2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 1/32 Laboratory 2 : Plate Tectonics and the Rock Cycle Due Jan 21 at 11:59pm Points 15 Questions 40 Available Jan 12 at 9am - Jan 21 at 11:59pm Time Limit None Allowed Attempts 3 Instructions Use the quiz questions below to complete the answer sheet for the Laboratory 2 (Plate Tectonics and the Rock Cycle) exercise. The Pre-lab Video serves as an introduction to the topics covered in this lab. Find the Pre-lab Video here (https://www.youtube.com/watch?v=b5P_OQ_5gyg&feature=youtu.be) . NOTE ABOUT IMAGES : You can find all of the figures embedded in this quiz in Files --> Lab Instructions --> Lab 2: Plate Tectonics & the Rock Cycle . Figures in the Questions are in that folder and are labeled with the relevant question number. Figures in the Introduction are within the folder Figures in Introduction . You have two attempts for this quiz. Some thought-provoking questions and discussion ideas to think about. Before you make your first attempt on Lab 2 this week watch the video (link embedded below) showing the tectonic plate and paleogeographic evolution of Earth over the past 540 million years. Pay attention to where the continents (or segments of continents) are located over geologic time and the tectonic boundaries (divergent, convergent and transform) and motion that cause the change. Pay attention paleo-sea level and mountain building events that occur over time. Think about how the paleogeographic changes (i.e., latitude location, altitude, continentality) will affect the climate (modern climate zone map shown below the Plate Tectonic video) and paleoenvironment of a given location. For example 320 million years ago the continental landmasses presently comprising India, southern South America, southern Africa, Australia, and Antarctica were situated over the south pole. Think about polar latitudes and climates today? At this time period (320 million years ago) North America and western Europe were located near the equator. Think about equatorial latitudes and climate today. Of course, life forms were very different way back in time, but the paleoclimate zones would be strongly controlled by tectonic plate configurations. Some questions to think about: 1. Why does Australia have such unique faunal (animals) assemblages that have evolved over the past 150 million years. 2. Why do you think North America and Eurasia have similar grazing animals (deer family, ungulates) that have evolved over the past 60 million years.

2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 2/32 This quiz was locked Jan 21 at 11:59pm. Attempt History Attempt Time Score LATEST Attempt 1 155 minutes 13 out of 15  Answers will be shown after your last attempt Score for this attempt: 13 out of 15 Submitted Jan 21 at 6:05pm This attempt took 155 minutes.  Question 1 0.2 / 0.2 pts 3. Africa and South America have primates present on both continents. What does this tell you about the timing of when a common primate ancestor lived on earth. Human evolved from the African primate group at a later time. Plate Tectonics, 540Ma - Modern World - Scotese Animatio Plate Tectonics, 540Ma - Modern World - Scotese Animatio … climate-zones2.jpg 5 major climate zones of the world. Cheating or plagiarism of any kind will not be tolerated in ESS 101. This includes copying answers from a friend or classmate, copying answers verbatim found on the internet or other literary sources, or copying any work that may answer the question being asked. Make sure you always use your own words when answering the questions in the homework and cite appropriate references if you use them to help you answer the

2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 4/32 Figure 2-1: Earth’s tectonic plates. The black lines indicate the boundaries between plates, and the red arrows indicate the relative motions at plate boundaries . Chemical and physical layers of the earth Earth’s structure can be classified by chemical composition or by physical properties. The chemical layers of the Earth are the crust, mantle, and core. The crust is mainly composed of igneous rocks (that is, rocks that formed when hot magma cooled at earth’s surface). Continental crust is made of felsic (silica-rich) rocks like granite, and oceanic crust is made of mafic (silica-poor) rocks such as basalt. Below the crust is the mantle , which is made of silicate minerals that are rich in iron and magnesium. Generally, rocks that are silica-rich tend to have relatively lower iron-magnesium (Fe-Mg) content. The physical layers of the outer earth are the lithosphere and the asthenosphere (Figure 2-2). Tectonic plates are pieces of the lithosphere , a layer of brittle rock. The plates slide over the asthenosphere, a layer of ductile, mantle rock. 1

2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 5/32   Figure 2-2: Cross-section of the outer solid Earth . The lithospheric plates slide over the asthenosphere . Oceanic lithosphere forms at mid-ocean ridges (divergent margins) and descends back into the asthenosphere in subduction zones (convergent margins). 2 Plate Boundaries Volcanoes and mountains form at plate boundaries, and plate boundaries produce strong earthquakes. There are three types of plate boundary: 1. Divergent , where two plates are moving apart. 2. Convergent , where two plates are moving together. There are three different types of convergent margins: Ocean-ocean , where oceanic crust converges with oceanic crust. At this type of margin, the denser of the two plates will dive beneath the other, and create a subduction zone (e.g. the Marianas Trench). Ocean-continent , where oceanic crust converges with continental crust. At this type of margin, the denser oceanic crust will dive beneath the less dense continental crust and create a subduction zone (e.g. the Cascadia subduction zone). Continent-continent , where continental crust converges with continental crust. At this type of margin, both plates are relatively buoyant and do not want to sink down. Therefore, subduction does not occur and the two plates collide together to form mountain ranges such as the Himalaya Mountains (formed by the collision of the Indian and Eurasian plates). 3. Transform , where two plates with ocean and/or continental crust are sliding past each other. Volcanoes Volcanoes are places where liquid rock erupts onto the surface of the earth. Volcanoes often form at divergent and convergent boundaries, but they can also form in the middle of plates due to mantle hot spots or rifting. Some important concepts and distinctions for volcanic systems include:

2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 7/32 from basalt to andesite . Continental arc magmas pass through and mix with continental lithosphere, which is more felsic. As a result, continental-arc magmas are on average andesitic and range in composition from basaltic to rhyolitic. Figure 2-4: A Schematic of an island arc at an ocean-ocean convergent margin. B Schematic of a continental arc at a continent-continent convergent margin. Table 2-1 provides an overview of the different magma generation processes, magma compositions, and landforms found at each type of plate boundary. Intraplate Volcanoes: (1) Hot spot Volcanism A hotspot is caused by the upwelling of hot, buoyant material in the deep mantle. The upwelling rock melts as it nears the earth’s surface and causes a volcano to form. As the tectonic plate moves over the stationary hot spot, a line of volcanoes is created over the course of millions of years. If a hotspot is located beneath oceanic crust, then it can produce a chain of basaltic islands erupted onto the ocean floor, such as the Hawaii-Emperor Seamount Chain (the Hawaii hotspot, Figure 2-5C). If a hotspot is located beneath continental crust, then it can produce a chain of volcanoes on land, such as the eastern Snake River Plain (the Yellowstone hotspot). Hot spot volcanism is typically basaltic. See this video about hot spots. (https://www.iris.edu/hq/inclass/animation/hotspot_volcanism_thermal_plume) Figure 2-5: Schematic of hot spot volcanism. A Rising plume of hot mantle rock B Hot spot with a large pool of magma under plate, causing lava to flood onto the surface and cool to form basalt. C Formation of an island chain as the plate moves over the stationary hot spot . 3 4

2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 8/32   Table 1 : A Synthesis of plate boundaries, magma formation processes, magma compositions, plate tectonic landforms, and real-world examples Plate Boundary Magma generation Magma composition Landforms produced Examples DIVERGENT decrompression of mantle basaltic (mafic) mid-ocean ridge; continental rift Mid-Atlantic Ridge, Juan de Fuca Ridge, East African Rift CONVERGENT (ocean-continent subduction) dehydration of subducting slab, hydration melting of mantle, and mixing with continental crust andesitic to dacitic (intermediate) continental volcanic arc Cascadia Subduction zone (PNW), Andes Mountains (South America) CONVERGENT (ocean-ocean subduction) dehydration of subducting slab, hydration melting of mantle basaltic to andesitic island arc Aleutian Islands, Philippines CONVERGENT (continent-continent collision) partial melting of continental crust due to collision thickening granitic (plutonism) high non-volcanic mountain range (interior of continent) Himalayas Alps, Appalachian Mountains (ancient collision mountain range) TRANSFORM uncommon N/A small mountains and basins along "bends in fault" San Andreas Fault, California Note: We do not discuss continent-continent convergence in this lab. For questions 1 to 28, open up the large JPEG file of the Plate Tectonics Map of the Circum- Pacific Region (https://canvas.uw.edu/courses/1699809/files/113584913/download? download_frd=1) and/or look at the cropped figures provided below The map title is located in the upper left corner of the map. Directly below the map's title, the bathymetry ( ocean depth ) scale is shown. Use this information to answer question 1 (a-c).

2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 10/32 0 Answer 3: 8000 Answer 4: darker   Question 3 0.4 / 0.4 pts Let's move down to the bottom left corner of the map. The contributing geoscientists, publication information, and map scale are shown on this portion of the map. Use this information to answer question 2 (a-d). Look at the publication information. (a) What organization published the map? [ Select ]

2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 11/32 Answer 1: U.S. Geological Survey American Association of Petroleum Geologists U.S. Forestry Service U.S. National Park Service Answer 2: 1984 1971 1996 2000 Answer 3: miles kilometers nautical miles feet Answer 4: 100,000 17,000,000 1 24,000  (b) What year was the map published? [ Select ] Look at the bar scales and the representative fraction. (c) What distance units are not used for the three bar scales shown on the map? feet (d) One distance unit on the map equals [ Select ] distance units on the surface of the earth. Look at the map information shown on the upper right corner of the map. The Map Explanation is shown here (i.e. symbols showing tectonics plate motions, paleo-magnetic anomalies, volcanoes, and earthquake epicenters and focal depths). We cropped this section of the map and enlarged it so you can focus on the important information conveyed in the map explanation . Use this to answer questions 3-9.

2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 13/32 Transform Boundary A Divergent Boundary B  Question 5 0.2 / 0.2 pts True False  Question 6 0.2 / 0.2 pts kilometers centimeters meters inches feet  Question 7 0.3 / 0.3 pts using measurement from the paleomagnetic stripes using high-resolution gps satellites measuring the rate of displacement between the coastline of North America and Europe using traces of active mantle hotspots using displacement markers on ocean floor  The open displacement arrows shown adjacent to the respective plate boundaries in question 4 show relative motion of the tectonic plates. Plate motion velocities on the map are shown in ____________ per year. Absolute plate velocity was determined ______________ the time this map was published? Hint: Read the detailed explanation provided by the absolute plate motion vector arrow shown in the map explanation.

2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 14/32 Question 8 0.2 / 0.2 pts 500 150 5000 100,000 1000  Question 9 0.2 / 0.2 pts hot spot traces potassium argon ages plate velocities geomagnetic polarity time scale  Question 10 0.2 / 0.2 pts blue purple green red  Volcanoes are designated on the map by magenta colored patterns. Active volcanoes in historic time are differentiated by eruption histories that have occurred within the past _________ years. Magnetic lineations (magnetic stripes or anomalies) are designated on the tectonic map by thin black lines. The magnetic anomaly numbers are correlated with the ______________ on the map. What color of dot/triangle designates the shallowest focused earthquakes? The Geomagnetic Polarity Time Scale (GPTS) is located directly below the map explanation. We cropped this section of the map and enlarged it so you can focus on the important information conveyed by this time scale (enlarged section shown as GPTS jpeg). As we discussed in lecture, geoscientists believe that the magnetic field is generated by electric currents due to the motion of convection currents of molten iron in the Earth's outer core. The magnetic field polarity can flip-flop (reverse) due to complexities in convection and field strength within different regions of the outer core (leave the details to geophysicists, paleomagnetists and geochronologists).

2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 16/32  Question 11 0.2 / 0.2 pts Answer 1: black Answer 2: white  Question 12 0.2 / 0.2 pts the numbers increase over the first million years and then decrease they increase with increasing age there is no relationship between paleomagnetic numbers and age of ocean crust they decrease with increasing age  Question 13 0.5 / 0.5 pts Normal polarity anomalies (i.e., earth’s north and south magnetic poles were the same as today, where compass needles all point towards the magnetic north pole) are shown by black colored stripes and reversed polarity anomalies (i.e., compass needles, or magnetite crystal within basaltic ocean crust, all point towards the magnetic south pole) are shown by white colored stripes. Each magnetic anomaly (stripe) interval is defined as chron. Note that some chrons are subdivided into subchrons, where brief excursions occur and the magnetic field direction changes from the dominant direction. Look closely at the paleomagnetic time scale. How do the paleomagnetic numbers change with increasing age? If you look at the Atlantic ocean floor adjacent to the east coast of the United States, the oldest paleomagnetic stripe is Number M25 . How old is the basaltic ocean crust based on the presence of magnetic stripe M25 on the ocean floor?

2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 17/32 200 million years 5.5 million years 60 million years 15 million years 147 million years  Question 14 0.5 / 0.5 pts after 100 million years ago after 147 million years ago prior to 147 million years ago prior to 200 million years ago exactly at 147 million years ago  Based on the paleomagnetic age from question 13, you can infer that the timing of initial rifting of North America from North Africa and the initial formation of the North Atlantic Ocean occurred ___________. Now that you have an understanding of the diverse information provided on these maps, we will now look at different geographic regions of the circum-Pacific Basin. You

2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 19/32 Granitic - the magma is derived from partial melting of continental crust Basaltic - the magma is derived from partial melting of the upper mantle (asthenosphere) and forms the ocean crust  Question 18 0.2 / 0.2 pts True False  Question 19 0.5 / 0.5 pts The stripes form as magnetite crystals are aligned with the prevailing magnetic field direction as ocean crust forms and solidifies. The stripes represent different composition of ocean crust. The presence of these stripes reinforces the idea that the plates are moving apart. The stripes form from transform faults offsetting the seafloor spreading ridge.  Question 20 0.5 / 0.5 pts differential seafloor spreading rate on each side of the ridge error in the radiometric dating of the seafloor hotspot volcanism cause plate to change directions magnetic stripes were not recorded within all segments of ocean crust   The topography is higher at this plate margin compared to the surrounding ocean basin. Observe the nearly symmetrical ‘stripes’ oriented parallel to the mid-ocean ridge. Which of the following statement are correct regarding paleomagnetic stripes? What could be a possible explanation for the asymmetry in these stripes (i.e., paleomagnetic stripes do not have the same spacing on each side of the spreading ridge)? Find the west coast of South America on the plate tectonic map of the circum-Pacific region (southeast quadrant). Use this part of the map to answer questions 20 to 23 .

2/25/24, 6:21 PM Laboratory 2 : Plate Tectonics and the Rock Cycle: ESS 101 B Wi 24: Introduction To Geology And Societal Impacts https://canvas.uw.edu/courses/1699809/quizzes/1953691 20/32 Question 21 0.2 / 0.2 pts divergent collision (continent-continent) transform convergent (ocean-ocean) convergent (ocean-continental)  Question 22 0.2 / 0.2 pts Pacific, South American African, Scotia Carribean, Cocos South American, Nazca  Question 23 0.2 / 0.2 pts Andes Mountains Tibetan Plateau Appalacian Mountains Amazon Rainforest  Question 24 0.2 / 0.2 pts Basaltic - the magma is derived from partial melting of the upper mantle (asthenosphere) and forms the ocean crust Granitic - the magma is derived from partial melting of continental crust Andesitic - the magma is derived from partial melt of ocean crust as it is subducted under continental crust, and it also contains marine sediment and water  What type of plate boundary is this? Which tectonic plates share this boundary? What topographic feature is produced on the continent by this plate motion? What type of igneous rock (formed from magma/lava) is produced here? We've cropped the map to show the Juan de Fuca plate off the coast of Washington State on the plate tectonic map of the circum-