Geo 7

What percentage of Earth's atmosphere is carbon dioxide?

0.2%

sediments that roll or slide along the channel floor or bounce up temporarily into the water column. Saltation is a type of bed load in which sediments move by continually bouncing into the water column.

Bed load

occurs when rock disintegrates due to the chemical and/or physical activity of a living organism

Biological weathering

Carbon dioxide increases the acidity of water to create ______, which is an effecting chemical weathering agent that causes hydrolysis, dissolution, and oxidation.

Carbonic acid

the chemical decomposition of minerals in rock.

Chemical Weathering

Spheroidal weathering is caused by:

Chemical weathering of angular rocks.

Karst topography is the result of:

Chemical weathering of carbonate rock

Hydrolysis breaks down feldspar, the most abundant mineral in Earth's crust, and creates _____ the most abundant sediment

Clay

The variables that most affect the weathering process are rock composition and _____________.

Climate

Forrested regions with moderate rainfall tend to develop strong horizons execept for

E

various sedimentary basins where sediments come to rest

Environments of deposition

The uplift weathering hypothesis:

Explains global cooling.

Acidic rainwater forms naturally when hydrogen in the atmosphere (or the ground) dissolves in water, to produce carbonic acid.

False

Crystal growth usually accompanies precipitation.

False

For the silicate minerals, the order of their stability in Earth's surface environments is the same as the order of Bowen's reaction series.

False

Saltation is a type of bed load in which sediments move by continually cracking in the water column and being carried away by running water.

False

Sedimentary quartz, hematite, and calcite are important natural cements that precipitate from the oceans' saline water and bind igneous particles to form solid sedimentary rock.

False

Water enters a crack in a rock, the water freezes and expands the crack and repetition the pressure releases and the rock cracks creating sharp jagged scree.

Freeze-thaw weathering

When overlying pressure is released by tectonic forces or by erosion it causes rock to break. This pressure release leads to:

Joints

Biological weathering is the product of organisms causing weathering that is either chemical or physical in character, or a combination of the two.

True

Biological weathering occurs when rock disintegrates due to the chemical and/or physical activity of a living organism.

True

Felsic minerals are among the most stable on Earth, where the environment is most similar to the environment of their crystallization.

True

Having been formed under conditions of low temperature and pressure, sedimentary materials are unstable in the high temperature and pressure of Earth's surface. Therefore, they tend to be decomposed by weathering.

True

Higher levels of carbon dioxide (and other types of greenhouse gases, such as water vapor and methane) in the atmosphere tend to warm the climate; lower levels of carbon dioxide in the atmosphere tend to cool the climate.

True

Humid midlatitude climates with seasonal freezing (as in much of the northern two-thirds of the United States) allow dead vegetation to accumulate in the soil.

True

Most chemical weathering is the result of water interacting with minerals in a rock.

True

One reason Earth is habitable is that weathering governs the amount of carbon dioxide (CO2) in the atmosphere, and carbon dioxide influences the average temperature of the air.

True

Weathering is a set of physical, chemical, and biological processes that break down rocks and minerals in the crust to create sediment, new minerals, soil, and dissolved ions and compounds.

True

Because of negligible rainfall, little organic matter, and low biological activity, arid climates soils are comprised of all of the following, except:

quartz

occurs when sedimentary particles collide, leading to mechanical wearing or grinding on their surfaces. creates sand and silt

abrasion

Hydraulic action is caused by:

breaking waves

the production, storage, and movement of carbon on Earth

carbon cycle

Starting about 55 million years ago, Earth's atmosphere began a long, but steady period of _______?

cooling

Low moisture also means that fine particles are easily blown away while large particles remain behind to form a tightly packed layer known as

desert pavement

chemical weathering reaction in which carbonic acid dissolves the mineral calcite, usually found in limestone (a common sedimentary rock)

dissolution

The most important weathering process from the standpoint of lowering carbon dioxide levels is

hydrolysis of continental silicate materials

What is the major weathering process affecting the crust in cold climates?

ice wedging

occurs when water flows into a joint and freezes. Water increases in volume by 9% when it turns into ice, and the growth of ice crystals forces the joint to split open

ice wedging

The western portion of the Midwest, which were former prairies, are dominated by what type of soil?

mollisols

As the rock dissolves, large underground caverns are created. This process is called karstification. Over time, the caverns grow, coalesce, and undermine an area, until finally the roof collapses, producing a depression called a

sinkhole

The critical importance for governments to conserve and manage their soil resources for the economic, environmental, and agricultural needs of its citizens has led to what science?

soil classification

As rain soaks through the humus layer, the water picks up dissolved ions that may recombine to form clay minerals, creating a set of layers called:

soil horizons

Any weathering process that tends to produce a spherical shape from an initially blocky shape

spheroidal weathering

Over geologic time, carbon dioxide enters Earth's atmosphere through

volcanic outgassing

In North America, six types of soils account for approximately what percentage of all soils?

75%

How much of the Earth's curst is composed of igneous or metamorphic rock?

95%

soil profile

All the vertical layers or horizons that make up a soil in a particular place

The tendency of silicates to weather on Earth's surface is predicted by:

Goldich Stability Series.

Aluminum ore comes from:

Humid tropical settings.

The most important form of chemical weathering of silicate minerals is:

Hydrolysis

the most common chemical weathering process because it causes the decomposition of silicate minerals, the most widespread inorganic substances in Earth's crust

Hydrolysis

Iron oxide and aluminum oxide soils are:

Insoluble residues.

Insoluble Residues are:

Minerals produced by weathering

The major agricultural lands in the United States are based on which soil?

Mollisols

Layers of the soil profile

O - Humus A - Topsoil E - Zone of eluviation B - Subsoil C Transition zone between bedrock and soil. Unweathered parent (bedrock)

Sediment produced by weathering is transported across the landscape by what process?

Physical

occurs when rock is fragmented by physical processes that do not change its chemical composition

Physical weathering

unconsolidated mineral and organic material constituting the uppermost layer on Earth's surface

Soil

rocks shaped by wind blown sediments

ventifacts

Give examples of weathering products

dissolved compounds, hematite, new sedimentary minerals that form from crystallization, gases.

What type of erosion occurs when heavy winds strip sediments and soil from the land?

eolian erosion

when slabs shift and uncover the underlying rock. Half Dome in Yosemite National Park is part of a large exfoliated granite batholith that was exposed by glacial erosion

exfoliaton

active movement of particles by running water is called

fluvial erosion

Because of the cool, moist climate and abundance of coniferous forests, New England and the Appalachian Mountain belt are dominated by which two types of soils? Select all that apply. A mollisols B gelisols C ultisols D inceptisols E spodosols

gelisols (I think it's inceptisols), spodosols

in the summer, weathering in cold climates is accelerated by:

high latitudes, long daylight hours, and fluid water

A layer on top of the soil composed of dead and decaying material. Contains dark brown or black plant matter.

humus layer

weathering by expansion and contraction due to daily changes in rock temperature (debated)

insolation weathering

Humid tropical climates lead to intense chemical weathering that produces soils largely composed of

insoluble residues

openings, or "partings," in rock where the two sides of the break are not offset, or laterally displaced

joints

Dissolution of limestone on a large scale can yield a unique kind of landscape called

karst topography

A red, highly leached soil type found in the tropics that is rich in oxides of iron and aluminum

laterite

Rocks have predictable susceptibility to weathering based on _______?

mineral content

Chemical weathering is the chemical decomposition of minerals in rock. This process may result in the formation of the following, except:

new igneous minerals

the building of mountain ranges by continental collision

orogenesis

involves the loss of an electron from a cation in a crystal, and its use by free oxygen in the environment. high temperatures and wet conditions accelerates it.

oxidation

Crystallize between sediments from groundwater, from dissolved elements in water, and in the absence of oxygen

sedimentary minerals

when rock is slowly uplifted by tectonic forces or by the removal of overlying layers by erosion

sheeted joints

What are the important biological weathering processes?

simple breaking of particles, movement and mixing of materials, production of carbon dioxide by animal respiration or organic decay, changes in moisture content of soils.

Water carries sediment in one of two ways:

suspended load, bed load

s a process in which sediments are kept in a perpetual state of movement in the water without touching the floor of the channel. Light (small) grains of sediment are held suspended in the water column by turbulence in streams and rivers.

suspension

An accumulation of rock debris at the base of a cliff from ice wedging

talus

What is generally the most productive layer of the soil profile in cultivated fields?

topsoil

the hypothesis that Orogenesis exposes large areas of fresh silicate rock to hydrolysis, leading to withdrawal of carbon dioxide from the atmosphere

uplift weathering hypothesis

The humid temperate climate of the southeastern United States is dominated by which type of soil?

utilsols