Quizzes

Which two gemstones are polymorphs of the mineral corundum (Al2O3)?

sapphires and rubies

A rock that forms from the weathered products of preexisting rocks is classified as _______.

sedimentary

Which of the following sedimentary rocks would you expect to have been deposited in the calmest (i.e., slowest moving) water?

shale

The most common minerals in the Earth's crust are _______.

silicates

Which silicate structure is represented by Figure 6.1?

single chain

The faster a magma cools, the ________ the crystals will be in the resulting igneous rock.

smaller

Most of the Earth's economic occurrences (ores) of industrial metals occur in the form of ________ minerals.

sulfide and oxide

Mount St. Helens, Soufrière Hills, Lassen Peak, Krakatoa, Vesuvius, and Mount Pinatubo are all examples of _______.

volcanoes that have erupted explosively

Which one of the following is not a property of magma that directly determines the nature of a volcanic eruption?

volume

The most abundant gases typically emitted during volcanism are _______.

water and carbon dioxide

The great sheets or floods of magma that are extruded to form large igneous provinces tend to have what composition?

basaltic

The solids most commonly precipitated by water-dwelling organisms in order to build their shells and skeletons are ______.

calcium carbonate (CaCO3) and silica (SiO2)

The approximate age of the Earth that is currently most widely accepted in the geologic community is _______.

4.6 billion years

The range of typical magma temperatures in the Earth's crust is approximately _______.

600-1300 °C

Which of the following is not thought to contribute to the motion of the Earth's tectonic plates? A. downward slope of the lithosphere between mid-ocean ridges and oceanic trenches B. magnetic attraction between the Earth's liquid outer core and the lithosphere C. increasing density of the plate with increasing distance from the divergent plate boundary D. convective motion of the Earth's mantle

B

What is the tendency of some minerals to break preferentially in certain directions called?

Cleavage

The longer sediment has been transported before it is deposited and lithified into a sedimentary rock, ___________________. A. the smaller the sediment particles B. the more rounded the sediment particles C. the better the sorting of the sediment particles D. all of the above E. none of the above

D

Which is true about continental landmasses on opposite sides of the Atlantic Ocean? A. They appear as if they could fit together like pieces of a jigsaw puzzle. B. They contain some similar rock formations that look as if they could once have been connected. C. They contain some fossils of identical land animals and plants that could not easily have arisen independently on opposite sides of the ocean. D. all of the above E. none of the above

D

Which of the following represents a process by which minerals can form? A. solidification of a melt B. precipitation from water C. solid-state diffusion D. all of the above E. none of the above

D

What is the name of the feature indicated by the arrow in Figure 9.2?

Dike

Which statement about dolostone is true?

Dolostone forms by alteration or replacement of limestone by magnesium-rich fluids.

Pick out the false statement. A. When an oceanic plate subducts under another oceanic plate, a volcanic island arc is formed. B. Mountain-building is particularly intense where two plates of continental lithosphere converge. C. Oceanic lithosphere eventually subducts into the mantle and probably melts there. D. Continental rifts represent incipient divergent plate boundaries. E. When a tectonic plate consisting of oceanic lithosphere converges with a plate consisting of continental lithosphere, the two plates will annihilate each other.

E

What does the formation of sedimentary rocks involve? A. weathering of preexisting rock B. transportation of rock fragments or matter dissolved in water (solute) C. deposition of rock fragments or precipitation of solutes D. burial and diagenesis E. all of the above

E

Which of the following geologic features or processes tends to be strongly associated with tectonic plate boundaries? A. earthquakes B. mountain ranges C. volcanoes D. rock deformation E. all of the above

E

Which of the following is a contribution of the science of geology to human society? A. identification and extraction of mineral and energy resources B. mitigating the dangers of natural hazards like earthquakes, volcanoes, landslides, and floods C. cleaning up and preventing environmental contamination D. revealing Earth's history E. All of the above

E

Which of the following is false about hot spots? A. They are caused by a narrow plume of rising mantle rock originating near the core-mantle boundary. B. The Hawaiian Islands were formed by a hot spot. C. The position of hot spots with respect to the Earth's axis is relatively stationary over time. D. The geothermal activity in Yellowstone National Park is probably caused by a hot spot E. Only five hot spot localities have so far been identified worldwide.

E

Which of the following is not true of the origin of the solar system? A. The planets are thought to have formed predominantly through a process of accretion of smaller masses. B. The leading hypothesis for the origin of the solar system is called the "Nebular Hypothesis." C. The heavier elements making up the terrestrial planets are thought to be from the remains of a burned-out star. D. The solar system is thought to have been derived from a rotating mass of gas and dust. E. The solar system is thought to have originated at the same time as the Big Bang.

E

Which of the following statements about basalt is false? A. Basalt is the dominant rock type of the upper oceanic crust. B. Pyroxene and plagioclase feldspar are major mineral constituents of basalt. C. Basalt may have pahoehoe texture. D. Basalt generally forms from magma extruded at or near the Earth's surface. E. Basalt has felsic composition.

E

Rocks are permanent features of the Earth that do not undergo change over geologic time scales.

False

Topaz, which has a hardness of 8 on the Mohs scale, is twice as hard as fluorite, which has a hardness of 4 on the Mohs scale.

False

Magma produced by partial melting of diorite (intermediate composition rock) would be most likely to have what composition?

Felsic

Which of the following magma compositions is the most viscous?

Felsic

Which of the following two igneous rock types have the same chemical composition?

Gabbro and Basalt

Why does high magma viscosity increase the likelihood of an explosive eruption?

Gases are not able to flow through and escape viscous magmas as easily as fluid magmas, allowing large pressure differences to develop between viscous magmas and their surroundings.

Which of the following statements about the paleomagnetic record is false?

It is a puzzle; it contradicts the sea-floor spreading concept.

Which of the following is true of the asthenosphere?

It underlies the lithosphere

Which statement about shield volcanoes is true?

Shield volcanoes tend to form as a result of relatively quiet eruptions.

Which statement about sills is true?

Sills require the overlying rock to be lifted during their emplacement

Which of the following statements about the Earth's magnetic field is false?

The Earth's magnetic field arises because of convection of rock in the Earth's crust.

Why does exhumation of a rock body leads to mechanical weathering?

The removal of overlying rock reduces pressure on the rock body, causing it to expand and fracture

Which of the following is true of carbonate minerals?

They are probably the second most abundant type of mineral in the Earth's crust after silicate minerals.

The diagram in Figure 3.2 is an example of what kind of plate boundary?

Transform fault

Clastic sedimentary rocks are much more abundant in the Earth than chemical sedimentary rocks.

True

In what geologic setting are violent volcanic eruptions most likely to occur?

Volcanic arc at a subduction zone

Which of the following is a reason that has commonly attracted people to live near volcanoes?

Volcanic rocks commonly produce fertile soils for agriculture

The simplest, most fundamental unit of composition of matter is _______.

a mineral

The lava flow shown in the foreground of the photograph (Figure 9.1) is an example of _______.

aa

Which of the following minerals is a common product of chemical weathering?

clay

The aerial photograph shown in Figure 9.3 shows a coastline with open ocean at the top of the photograph, land at the bottom of the photograph, and several shallow inlets or bays of ocean water, the largest of which is labeled. These ocean inlets would be favorable for the formation of what type of rock?

evaporites

Which magma composition has the highest silica concentration?

felsic

Light emitted from a star that was moving away from an observer would

have a longer wavelength.

Which of the following is one of the two main ongoing driving forces for Earth's geologic change?

heat energy contained within the Earth

For most minerals, the streak color obtained when the mineral is scratched against a porcelain plate is _______.

less variable than the color of individual specimens of the mineral

Where do the Earth's tectonic plates occur?

lithosphere

What is the feature labeled B in Figure 3.1 called?

magmatic arc

Which of the following minerals crystallizes from magma at the highest temperatures?

olivine

According to the theory of continental drift that predated the modern theory of plate tectonics:

the continental landmasses plowed their way through stationary oceanic crust.

Magma formation at convergent plate boundaries is caused by _______.

the evaporation of water in the subducting plate which produces steam that infuses rock in the overlying plate and lowers its melting temperature

Which condition causes the rate and magnitude of the weathering of rocks to increase?

the wetter the climate

The Earth's Moon is thought to have originated:

through the collision of a large meteorite with the Earth