Geosphere Final Exam Study Guide
Chapter 1 Intro to Earth Systems 1. Name and describe Earth s 4 major spheres Geosphere-- nonliving, mostly solid rock divided into crust, mantle, and core Atmosphere a life-sustaining, thin, gaseous envelope surrounding earth Biosphere includes all life on earth Hydrosphere-- all of the water on earth
Chapter 4 Interactions with the Geosphere 2. What are fossil fuels? How are they formed? A carbon-containing fuel that formed over millions of years from the remains of living things. Ex: Coal (plant material), petroleum (plants and animals buried in ancient seas), and natural gas (plants and animals buried in ancient seas)
Chapters 3, 5, and 6 Earth s Changing Surface 3. What is the rock cycle? Describe how a rock can be transformed from an igneous rock, to a sedimentary rock, and then to a metamorphic rock. The rock cycle describes how each type of rock can be transformed from one type to another Igneous rock would need to be weathered, eroded away, and deposited in layers. The layers would need to be compacted and cemented together into a sedimentary rock. Sedimentary Rocks pushed deep into the earth that are under intense heat and pressure are transformed into metamorphic rocks
Chapters 3, 5, and 6 Earth s Changing Surface 4. What is the difference between weathering, erosion, and deposition? Weathering the breakdown of rock into sediments Erosion the picking up and carrying away of sediments Deposition the dropping of sediments 5. Describe the 2 categories of weathering. Explain the difference and provide and example. Mechanical Weathering physical forces break rock into smaller pieces without changing the rock s composition Ex: Frost wedging, roots growing between rocks Chemical Weathering transformation of rock into 1 or more new compounds Ex: Water creating acid rain that eats away at limestone, or causes rust on metal structures
Chapters 3, 5, and 6 Earth s Changing Surface 6. How does running water affect sediments? Running water erodes soil and can cause sediments to be moved far from their origin. Humans have drastically increased the amount of sediments carried by rivers 7. 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 10 Earth s Structure and Plate Tectonics 8. List the layers of the Earth in order, starting from the surface: Crust Mantle Core 9. How do we study the interior of the earth? Using seismic waves P & S waves travel at different speeds through different materials
Chapters 8, 9, and 10 Earth s Structure and Plate Tectonics 10. What is the continental drift hypothesis? What were Wegener s 5 pieces of evidence to support it? The continents had once been joined to form a single supercontinent 1. Continental jigsaw puzzle 2. Evidence of glacial scarring in areas too warm today for glaciers 3. Evidence of tropical plants (coal deposits) in areas too cold today for tropical plants 4. Fossils of same organism across oceans that couldn t have swum 5. Matching rock types across continents
Chapters 8, 9, and 10 Earth s Structure and Plate Tectonics 11. What is the theory of plate tectonics? Earth s surface is broken into plates that move slowly relative to one another 12. 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 ocean basins
Chapters 8, 9, and 10 Earth s Structure and Plate Tectonics 13. What evidence do scientists have that sea-floor spreading actually occurs? Magnetic strips in ocean floor rock Earthquake patterns Measurements of the ages of ocean floor rocks 14. What is subduction? What occurs at subduction zones? More dense oceanic lithosphere sinks beneath less dense lithosphere recycles back into the mantle Deep ocean trenches and earthquakes occur with volcanic mountains or islands
Chapters 8, 9, and 10 Earth s Structure and Plate Tectonics 15. What occurs at a convergent boundary, divergent boundary, and transform? Convergent: mountains, deep ocean trenches, volcanoes, earthquakes Divergent: rift valley at mid ocean ridges, earthquakes Transform: earthquakes 16. What is formed at continental-continental collisions, continental-oceanic collisions, 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 10 Earth s Structure and Plate Tectonics 17. Why do convection currents occur? Due to differences in temperature and therefore density of magma in the mantle Hot, Less dense magma rises Cool, more dense magma sinks
18. Define relative dating. 19. What is the law of superposition? 20. What is an index fossil? Chapter 12 Earth s History Determining whether an object or event is older or younger than other objects or events The principle that states that younger rocks lie above older rocks in undisturbed sequences Fossils of organisms that lived during a relatively short, well-defined geologic time span (trilobites)
21. Define absolute dating. Chapter 12 Earth s History Any method of measuring the age of an event or object in years 22. What do scientists use Carbon-14 to date? Uranium-238? Why can t they use 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 of radioactive isotope remaining would be too small to measure 23. How old is the earth (so far)? 4.6 Billion-ish years old
Chapter 12 Earth s History 24. List the 3 Geologic Eras from Youngest to oldest. What life dominated each era? Cenozoic Era Mesozoic Era -- Mammals, primates, and humans -- Early birds appear, first flowing plants, dinosaurs dominant Paleozoic Era -- dominated by fish, Amphibians, Early Reptiles, Land plants emerge