Geology Test 1

Choose the list that accurately shows rock composition decreasing in silica and increasing in iron and magnesium. Select one: a. granite, basalt, peridotite b. peridotite, basalt, granite c. basalt, peridotite, granite d. granite, peridotite, basalt

a. granite, basalt, peridotite

The rate of sea-floor spreading: Select one: a. is fast enough to account for the formation and destruction of oceans many times in Earth's history. b. depends on the type of plate boundary (i.e., convergent, transform) at which it occurs. c. is faster along the Mid-Atlantic Ridge than along the East Pacific Rise. d. has remained constant throughout Earth's history.

a. is fast enough to account for the formation and destruction of oceans many times in Earth's history.

Identify the FALSE statement. Stellar nucleosynthesis: Select one: a. is the term for the process by which supernovae create the heavier elements. b. produces elements up to atomic number 26 (iron) in low-mass stars like our Sun. c. is a normal process that happens during the life cycle of stars. d. reactions vary and are dependent on the mass of the star.

a. is the term for the process by which supernovae create the heavier elements.

Accretionary prisms form due to what process? Select one: a. subduction b. divergence c. rifting d. transform motion

a. subduction

Earthquakes but not volcanoes occur in San Francisco because: Select one: a. two plates are moving past each other there. b. a continental plate is colliding with another continental plate there. c. an oceanic plate is converging with a continental plate and subducting there. d. two plates are diverging there.

a. two plates are moving past each other there.

Earthquakes are generated: Select one: a. when rock moves along faults. b. as pressure and temperature increase with depth in the Earth. c. by the Earth's magnetic field. d. in the mantle.

a. when rock moves along faults

Identify the FALSE statement. Select one: a. Positive magnetic anomalies occur over areas of sea floor when the poles of Earth's magnetic field and the paleopoles preserved in the sea-floor basalt agree; negative anomalies occur when they are opposite each other. b. All polarity chrons are the same length of time; they differ only in the magnetic strengths they represent. c. The series of rock stripes parallel to and bilaterally symmetrical across the mid-ocean ridge record the sequence of Earth's magnetic reversals over time. d. The width of each rock stripe is a measure of how long the polar direction remained constant.

b. All polarity chrons are the same length of time; they differ only in the magnetic strengths they represent.

Identify the FALSE statement. Select one: a. Most meteoroids are fragments derived from the Oort Cloud, Kuiper Belt, or asteroid belt; some are chips of the moon or Mars. b. Meteoroids that explode into fireballs are termed chondrites. c. Catastrophic collisions of meteoroids with Earth are rare, but have happened during Earth's past and probably will happen again. d. A glowing streak of atmospheric gas roughly 150 km high is termed a meteor ("shooting star").

b. Meteoroids that explode into fireballs are termed chondrites.

Identify the FALSE statement. Select one: a. As the sea floor spreads, the asthenosphere rises, melts to become magma, and fills the space between plates. b. Some magma generated during sea-floor spreading spills out to produce a new layer of sea floor called gabbro. c. Some magma generated during sea-floor spreading erupts from submarine volcanoes. d. Observers in research submersibles have seen submarine volcanoes.

b. Some magma generated during sea-floor spreading spills out to produce a new layer of sea floor called gabbro.

Which of the following serve as a trap for cosmic rays and shield life on Earth from excessive radiation? Select one: a. Oort Cloud b. Van Allen belts c. Kuiper Belt d. Asteroid belt

b. Van Allen belts

Identify the FALSE statement. Bathymetric maps show the following features of the sea floor: Select one: a. broad flat abyssal plains at depths of 4 to 5 km below sea level. b. bands of vertical fractures (fracture zones) that run parallel to mid-ocean ridges. c. elongate trenches that reach 8 to 12 km deep. d. chains of seamounts (submarine mountains), some of which are active volcanoes.

b. bands of vertical fractures (fracture zones) that run parallel to mid-ocean ridges.

Fusion reactions happen at a slower rate: Select one: a. in stars farther away from Earth? b. in smaller stars than in bigger ones. c. in hotter stars than cooler ones. d. in stars in larger galaxies than stars in smaller galaxies.

b. in smaller stars than in bigger ones.

The center of a mid-ocean ridge is where: Select one: a. molten basalt subducts back into Earth. b. new oceanic lithosphere is being created. c. you find the oldest, densest, hottest oceanic crust. d. two continental plates converge.

b. new oceanic lithosphere is being created.

Select the FALSE statement. The Doppler effect: Select one: a. occurs when the frequency of sound waves received is greater if the wave source is moving toward you than if it's moving away. b. occurs when the pitch of a sound will get higher if the source is receding. c. is relevant to sound but can also be applied to the behavior of light waves. d. is the basic explanation for the red shift of light in our Universe.

b. occurs when the pitch of a sound will get higher if the source is receding.

Continents: Select one: a. plow their way through the sea floor. b. passively ride along as the sea floor spreads. c. may subduct if they are old and dense enough. d. have retained the same size and shape througout Earth's history

b. passively ride along as the sea floor spreads.

Which of the following was NOT a line of evidence used by Wegener to develop this theory that continents drift? Select one: a. the distribution of fossil species b. the presence of earthquakes in seismic belts along trenches, ridges, and fracture zones c. the location of ancient till deposits and striations that indicated glacial movement toward the interior of continents d. matching mountain chains on continents currently separated by oceans

b. the presence of earthquakes in seismic belts along trenches, ridges, and fracture zones

The global occurrence of earthquakes reveals that: Select one: a. their locations are randomly scattered. b. they usually occur on the boundaries of plates or at hot spots. c. they usually occur at the center of plates. d. they prove that Earth is splitting apart (rifting) at all plate boundaries.

b. they usually occur on the boundaries of plates or at hot spots.

Radiometric dating of a magnetic anomaly stripe of rock that is 225 km away from the mid-ocean ridge axis gives an age of 4.5 million years. Assuming a constant rate, sea-floor spreading in this area occurs at a rate of: Select one: a. 50 km per year. b. 1,012.5 km per year. c. 5 cm per year. d. 20,000 cm per year.

c. 5 cm per year.

Identify the FALSE statement. Select one: a. A fifth-generation star would have a greater proportion of heavier elements than a second-generation star. b. An accretionary disk eventually grows hot and massive enough to become a protostar, then a star. c. Our Universe is so old there are no first-generation stars left in it. d. Dense regions of a nebula pull in surrounding material and therefore grow in mass and density and rotate faster.

c. Our Universe is so old there are no first-generation stars left in it.

Plate tectonics theory took decades to be accepted because: Select one: a. most of Wegener's ideas turned out to be wrong. b. of pure stubbornness by the scientific community. c. Wegener couldn't explain how continents moved. d. climate, fossil distributions, and land shape offered conflicting evidence

c. Wegener couldn't explain how continents moved

The chain of volcanoes along the west coast of South America (the Andes Mountains) exists because: Select one: a. an oceanic plate is sliding past the South American Plate and heading toward the northwest. b. an oceanic plate is rifting apart from the South American Plate. c. an oceanic plate is subducting under the western edge of the South American Plate. d. basalt is pushing up through the trench that parallels the west coast of South America.

c. an oceanic plate is subducting under the western edge of the South American Plate.

The heavier elements on Earth (those with atomic numbers greater than 5): Select one: a. were in existence at the moment of the Big Bang. b. were formed immediately after the Big Bang. c. are formed by stellar nucleosynthesis during the life cycles of existing stars. d. are constantly being created by fusion in our Sun and blown here by the solar wind.

c. are formed by stellar nucleosynthesis during the life cycles of existing stars.

Boundaries between Earth's layers: Select one: a. are noted by the changing metal content of each layer. b. are defined by abrupt changes in earthquake density. c. are places where there is an abrupt change in the density of rock. d. occur because of tides.

c. are places where there is an abrupt change in the density of rock.

Identify the FALSE statement. Oceanic lithosphere: Select one: a. gets older and thicker as it gets farther from the ridge axis. b. gets cooler as it gets farther from the ridge axis. c. attains its maximum thickness when it is about 800 million years old. d. that is 10 million years old is cool enough to be denser than the asthenosphere, so it can sink down through the asthenosphere.

c. attains its maximum thickness when it is about 800 million years old.

Choose the FALSE statement. Pangaea: Select one: a. means "all land." b. started to break apart during the Mesozoic. c. broke apart due to the force created by Earth's rotation. d. is the name for the most recent supercontinent; others have existed.

c. broke apart due to the force created by Earth's rotation

Identify the FALSE statement. The rate of plate motion: Select one: a. can be determined to within millimeters by using the Global Positioning System (GPS). b. can be expressed as relative plate velocity, which describes movement of one plate in relation to another plate. c. can range from 100 to 150 cm per year. d. can be expressed as absolute plate velocity, which describes movement of a single plate relative to a fixed point.

c. can range from 100 to 150 cm per year.

Choose the FALSE statement. Magnetic anomalies are: Select one: a. places where the magnetic field strength is either greater or less than the expected strength. b. termed normal if the atomic dipoles match Earth's current magnetic field and point from north to south. c. found only on the sea floor. d. measured with an instrument called a magnetometer.

c. found only on the sea floor

Choose the FALSE statement. Magnetic reversals: Select one: a. have occurred many times, but not at regular intervals. b. reflect changes in the direction of flow of molten iron in Earth's outer core. c. happen slowly as the magnetic poles wander and finally cross the equator. d. are a global phenomenon.

c. happen slowly as the magnetic poles wander and finally cross the equator.

After reclassification in 2005, Pluto is no longer classified as a planet because it: Select one: a. does not orbit a star. b. is not spherical. c. has not cleared its orbit of other matter. d. is not large enough.

c. has not cleared its orbit of other matter

Imagine that the light you observe from space is exhibiting a blue shift. This would mean that the Universe: Select one: a. is expanding. b. is traveling faster than the speed of light. c. is collapsing. d. is traveling slower than the speed of sound.

c. is collapsing.

Which of the following statements is FALSE? Peridotite: Select one: a. is rare at Earth's surface. b. is the most abundant rock in Earth. c. is felsic. d. is very rich in iron and magnesium, very poor in silica

c. is felsic.

Identify the FALSE statement. The categories of materials that constitute Earth include: Select one: a. melts; solid materials that have melted due to heat. b. volatiles; materials that easily become gases at ordinary Earth surface temperatures. c. organic chemicals; all carbon-containing compounds, including oil, protein, carbon dioxide, and calcium carbonate. d. alloys; mixtures of more than one type of metal atom.

c. organic chemicals; all carbon-containing compounds, including oil, protein, carbon dioxide, and calcium carbonate.

Identify the FALSE statement. The Big Bang theory states that: Select one: a. nebulae condensed and heated to become spinning accretion disks, then protostars, then stars. b. the temperature had to fall below 1 billion degrees to allow elements above Hydrogen to form. c. the process of atom creation, termed Big Bang nucleosynthesis, produced all known natural elements. d. as the Universe cooled, atoms and molecules accumulated in patchy clouds of gas called nebulae.

c. the process of atom creation, termed Big Bang nucleosynthesis, produced all known natural elements.

Choose the one type of deposit that is not typical of a tropical/subtropical climate. Select one: a. coal b. reefs c. till d. salt

c. till

Jupiter, Saturn, and Neptune are: Select one: a. terrestrial planets. b. planetesimals. c. rocky planets. d. Jovian planets.

d. Jovian planets.

Identify the FALSE statement. According to the mantle plume model, hot-spot plumes: Select one: a. stream upward slowly because their hot rock is less dense than the overlying rock. b. partially melt the base of the overlying lithosphere, and the magma that is formed rises toward the surface. c. produce volcanoes that do not always coincide with a plate boundary. d. are thought to originate at the crust-mantle boundary.

d. are thought to originate at the crust-mantle boundary.

Which of the following groups of elements make up the most mass of the whole Earth? Select one: a. magnesium, iron, carbon dioxide, and argon b. nitrogen, oxygen, helium, and carbon dioxide c. silicon, iron, potassium, and sodium d. iron, oxygen, silicon, and magnesium

d. iron, oxygen, silicon, and magnesium

The two most common gases of Earth's atmosphere and their percentages are: Select one: a. carbon dioxide (CO2), 21%, and oxygen (O2), 78%. b. water (H2O), 21%, and oxygen (O2), 78%. c. oxygen (O2), 21%, and carbon dioxide (CO2), 78%. d. nitrogen (N2), 78%, and oxygen (O2), 21%

d. nitrogen (N2), 78%, and oxygen (O2), 21%

Earths magnetic field is generated in: Select one: a. the crust. b. the upper mantle. c. the inner core. d. the outer core.

d. the outer core.

The heliocentric model: Select one: a. states that the Earth is the center of the Universe, and the Moon and planets revolve around it. b. was developed by Ptolemy and supported by his mathematical equations. c. was widely accepted during the Middle Ages (~476-1400 C.E.). d. was supported by Johannes Kepler's observation that planets follow an elliptical orbit.

d. was supported by Johannes Kepler's observation that planets follow an elliptical orbit.