Geo evol parrish

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Geo evol parrish

  1. 1. Geological EvolutionGeological Evolution
  2. 2. What are Rocks?What are Rocks? A rock is a naturally occurringA rock is a naturally occurring solid mixture of one or moresolid mixture of one or more minerals, or organic matterminerals, or organic matter Rocks are classified by how theyRocks are classified by how they are formed, their composition,are formed, their composition, and textureand texture Rocks change over time throughRocks change over time through the rock cyclethe rock cycle
  3. 3. AnimationAnimation http://www.bbc.co.uk/schools/ks3 bitesize/science/environment_eart h_universe/rock_cycle/activity.sht ml
  4. 4. Types of RocksTypes of Rocks Sedimentary Rocks Metamorphic RocksIgneous Rocks
  5. 5. Igneous RocksIgneous Rocks Igneous rock begins as magma.Igneous rock begins as magma. Igneous rocks form from theIgneous rocks form from the cooling of magma or lava.cooling of magma or lava. The nameThe name igneousigneous comes from the Latincomes from the Latin wordword ignisignis, which means “fire”., which means “fire”. http://www.fi.edu/fellows/payton/rocks/create/igneous.htm
  6. 6. Sedimentary RocksSedimentary Rocks http://www.fi.edu/fellows/payton/rocks/create/sediment.htm  Sedimentary rock is formed by erosion  Sediments are moved from one place to another  Sediments are deposited in layers, with the older ones on the bottom  The layers become compacted and cemented together
  7. 7. Sedimentary RockSedimentary Rock
  8. 8. Metamorphic RockMetamorphic Rock http://www.fi.edu/fellows/payton/rocks/create/metamorph.htm  Meaning to change shape  Changes with temperature and pressure, but remains solid  Usually takes place deep in the Earth
  9. 9. THE ROCK CYCLE SEDIMENTARY METAMORPHIC Heat & Pressure IGNEOUS Heat & Pressure Weathering, Erosion, Deposition, Cementation, Compaction Weathering, Erosion, Deposition, Cementation, Compaction Melting & Cooling Melting & Cooling Weathering, Erosion, Deposition, Cementation, Compaction Heat & Pressure Melting & Cooling
  10. 10. Where do IGNEOUS ROCKS form?
  11. 11. Extrusive igneous rocks form on or near the surface. Intrusive igneous rocks form below the surface.
  12. 12. Where do sedimentary rocks form?
  13. 13. SEDIMENTARY ROCKS form near the surface under water by COMPACTION from a few layers above.
  14. 14. Where do METAMORPHIC ROCKS form?
  15. 15. METAMORPHIC ROCKS form deep underground by Pressure from many layers above.
  16. 16. THE ROCK CYCLE
  17. 17. http://www.bbc.co.uk/schools/ks3bitesize/shttp://www.bbc.co.uk/schools/ks3bitesize/s cience/environment_earth_universe/rock_cience/environment_earth_universe/rock_ cycle/activity.shtml ****cycle/activity.shtml **** http://www.makemegenius.com/video_plahttp://www.makemegenius.com/video_pla y.php?id=108y.php?id=108
  18. 18. FossilsFossils Fossils are usuallyFossils are usually found infound in sedimentarysedimentary rocks.rocks. When an organismWhen an organism dies, its soft partsdies, its soft parts often decay quicklyoften decay quickly leaving only theleaving only the hard parts tohard parts to fossilize.fossilize. Ex. Bones, Shells,Ex. Bones, Shells, Teeth, or SeedsTeeth, or Seeds
  19. 19. FossilsFossils FossilsFossils areare preserved remains orpreserved remains or traces of living things.traces of living things. Most fossils formMost fossils form when living things diewhen living things die and are buried byand are buried by sediments.sediments. The sediments slowlyThe sediments slowly harden into rock andharden into rock and preserve the shape ofpreserve the shape of the organisms.the organisms. Scientists who studyScientists who study fossils arefossils are paleontologists.paleontologists.
  20. 20. Types of FossilsTypes of Fossils Petrified FossilsPetrified Fossils:: fossils in whichfossils in which minerals replace all orminerals replace all or part of the organism.part of the organism. Ex: petrified woodEx: petrified wood When the object isWhen the object is buried by sediment,buried by sediment, water rich in mineralswater rich in minerals seeps into the cells.seeps into the cells. After the waterAfter the water evaporates, hardenedevaporates, hardened minerals are leftminerals are left behind.behind.
  21. 21. Types of FossilsTypes of Fossils Molds andMolds and CastsCasts AA moldmold is ais a hollow area inhollow area in sediment in thesediment in the shape of anshape of an organism or partorganism or part of an organism.of an organism. AA castcast is a copyis a copy of the shape ofof the shape of an organism.an organism.
  22. 22. Types of FossilsTypes of Fossils Trace FossilsTrace Fossils provide evidence ofprovide evidence of the activities ofthe activities of ancient organisms.ancient organisms. Ex: footprints, animalEx: footprints, animal trails, or animaltrails, or animal burrows.burrows.
  23. 23. Types of FossilsTypes of Fossils Carbon FilmsCarbon Films:: anan extremely thin coatingextremely thin coating of carbon on rock thatof carbon on rock that forms when materialsforms when materials that make up anthat make up an organism becomeorganism become gases and escapegases and escape leaving only carbonleaving only carbon behind.behind.
  24. 24. Types ofTypes of FossilsFossils PreservedPreserved RemainsRemains areare formed when anformed when an organism isorganism is preserved with littlepreserved with little or no change.or no change. For example whenFor example when organisms becomeorganisms become preserved in tar,preserved in tar, amber (tree sap),amber (tree sap), and freezing.and freezing.
  25. 25. Why Study Fossils?Why Study Fossils? Scientists studyScientists study fossils to learn whatfossils to learn what past life forms werepast life forms were like.like. PaleontologistsPaleontologists classify organisms inclassify organisms in the order in whichthe order in which they lived.they lived. All the informationAll the information scientists havescientists have gathered is called thegathered is called the fossil recordfossil record..
  26. 26. Fossil RecordFossil Record The fossil recordThe fossil record provides evidenceprovides evidence about the history ofabout the history of life on Earth.life on Earth. The fossil recordThe fossil record also shows howalso shows how different groups ofdifferent groups of organisms haveorganisms have changed over time.changed over time. It also providesIt also provides evidence to supportevidence to support thethe theory oftheory of evolution.evolution.
  27. 27. Remember!Remember! A scientific theory isA scientific theory is a well-tested concepta well-tested concept that explains a widethat explains a wide range ofrange of observations.observations. The fossil recordThe fossil record shows that millionsshows that millions of types ofof types of organisms haveorganisms have evolved.evolved. However, manyHowever, many others becameothers became extinct.extinct.
  28. 28. Finding the Age of Rocks ThroughFinding the Age of Rocks Through Rock DatingRock Dating
  29. 29. R O C K D A T I N G
  30. 30. Ages of RocksAges of Rocks TheThe relative agerelative age ofof a rock is its agea rock is its age compared to othercompared to other rocks.rocks. Use words like:Use words like: “older or younger”“older or younger” TheThe absolute ageabsolute age of a rock is theof a rock is the number of yearsnumber of years since the rock wassince the rock was formed.formed. Ex: 358-360 myaEx: 358-360 mya
  31. 31. Rock Joke!!Rock Joke!! What does a rock wantWhat does a rock want to be when it growsto be when it grows up?up? A Rock Star!!A Rock Star!!
  32. 32. The Position ofThe Position of Rock LayersRock Layers It can be difficult toIt can be difficult to determine a rocksdetermine a rocks absolute age. So…absolute age. So… scientists use thescientists use the lawlaw of superpositionof superposition.. According to theAccording to the lawlaw of superpositionof superposition, in, in horizontalhorizontal sedimentary rocksedimentary rock layers the oldest layerlayers the oldest layer is at the bottom. Eachis at the bottom. Each higher layer ishigher layer is younger than theyounger than the layers below it.layers below it.
  33. 33. Law of SuperpositionLaw of Superposition TheThe Law of SuperpositionLaw of Superposition states thatstates that inin undisturbedundisturbed rock layers the oldestrock layers the oldest layer is on the bottom and thelayer is on the bottom and the youngest rock layer is on the top.youngest rock layer is on the top.
  34. 34. The Grand CanyonThe Grand Canyon Youngest Oldes t
  35. 35. UnconformitiesUnconformities AnAn unconformityunconformity is ais a gap in the geologicgap in the geologic record that mostrecord that most commonly occurs whencommonly occurs when rock is erodedrock is eroded exposing older rockexposing older rock and then new rockand then new rock forms on the muchforms on the much older rock.older rock. The layering of newThe layering of new rock on the much olderrock on the much older rock leaves a gap inrock leaves a gap in the geologic record.the geologic record.
  36. 36. Other types of UnconformitiesOther types of Unconformities Faulting- Movement of the Earth’s plates causes rock to crack and shift. Intrusion- Magma from the Earth’s mantle moves into the rock layers, cools and hardens. (Igneous Rock)
  37. 37. Other types of Unconformites (cont.)Other types of Unconformites (cont.) Folding- Earth’s plates are pressing together. This movement causes them to bend and fold. This process forms mountains. Erosion- described earlier. Layers of rock are washed away and new rock built on top. Leaves gaps in geologic record.
  38. 38. Examples of when the Law ofExamples of when the Law of Superposition may notSuperposition may not apply…apply… FoldingFaulting Intrusion Erosion
  39. 39. Use the link below to watchUse the link below to watch a simulation ofa simulation of unconformities.unconformities. www.classzone.comwww.classzone.com
  40. 40. Rock Joke!!Rock Joke!! How do rocks washHow do rocks wash their clothes?their clothes? The Rock Cycle!!The Rock Cycle!!
  41. 41. Other Clues toOther Clues to Relative AgeRelative Age Clues FromClues From Igneous RockIgneous Rock Lava that cools at theLava that cools at the surface is called ansurface is called an extrusion. Rockextrusion. Rock below an extrusion isbelow an extrusion is always older.always older. Magma that coolsMagma that cools beneath the surfacebeneath the surface is called an intrusion.is called an intrusion. An intrusion isAn intrusion is always younger thanalways younger than the rock layersthe rock layers around an beneath it.around an beneath it.
  42. 42. Other Clues to Relative AgeOther Clues to Relative Age FaultsFaults (a break in the(a break in the rock) are alwaysrock) are always younger than theyounger than the rock it cuts through!rock it cuts through! UnconformitiesUnconformities: An: An unconformity is aunconformity is a gapgap in the geologicalin the geological recordrecord that can occurthat can occur when erosion wearswhen erosion wears away rock layers andaway rock layers and other rock layersother rock layers form on top of theform on top of the eroded surface.eroded surface.
  43. 43. Mechanical WeatheringMechanical Weathering A type of weathering in which rock is physicallyA type of weathering in which rock is physically broken into smaller pieces is calledbroken into smaller pieces is called MechanicalMechanical WeatheringWeathering.. Types of mechanical weathering include:Types of mechanical weathering include:  Freezing and thawingFreezing and thawing  Release of pressureRelease of pressure  Plant growthPlant growth  Actions of animalsActions of animals  Abrasion from small particles(sand) and water.Abrasion from small particles(sand) and water.
  44. 44. Chemical WeatheringChemical Weathering Chemical WeatheringChemical Weathering is the process thatis the process that breaks down rock through chemicalbreaks down rock through chemical changes.changes. Types of chemical weathering include:Types of chemical weathering include:  Water dissolving minerals in rocksWater dissolving minerals in rocks  Exposure to gases such as oxygen andExposure to gases such as oxygen and carbon dioxidecarbon dioxide  Acids from living organisms, such as plantsAcids from living organisms, such as plants  Acid rainAcid rain
  45. 45. A. Chemical Weathering- Reaction with gases in the air. B.Mechanical Weathering- pounding of water on rocks
  46. 46. C. Mechanical Weathering- Volcano, pressure D. Chemical Weathering- Acid rain
  47. 47. E. Mechanical Weathering- Plant growth F. Mechanical Weathering- Abrasion from sand being picked up by wind and thrown against rock.
  48. 48. Using Fossils to Date Rocks!Using Fossils to Date Rocks! Scientists use indexScientists use index fossils to match rockfossils to match rock layers.layers. AnAn index fossilindex fossil mustmust be widely distributedbe widely distributed and represent a typeand represent a type of organism thatof organism that existed only briefly.existed only briefly. They are usefulThey are useful because they tell thebecause they tell the relative agesrelative ages of theof the rock layers they arerock layers they are found in.found in.
  49. 49. The TrilobiteThe Trilobite One example of an indexOne example of an index fossil is a trilobite.fossil is a trilobite. Trilobites were a group ofTrilobites were a group of hard-shelled animalshard-shelled animals whose bodies had threewhose bodies had three distinct parts.distinct parts. They evolved in shallowThey evolved in shallow seas more than 500seas more than 500 million years ago.million years ago.
  50. 50. How might scientist use the age of fossils to dateHow might scientist use the age of fossils to date rock layers?rock layers? Answer: A fossil found in an older rock layerAnswer: A fossil found in an older rock layer would be older than a fossil found in a youngerwould be older than a fossil found in a younger rock layer.rock layer. Research the term index fossil. How might anResearch the term index fossil. How might an index fossil allow scientists to determine the ageindex fossil allow scientists to determine the age of rock layers?of rock layers? Answer: Index fossils are organisms that wereAnswer: Index fossils are organisms that were widespread but only lived for a short period ofwidespread but only lived for a short period of time, so if a scientist finds a well known indextime, so if a scientist finds a well known index fossil (ex. Trilobite) in an unknown rock layer hefossil (ex. Trilobite) in an unknown rock layer he can date the rock layer.can date the rock layer.
  51. 51. Relative Dating of RocksRelative Dating of Rocks Relative DatingRelative Dating occurs when the age of a rockoccurs when the age of a rock is determined byis determined by comparingcomparing it to the age ofit to the age of another.another. Scientist use the Law of Superposition as theirScientist use the Law of Superposition as their first step in Relative Dating of rocks, however,first step in Relative Dating of rocks, however, when rock layers are disturbed the Law ofwhen rock layers are disturbed the Law of Superposition may not apply.Superposition may not apply. Index FossilsIndex Fossils are organisms that wereare organisms that were widespread but only lived for a short period ofwidespread but only lived for a short period of time. They are useful because they tell thetime. They are useful because they tell the relative ages of the rock layers in which theyrelative ages of the rock layers in which they occur.occur.
  52. 52. This online, interactive activity will helpThis online, interactive activity will help with your understanding of Index Fossilswith your understanding of Index Fossils and how they help with Relative Datingand how they help with Relative Dating www.phschool.comwww.phschool.com Webcode: cfp-2042Webcode: cfp-2042
  53. 53. Absolute Dating of rocksAbsolute Dating of rocks Absolute Dating/Radioactive DecayAbsolute Dating/Radioactive Decay is when scientists useis when scientists use radioactiveradioactive datingdating to determine the absolute agesto determine the absolute ages of rocks.of rocks. –Radioactive decay-over time certain elements break down, or decay, by releasing particles and energy. –Half life- The constant rate of decay of an element. (Carbon 14 has a half-life of 5,730 years)
  54. 54. Half life of Carbon-14Half life of Carbon-14
  55. 55. Will the amount of radioactive substance everWill the amount of radioactive substance ever be zero? Justify your answer.be zero? Justify your answer. Answer: No, the amount of radioactiveAnswer: No, the amount of radioactive material will never be zero because as longmaterial will never be zero because as long as you are cutting the material in half-thereas you are cutting the material in half-there will always be some left to cut.will always be some left to cut. How do scientists use the amount ofHow do scientists use the amount of radioactive elements found in rocks toradioactive elements found in rocks to determine the actual age of the rock?determine the actual age of the rock? Answer: Based on the amount of radioactiveAnswer: Based on the amount of radioactive material and what type of radioactivematerial and what type of radioactive material, they can calculate exactly how oldmaterial, they can calculate exactly how old the rock is.the rock is.
  56. 56. Is the process of absolute dating usingIs the process of absolute dating using radioactive elements error proof? Justify yourradioactive elements error proof? Justify your answer.answer. Answer: Yes, radioactive material decays at aAnswer: Yes, radioactive material decays at a constant rate always, therefore, the precise dateconstant rate always, therefore, the precise date will be reliable.will be reliable. How has the evolution of technology aidedHow has the evolution of technology aided scientists in their ability to date rock layers?scientists in their ability to date rock layers? Answer: This process would be impossible toAnswer: This process would be impossible to calculate without computers and necessarycalculate without computers and necessary technology to detect the amount of radioactivetechnology to detect the amount of radioactive material present.material present.
  57. 57. Remember the difference!Remember the difference! TheThe relative agerelative age of a rock is its ageof a rock is its age compared to other rocks.compared to other rocks. Use words like: “older or younger”Use words like: “older or younger” TheThe absolute ageabsolute age of a rock is the numberof a rock is the number of years since the rock was formed.of years since the rock was formed. Ex: 358-360 myaEx: 358-360 mya
  58. 58. Ice CoresIce Cores Scientists study ice cores to understandScientists study ice cores to understand how the climate has changed.how the climate has changed. Lower layers are older than higher layersLower layers are older than higher layers (Law of Superposition)(Law of Superposition) Layers record concentrations of gases likeLayers record concentrations of gases like COCO22 and deuterium (a heavy form ofand deuterium (a heavy form of hydrogen.hydrogen.
  59. 59. Where do scientists obtain ice cores from?Where do scientists obtain ice cores from? Answer: Scientists drive a hollow tube deep intoAnswer: Scientists drive a hollow tube deep into miles thick ice sheets in Antarctica andmiles thick ice sheets in Antarctica and Greenland or any glacier.Greenland or any glacier. Does global climate shift gradually or can it shiftDoes global climate shift gradually or can it shift rapidly?rapidly? Justify your answer by giving an example from theJustify your answer by giving an example from the link.link. Answer: Global climate can shift gradually,Answer: Global climate can shift gradually, sometimes in a matter of years. For example,sometimes in a matter of years. For example, she shift from the Pleistocene period (glacialshe shift from the Pleistocene period (glacial period) to today’s Holocene period occurred inperiod) to today’s Holocene period occurred in less than 5 years.less than 5 years.
  60. 60. What do scientists measure to determine whenWhat do scientists measure to determine when seasons occurred?seasons occurred? Answer: Scientists useAnswer: Scientists use lasers to measure the concentration of dustlasers to measure the concentration of dust particles in the ice core.particles in the ice core. Describe what is seen and can be interpreted byDescribe what is seen and can be interpreted by the image of an ice core analysis.the image of an ice core analysis. Answer:Answer: Based on the thickness of the bands scientistsBased on the thickness of the bands scientists can determine heavy or light snowfall amounts.can determine heavy or light snowfall amounts.
  61. 61. Continental Drift/PangeaContinental Drift/Pangea PangeaPangea-- ScientistsScientists believe today’sbelieve today’s continents oncecontinents once existed as oneexisted as one “supercontinent”“supercontinent” named Pangea.named Pangea. Pangea animation
  62. 62. Biological Evolution…evidence ofBiological Evolution…evidence of continental driftcontinental drift
  63. 63. Why do you think scientists believe that theWhy do you think scientists believe that the continents were once one big landmass?continents were once one big landmass? Answer: The shape of the continents seem to fitAnswer: The shape of the continents seem to fit together like a puzzle. Also, fossils of livingtogether like a puzzle. Also, fossils of living things found in one location can be found inthings found in one location can be found in another distant location across the ocean.another distant location across the ocean. What might have caused this landmass to driftWhat might have caused this landmass to drift apart?apart? Answer: Movement of tectonic plates.Answer: Movement of tectonic plates.

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