module 11 &12

What causes the same mineral to occur in varieties that are different colors?

A small amount of impurities in the crystal structure.

Which world region experienced the largest change in forested land between 1990 and 2000?

Africa

Yellowstone is best described as which of the following?

An active volcano that has erupted in the last 1 million years

Porphyritic igneous rocks

Andesite porphyry

Which of the following terms is best described as a massive pluton?

Batholith

Batholiths are known to form the cores of mountain ranges such as the Sierra Nevada. What is the implication of this observation?

Because batholiths form deep within Earth, the occurrence of one at the surface implies that it has since been uplifted and/or the rocks above have been removed.

What causes a lack of cleavage in some minerals?

Bonds of equal strength in all directions

The chemical weathering process known as dissolution is most effective in the breakdown of which of the following minerals?

Calcite

What mineral is not scratched by a fingernail, but is scratched by a copper penny?

Calcite

Depletion of the upper part of a magma chamber during a volcanic eruption can result in gravitational collapse of the volcanic summit to form a

Caldera

Which of the following states has the greatest earthquake hazard?

California

Which of the following best describes the term cleavage?

Cleavage is the splitting of minerals along natural planes of weakness.

The pipelike feature through which magma travels upward from an underground magma chamber is called a

Conduit

Which of the following would best describe the shape and composition of a volcano in the Cascade Range?

Cone-shaped volcano with alternating layers of lava and pyroclastic material

The majority of volcanoes are associated with which type of tectonic plate boundary?

Convergent boundaries

Suppose you found a mineral crystal that looked like topaz. What two minerals could you use in a scratch test to help determine if the mineral is indeed topaz?

Corundum and quartz

A __________ is formed on the volcano summit by explosive eruptions and is composed of accumulated volcanic debris.

Crater

Which of the following was a stage in the formation of Yellowstone caldera?

Crust bows upward above a magma chamber.

Consider a melt that has cooled to a temperature such that olivine, pyroxene, amphibole, and calcium-rich plagioclase feldspar have crystallized. Which elements will be enriched in the melt, and which will be depleted in the melt?

Depleted: Ca, Fe, Mg Enriched: K, Na, Si

Name the hardest and softest mineral on the Moh's scale.

Diamond (hardest) and talc (softest)

Why does magma composition change during fractional crystallization?

Different elements in the magma form crystals at different rates, leaving behind more of the unused elements.

What is the term for a tabular igneous pluton that occurs in an orientation that is discordant with the bedding surfaces of adjacent sedimentary rocks?

Dike

Earth's surface is subjected to unusually high rates of weathering. The Moon and some of the inner planets of our solar system are also subject to surface weathering, but at much slower rates. Which of the following statements most reasonably explains Earth's uniquely rapid weathering rates?

Earth has running water at the surface.

What discourages minerals from achieving habit?

Enclosed spaces

During hydrolysis, ions and clay minerals are produced by the decomposition of which of the following Earth materials?

Feldspars

What minerals make up half of Earth's crust?

Feldspars

While working in the field, you find a dike cutting across some sedimentary rocks. What grain size would you expect to find in this pluton?

Fine-grained

You have found a mafic rock with a phaneritic texture. What is a potential rock name?

Gabbro

Which of the following exhibits three sets of cleavage at 90° angles?

Galena

Why glass is not considered a mineral?

Glass has a disorderly atomic structure.

In the list below, indicate which of the items are minerals.

Gold nugget and quartz

Intrusive igneous rocks

Granite Diorite

Unlikely to bond

H and Ne Li and Ar O and Kr

Sand dunes are typically dominated by quartz grains and very little other mineral matter. Why does this selection occur?

Quartz is extremely resistant to all forms of chemical weathering.

The chemical weathering process known as oxidation would be most effective in the breakdown of which of the following Earth materials?

Pyroxenes

The principal mineral used in making glass is:

Quartz

Which of the following substances is a mineral?

Quartz

Based on what you learned in this video, what minerals make up rhyolite?

Quartz, K-feldspar, and plagioclase feldspars, with relatively fewer biotite and amphiboles

Which of the following bodies of water is associated with seafloor spreading?

Red Sea

Extrusive igneous rocks

Rhyolite

The micas (biotite and muscovite) exhibit what type of silicate structure?

Sheet

Of the physical features listed, which is associated with the greatest earthquake hazard?

Sierra Nevada

Which of the following pairs of elements are the most abundant in the continental crust?

Silicon and Oxygen

What is the term for a tabular igneous pluton that occurs in an orientation that is concordant with the bedding surfaces of adjacent sedimentary rocks?

Sill

Which of the following best describes the term streak?

The color of a powdered form of a mineral produced by rubbing it across a hard surface.

Which of the following statements best represents the relationship between magma and crystals formed from that magma?

The crystals are denser than the magma

Which of the following statements is/are accurate based on the information in this graph?

The information in this graph is consistent with the information in the graph of harvesting and growth in U.S. forests from Step 2. Loss of forested land appears to be greater in the developing world than in the developed world. The world overall is experiencing a net loss of forest. -All of the above.

Which of the following is a reason that limestone is formed in a relatively offshore position?

The lack of sediment derived from land.

Neighboring sedimentary facies generally show __________.

a gradational relationship

The mineral fluorite is an example of:

a halide mineral.

What type of magma would you expect to see after crystallization of minerals containing significant amounts of iron?

a magma depleted in iron

Minerals must be solid, have an orderly atomic structure, have a recognized chemical composition, be naturally occurring, and

be generally inorganic in origin

What coal is soft, black in color, and produces soot upon handling?

bituminous

Which type of land lost the largest proportion of its timber in 1996?

can't answer with the available information

Quartz exhibits __________.

conchoidal fracture

For a detrital sedimentary rock that contains mudcracks, you could be confident that the environment in which it formed was _____.

covered with abundant terrestrial vegetation

What is fractional crystallization?

crystallization of part of a magma, leaving behind melted rock with a different composition from the original magma

For which type of land is the total volume of forest (in cubic feet) decreasing?

forest industry

Which structure is common in sedimentary rock?

fossils mudcracks ripple marks cross-bedding -All of the selections are correct.

Hardness describes a mineral's __________.

resistance to being scratched

In your field area you find a quartz sandstone unit with cross-bedding in it that is on the order of 2 m high. In what environment would you deduce this rock formed?

sand dunes

What is the sequence of sediments you would pass over if you were to walk from the shoreline and then swim in the offshore direction?

sand, clay, carbonate

Weathering of rock

-Ice expanding in a crack in the road creating a pothole -Tree roots extending and cracking sidewalk

Erosion and transport of sediment

-The dirt going down the drain after you give your dog a bath and drain the tub -Dirt being blown off the patio

Deposition of sediment

-The dirt settling on the bottom of the tub after you give your dog a bath -Dust collecting on furniture

Which of the following is a mineral

Ice

What is the basic foundation of Moh's hardness scale?

If a mineral scratches an object, then the mineral is harder than the object

The arrangement of the silicon-oxygen tetrahedra in ferromagnesian (iron- and magnesium-bearing) silicate minerals is typically:

In a chain

__________ SiO4 4- tetrahedra join with __________ ions to produce the mineral olivine in the rock peridotite.

Independent; Mg2+ and Fe2+

All of the following criteria define a mineral except:

It is inorganic

Likely to bond

K and Br K and Cl Mg and O Na and Cl

By what process do ooids form?

Layers of CaCO3 are precipitated out of seawater and coat grains.

Since color is not a very useful way to identify a mineral, what other optical property or properties can be used?

Luster and streak

Which of the following is true about mafic igneous rocks?

Mafic igneous rocks are rich in Fe, Mg, and Ca.

A _________ results when magma collects or ponds due to its density being higher than that of overlaying materials.

Magma chamber

Regardless of their size, most rocks are made up of __________.

Minerals

A scientist creates diamonds using high-pressure laboratory experiments. These diamonds are not considered minerals because which of the following requirements has been violated

Minerals must occur naturally

Which of the following best represents the relationship between earthquakes and tectonic plates?

More earthquakes are found along tectonic plate boundaries than within a single tectonic plate.

Which of the following volcanoes is associated with the Ring of Fire?

Mt. Pinatubo

Based on the diagram shown in the video, name two minerals that are unlikely to coexist in the same igneous rock.

Muscovite and pyroxene

Which of the following statements is/are accurate based on the information in this graph?

Overall, U.S. forest land is experiencing net growth as of 1996. Lands other than forest industry land appear to be managed to produce net forest growth. National forest land had the greatest growth relative to the amount of harvesting. -All of the above.

What are the two most abundant elements in Earth's crust?

Oxygen and silicon

Which of the following statements describe a part of the process of the formation of the Cascade Mountain Range?

Partial melting due to the presence of water Eruption of material at the surface Rising of magma to the surface

Rank the rocks from fastest weathering to slowest weathering. To rank items as equivalent, overlap them.

Peridotite, Gabbro, Diorite, Granite

Match the silicate structure with the appropriate mineral example. Single Chain:

Pyroxene

Which of the following best describes mineral habit?

The shape a mineral grows into, given sufficient space.

What is an accurate description of the silicon-oxygen tetrahedron?

The silicon-oxygen tetrahedron is a four-sided figure with a silicon atom in the middle bonded to four neighboring oxygen atoms.

Other than space, what two additional factors are significant for a crystal to attain habit?

Time and necessary elements

A _______ is an opening where volcanic materials erupt at the Earth's surface, and can form on the flanks of a larger volcano in the case of a ______

Vent; parasitic cone

The Hawaiian Islands contain active volcanoes and are known for nutrient-rich soils and lush vegetation. What is the most powerful explanation for this?

Volcanic rocks contain minerals rich in iron, so they are susceptible to oxidation. There is abundant rainfall. Minerals in the volcanic rocks produce clay minerals as weathering by-products. Volcanic rocks contain minerals susceptible to hydrolysis. -all of the above

Not related to eruptions

Volcano at high elevation Volcano that has not erupted for a long time

Nonexplosive eruption

Volcano fed by magic magma Volcano fed by high temperature magma Volcano fed by magma with low amounts of dissolved gas

Explosive eruption

Volcano fed by silica-rich magma

Which of the following features at Yellowstone National Park is evidence for a magma chamber beneath the park?

Welded Tuff Rising ground near Yellowstone River Geysers and hot springs Actively flowing lava

In another field area you find a detrital sedimentary rock that contains particles larger than 264 mm that are angular and surrounded by finer-grained particles. In what environment might you think these sediments were deposited?

glacial moraine

What property of detrital sedimentary rocks can be indicative of the energy of sediment transport?

grain size

Once weathering begins and particles are produced, which factor is most influential in moving them around Earth's surface?

gravity

Igneous rocks of felsic composition have __________ and __________ relative to mafic igneous rocks.

greater silica; lower melting temperature

The ratio of silicon to oxygen atoms in silicate minerals depends on:

how the atoms in silicon-oxygen tetrahedra are shared.

Abundant plant material accumulating in a swampy environment with __________ is required for peat to form.

low oxygen levels

The amount or quality of light that is reflected from a mineral surface is known as __________.

luster

How is anthracite produced from bituminous coal?

metamorphism

The silicon-oxygen tetrahedron contains:

one silicon atom and four oxygen atoms.

Name the progression of coal types with increased heat and pressure from burial.

peat, lignite, bituminous, anthracite

The same formation changes laterally from layered evaporites to mudcracked sandstone to conglomerate. Using the facies concept, which of the following is an accurate interpretation?

shallow lake, shoreline, mountain front setting

In which of the following regions does the greatest number of people live in areas exposed to the risk of earthquakes?

southeastern Asia

In the United States, the most common type of coal is __________ and the largest producing state is __________.

sub-bituminous; Wyoming

How much more timber was removed from "other private" lands versus "national forest" land?

ten times as much

Of the responses provided, which is the predominant source of energy for most external processes that operate on Earth?

the Sun

Crystal habit is the shape that a mineral develops by the repetition of __________.

the basic unit cell of a mineral

In silicate minerals, the type of cleavage or fracture is influenced by:

the bonding of the silicon-oxygen tetrahedra within the mineral.

Hornblende has _____ cleavage planes at _____ angles.

two; non-90°

Of the following, which is not an example of Earth's external processes and/or external process-driven phenomena?

volcanoes

All modification of Earth's outer surface is initiated by which of the following processes?

weathering