begins with this explosion

o Explosion in life and biodiversity, at end of Precambrian period we have a blob of things  and at the beginning of Paleozoic we see establishment of diverse ecosystem  o Formation of the Appalachians

o Formed 300 million years ago as Gondwana and Laurentia converge  

o When rodinia breaks apart but then during Paleozoic the fragments reform into Pangea, the Appalachians are formed

o Fish, fins, and jaws

o Fish: the first ones evolve during the Paleozoic and they have no fins and no jaws  o Fins: they quickly appear, the dunkleosteus:  

o Land plants and vascularity

o On land plants become vascular the first of two steps which will alow them to become  as large as they are today because with these tubes they carry things around like water  and minerals  

o First land animals

o Millipedes and then insects and scorpions  

o Soon fins become legs during the late Paleozoic and the first amphibians appear, from  this evolves repitlres and mammal like reptiles called dimetrodoon:  

o By the end of the Paleozoic mammal like reptilres have become much more mammal  like, they lay eggs

o Wood

o Plants use wood to get big, they add this second trick during Paleozoic and they start to  get big, massive woody ferns  

o Fish evolve into amphibians, amphibians evolve into reptiles and mammal-like reptiles o the first land animals appear: millipedes: and soon insects and scorpions  o fins become legs during the late Paleozoic and the first amphibians appear  

▪ from these evolve the reptiles and mammal like reptiles: dimetrodon: an early  mammal like reptile:  

▪ by the end of the Paleozoic: mammal like reptiles have become much more  mammal like: they lay eggs, etc  

▪ soon a volcano occurred, the biggest known and the flood basalts may have  covered up to 7 million  

▪ the Permian Triassic extinction event: kills 96% of everything on land and 70 • this event allows reptiles to largely replace reptile like mammals

• they are related to crocodiles but are not dinosaurs  

• there are dinosaurs during this Mesozoic period but they are small  

o this happens because we have Pangea and we start breaking it  

apart and start getting volcanoes we get the central atlantic  

magmatic volcano  

• therapods and then birds evolve from dinosaurs: the carnivorous ones  

• during dinosaurs time flowers evolve: flowers are dominant plant on  

earth even grass is a flowering plant  

o The Great Dying

o Permian Triassic Extinction, killed 96% of marine species and 70% of terrestrial vertebrates, largest known volcanoic eruption in history occurred

o Early reptiles and the End-Triassic Extinction Event

o Second period of the Phanerozoic is the Mesozoic, the age of the reptiles

▪ The PT extinction event allows reptiles to replace mammals  

▪ The first ones are related to crocodiles:  

▪ During first part of Mesozoic, they are small and only two legs, and omnivorous  ▪ Pangea breaks apart causing another volcanic event,  

o Recognize non-dinosaurs (pterosaurs, marine reptiles, Dimetrodon)

o Look at powerpoint  

o Sauropods and stegosaurs (note: if I mention dinosaurs on the exam, I will also show a picture) o Sauropods: dominant animals on earth,  

o Stegosaurus: 30 ft, spikey leaves on top

o Therapods: bipedal carnivorous,had feathers  

o Evolution of birds

o During Jurassic first birds evolve from therapods  

o Flowering plants

o At end of Jurassic first flowering plants  

o T-rex and triceratops

o Same time stegosaurs go extinct and  

o Extinction of the dinosaurs

o What is the main reason for the five main groups of mammals? (Or, why does Australia have  such weird mammals?)

o Because they begin to evolve all the ecological niches that dinosaurs left behind  o Himalayas and climate

o India collides with Eurasia and forms Himalayan plateu, the new rock tends to weather  quickly and it causes CO2 to come out of atmosphere cooling the earth

o Grasses and herbivores

o Around 55 million years ago  

o Fast growing, which allows them to quickly colonize areas where trees have been  destroyed and grow from bottom up  

o Extinction of the mammal megafauna  

o Outside Africa every mammal over 2000 lbs went extinct about 100,000 to 10,000 years  ago  

o Late quaternary extinction  

Chapter 15 and 16  

o How does an ordinary power plant work? Source of most power in the U.S. o It spins a coil of wire in a magnetic field  

o You spin it near magnets and get electricity  

o Plants boil water to drive a steam turbine  

o Source of most power in Us is from fossil fuels: gas and natural gas  

o What are fossil fuels?

o Fossil fuels are mostly gas and natural gas  

o Formation of coal  

o Coal used to be the big fossil fuel but in the last few years its been gas  

o Coal is formed during carboniferous about 350 million years ago time before dinosaurs,  its found in moist conditions with a lot of treas  

o Mostly made of wood, wood is compressed and gently heated it turns into carbon and  then coal is compressed cooked wood  

o Formation of petroleum

o Petroleum mostly comes from algae when they sink to bottom of waters in oceans and  lakes, as the material is heated and compressed it turns into oil and gas, during the  Jurassic times when stegosarus and sauropods ruled earth much of north America was  a shallow sea, this piled up fair amounts of salt which builds up algae  

o Salt domes and oil and gas in the Gulf of Mexico

o Repeated evaporation of sea caused salt deposits,  

o Jurassic salt domes are major oil and gas traps in the gulf of mexico  

o Conventional vs. unconventional oil

o Conventional: petroleum reserves which only need pumping by an ordinary oil  o Unconventional: some reserves are more difficult to extract oil and gas from, Canada has unconventional oil

o Shale oil and fracking

o Shale oil: is porous but not permeable

o Fracking: breaks apart hydrocarbon-containing rocks which are porous but not  permeable  

o Other types of power: nuclear, geothermal, hydroelectric, wind, solar photovoltaic, solar thermal o Nuclear: uranium forces to decay by hitting it with a neutron and decaying uranium  produces neutrons which causes a chain reaction, 20% of Us power is nuclear  o Geothermal: hot water pumped deep from earth, Iceland

o Hydroelectricity: largest source of renewable energy in use, Paraguay 100 percent hydro  o Wind power: wind turbines to extract energy from moving air

o Solar photovoltaic:  

o Solar Thermal energy: focusing the suns rays on a single point  

o Metals

o Hard, shiny, and opaque materials which are electrically and thermally conductive, as  well as malleable and ductile  

o Distribution of metals in the Earth

o Most in core of earth, and only a few in surface of earth  

o Enrichment factors and ores

o Most metals are locked away chemically in minerals, granite for example, so if we want  aluminum we just don’t get it out granit, its expensive

o Five main processes for producing ores: magmatic, hydrothermal, placer, sedimentary, residual o Mineral imports and security

o Conflict minerals  

o

• What is a volcano?

o Vent in the earth’s crust through which magma, gases, and ash erupt.

o There are 1300 active volcanoes today and over 1 million extinct  

• Where do volcanoes occur?

o At plate edges and hot spots  

• What comes out of a volcano?

o Lava, rock and gasses  

• Silicate and magma viscosity

o Magma is composed of silicate and metals but it also contains about .3% dissolved  gasses which are mostly water and carbon dioxide

▪ The viscosity is higher when there is more silicate, so in general basalt magmas  and volcanoes will be different from andesitic and rhyolotic magmas and  

volcanoes  

▪ The lower the viscosity and when its basaltic magma it means they are non  explosive volcanoes, like Hawaiian volcanoes

▪ Andesitic and rhyolite do expode because they have higher visocity, they are  found in North America, they occur where subduction is occurring, formed over  continental hotspots  

• Pyroclasts and tephra

o Volcanoes eject these stuff, and glassy ash- malten rock that has been cooled down fast  enough

o Tephra: tiny mineral particles that volcanoes eject  

• Volcanic carbon dioxide and climate

o Gas comes out of volcanoes: and when you combine Carbon dioxide with rain water it  makes it very acid which creates chemical weathering, the carbon dioxide controls the  climate because with more carbon dioxide there is hotter climate  

o Volcanoes and chemical weathering are the main controls of earth’s long term climate  and temperature is controlled by volcanoes  

• Volcanic sulfur dioxide and climate

o Volcanoes emit large amounts of sulfur dioxide, which forms aerosols that can cause  short term changes in climate  

o These aersols are fine liquid particles that don’t get washed out of atmosphere easily  and make the earth’s climate cooler  

• Basalt and non-explosive eruptions

o Low viscocity and basalt create non explosive volcanoes called Hawaiian eruptions and  are found in Hawaii,  

o It’s a thin liquid with a lot of gas in it and if pressure is dropped then gas fizzes out but  the volcano pours down it doesn’t explode it goes inside volcano  

• Aa, pahoehoe, pillow basalts, vesicular basalt, lava tubes

o AA:  

▪ crumply stuff at top of volcano:

▪ very hot magma that as you heat something up it gets thinner and thinner and  its flowing pretty quickly it freezes quickly and drops down, however its very  spikey and rough and so you cant walk on it  

o Pahoehoe:  

▪ Bottom smoother texture rock of the picture, its liquid that is flowing slow and  its like AA but it flows slower so you get more muddy rock that easier to walk on  ▪ Same rock but cools at different rates  

o Pillow basalts:  

▪ mid ocean ridges, basalt coming up to bottom of sea

▪ underwater you don’t get a flat rock but rather a bolbus kind of pillowy texture,  rounded blobs, you can make this only underwater  

o vesicular basalt  

▪ basalt that is cooled down, and there is gas trapped in it, so you get bubbles in  it  

▪ basalt with gas bubbles in it

o lava tubes

▪ basalt can form lava tubes, the top part of lava freezes and theres an inside area  that doesn’t cool so fast, so the outside part of liquid is frozen and inside I svery  hot fast lava flowing along lava cave  

• Where do non-explosive volcanoes occur?

o At oceanic hot spots, pacific ocean, Hawaii,  

• Andesite, rhyolite, and explosive volcanoes

Where do explosive volcanoes occur?

o Sticky magma has gasses inside but instead of fizzing out they get stuck because much  thicker pressure will keep building up and then they explode  

o High in silicate and high viscosity

o North American plate, also where subduction occurs, continental hotspots  • The Andesite Line

o Oceanic plate going down so ocean gets way deeper  

• Pumice

o Comes out of andesitic and rhyolite volcanoes, a lot of bubbles, very sticky, harder for  gas to get out, a much more coarse rock that floats  

• Three main types of volcanoes and how they form: cinder cone, shield, composite/stratovolcano o Cinder Cones: basalt lava flow spills out from base of cinder cone, and there is a cinder  cone eruptive vent  

▪ They are small, and they are none explosive Hawaii volcanoes,  

▪ The lava fizzes up and magma is up in the air, it cools down quickly with gassy  dusty stuff that piles up and becomes spikey lose pile of bits of rocks, they  

erode and break down quickly, lots of holes and very coarse  

o Shield volcanoes

▪ It’s a sloping dome that’s built of thousands of high fluid, it has low viscocity,  and basaltic lava flows, such as the Hawaiian islands  

▪ Basalt piles up but not steeply, it’s a very wide volcano with shallow grains, and  it keeps pumping basalt for a long time that the pile gets very big, they are the  largest single volcanos

▪ Mauna Loa: volcano size of Miami dade county  

▪ Tamu: largest volcano on earth, extinct now  

o Stratovolcano

▪ Composite volcano, mountain size, they are explosive andesitic and rhyolite  volcanoes, they are found on edges of pacific  

▪ Figi in japan

▪ It explodes through pyroclastic stuff and makes piles of stuff, then the magma  starts flowing out but very thick and sticky so its not fast or far rather just down  the side of the volcanoes so it recollects and puts together stuff again and  

another explosion occurs  

• Calderas

o All volcanoes have these, gigantic mountain size piece of rock underneath the blob of  magma, the magma goes on top of the mountain when the volcano erupts, and there is  not a lot of magma underneath so the mountain drops forming a caldera, a huge hole in  ground

• Large Igneous Provinces

o Bunch of volcanoes stuck all together: india, mile thick slap of basalt that’s huge and  covers most of India

• Volcanic hazards: lava, lateral blast, pyroclastic flow, poisonous gas, long-term tephra damage,  lahars, tsunamis  

o Pyroclastic flow: hot gas and ash flows down the side of a volcano and can cause  destruction like Pompeii

o Lava: flows that can destroy things

o Lateral blast: st helen eruption

o Long term damage from tephra

o Landslides and lahars  

Chapter 10: Earthquakes

• Causes of earthquakes: elastic rebound theory and stick-slip motion  

o Andrew Lawson: says that we know plate tectonics and we know of the large cracks  called faults but everyone at that time believed faults were caused by earthquakes  ▪ However, it’s the other way around, faults cause earthquakes  

▪ Rocks move around gigantic cracks and faults and this causes the earthquake  o Harry Reid: used lawsons observations to find out more  

▪ Elastic rebound: relative motion along the cracks in the ground and the faults,  but because on each side of the crack there is rock being pressed and pushed  together, there is no smooth sliding and so they stick and twist and build up  with a lot of stress and causes earthquake  

o Stick slip motion along faults causes earthquakes  

o Reverse thrust fault: faults moving together  

o Normal fault: faults moving apart  

o Stick slip: past each other  

• Epicenter and focus

o ??

• Seismometers and the Richter scale/moment magnitude scale

o Seismometers: instrument that records the earthquake motion:  

o Ritcher scale: says that a 5.0 earthquake has waves ten times larger than a 4.0 and  generates thirty times more energy  

▪ So if you go from 1,2,3,… everytime you go up one point the amount of energy  and motion in ground goes up by 30 times and ten times respectively  

▪ A 7 on ritcher scale is about 900 times worse than a 5

▪ Its magnitude scale no one uses anymore  

▪ Now we use a moment magnitude scale: its similar but its more general  • Body waves and surface waves  

o Body waves: they move through the body of earth  

▪ Split into p waves and s waves  

o Surface waves: move along the surface of the earth, slowly and dissipate quickly, they  aren’t a big deal  

• P-waves and s-waves

o P- waves: primary waves or pressure waves that move faster than s waves and pass  through solids, liquids, and gases

o S- waves: more squigglier, and move up and down, they move slower than p waves and  can only pass through solids  

o When talking P waves sound most because S waves don’t move through liquids

• Calculating the distance to an epicenter, and triangulating the position of an epicenter Where  earthquakes occur

o Calculating the distance to epicenter:

▪ Three seismometers can show where the epicenter was by triangulation

• Andrija Mohorovicic and the M-discontinuity

o Meteorologist who observed two sets of p and swaves during an earthquake in Croatia  o He sees that the same waves take different routes during the earthquake and come out  at different times, some where moving more directly through earth the others would hit  boundary and bend out. This shows that some waves travel faster through the denser  mantle, and that the stiffer the material is the faster the seismic waves move through it,  the ocean floor is made of basalt so high speeds of seismic waves, continental crust is  slower waves because its less dense  

• Using earthquake waves to map the Earth’ interior

o Earthquake waves are like light waves sound waves all similar  

o When light goes through one material to another the light changes direction, so we can  know whether each layer is liquid or salt based on the S and P waves  

o Whatever is inside planet the p waves will move through it  

o But S waves will stop when they hit a liquid  

o Lehmann used seismic data to see inner core of earth,  

• How do we know that parts of the Earth’s interior are liquid?

• Earthquake hazards: ground splitting and motion, landslides, liquefaction, fire, tsunamis  Earthquake prediction  

o Ground splitting and motion: the ground is shaking a lot it splits and you can fall over or  things can fall over  

o Landslides: slide down a hill

o Liquefaction: sediment can undergo this, sand is damp held together by capillary forces:  thin layer of water between two things sticks the two things together

▪ Sand with moisture, liquid will act as glue  

▪ Shake it grains will move apart and will have thicker layer of water acting as a  lupicrent: things can sick in  

o Fires and tsunamis  

o Check powerpoint for location of earthquakes  

Chapter 11:  

• Stress and strain

o Stress: force we apply to rock to cause it to bend

o Strain: rocks respond to stress with this by moving, bending or breaking. The more  stress we apply the more strain it undergoes

• Tensional, compressional, and shear stress

o Tensional stress: expands rock like a divergent boundary

o Compressional: the rock comes in towards eachother: converget boundary  o Shear stress: past eachother, twist rocks, transform boundary

• Elastic deformation, ductile deformation, fracture Faulting and folding

o Three things happen with stress  

o Elastic deformation: first you change the shape of the rock but when you let go of the  stress it has only moved a little so its able to go back to how it was before: temporary  o Ductile deformation: comes after elastic where it’s a permanent bend in the rock, you  

bend something and then it stays bent when you stop applying the stress, not  temporary

o Fracture faults: this comes next, you twist the rock around and it snaps, it’s a fracture,  your actually breaking the rock

• Factors influencing whether a rock will break or bend Brittle-ductile transitions in the crust and  mantle  

o Whether a rock will break or bend depends on temperature pressure composition and  the rate of deformation

o Temperature: something that breaks easily and warms up its going to break more  ▪ Temperature increases rock becomes more ductile  

▪ Surface rocks are cooler but the deeper you burry a rock more likely it is to be  bendable  

o Pressure: if you have a rock and you try to break it the higher pressure puts the atoms  together, they get stronger and stronger but pressure becomes so high so you cant  break the rock if you want to break something you need space and with high pressure  there is no space  

o Rate of deformation: the slower you apply stress to something the more likely it is to  bend

o As you keep going down to crust you go from ductile to brittle because the bottom of  the crust and top of mantle are made of different things, it’s the same temperature and  pressure because different material its breakable, but as you go down temperature  increases and it becomes brittle again, brittle ductile brittle ductile  

• Footwall blocks and hanging wall blocks

o

• Strike-slip, normal, and thrust/reverse faults

o Strike Slip: occur near transform boundaries

o Normal: divergent boundaries, two rocks move apart, and have a huge gap in ground  which slides down horizontal and vertical motion, the rocks move apart you get a sliding  vertical motion  

o Reverse fault: convergent boundaries, you get horizontal and vertical movement, if you  pile up rocks and the first and oldest rocks are in the bottom of stuff and the newest at  the top, older rocks on top of younger rocks do happen in reverse faults

▪ Keystone thrust in Nevada  

• Normal faults and fault scarps

o Fault scarp: step in the landscape, as they move apart hanging wall block slides down  foot wall block and theirs a scar that forms  

▪ When a normal fault exposes the footwall block it is formed  

• Horst and graben landscapes

o Us basin and Range Province is an example of horst and graben  

• Monoclines, synclines, and anticline

o When rock doesn’t fault it folds  

o Monocline: simplest type of fold,  

o Syncline: fold which dips in the middle  

o Anticline: up in the middle, fold which rises in the middle  

• Collisional uplift: volcanic arcs and crustal shortening Extensional uplift

o Collisoional uplift: two tectonic plates bang them together and some land goes up to  make a mountain

▪ Continental plate is at one or both sides of a convergent boundary  

▪ Volcanic arcs form in subduction zones because of collision

o Crustal Shortening: convergence between two continents causes this which makes the  crust thicker  

▪ Himalayas  

o Extensional uplift: where a plate is rifting or being stretched apart by upwelling magma  • Isostatic uplift

o Occurs over hot spots and areas of mantle convective upwelling  

• Delamination  

o When two continental plates collide, the dense mantle portion of the lithosphere can be  come delaminated  

▪ Under Himalayas  

• Erosion and young vs. old landscapes  

o Mountains tend to erode, fresh unweathered rock but weathers fast at top  o Mountains break apart very fast  

o Three stage cycle  

▪ If erosion happens faster than uplift you get flatter more sloping areas  

Chapter 12

• Stratified rock: sedimentary rock

• Relative vs. absolute dating

o Relative: the order in which these occurences happen  

o Absolute dating: specifc years, how many years old is the thing

• Original horizontality, superposition, original continuity

o Nicolas Steno proposed three laws to determine relative ages of rock layers o Original horizontality: sediments are laid down in horizontal layers  

o Superposition: younger sediments lays on top of older sediment  

o Original continuity: rocks were laterally continuous when they were deposited may end  against a boundary or thin and pinch out

• Fossil correlation, principle of fossil succession, index fossils Index fossils and geologic time o Fossil Correlation: species used for this are index species, they are usually abundant,  cosmopolitan and quickly evolving marine species with hard parts  

o Fossil succession: most periods are defined by index fossils that implies that geologic  time is arranged by changes in the ecosystem  

• Chemical correlation

o K-pg boundary is an example: all similar layers world wide are the same age  • Cross cutting

o Any geological event which cuts through rocks is more recent than those rocks  o Igneous rock will cut through sedimentary rocks  

• Unconformities

o Changes in sea level can cause gaps in the geological record  

• Faults and relative dating

o Faults can complicate relative dating  

o Rocks can break- fault but also fold bend,  

• Folding, overturned strata, and relative dating

o Overturned strata: rock layer that has been completely flipped over, mirror image is a  clue  

o Be able to relatively date rock layers (as in slide 24)  

Chapter 13

o Ussher’s attempt to calculate the age of the Earth

o Based on study of the bible and historical documents he placed the creation of the earth  at 6pm Oct 22, 4004 BC  

o Catastrophism, uniformitarianism, and evolution

o Catastrophism: if the earth is young than differences in layers are caused by  catastrophic events. Young earth and ecosystem gets wiped up, young earth with rapid  geological changes  

o Uniformitarianism: james hutton: theorized that igneous rock had been laid down by  volcanoes in the past and then tilted and eroded. Geology happens really slow. Present  is the key to the past, everything rocks do in the past has to do and be the same with  the rock processes today because geological processes are really slow, so earth must  be really old  

o Evolution: Darwinian: very gradual changes in generations of animals and plants, and  they add up to evolution of stuff, earth has to be old, things happen slowly  

o Kelvin’s calculation of the age of the Earth, and why it was wrong Dendrochronology, climate,  and wiggle matching

o Kelvin’s calculation of the age of the earth: estimated the time that it would take for the  earth to cool from a molten mass to current temperatures  

o Estimated 20-100 million years  

o Not enough time for uniformitarian to occur or for Darwinian so he neglected this,  however the opening of the atlantic ocean slowly gets bigger and bigger, and how fast  this is occurring is 120 million years, how thick sediment is at bottom of ocean and how  fast it piles up is 200 million years so kelvins estimate was wrong because he didn’t  know about radioactive decay, which produces heat at earths interior  

o Dendrochronology: how old a tree is by cutting it down and counting its rings, summer  you grow and make a new ring and winter you stop making rings, every summer adds a  ring  

o Climate and wiggle matching:  

o Ice cores

o Have annual layers, during winter no snow in antartica but dust settles into ice and  summer comes around warmer so you get snow, so summer snow, winter dust, count  layer of dust of snow, and its on year  

o Radiation and half lives

o Atoms are made of protons electrons and neutrons, but neutrons change the mass and  radioactive nature of the atom, so you add neutrons you change atom, the radioactive  properties change but chemistry is the same  

o Radiation; atom undergoes radioactive decay and it starts to fall into bits and change  into another atom or isotope, it ejects energy and subatomic stuff:  

o We are carbon base: carbon 14 is radioactive and unstable, the half life of carbon 14 is  around 6000 years and if you have a pile of c14 and wait 6000 years half of it will change  to nitrogen 14

o Everyday we lose c14 but we gain one, amount of C14 in living things is always the  same  

o Isotopes

o Everytime an atom of a radioactive parent isotope decays it changes into a daughter  isotope, so overtime you lose the parent you gain the daughter  

o Carbon dating (also called radiocarbon dating or C-14 dating)

o Why is there always the same amount of radiocarbon in the atmosphere? Why is there always  the same amount of radiocarbon in similar living things? Be able to do simple radiometric  calculations

o Why can’t we use radiocarbon dating on rocks?

o Because it will not tell you how old it is it will just tell you how long ago it was crystalized  out of liquid magma  

o Starting the radiometric clock on an igneous rock

o Magma crystalizes into igneous rock with specific chemical formulas, daughter isotopes  of decaying isotopes will contaminate those minerals  

o 20K and 10Ar: just add the numbers so 30K is original rock  

o Calculating the age of the Earth

Chapter 14

o Homogenous accretion and differentiation of the Earth

o It accretes from a cloud of gas that’s mostly hydrogen and dust  

o Accretion forms a large planetesimal, then homogenous protoplanet forms, and then  differentiation begins the separation of materials  

o The geologic timescale: Precambrian, Paleozoic, Mesozoic, Cenozoic (you do not need to  memorize any of these numbers)

o Precambrian: four billion years

▪ We only find rocks four billion years old on moon

▪ Most precrambian rocks on earth have cut off at four billion years  

▪ Acasta gneiss: oldest exposed surface rock in the world  

o Formation of the Moon

▪ The giant impact hypothesis: one planet and another planet crashes into our  planet, the earth and this other planet that’s the size of mars crashes into us all  things get mixed together and big chunk of it goes into space, all the stone stuff  congeals and forms the moon

o Late Heavy Bombardment

o Causes the cut off of rocks at around 4 billion years

o Asteroids collided with early terrestrial planets  

o Earth’s early atmosphere and where it comes from

o Volcanic activity released nitrogen, water, and carbon dioxide gases from rocks, forming  the earths early atmosphere  

o Some of earths water also came from comets and asteroids  

o Plate tectonics and liquid water

o Plate tectonics must have been operating, four billion year old granite like materials tell  us that plate tectonics were making continents  

o We find pillow basalts made of volcano and flows into water showing there was liquid  water after crust and earth forms  

o Isotopic evidence for early life

o 3.7 billion year old scraps of carbon implies that there was life on earth almost  immediately after the bombardment

o plants prefer carbon 12 so they take extra carbon 12 and less carbon 13 so the plant  has extra carbon 12 and in it there is less carbon 13 in the atmosphere, when they die,  carbon gets locked into fossilized rock  

o Fossil evidence for early life

o Stromatolies are earliest fossils of living things, films of slime on bottom of ocean, the  goo doesn’t need oxygen to stay alive, so doesn’t care but soon stuff starts to  photosynthesize and you start to oxygeniate earths atmosphere  

o Source of Earth’s atmospheric oxygen

o It initially lacks oxygen but when photosynthetic life appears that oxygen can begin to  build up

o Grenville orogeny, Rodinia, Pangea, and Wilson cycles

o Grenville orogeny: boundaries between cratons, remains of eroded mountain chains, the  Greenville ones run up east coast of US and are 1.6 billion years old

o Rodinia: 1.5 billion years ago all continents were stuck together and called Rodinia,  which existed before Pangea  

o Pangea: they break apart and make ocean and then crash again to make Pangea  o Wilson Cycle: the atlantic ocean basin opened and closed roughly every 500 million  years  

o Cambrian explosion

o The Paleozoic era begins with this explosion

o Explosion in life and biodiversity, at end of Precambrian period we have a blob of things  and at the beginning of Paleozoic we see establishment of diverse ecosystem  o Formation of the Appalachians

o Formed 300 million years ago as Gondwana and Laurentia converge  

o When rodinia breaks apart but then during Paleozoic the fragments reform into Pangea, the Appalachians are formed

o Fish, fins, and jaws

o Fish: the first ones evolve during the Paleozoic and they have no fins and no jaws  o Fins: they quickly appear, the dunkleosteus:  

o Land plants and vascularity

o On land plants become vascular the first of two steps which will alow them to become  as large as they are today because with these tubes they carry things around like water  and minerals  

o First land animals

o Millipedes and then insects and scorpions  

o Soon fins become legs during the late Paleozoic and the first amphibians appear, from  this evolves repitlres and mammal like reptiles called dimetrodoon:  

o By the end of the Paleozoic mammal like reptilres have become much more mammal  like, they lay eggs

o Wood

o Plants use wood to get big, they add this second trick during Paleozoic and they start to  get big, massive woody ferns  

o Fish evolve into amphibians, amphibians evolve into reptiles and mammal-like reptiles o the first land animals appear: millipedes: and soon insects and scorpions  o fins become legs during the late Paleozoic and the first amphibians appear  

▪ from these evolve the reptiles and mammal like reptiles: dimetrodon: an early  mammal like reptile:  

▪ by the end of the Paleozoic: mammal like reptiles have become much more  mammal like: they lay eggs, etc  

▪ soon a volcano occurred, the biggest known and the flood basalts may have  covered up to 7 million  

▪ the Permian Triassic extinction event: kills 96% of everything on land and 70 • this event allows reptiles to largely replace reptile like mammals

• they are related to crocodiles but are not dinosaurs  

• there are dinosaurs during this Mesozoic period but they are small  

o this happens because we have Pangea and we start breaking it  

apart and start getting volcanoes we get the central atlantic  

magmatic volcano  

• therapods and then birds evolve from dinosaurs: the carnivorous ones  

• during dinosaurs time flowers evolve: flowers are dominant plant on  

earth even grass is a flowering plant  

o The Great Dying

o Permian Triassic Extinction, killed 96% of marine species and 70% of terrestrial vertebrates, largest known volcanoic eruption in history occurred

o Early reptiles and the End-Triassic Extinction Event

o Second period of the Phanerozoic is the Mesozoic, the age of the reptiles

▪ The PT extinction event allows reptiles to replace mammals  

▪ The first ones are related to crocodiles:  

▪ During first part of Mesozoic, they are small and only two legs, and omnivorous  ▪ Pangea breaks apart causing another volcanic event,  

o Recognize non-dinosaurs (pterosaurs, marine reptiles, Dimetrodon)

o Look at powerpoint  

o Sauropods and stegosaurs (note: if I mention dinosaurs on the exam, I will also show a picture) o Sauropods: dominant animals on earth,  

o Stegosaurus: 30 ft, spikey leaves on top

o Therapods: bipedal carnivorous,had feathers  

o Evolution of birds

o During Jurassic first birds evolve from therapods  

o Flowering plants

o At end of Jurassic first flowering plants  

o T-rex and triceratops

o Same time stegosaurs go extinct and  

o Extinction of the dinosaurs

o What is the main reason for the five main groups of mammals? (Or, why does Australia have  such weird mammals?)

o Because they begin to evolve all the ecological niches that dinosaurs left behind  o Himalayas and climate

o India collides with Eurasia and forms Himalayan plateu, the new rock tends to weather  quickly and it causes CO2 to come out of atmosphere cooling the earth

o Grasses and herbivores

o Around 55 million years ago  

o Fast growing, which allows them to quickly colonize areas where trees have been  destroyed and grow from bottom up  

o Extinction of the mammal megafauna  

o Outside Africa every mammal over 2000 lbs went extinct about 100,000 to 10,000 years  ago  

o Late quaternary extinction  

Chapter 15 and 16  

o How does an ordinary power plant work? Source of most power in the U.S. o It spins a coil of wire in a magnetic field  

o You spin it near magnets and get electricity  

o Plants boil water to drive a steam turbine  

o Source of most power in Us is from fossil fuels: gas and natural gas  

o What are fossil fuels?

o Fossil fuels are mostly gas and natural gas  

o Formation of coal  

o Coal used to be the big fossil fuel but in the last few years its been gas  

o Coal is formed during carboniferous about 350 million years ago time before dinosaurs,  its found in moist conditions with a lot of treas  

o Mostly made of wood, wood is compressed and gently heated it turns into carbon and  then coal is compressed cooked wood  

o Formation of petroleum

o Petroleum mostly comes from algae when they sink to bottom of waters in oceans and  lakes, as the material is heated and compressed it turns into oil and gas, during the  Jurassic times when stegosarus and sauropods ruled earth much of north America was  a shallow sea, this piled up fair amounts of salt which builds up algae  

o Salt domes and oil and gas in the Gulf of Mexico

o Repeated evaporation of sea caused salt deposits,  

o Jurassic salt domes are major oil and gas traps in the gulf of mexico  

o Conventional vs. unconventional oil

o Conventional: petroleum reserves which only need pumping by an ordinary oil  o Unconventional: some reserves are more difficult to extract oil and gas from, Canada has unconventional oil

o Shale oil and fracking

o Shale oil: is porous but not permeable

o Fracking: breaks apart hydrocarbon-containing rocks which are porous but not  permeable  

o Other types of power: nuclear, geothermal, hydroelectric, wind, solar photovoltaic, solar thermal o Nuclear: uranium forces to decay by hitting it with a neutron and decaying uranium  produces neutrons which causes a chain reaction, 20% of Us power is nuclear  o Geothermal: hot water pumped deep from earth, Iceland

o Hydroelectricity: largest source of renewable energy in use, Paraguay 100 percent hydro  o Wind power: wind turbines to extract energy from moving air

o Solar photovoltaic:  

o Solar Thermal energy: focusing the suns rays on a single point  

o Metals

o Hard, shiny, and opaque materials which are electrically and thermally conductive, as  well as malleable and ductile  

o Distribution of metals in the Earth

o Most in core of earth, and only a few in surface of earth  

o Enrichment factors and ores

o Most metals are locked away chemically in minerals, granite for example, so if we want  aluminum we just don’t get it out granit, its expensive

o Five main processes for producing ores: magmatic, hydrothermal, placer, sedimentary, residual o Mineral imports and security

o Conflict minerals  

o

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