Geosphere Final Exam Study Guide

Geosphere Final ExamStudy Guide

Chapter 1Intro to Earth Systems1. Name and describe Earth’s 4 major spheresGeosphere-- nonliving, mostly solid rock divided into crust,mantle, and coreAtmosphere– a life-sustaining, thin, gaseous envelopesurrounding earthBiosphere– includes all life on earthHydrosphere-- all of the water on earth

Chapter 4Interactions with the Geosphere2. What are fossil fuels? How are they formed? A carbon-containing fuel that formed over millionsof years from the remains of living things. Ex: Coal (plant material), petroleum (plants andanimals buried in ancient seas), and natural gas(plants and animals buried in ancient seas)

Chapters 3, 5, and 6Earth’s Changing Surface3. What is the rock cycle? Describe how a rock can be transformedfrom an igneous rock, to a sedimentary rock, and then to ametamorphic rock. The rock cycle describes how each type of rock can betransformed from one type to another Igneous rock would need to be weathered, eroded away,and deposited in layers. The layers would need to becompacted and cemented together into a sedimentaryrock. Sedimentary Rocks pushed deep into the earth that areunder intense heat and pressure are transformed intometamorphic rocks

Chapters 3, 5, and 6Earth’s Changing Surface4. What is the difference between weathering, erosion, anddeposition? Weathering– the breakdown of rock into sediments Erosion– the picking up and carrying away of sediments Deposition– the dropping of sediments5. Describe the 2 categories of weathering. Explain the differenceand provide and example. Mechanical Weathering— physical forces break rock intosmaller pieces without changing the rock’s composition Ex: Frost wedging, roots growing between rocks Chemical Weathering– transformation of rock into 1 ormore new compounds Ex: Water creating acid rain that eats away atlimestone, or causes rust on metal structures

Chapters 3, 5, and 6Earth’s Changing Surface6. How does running water affect sediments? Running water erodes soil and can cause sediments tobe moved far from their origin. Humans have drastically increased the amount ofsediments carried by rivers7. What is a mass movement? What causes them? The transfer of rock and soil downslope due to gravity 4 Triggers: Saturation of surface materials with water Over-steepening of slopes Removal of vegetation Earthquakes

Chapters 8, 9, and 10Earth’s Structure and Plate Tectonics8. List the layers of the Earth in order, starting from the surface: CrustMantleCore9. How do we study the interior of the earth? Using seismic waves P & S waves travel at different speeds throughdifferent materials

Chapters 8, 9, and 10Earth’s Structure and Plate Tectonics10. What is the continental drift hypothesis? What were Wegener’s 5pieces of evidence to support it? The continents had once been joined to form a singlesupercontinent1. Continental jigsaw puzzle2. Evidence of glacial scarring in areas too warm todayfor glaciers3. Evidence of tropical plants (coal deposits) in areas toocold today for tropical plants4. Fossils of same organism across oceans that couldn’thave swum5. Matching rock types across continents

Chapters 8, 9, and 10Earth’s Structure and Plate Tectonics11. What is the theory of plate tectonics? Earth’s surface is broken into plates that move slowlyrelative to one another12. What is sea-floor spreading and where does it occur? The process of new ocean floor forming along Earth’s midocean ridges and slowly moves outward across oceanbasins

Chapters 8, 9, and 10Earth’s Structure and Plate Tectonics13. What evidence do scientists have that sea-floor spreading actually occurs? Magnetic strips in ocean floor rockEarthquake patternsMeasurements of the ages of ocean floor rocks14. What is subduction? What occurs at subduction zones? More dense oceanic lithosphere sinks beneath less denselithosphere– recycles back into the mantleDeep ocean trenches and earthquakes occur with volcanicmountains or islands

Chapters 8, 9, and 10Earth’s Structure and Plate Tectonics15. What occurs at a convergent boundary, divergent boundary, and transform? Convergent: mountains, deep ocean trenches,volcanoes, earthquakesDivergent: rift valley at mid ocean ridges, earthquakesTransform: earthquakes16. What is formed at continental-continental collisions, continental-oceaniccollisions, and oceanic-oceanic collisions? C-C: mountains & earthquakes (Himalayas)C-O: Deep ocean trenches, volcanic mountains,earthquakes (Andes Mountains in S. America)O-O: Deep ocean trenches, volcanic islands, earthquakes(Japan)

Chapters 8, 9, and 10Earth’s Structure and Plate Tectonics17. Why do convection currents occur? Due to differences in temperature and therefore densityof magma in the mantle Hot, Less dense magma rises Cool, more dense magma sinks

Chapter 12Earth’s History18. Define relative dating. Determining whether an object or event is older or youngerthan other objects or events19. What is the law of superposition? The principle that states that younger rocks lie above olderrocks in undisturbed sequences20. What is an index fossil? Fossils of organisms that lived during a relatively short,well-defined geologic time span (trilobites)

Chapter 12Earth’s History21. Define absolute dating. Any method of measuring the age of an event or object inyears22. What do scientists use Carbon-14 to date? Uranium-238? Why can’t theyuse the same isotope for both? Carbon-14 is used to date once living things Uranium 238 is used to date rocks Carbon-14 has such a short half life, the amount ofradioactive isotope remaining would be too small to measure23. How old is the earth (so far)? 4.6 Billion-ish years old

Chapter 12Earth’s History24. List the 3 Geologic Eras from Youngest to oldest. What life dominated each era?Cenozoic Era -- Mammals, primates, and humansMesozoic Era -- Early birds appear, first flowing plants,dinosaurs dominantPaleozoic Era -- dominated by fish, Amphibians,Early Reptiles, Land plants emerge

11. What is the theory of plate tectonics? Chapters 8, 9, and 10 Earth’s Structure and Plate Tectonics Earth’s surface is broken into plates that move slowly relative to one another The process of new ocean floor forming along Earth’s mid-ocea