Origin of the Solar System-big bang-universe started in hot tiny space, expanded as result of BB-continuing to expand from big bang-came up with theory by studying properties of light-red shift-cosmic microwave background-red shift-hubble created hubble law-by looking at light from starts, was able to correlate distance of star from earth and what stars were made of-able to create spectrum of light from stars-light of stars like Doppler effect-farther away caused light to turn red red shift-moving towards blue shift, light turned blue-fratehr away the star, faster away star is moving implies universe expanding-hubble law recession speed = Ho x distance-could find age of universe by finding distance of stars-since universe was originally in tiny space-supports age of 13.5 Ga for universe, expanding for 13.5 Ga -light shifted red from further galaxies-cosmic microwave background (CMB)-recombination, 380,000 years after BB-universe cooled enough to allow protons and electrons to form atoms-evidence CMB-scientists discovered ambient radiation in universe-radiation was everywhere-photons leftover from 380k ABB still bouncing around everywhere-CMB -Penzias and Wilson built horn antenna discovered CMB-afterglow of big bang-released a glow of photons-supports an age of 13.7 Ga for universe and supports red shift calculations-temp differs in photon field by only about .0002 kelvin-photons still bouncing around universe did not come from specific source like stars-cosmic dark ages 380k and 200 mil years ABB-no new light in universe-time of reionization-200mm yrs ABB-mass locally condense to form stars-known as time of reionization relighting-first galaxies 1 Ga ABB-our solar system forms 8.4 Ga ABB-origin of our solar system-star formed earlier explodes -creates big ball of matter-forms nebula-solar nebula condenses from past star-rotates in disc shape to create solar system-evidence excess of heavy elements elements wit higher atomic weight-heavier elements only forms when supernova occur-most abundant elements = lighter elements formed during BB-many stars made of lighter elements-presence of heavy elements in solar system = formed from supernova-inner planets mercury, venus, earth, mars-outer planets Jupiter, Saturn, Uranus, Neptune, pluto-age of our solar system-meteorites date to 4.53 to 4.58 Ga-leftover bits from time of solar system formation-formation of planets-gas and dust spinning around, smacking into each other and growing-turns into solar system of sun and planets-asteroid belt = leftovers from collisions-formation of the earth-condense out of solar nebula-material left over after the formation of the sun-grew via accretion/condensation -age of earth-earth dated indirectly: 4.5 Ga-from meteorites-moon-variety of ages, oldest are between 4.4 and 4.5 Ga-no rocks from original earth, so used asteroids/moon-differentiation of earths core-at first homogenous, no layers/core-however, a lot of iron on Earth-heavier and denser sank to bottom-less dense material rose and formed mantle and crust-asteroids hit earth as well and could have heated up and melted earths surface-led to layered earth today-differentiation of Earths core-crust, mantle, liquid outer core, solid iron inner core-at first elements scattered randomly-rotation caused elements to sort themselves-heavy elements at core, next heaviest at mid, lightest at surface-formation of moon-glancing blow by a mars size object (theia) hits earth-collision melts surface/mantles of both bodies-hit earth at angle and put earth on tilt and caused earth to spin more-collision did not melt cores-debirs from collision eventually forms moon-rotation of earth captures debris-great bombardment early earth/moon affected by constant rain of impactors-surface of moon filled with craters-continued until earth cleaned up neighborhood by gravitational rotation-Hadean Eon-from origin of earth to the oldest rocks-term coined by preston cloud-no rocks remain from this eon-magma ocean, very volcanic-eventually magma ocean cooled to form a layer of basaltic crust-earths initial crust was likely re-melted several ties due to impacts with large asteroids-stable liquid water-eventually earth cooled enough to support liquid water-mineral evidence suggests ~4.4 Ga-tentative-oldest sediments 3.8 Ga -for sure-consequences need H2O for life-End of Hadeon Oldest Rocks ~4 Ga- Acasta Gneiss, Isua, Greenstone belt

History of ContinentsArchean Eon-Starts with oldest rocks on earth and ends with emergence of continents

Oldest Rocks Acasta Gneiss (currently) 4.03 Ga Near Great Slave Lake, Canada

-pillow basalts -significance presence of water 3.8 Ga

-Archean rocks different from modern rocks-ultramafic lava komatiites-1600 degrees C to erupt-proto continents -granite/gneiss terranes and greenstone belts-granite formed from differentiation of mafic/ultramafic minerals-gneiss after formation, many granites went through metamorphism-high heat flow-Greenstone belt sequence-ultramafic lavas and mafic lavas on bottom w/ some pillow basalts-felsic lavas + sedimentary rocks on top-Archean Observations-greenstone belts sandwiched between granite/gneiss terranes-no large continents-weird rock types ultramafic lava-Archean tectonics-proto continents bumping into each other combining/rifting-greenstone belts likely former rift zones-metamorphosed volcanic rocks -high heat flow vs today too hot for regular plate tectonics ultramafic lavas-cratons very ancient, now stable part of continental crust-archean granite/greenstone coalesced to form stable core of todays continents-Archean Proterozoic boundary-theoretical global emergence of continents large scale creation of continental crust-cratonization not synchronous around the world 2.5 Ga-i.e. South Africa (older craton) vs North America (newer craton)-south Africa oldest craton kaapvaal craton (size of Madagascar)-marine Pongola supergroup-North America one of the younger cratons-Witwatersrand Basin first land-McLennan and Taylor most accepted continental growth summary-Tectonics in the Proterozoic-Wopmay Canada (~2.0 Ga) rifted continent-Jormua Complex, Finland (1.96 Ga)-normal plate tectonics operating by 2.0 Ga-Wopmay significance-rifting of a continent-opening of ocean basin-forming a passive margin-Jormua Significance -oldest complete ophiolite (ocean crust cross section)-proterozoic crust similar to todaysPost Archean Growth of N. America-series of larger continental masses sutured to original Archean N. AmericaGrenville Orogenic Belt-can be traced all over world-implications assembly of a super continent Rodinia-orogeny mountain building event

History of the Atmosphere-Atmosphere slowly developed-two major hypothesis:1) comet impacts during great bombardment comets very gassy2) degassing from volcanic eruption most widely accepted theory-gas from volcanos found in atmosphere-largely water, CO2, SO2 -no water in modern atmosphere-Where did water go?-most water condensed on surface of earth ocean/lakes-evaporation from ocean clouds, rain, snow, etc-Earth Goldilocks zone-far enough from sun for H2O to condense into water-close enough to sun for H2O not to freeze-most of time ice ages-Venus -closer to sun water vapor does not condense, no oceans/rainfall -CO2 does not dissolve, a lot of CO2 in atmosphere-runaway greenhouse effect 900 degrees F, 484 degrees C-volcanoes continually adding gas to venus-Mars-further from the sun colder, possibly had water on surface-ice forms on planet once a year-smaller than earth-most of atmosphere escaped into space less gravity-Where does CO2 go?-most dissolves into ocean-most CO2 in deep oceans-fossil fuels and vegetables store a lot of CO2-only small amount of CO2 goes into atmosphere-Where did N2 come from?-volcanic outgassing-N2 does not react, therefore builds up overtime like a steady drip-Where did O2 come from?-photosynthesis waste product of photosynthesis-Studying Ancient Atmosphere-cannot sample past air directly need proxies to study past air-proxy a measurable quantity that substitutes for something no longer measurable-constraints on atm O2 over time-no O2 in atmosphere until photosynthesis-3 main proxies-Red beds, UO2 uranium dioxide, BIFs Banded Iron Formations -Iron good proxy for oxygen-dissolves in water in absence of oxygen Fe2+-forms a solid when oxidized rust, Fe3+-Red Beds red due to presence of iron oxide oxygen when sediments deposited-No red beds before 2.2 Ga, no O2 in atm before this-Fe-rich minerals in Paleosols (ancient soil horizons) not oxidized-formed on land, need air in soil doesn't occur underwater-Uranite (UO2)-very sensitive to oxidation, disappears when exposed to O2-doesn't exist in normal environments today-forms clasts in sandstones before, but not after 2.45 Ga-if found in stream no oxygen when deposited-Banded Iron Formations-Laminated (layered)-Alternating Fe rich (red) and Fe poor (white) formations-found in ocean basins-chemical sed rock-Fe in water cobines with O2 in water to form rust, then deposited-oldest BIF 3.2 Ga but after certain point, stopped forming-O2 combines with Fe in ocean and oxidized all Fe in ocean no more BIFs-Evidence for oxygen post-1.9 Ga-redbeds-Paleosols (ancient soil) heavily oxidized like today-iron weathered from Fe rich minerals turned to rust right away -no more BIFs/detrital UO2-Faint young sun paradox Carl Sagan-stars increase in brightness over time-sun 30% less bright in archean -thus earth should have been frozen-geologic evidence contradicts this paradox-greenhouse gasses more abundant in archean vs today-esp methane and CO2-why? O2 lower allows stronger methane GH effectHistory of North America-Rodinia starts to split ~750 Ma-East Coast Perspective-Precambrian-rifting-Ediacaran Ordovician-passive margin-ordovician-permian-slam, quit, slam, quiet, SLAM!-coal-Triassic-Jurassic-rifting-Jurassic-Present (passive margin)-cambrian (~500 Ma)-continent flooded by a lot of water-passive margin still present-tectonic quiet time-epicontinental sea forms on east coast-ordivician (~450 Ma)-America submerged under epicontinental sea-taconic arc (chain of volcanoes) collides with passive margin-forms Taconic orogeny (mountains)-global perspective gondwana assembled-Australia, Antarctica, Africa, India, S. America-near south pole Glaciation-Silurian(~420 Ma)-tectonic quiet time-not as much flooding-reefs form a lot of limestone from reef organisms-Devonian (~360 Ma)-Baltica hits from north, Avalonia hits from south, hits Lorentia (NA)-Acadian-Caledonian orogeny-Great Britain clastic wedge from caledonian orogeny-New york Clastic wedge from Acadian Orogeny-Caledonian = Acadian -more flooding towards late Devonian

-Carboniferous (290 Ma)-tectonic quiet time-coal swamps carbon rich sed rock, coal = carbon = carboniferous-during late carboniferous africa smashes into NA forming appalacian mountains -Permian (251 Ma)-Africa swings around and forms Ouachita Mountains to south of Appalacian-no more sea between NA and Africa-africa sutured to NA-Allegheny orogeny (appalacians) formed, pangea assembled-once as high as Himalayas, roots of mountains all that's left-Pangea formed-Triassic (206 Ma)-Pangea split apart-rifting of pangea at NA-convection cell forming below-water begins to creep in dries and forms evaporate (dried salt)-evaporate = proof of rifting -Jurassic (142 Ma)-splitting of Pangea continues-NA and EU pulled apart, forms passive margin and Atlantic Ocean-Cretacious (65 Ma)-More splitting -NA and EU split further apart and form atlantic towards the north-north America flooded with water-Paleogene-north America and Europe rifting farther apart-Neogene-continental ice sheets-today continental ice sheet mostly melted only left in GreenlandWest Coast Perspective-passive margin until devonian-nearly continuous collision from Devonian-Miocene-strike slip tectonics (San Andreas) until present day-Cambrian-passive margin-spring mountains formed-Ordovician-flooded limestone-Slurian-flooding drains off-klamath island arc forms-Devonian-island arc moves into and smashes into NA, forms thrust fault-forms antler orogeny, late Devonian carboniferous -cordilleran orogeny continuum of subduction, rather than distinct mountain building events-key times given names: sonoman, Nevadan, sevier, laramide-carboniferous-a lot of flooding-Permian-sonomia docks into NA forms sonoma orogeny (L. Permian/Early Triassic)-microplate composes much of present day northern Nevada, northern California and southeast Oregon-Triassic-sonomia orogeny-Jurassic-ocean crust subducts, creating volcanoes and forming Nevadan orogeny-late Jurassic early crustaceous -ocean crust melts creating volcanoes around Oregon/WA-steep angleCrestacious-sea forms through NA to Colorado sundance sea-forms crestaceous interior seaway gone by end of crestaceous-Sevier orogeny (early to late crestaceous)-eastward migration of igneous activity, metamorphic belts, and fold and thrust belts-formed volcanoes in Idaho-paleogene -laramide orogeny-late crestaceous to Eocene continued compressional tectonics -thick skinned thrusting-farallon plate subducting under NA -Neogene-farallon ridge system reaches subduction zone ~20 Ma or so-compressional tectonics replaced by strike slip/oblique tectonics-San Andreas fault system begins -San Andreas Fault-right lateral strike slip faul-subduction of farallon plate caused transform boundary between pacific plate and north American plateHistory of Climate-weather state of the atmosphere at given time-highly variable due to chaotic nature of atmosphere over short timescales-chaotic nature makes weather hard to predict more than a few days-climate average weather-temperature, precipitation, and wind averaged over time period-typically 30 years-different climates tropical, dry, moderate, continental, polar

-What keeps the earth warm?-energy in solar evolution -very long term-green house the atmosphere-insolation the energy that reaches the earth-energy out lost to space-Greenhouse effect-methane, CO2, water vapor-traps heat (infra red) in atmosphere-analogy based on how heat is trapped, not on actual process-insolation energy that reaches the earth-depends on earths orbit-eccentricity, obliquity (tilt), precession-eccentricity orbit-alternates between circular/elliptical orbit about every 100,000 years-olbiquity (tilt)-cycle every 41k years-minimum tilt 22.5 degrees, today 23.5, max 24.5 degrees-precession (wobbles)-points to north star (now) and vega-cycle every 20,000 yearsHistory of Climate when it got cold-ice expanding and contracting-usually earth does not have a lot of ice on surface-before today, last time with ice 240 Ma-currently going down into cold phase-use proxy to determine earths temperature in the past-oxygen isotopes use to determine past temperatures-isotopes elements with same # of protons, but different # of neutrons-16O vs 18O-isotop fractionation-more neutrons=heavier-chemical reactions discriminate between heavier/lighter isotops because of their mass fractionation-oxygen isotopes two important isotopes-16O and 18O-99.8% 16O and .2% 18O-oxygen isotopes fractionated by evaporation-16O evaporated preferentially said to be lighter-18O is left behind in seawater said to get heavier-oxygen isotopes and ice ages-when climate is cold, more water is tied up in glaciers-glaciers store 16O on land lighter so evaporates and comes back as snow-18O/16O ratio in ocean goes up-sea level falls-when climate is warm, more water is in ocean-glaciers melt/release stored 16O -18O/16O ratio goes down-sea level rises-glaciers like a bank for 16O-stored during ice ages (18O/16O) goes up-released during warm times (ocean returns to normal, 18O/16O goes down)-eocene optimum ice free earth-shells as proxies, from ocean cores-shells are CaCO3-CaCO3 contains oxygen that came from the water-measure shells to get 18O/16O ratio from past oceans-can also look at ice cores in glaciers-ice preserves bubbles of prehistoric air from when snow was deposited-can figure out composition of earths atm at that time-glaciers like sed rock, except with ice and snow has layers-Plio-Pleistocene Ice Age Land vs Sea record-evidence on land 3 glacial stages Wisconsin stage, illinoian stage, pre-illinoian stage-not whole story -land record is self destructive glaciers pushses rocks destroying previous evidence -could be something from previous ice sheet and new one comes and destroys it-evidence in the ocean: many more, more trustworthy one-sediments accumulate on bottom floor, nothing to self destruct it-glaciers create moraines rocks carried by glaciers-however, subsequent glaciers create more moraines, destroying previous evidence-what caused the ice age?-changes in ocean circulation-changes in atmospheric composition methane, CO2-plate tectonics-position of continents can affect ocean currents creating insolation that keeps ice-circumpolar current keeps warm currents out of Antarctica causing ice to stay (middle Eocene early Oligocene)-ice ages relatively rare, warm/hot times much more common-is climate change real?-proxy leaf stomata where CO2 enters and O2 exits-high atmospheric CO2 fewer stomata leaf doesn't want as much high global temp-low atm CO2 more stomata needs more stomata for CO2 lower temp-stomata preserved in plant leaf fossils-can know atm CO2 by counting amount of stomata -when was the last time CO2 levels were near 500ppm (ice free point)?-last time = Oligocene (25 Ma)-oligocene 2-4 C warmer-sea level 20m higher-when was the last time CO2 levels were near 1000ppm?-eocene-ice free even in Antarctic-6-8 C warmer, sea level 60+ meters-source vs sink-photosynthesis co2 + water sugar + O2