Earth History and Resources
Earth History and Resources 012 003
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12003 Intro Earth Science FINAL EXAM Tuesday 10 May at 730 am Study Guide 60 of the final exam will focus on material covered in lectures and readings since the last exam ie Lectures 20 28 including but not exclusive to the following terms and concepts Note that the other 40 of the final exam will review material covere d throughout the semester ie Lectures 1 19 which is NOT reviewed on this study guide RE 20 DESERTS ampWINDS Chapter 19 LECTU What is a desert Precipitation evaporation 30 of Earth s land surface is arid Types ofdeserts Hot amp dry semiarid coastal cold Where do deserts form Lowlatitude midlatitude rain shadows continental interior Weathering in arid climates mostly mechanical relatively little chemical Desert erosion by water oods Desert rivers groundwater drainage systems Desert landscape evolution Wind transport erosion deposition Suspended load saltation bedload De ation desert pavement Blowout dunes yardangs ventifacts Loess deposits Dune formation migration cross beds Types of sand dunes longitudinal barchan transverse parabolic LECTURE 21 SHORELINES chapter 20 Shoreline vs coastline Windgenerated waves Measuring waves crest trough height length period Formation of surface waves wind Oscillation waves Effects of shallowing on waves Translation wave surf Offshore nearshore foreshore backshore Wave erosion impact abrasion Beach formation features Variation in shorelines Terrace berm dunes Emergent coast vs submergent coast Coastal erosion and deposition Wave refraction effects on shoreline Oblique waves beach drift longshore currents Shoreline stabilization LECTURE 22 OCEANS chapter 13 Coastal zone neritic zone oceanic zone Ocean circulation surface currents depth Differences in temperature salinity density Mixed layer pycnocline pelagic zone benthic zone Winddriven circulation Gulf stream thermohaline circulation Tides tidal currents patterns Pycnocline thermocline halocline Why is seawater salty Deep ocean circulation downwelling upwelling Coriolis effect on ocean currents Gyres eddies great pacific garbage patch Effects of global climate change LECTURE 23 ATMOSPHERE Chapter 21l Composition of Earth s atmosphere Origin of atmosphere oceans hydrologic cycle Exosphere thermosphere mesosphere stratosphere troposphere Ozone layer Temperature and composition of atmosphere layers Auroras Coastal breezes Atmospheric convection pressure Adiabatic changes Cloud formation high pressurelow pressure zones Cyclones hurricanes tornadoes Weather fronts cloud types amp formation Precipitation thunder storms lightning Global wind patterns seasonal variations Midlatitude seasons vs equatorial seasons monsoons Continental interior vs coastal weather LECTURE 24 CLIMATE Chapter 21l Weather vs climate Regional climate variation Global climate zones Louis Agassiz proposal ofice age Evidence of ancient glaciations ampwarm intervals Pleistocene ice ages paleoclimatology instrument records historical information proxy data Tree rings ice cores sea oor sediments oxygen isotope analysis We are living in an ice age Phanerozoic climate variations Causes of climate change Plate tectonics variation in Earth orbit volcanic eruptions Greenhouse effect greenhouse gases carbon dioxide levels Aerosols smog Recent changes in temperature sea level glacial thickness Effects of global climate change LECTURE 25 FOSSIL RECORD ChaDter 22l Distribution of fossils Process of fossilization Enemies ofpreservation Depositional environments Preservation of communities autochthonous vs allochthonous Effects ofbioturbation diagenesis metamorphosis exposure Modes ofpreservation body fossil ichnofossil Trackways coprolites burrows Hard parts vs soft parts Permineralization replacement petrifaction compression impressions moldscasts Conservation lagerstatte vs concentration lagerstatte Resin fossils amber Taphonomy preservation rates taphonomic filters Number of parts population abundance Livedead study percentage of community fossilized Spatial sampling LECTURE 26 BIODIVERSITYamp EXTINCTION chapter 22 Taxonomy Linnaean taxonomy binomial nomenclature Describing a species peerreview system type specimens Taxonomic relationships phylogeny Stratigraphic range Phanerozoic marine animal biodiversity Diversity turnover Origin of atmosphere water vapor amp carbon dioxide Precambrian landscape physical amp chemical weathering Evidence of Precambrian oxygen production Banded iron formations stromatolites red beds Great oxidation event Ozone in atmosphere Prokaryotes eukaryotes Grypannl39a multicellular eukaryote Bangiomorpha sexual eukaryote Vendian biota Doushantuo microfossils embryos Burgess Shale Paleozoic invasion of land Iowa Carboniferous Mass extinctions vs background extinctions CretaceousTertiary mass extinction causes effects Dinosaurs and birds Life in the Cenozoic hominid fossils in Pleistocene last 3 million years LECTURE 27 ENERGY RESOURCES chapter 23 Resources renewable vs nonrenewable US energy consumption over time energy sources Global distribution of oil reserves Fossil fuels hydrocarbons pros amp cons Coal formation types of coal Oil Traps cap rock reservoir rock Anticlinal trap fault trap salt dome trap stratigraphic trap Drilling for oil amp natural gas Oil sands oil shales gas hydrates Hydraulic fracturing fracking Biofuels bioethanol switch grass wind energy LECTURE 28 MINERAL RESOURCES chapter 23 Mineral resources reserves known deposits Ore metallic minerals Magmatic segregation diamonds Hydrothermal deposits vein deposits disseminated deposit surface deposit Metamorphic ore deposits contact metamorphism regional metamorphism Secondary enrichment placer deposits Nonmetallic mineral resources building materials industrial minerals Deserts 0 Desert an area where annual precipitation is less than potential water loss by evaporation o Steppe semiarid borders of deserts Dry regions steppes and deserts cover 30 of Earth s land surface 42 million kmz 0 Types of deserts 0 Hot and Dry warm all year very hot in summer Very low rainfall that often evaporates in air 0 Semiarid summers long and dry winters have low precipitation rainfall very low but concentrated when it does come 0 Coastal semilong warm summers cool winters Rainfall low and in short bursts 0 Cold short warm summers long cold winters with snow High precipitation in winter 0 Where deserts form 0 Lowlatitude 2030 degrees N and S In high pressure zones 0 Midlatitude areas by mountains 0 Rain shadows winds move precipitation to one side of mountain leaving arid desert on other 0 Continental interior inlands of large land masses Weathering is mostly mechanical instead of chemical Most desert erosion is the result of running water Rain rare but usually very heavy resulting in ash oods and a lot of erosion Rivers usually form outside of desert in mountains and pass through 0 Groundwater water table usually very deep forming oasis where it intersects the surface Deserts have poor drainage systems most runoff does not reach sea causing erosion 0 Landscape evolution 0 Early often driven by block faulting and tectonic uplift of mountains Running water and streams also contribute 0 Late mountains lower and basins fill with sediment Alluvial fans form at canyon mouth Playa lakes form in at central area of un drained desert basins Bajada an apron of sediment along a mount front Inselbergs isolated mountain remnants Wind 0 Transport moves particles and can result in dust and sand storms I Suspended load fine particles transported within the air I Saltation transport of particles through a series of bounces I Bed load particles moved along the ground surface by wind creep o Erosion I De ation wind lifts loose sediment and leaves behind larger grains I Blowout dunes depression excavated by wind I Yardangs wind sculpted ridges I Ventifacts stones with at ridges 0 Deposits form dunes and loess I Loess wind silt accumulates extremely fertile farm land I Dunes hill or ridge of sand Transverse series of long rides perpendicular to wind Longitudal parallel with wind Barchans shaped like crescent with tips pointing downwind Parabolic tips point into with instead of with wind Shorelines Shoreline line that marks the contact between land and sea constantly moving Coastline coast s seaward edge landward limit of the effect of the highest storm Windgenerated waves provide most of the energy that shapes and modi es coastal zones Crest high point ofa wave Trough low point between two waves Wave height distance between trough and crest Wave length horizontal distance between two crests Formation of waves wind is primary factory Energy transfers from wind to water through pressure and friction Oscillation waves occur in open water water travels in circular orbits Rock back and forth Effect of Shallowing water moves increasingly elliptical towards oor Crest heights increase and wave length gets shorter Turbulent water advances up shore and forms surf Translation Waves turbulent advance of water created by breaking waves in shallows Shore Zones 0 Offshore seaward of where waves break at low tide o Nearshore zone between where waves break at low tide to lowtide level 0 Foreshore area between lowtide and coastline most active area typically wet o Backshore area inland of foreshore affected by storm waves and high tides Wind effects Wind Erosion 0 Wave impact and pressure erode land 0 Abrasion from rock fragments erode as well Beaches waves act to accumulated sediment along land 0 Form from breaking waves moving sediment Shoreline features vary by rockiness of shore currents wave intensity and whether the coast is stable sinking or rising Terrace at area exposed during low tide composed of fine grained sediment Berm ridge of poorly sorted sediment from waves at upper limit of high tide Dunes hill of fine grained sand relative to shore Can go for miles or be stopped by cliffs Emergent coast when coast rises or sea level drops Cliffs retreat while beach extends at base 0 Jagged cliffs wavecut notch or platforms Can form sea caves or sea stacks Submergent coast sea level rise or land subsides 0 River valleys become estuaries drowned river mouths hills become islands Highly irregular shoreline Factors of erosion and deposition degree and type of tectonic activity topography and composition of land configuration of coastline and nearshore prevailing wind and weather patterns proximity to rivers Wave Refraction waves slow as they enter shallow waters 0 Concentrated against sides and end of headlands forms beaches and irregular coastlines Erosion will eventually straighten out coastline Oblique Waves ow parallel with coast instead of perpendicular Cause current to ow parallel making longshore current Beach drift oblique waves and longshore current cause sediment to move along beach in zigzag pattern Baymouth Bar a sand bar that completely crosses a bay Tombolo a ridge of sand that connects an island to the mainland or other island Barrier Island low sand ridges formed parallel to coast Shoreline stabilization manmade structures that prevent erosion Sea wall parallel to shore and close to beach stops waves from reaching shoreline Breakwater parallel to shore protects from large breaking waves Groin short wall built at a right angle to trap moving sand Jetty pair of structures built to protect harbors against storm waves and deposition 0 OOO Oceans O Melti Coastal Zone area between lowtide line and landward limit of highest storm waves Neretic Zone shallow water zone above continental shelf rich shing grounds Oceanic Zone completely open water Ocean circulation water at different depths often moves in different directions Ocean current directed movement of ocean water in uences by wind earth s rotation temperature and salinity and gravitational pull Mixed layer surface zone of ocean warmed by sun and mixed by wind and waves Wind generated waves create turbulence o Pycnocline transition zone of abrupt vertical density change 0 Pelagic zone all open ocean not near coast or sea oor 0 Benthic zone water near coast or sea oor affected by both significantly Winddriven circulation shallow surface ocean currents are primarily driven by prevailing winds Gulf Stream strong warm wind driven ocean current Tidal currents gravitational pull from moon and sun cause alternating horizontal movement of surface water 0 Flood current movement of ocean water toward shore as tide rises o Ebb current movement of ocean water away from shore as tide falls Causes gravity from moon causes bulges Coast experiences two high tides and two low tides each day 0 Spring tides highest of tidal range near time of new and full moons when forces of moon and sun work together 0 Neap tide lowest tidal range when moon and sun are offset Patterns 0 Diurnal one high tide and one low tide each tidal day 0 Semidiumal two of each everyday 0 Mixed large inequality in high water heights low water heights or both Pycnocline transition from mixed layer to pelagic zone abrupt density change 0 Temperature based pycnoline thermocline o Salinity based pycnocline halocline Ocean is salty because sodium leached of sea oor sediments Chloride from underwater volcanoes Carried into water from land by runoff Deep Ocean Circulation dense bottom water spreads out and moves around ocean oor Currents can force deep water back to surface 0 Downwelling water sinks because of converging currents or because surface water is denser than deep water 0 Upwelling deep water rises because it is less dense than surface waters or pulled up to replace surface water driven away by winds 0 Coriolis Effect a water droplet that leaves the North Pole headed directly to the equator will arrive slightly west of the intended destination Gyre rotational circulation forms in ocean basins centered on subtropical highpressure regions acceleration causes seas level to fall along coast Eddy circular current at ocean surface about 50200km in diameter Great Paci c Garbage Patch currents trap and concentrate trash twice the size of Texas ng glaciers and higher precipitation increase freshwater runoff into oceans Increased evaporation of ocean water increases salinity and decreases water temp Effects of global warming Atmosphere Composition created by layers of gases surrounding planet retained by gravity Mainly nitrogen 78 and Oxygen 21 Origin gases were trapped from volcanic eruptions Ancient atmosphere consisted of water vapor and carbon dioxide Without atmosphere Earth would be 60 degrees cooler Oceans started when water vapor accumulated producing precipitation Rain turned into runoff into large basins producing oceans Hydrologic Cycles runoff and groundwater dissolved salts and carried into ocean water moved from oceans to atmosphere by precipitation and salt concentrated in oceans Atmospheric Layers denser gases sink 90 in troposphere no distinct upper limit 0 Layers top to bottom Exosphere 600km Thermosphere 90km Mesosphere 50km Stratosphere 10km Troposphere where we are ground level Ozone layer within stratosphere with high concentration of ozone molecules absorbs UV thickness varies from year to year and is thinner at Poles Temp of Atmosphere Troposphere cools with altitude ozone heats upper stratosphere mesosphere cools with altitude Uppermost layer is coldest place on earth 0 Thermosphere and Exosphere oxygen molecules absorb solar radiation temp increases with altitude until gas is too thin to have effect 0 Auroras solar winds drive charged particles into upper atmosphere colorful lights 0 Troposphere convections moves air here air parcels displace others Coastal Breezes wind direction changes from day to night because of temp differences 0 Sea breeze during day air moves from sea to land 0 Land breeze during night air moves from land to sea because of water s retention of heat Atmospheric Convection moving air masses create pressure zone low where they begin high where they re going Air masses create wind when moving from high to low pressure zones 0 Barometric pressure force per unit area exerted by atmosphere on surface beneath or within it Adiobatic Changes gas changes pressures so temp changes 0 Heating air sinks pressure increases and forces parcel volume to contract 0 Cooling air rises pressure decrease and parcels expand Cloud Formation rising air is moist water vapor condenses to water droplets as parcels cool 0 Low pressure zone converging winds to rising air mass cloud formation and precipitation 0 High pressure zone diverging winds from sinking air clear and cool weather Cyclones low atmospheric pressure produces inward spiraling wind Hurricanes tropical cyclones sustained nearsurface winds exceed 73 mph Tornadoes small cyclones with strong winds tube like condensations funnel from rotation cloud Weather fronts transition zone between air masses of different densities Extend horizontally and vertically and are marked by cloud formation Clouds visible mass of condense water or ice suspended in atmosphere 0 Types are defined by altitude and whether they are layered or convective o Formed by orographic uplift most winds forced up by hills cool and precipitate on wind side 0 Convectional lifting air mass is warmed and rises then expands and cools higher clouds o Frontal lifting convergence of air masses warmer moister air mass will override cooler o Radiative cooling air above ground cools and turns to fog after sun sets Precipitation condensation of atmosphere water vapor that falls to surface Thunderstorms form when an air mass with a lot of condensation is forced upward rapidly in an unstable atmosphere where temperature drops Lighting electricity resulting from differently charged particles in air Typical of thunderstorms Global wind patterns result from tempdriven convection adiabatic effects coriolis effect and seasonal shifts o Convection circulates air by the unequal warming at different latitudes 0 Variation in moisture levels results from evaporation and condensation Patters cause cool dry air to sink Coriolis de ects air currents to right in northern hemisphere and left in southern Seasonal changes solar heating of Earth s surface affects distribution of high and low pressure areas Seasonal Variations result from variation in solar radiation reaching ground The bariation happens when the tilt of earth s aXis rotates One part of planet gets more sun as result Midlatitude seasons seasonal latitude marked by changes in earth s axis Equatorial seasons amount of precipitation often varies more than temp resulting in distinct seasons I Monsoon heavy rainy season that lasts for several months with lasting climatic effects Temperature varies more in continental interiors than on coasts OO Climate 0 Weather state of Earth s atmosphere at a specific place and time particularly as regards to temperature barometric pressure wind velocity humidity clouds and precipitation 0 Climate characteristic weather of an area averaged over time particularly as regards to temperature and precipitation 0 Regional Climate Variation clime varies as a result of solar radiation prevailing atmospheric circulation patterns and landscape features mountain oceans etc 0 Global Climate Zones classi cation of climate into zones based on mean annual temperature variation in temperature precipitation and seasonality of precipitation 0 Louis Agassiz proposed ice age in which sheets of ice covered all the countries where unstratified gravel is now found 0 Evidence of glaciers moraines ushaped valleys drumlins glacial erratic and till icecontact deposits altered drainage patterns 0 Pleistocene Ice Age extensive glaciations 3 million years ago Ice covered 30 of land area 0 Paleoclimatology the study and reconstruction of ancient climates and climate change 0 Instrumental Records increasingly inaccurate as they get older Records of climate found using thermometers and barometers up to 100 years ago 0 Historical information documents and old artwork tell more about ancient climate 0 Proxy data natural recorders of climate such as vegetatitional analysis 0 Tree rings trees add a new wood layer each summer Size of rings tell about conditions 0 Ice cores from glaciers provide info on changing air temperature and snowfall Can assess temperature dust and carbon dioxide levels 0 Sea oor sediments shells of marine organisms tell of different temperature preferences and migration to different climate zones 0 Oxygen Isotope analysis ratio in organism s shell bones and teeth tell of climate conditions We are living in an ice age currently 0 Phanerozoic Climate Change global warming and cooling has varied over the last 500 years 0 Natural causes changing in global geography variation in Earth s orbit volcanic eruptions 0 Human causes addition of greenhouse gases to atmosphere and humangenerated aerosols 0 Plate tectonics gradual movements of lithospheric plates bring continents closer and farther from equator Distribution of continents effect climate 0 Earth Orbit causes climate change 0 Eccentricity elliptical shape of Earth s orbit every 26000 years 0 Obliquity tilted angle of Earth s axis every 22000 years 0 Precession wobble of Earth s axis every 41000 years Ice age cycles predicated every 100000 years based on interaction of orbit changes 0 Volcanic eruptions spew massive quantities of ash and gases into atmosphere Can block sunlight 0 Greenhouse effect increase of gases in atmosphere increases the retention of radiated and re ective heat 0 Gases include carbon dioxide water vapor methane ozone nitrous oxide Carbon dioxide most increased levels since industrial revolution Aerosols tiny droplets and particles in air Caused by fossil fuels and burning vegetation Re ect sunlight and have cooling effect Smog large amounts of air pollution from smoke and fog Major health hazard Recent changes 0 Average global temperature has increased from 1850 to 2000 0 Average seal level has increased from 1880 to 2000 0 Average glacial thickness is declining due to rise in temperature Future rise in sea levels will produce oods on major coastal cities mass extinctions etc Fossil Record Distribution of Fossils may be found in sedimentary rock but most common in rocks formed in environments with rapid deposition and minimal diagenesis review map Process first something dies then it is buried then diagenesis takes over Remains must survive long enough to be discovered Enemies of preservation destructive scavenging transport of organism by wind or water or slowed delayed deposition of sediment oxygen decay Deposition environment an organism that dies in a place where it can be immediately buried is more likely to fossilize Autochthonous organisms preserved in their original position Allochthonos fossil assemblages preserving organisms that were transported prior to deposition Bioturbation organisms burrowing through sediments Dissolution hard parts can and will dissolve from certain pH levels or other chemicals Diagenesis physical and chemical changes during lithification of sediment Metamorphosis folding or heating of fossiliferious rocks Exposure rock must be exposed or discovered to be studied erosion uplift drilling etc Modes of Preservation 0 Body Fossil preserved remnants of an organism o Ichnofossil tracks burrows or other indications that living organisms were present Trackway series of tracks or footprints left by a single organism Can provide info on tissue movement and behavior of organism Coprolites fossilized feces can show diet of species Burrows shows info on behavior preserved when burrow is ooded and filled with sediment Hard vs soft parts soft tissue is less likely to be preserved than bone shell wood etc Permineralization pore spaces in hard parts are filled by minerals from ground water Replacement pore spaces and other parts are completely replaced with minerals mostly wood 0 Petrifaction Silica binds to cellulose and crystallizes and preserves it Compression 2D often distorted Physically compressed organism by overlying sediments Impression organism is lost but imprint is left in sediment details preserved o Molds and Cast mold is the impression it is a mirror image A cast fills the mold and leaves a replica of the organism Lagerstatte extraordinary fossil deposit 0 Conservation a deposit with preservation of morphology soft parts that are usually not found 0 Concentration exceptional taxonomic preservation due to high preservation rates Resin Fossils mode of fossilization that often preserves morphological detail Usually plants or insects are trapped in tree sap or amber and are completely reserved in their original state Taphonomy study of all processes that happen between death of an organism and fossilization Preservation rates used to asses completeness of a fossil record Taphonomic Filters 0 Number of parts the more an organism has the more are likely to get lost 0 Population Abundance the more of an organism that existed the more likely it is to be fossilized Livedead study a census of the organisms living in an ecosystem is compared to the species preserved in the sediment Life assemblage to death assemblage Used to find preservation rates Study slides on page 7 for percentages of organisms fossilized in a certain community Spatial sampling finding the percent Most fossil assemblages are part local part regional Biodiversity and Extinction Taxonomy the classi cation identi cation and the naming of organisms Started by Carl von Linne o Linnean Taxonomy a method of classifying living things in a ranked hierarchy Similar organisms are a species similar species are a genus and similar genus is a family 0 Binomial nomenclature species get atwo part name Genus name and species name Homo sapien First name capitalized second not Always italicized or underlined Describing species scientists write a summary of new taxon s characteristics such as traits it shares and those that make it unique PeerReview system to publish a scientist sends work to an appropriate journal 24 other scientists review the topic and author acceptsrejects changes Type Specimen a specimen identi ed as the example of the taxon illustrated by the formal description Taxonomic Relationships species with common ancestors and similar traits are categorized together Phylogeny relationship among species Closely related species are branched together while others are branched apart Stratigraphic Range the duration of time between the oldest occurrence of a fossil species origin and the youngest occurrence of that species extinction Basically duration of a species Phanerozoic marine animal biodiversity graph on page 5 slide 4 Diversity turnover average stratigraphic range is 520 million years About 99 of all species that have ever lived on Ea1th are now extinct Origin of Atmosphere gases were trapped from volcanic eruptions Ancient atmosphere consisted of water vapor and carbon dioxide Without atmosphere Earth would be 60 degrees cooler Precambrian spans rst 4 billion years of Earth s history Hadean 4600 to 4000mya Archean 4000 2500mya and Proterozoic2500 to 542mya 0 Physical and Chemical Weathering out gassing produced acidic conditions accelerated chemical weathering Precipitation and runoff increases physical weathering sediment deposits and salinity Precambrian Oxygen photosynthetic organisms started producing oxygen about 35bya o Banded Iron Formations early iron oxide deposits accumulated on the sea oor as alternating layers of ironrich rocks and chert o Stromatolites distinctively layered mounds of calcium carbonate and lamentous bacteria 0 Red Beds evidence of chemical oxidation especially iron in continental sediments Great Oxidation Event 24bya excess oxygen released in atmosphere became toxic to dominate organisms anaerobic bacteria and led to ecological crisis then metabolic revolution Ozone in Atmosphere ha1mful to most cells ocean water shields marine organisms Formed in UV radiation Became protective layer allowing organisms out of Deep Ocean Prokaryotes organisms lacking nucleus or other membranebound organelles Mostly unicellular Eukaryotes cell that engulfs another cell Membrane bound organisms o Grypannia multicellular eukaryote o Bangiomorpha sexual eukaryote Intercalary pattern of cell division Vendian biota oldest fossil evidence of multicellular organisms Algae lichens etc Doushantuo Microfossils from late Proterozoic marine rocks in southern china Appear to preserve embryos of ancient organisms Embryos go through a rapid series of cell divisions without cell growth or cell differentiation cleavage Burgess Shale rocks that preserve a 500ma ecosystem from the sea oor Paleozoic invasion of land animals and plants evolved to protect against solar radiation dehydration and breathing oxygen Insects and plants eventually moved to shore Lobe nned shes adapted and became rst amphibians Iowa Carboniferous About 300mya Iowa was warm and humid Extensive swamps and tree ferns Swamp plants became coal deposits over time after compression Mass EXtinctions an event when there is amassive decline of life and biodiversity 5 in Phanerozoic Causes of CretaceousTertiary EXtinctions probably asteroid impact accompanied by volcanic eruptions climate change and wildfires o Shocked Quartz a unique form of quarts crystal that has multiple fracture layers and is found only at impact craters and nuclear test sites 0 Tektites glassy spherules created when rock is vaporized by tremendous heat ejected and cooled rapidly Effects blasted dust into atmosphere blocking out sun Caused many tsunamis and global cooling Killed about 60 of species Dinosaurs and birds birds are closest living relative to ancient dinosaurs They share many homologous traits and a common ancestor Life in Cenozoic after KT extinctions Land angiosperms and mammals rapidly diversified Oceans bony fish diversified along with some marine mammals Hominid Fossils oldest fossils ofHomo sapiens and closely related species are Pleistocene 3mya Only partially reserved skeletons skulls or teeth Many from Africa Energy Resources 0 Nonrenewable form or accumulate over millions of years so quantities are considered fixed Coal iron natural gas 0 Renewable virtually inexhaustible or can be replenished relatively quickly sun wind tides 0 Consumption US energy consumption has increased over last 100 years Usage of different resources has also changed Review graph page I slide 5 and map slide 6 0 Fossil Fuel general term for any hydrocarbon organic material that may be used as fuel coal natural gas bitumen from oil sand and oil shale 0 Coal readily combustible sedimentary rock formed by compaction of plants over millions of years 0 Single most used energy resource worldwide 0 Limited resource mining can cause major environmental damage and air pollution 0 Oil and Natural gas consist of hydrocarbons from marine plants and animals Takes millions of years Must accumulate between cap rock and reservoir rock 0 Cap rock a rock impermeable to oil and gas 0 Reservoir rock a porous and permeable rock 0 Oil Trap A geologic environment that allows significant amounts of oil and natural gas to accumulate underground 0 Anticlinal trap rising oil and gas collect at a fold apex in an uparched series of sedimentary strata 0 Fault Trap upward migration of oil and gas is trapped where displaced strata bring a dipping reservoir rock opposite an impermeable bed 0 Salt Dome Rising oil and gas accumulate in deformed upturned sandstone beds adjacent to salt dome o Stratigraphic trap trapped by an original sedimentary structure a sloping bed of reservoir rock thins to point of disappearance pinches out o Drilling Cap rock is punctured Oil and natural gas under pressure migrate from pore spaces to surface Stored in tanks 0 Oil Sands a mixture of clay and sand combined with water and bitumen Several substantial deposits exists but major environmental drawbacks and expenses exist when drilling 0 Oil Shales finegrained sedimentary rock with enough organic material to yield oil or gas Currently too expensive with current technology 0 Gas Hydrates a solid form of water that contains large amounts of methane within its icelike crystals 0 Hydraulic Fracturing Fracking process for arti cially increasing a reservoir rock s permeability to get oil and gas 0 Fluid is pumped into rock causing it to fracture High pressure forces gas out 0 Large amounts exist but can contaminate water and cause earthquakes o Biofuels fuel derived from biomass recently living organisms Renewable but produce greenhouse gases 0 BioEthanol most common type of biofuel Obtained from starch or sugar found in many crops 0 Switchgrass a hardy perennial grass native to North American prairies considered good candidate for biofuel Rapid growth and in large quantities Doesn t need to be replanted 0 Wind Energy wind pushes objects creating kinetic energy Windmills make this kinetic energy into electricity Iowa is 2quotd largest producer of wind energy next to Texas Mineral Resources 0 Mineral Resources naturally occurring useful and essential minerals from Earth s crust ultimately available commercially according to value iron ore lead tin copper zinc mercury bauxite 0 Reserves already identi ed deposits of minerals that can be extracted pro table o Knowndeposits exists but are not 39 quotJ or 39 quoty v ML yet 0 Ore rock containing useful metallic minerals that make it valuable for mining o Magmatic Segregation local concentration of minerals formed during cooling and crystallization of magma 0 Separation of heavy minerals that crystallize early 0 Enrichment of rare elements in the residual melt 0 Diamonds form of carbon created at great depths under high pressure once crystallized diamonds are carried up through conduits within ultrama c rock called kimberlite pipes o Hydrothermal deposits solutions of hot metalrich uids move through rock depositing metals usually as sul des as the uid cools Among best known and important minerals o Vein deposits solution moves along fractures cools and precipitates within cracks o Disseminated deposit ores precipitated as minute masses throughout entire rock mass 0 Surface deposit where magma is near surface dissolved metals precipitate when water cools in arr o Metamorphic ore deposits many of important deposits are produced by contact metamorphism Sphalerite Galena Chalcopyrite Produced by Contact metamorphism and regional metamorphism 0 Secondary Enrichment concentration of scattered minor amounts of metals by weathering processes 0 Chemical weathering and water percolation remove undesirable elements from decomposing rock Desirable elements found near surface are carried to lower zones and concentrated Examples copper silver bauxite I Bauxite principal ore of aluminum formed by secondary enrichment in rainy climates o Placer Deposits formed when heavy minerals are mechanically concentrated by currents most commonly streams and waves typically heavy and durable minerals gold tin platinum diamonds o Nonmetallic Mineral Resources 0 Building materials I Natural aggregates crushed stone sand gravel I Gypsum plaster and wallboard I Clay tile bricks and cement 0 Industrial Minerals I Fertilizers nitrate phosphate and potassium compounds I Sulfur sulfuric acid to manufacture phosphate fertilizers I Salt used in chemical industry softening residential water and keeping street icefree OO Earth s Systems Geosphere Hydrosphere Atmosphere Biosphere Answers to recent clicker questions should be recognizable on test 1 Earth s primitive atmosphere Water Vapor and Carbon Dioxide 2 Earth s atmosphere today Nitrogen and Oxygen 3 Banded iron formation and red beds 4 Birds closest ancestors to dinosaurs 5 Cap Rock and Reservoir Rock needed to make oil and natural gas 6 Swamp plants primary source of coal 12003 Intro Earth Science Exam 2 TUESDAY 5 APRIL 2011 Study Guide Exam 2 will be in a similar format as Exam 1 ie multiple choice and matching It will focus on material covered in lectures and readings since the last exam ie Lectures 10 19 including but not exclusive to the following terms and concepts LECTURE 10 Chapters 2 amp 13 PLATE TECTONICS Continental drift theory and evidence Sea oor spreading theory and evidence Plate tectonics and plate boundaries eg types motions driving forces San Andreas fault is a strikeslip shearing motion etc Origin of the ocean oor Mapping the sea oor Features of ocean basins Ocean ridges and sea oor spreading Nature ofocean crust Continental rifting Subduction zones LECTURE 11 Chapter 10 STRUCTURAL GEOLOGY Crustal deformation Deformation force and stress Types of stress Strain How rocks deform Mapping geologic structures Strike and dip Types of folds Basins and domes Dipslip faults Strikeslip faults Ioints LECTURE 12 Chapter 11 EARTHQUAKES Seismic waves Body waves vs surface waves Properties of pwaves and swaves Distribution of Earthquakes New Madrid Fault amp Midwest Earthquakes Faults Locating Earthquakes epicenter focus Measuring Earthquakes magnitude Richter scale Liquefaction and sand blows Earthquakes as triggers tsunamis and ground failures LECTURE 13 Chapter 12l EARTH S INTERIOR Earth s layers know their names composition and physical properties Compositionbased layers core mantle crust Propertybased layers inner core outer core mesosphere asthenosphere lithosphere Seismology types of seismic waves use in exploring planet s interior Temperature from planet surface to center Oceanic crust vs continental crust Heat convection in mantle LECTURE 14 Chapter 14l MOUNTAIN BELTS Convergent boundaries Subduction zones dynamics and features Mountain building Volcanic island arcs Andeantype margins Sierra Nevada Coastal ranges Great Valley Collisional mountain belts Terranes Continental collisions Himalayas Appalachians FaultBlock mountain building Basin amp range province Vertical movement of crust Isostasy Mantle convection LECTURE 15 Cha ter 24 PLANETARY GEOLOGY ShoemakerLevy 9 comet Impact craters Meteorites asteroids comets Effects ofmeteorites on Earth s atmosphere and climate Solar system Formation and composition of planets Moon Mars climate evidence of water LECTURE 16 Chapter 15l MASS WASTING Effect of gravity Oversteepened slopes Factors affecting angle of repose Mass wasting types and attributes Controls and triggers of mass wasting Permafrost LECTURE 17 Chapter 16l RUNNING WATER Earth s hydrologic cycle Hydrologic processes Distribution of Earth s water saltwater and freshwater Drainage basins networks and divides Calculation of stream discharge Stream capacity and competence Stream profile base level local vs ultimate Erosion by running water processes sequence River valleys Vshaped vs Ushaped Alluvial fan vs delta Features of oodplains LECTURE 18 Chapter 17l GROUNDWATER Soil moisture zone saturation zone aeration zone Water table capillary fringe A well must penetrate below the water table to pump water Factors affecting water table depth Movement of groundwater Gaining streams and losing streams Porosity vs permeability Aquitards and aquifers Hydraulic gradient conductivity and discharge Springs geysers artesian wells Groundwater contamination and depletion Karst topography LECTURE 19 Chapter 18l GLACIERS amp GLACIATION Types of glaciers alpine ice sheets etc Formation of glacial ice Movement of glaciers Glacial quotbudgetquot accumulation wastage snowline Glacial erosion Landforms created by glacial erosion Ushaped valleys Glacial deposits till tillite Moraines drumlins outwash plains Evidence of ancient glaciers Crustal subsidence amp rebound Sea level changes due to glacial intervals amp glacial melting