Finals Flashcards
Biologically active, porous medium that has developed in the uppermost layer of Earth’s crust. It is a mixture of organic matter, minerals, gases, liquids, and organisms that together support life.
Soil
True or False
Soils can be considered as a renewable resource
False. Nonrenewable
Earth’s body of soil is called
Pedosphere
The unconsolidated layer of material covering solid rock, which can come in the form of dust, soil or broken rock.
Regolith
Transported material by wind, water, or ice.
Sediment
The origin of soils ultimately begins when rocks physically disintegrate and chemically decompose in a process known as ____________.
Weathering
Refer to those processes that cause rocks to disintegrate into smaller particles by some mechanical means. Ex. frost wedging, root action, expansion and contraction.
Physical weathering
Refer to the process where individual mineral grains within a rock decompose due to chemical reactions. Ex. dissolution, hydration, hydrolysis, oxidation.
Chemical Weathering
As rocks undergo physical and chemical weathering and generate soil particles, there are other processes taking place within the soil which result in the formation of horizontal layers called _______________.
Soil horizon
Mostly minerals from parent material with organic matter incorporated. A good material for plants and other organisms to live.
Soil Horizon A - Topsoil
Mostly organic matter such as decomposing leaves.
Soil horizon O - Humus/Organic
Rich in minerals that leached (moved down) from the A or E horizons and accumulated here.
Soil horizon B - subsoil/zone of accumulation
Leached of clay, minerals, and organic matter, leaving a concentration of sand and silt particles of quartz or other resistant materials –missing in some soils but often found in older soils and forest soils.
Soil horizon E - Eluviated/Zone of leaching
The deposit at Earth’s surface from which the soil developed.
Soil horizon C - Parent Material
A mass of rock such as granite, basalt, quartzite, limestone or sandstone that forms the parent material for some soils –if the bedrock is close enough to the surface to weather. This is not soil and is located under the C horizon.
Soil horizon R - Bedrock
Soil characteristics can best be seen by digging a trench to obtain a vertical view called ___________.
Soil profile
Soil characteristic that is a result of different types of pigments.
Soil color
Organic matter gives soil a ___________ appearance.
blackish to brownish (ex. O and A horizon)
Iron oxide minerals generate ____________ colors.
Yellowish to reddish (ex. B horizon)
E horizons appear ______________ because they lack pigmenting materials.
whitish or blonde
40% sand grains, 40% silt, and 20% clay would be classed as
Loam soil
60% sand, 30% silt, and 10% clay
Sandy loam
The distribution of grain sizes within a soil is important since it plays a key role in determining a ?
soil’s permeability
ease of tillage
drought resistance
fertility
Soil characteristic that refers to the way in which soil particles are arranged.
Soil structure
Separate clumps that broke up from a previously undisturbed soil.
Peds or aggregates
This is a naturally occurring inorganic, solid with definite chemical composition where individual atoms are arranged in an orderly manner.
Mineral
This is simply an assemblage of one or
more minerals and/or mineraloids.
Rock
It is a concentration or occurrence of material of intrinsic economic interest in or on the Earth’s crust in such form, quality and quantity that there are reasonable prospects for eventual economic extraction.
Mineral Resource
Refers to the degree to which a mineral resource is concentrated above its average concentration in the crust.
Enrichment factor
Those that contain an element or compound that has some value to society.
Ore mineral
Can be defined as a body of rock or sediment whose concentration of ore minerals is sufficiently high so that it is economically feasible to extract.
Ore deposit
True or False
The terms low-grade and high-grade refer to the enrichment level of ore deposits.
True
It is a deposit that is economical to extract under current conditions; economically mineable part of a measure and/ore indicated mineral resource.
Ore reserve
Diamond deposits are unique in that they
are found associated with magnesium-rich igneous rocks that form from magmas originating at depths of 120-200 km in the upper
mantle
Kimberlite pipes
Early-formed minerals somehow become separated from the remaining magma before
the cooling is complete. One way this can
happen is through a process called crystal settling, whereby dense, early-formed minerals fall or settle to the bottom of the magma chamber. This process can create layered ore deposits that geologists refer to as layered intrusions. Layered ore deposits typically contain metallic minerals that are valuable sources
of chromium, titanium, and vanadium.
Intrusive deposits
Minerals that crystallize from highly enriched fluids form what are referred to as _____?
Hydrothermal deposits
Engineering controls (levees) help keep the town of _______________, dry when the Mississippi River overflows its banks.
Trempealeau, Wisconsin
Described as the volume of water moving through a channel over a given time interval, commonly measured in units such as cubic feet per second (ft3/s).
Stream Discharge
a process where water flows through stream channels
Runoff
Precipitation reaching the land surface moves downslope in thin sheets
Overland flow
allows water to return back to the atmosphere.
Evaporation and plant transpiration
discharge of groundwater into the surface environment; fairly continuous unlike the sporadic input of water to a stream and groundwater may travel anywhere from a few days to thousands of years before discharging into a stream channel.
Groundwater baseflow
Precipitation that falls on the land surface can take different paths through the ________
hydrologic cycle
These provide information about a river or stream by simply plotting the discharge versus time.
Stream hydrographs
amount of time for water to move across the landscape and into channels; will vary depending on the distance between where the rain is falling and the particular channel where discharge is being measured.
lag time
Continuous input of groundwater baseflow allows streams in many areas to keep flowing at some minimum level, often called
baseflow conditions
This contribution of groundwater baseflow keeps streams from going dry between rain events, thus is critical in maintaining the health of stream ecosystems.
baseflow conditions
High precipitation allows more water to infiltrate to the water table which causes the water table in humid regions to be higher than the streams channel, thereby forcing groundwater to flow into streams.
Gaining streams
result of less deep infiltration in arid areas resulting in a water table that is below the level of most stream channels. Under these conditions, the water in the stream will flow into the groundwater system.
Losing streams
water that infiltrates and slowly makes its way to a stream through the groundwater systems provides a steady supply of water
baseflow
network of stream channels where merging tributaries (smaller of any two merging channels) form progressively larger streams.
drainage system
often applied to the larger stream that serves as the principal channel within a drainage system
river
The upper portion of the drainage system
headwaters
found in the lower part of the system where a river empties into an ocean, lake, or another river
mouth
generally small and relatively fast moving and occupy narrow valleys, but then evolve toward the mouth into gently flowing rivers that occupy wider valleys.
headwater streams
Individual systems are separated from one another by a topographic high or crest in the landscape
drainage divide
represents the land area that collects water for an individual stream or river
drainage basin
it helps explain how rainfall can cause flooding in one basin, but yet have no impact on stream discharge in adjoining basins.
drainage basin concept
loose rock particles/sediments deposited on a stream
alluvium
One of the key factors in a stream’s ability to erode the landscape
velocity of the water
One of the key factors in a stream’s ability to erode the landscape
velocity of the water
unstable overhang located at the outer bank which is produced by the velocity increase on the outer bank which subsequently enhances the ability of the water to cut (erode) into the bank.
cutbanks
On the inner bank where velocity decreases, sediment tends to accumulate and form a deposit known as a ______
point bar
Downcutting by streams is not performed by the water itself, but rather by the sediment that physically scrapes or wears away rock in a process called ______.
Abrasion
form during periods of high stream discharge when the water column develops a swirling motion called an eddy current.
potholes
These currents cause sediment on the streambed to slowly rotate, such that it grinds progressively deeper holes into the solid rock.
eddy current
The velocity of a particular stream segment is controlled by the steepness of the channel, called _______.
stream gradient
This concept is used to describe the lowest level to which a stream can erode.
base level
Sea level is often referred to as _________ because the oceans represent the end or low point of most rivers (exceptions include isolated areas below sea level, such as the Dead Sea and Death Valley).
ultimate base level
as a river flows toward the ocean it may encounter a series of _______ that form when its ability to cut downward is reduced by a resistance rock body, lake, or inland sea.
temporary base levels
as a river flows toward the ocean it may encounter a series of _______ that form when its ability to cut downward is reduced by a resistance rock body, lake, or inland sea.
temporary base levels
The ability of running water to transport and deposit sediment is dependent on:
water velocity and the types of particles being transported
This describes the fraction of solid particles that is in a suspended state and moving at the same velocity as the water— suspended material is what makes streams appear muddy.
Suspended load
consists of sediment particles that roll, bounce, or remain stationary on the streambed.
bed load
The process whereby water separates sediment grains based on their size, shape, and density.
hydraulic sorting
mound-shaped channel deposits consisting of sorted material ranging in size from boulders to coarse gravel to fine sand
bars
Crescent-shaped bars that develop on the inside of meander bends where water velocity decreases.
point bars
formed when a river enters a lake or ocean and splits into smaller channels and begins to deposit sediment due to a decrease in velocity.
Deltas
are large fan-shaped deposits that form where steep mountain streams empty out onto valley floors at the mouth of rivers
alluvial fans
a channel that is choked with sediment
braided stream
migrates back and forth across the entrance to the valley, creating a characteristic fanshaped deposit
braided stream
What is the formula of stream discharge?
SD = velocity x cross-sectional area
= velocity x width x depth
It is the level at which a stream begins to
overflow its banks.
flood stage
It is the amount of time needed for
runoff/floodwaters from headwaters to
reach a specific point downstream.
Lag time
These are fluvial features that generally
develop due to significant changes in base
level owing to uplift and/or sea level regression.
Terracing
Streams that are fed by groundwater
discharge are termed as _____________.
Gaining streams
The erosion that occurs along the outside of meander bends produces wider valleys over time, whereas deposition on the inner banks helps to build a flat plain on the valley floor called a ______.
natural floodplain
pair of ridges that run parallel to the bank which are formed due to the deposition of sediment, commonly sand, at the edge of the bank
natural levees
areas on the floodplain that are poorly drained and can remain wet long after a flood
back swamps
It is an isolated rock hill, knob, ridge,
or small mountain that rises abruptly
from a gently sloping or virtually level
surrounding plain.
inselberg/monadnock
These are depositional landforms by
which an island becomes attached to the
mainland by a spit or bar.
tombolo
These are streams that carry water only
during and immediately after a heavy
rainfall event.
ephemeral
It is an ocean current that flows
parallel to the shore and is caused by
series of waves sweeping into the
shoreline at an angle and pushing down
the length of the beach in one direction
longshore current
Determine the wave base if the
distance between two wave crests is 3
meters.
1.5 m
What soil horizon is known as the
“zone of leaching”.
horixzon e
What is the grain size range of
pebbles?
4-64mm
It is the part of the shore between the
high tide and the highest water level,
which can only be reached by
exceptional storm waves.
backshore
Spring tides will achieve
their highest tidal range during apogee
and aphelion.
false
What process is responsible for the
formation of notches in coastlines?
wave action
What structural mitigation measure to
counter floods and/or coastal erosion
involves the use of wire cages that are
filled with boulders?
gabions
What Iron isotope accumulates in the
saprolitic zone/horizon B?
Fe (II)
True or False: Typically, soil
profiles in arid regions will develop a
full suite of horizon, except Horizon
O, owing to accelerated rates of
weathering.
false
It is the compass orientation of a
slope
aspect
It is a carbonate texture classification
scheme that is based on depositional
texture and mud content
dunham
The potential for flooding in a given area naturally increases as the ________ of rainfall increases.
intensity and duration
floods that have short duration with relatively high peak discharge; small streams and rivers tend to rapidly overflow their banks
flash floods
- can be defined as one where a river leaves its channel farther down in its drainage basin, flowing out onto its floodplain and inundating large areas of the valley floor.
- are caused by regional accumulations of water higher up in the drainage basin.
downstream floods
blanc fixe
barium sulfate
occurs when natural vegetation is removed from the landscape, which leads to increased overland flow and erosion that fills stream channels with excess sediment.
sediment pollution
Wetlands (swamps) are commonly found in topographic depressions and adjacent to river channels, in which case they are called __________.
Riparian wetlands
temporarily stores some the excesses water in a series of depressions which are constructed within the tributary network.
Retention basins
a type of barrier in which vegetated strips line the banks of stream channels, trapping sediment before it can enter the drainage network.
stream buffers
made of a synthetic fabric that is fine enough to trap sediment, but yet allows some water to pass.
silt fences
are ponds constructed for the purpose of trapping any sediment that makes its way into a drainage system.
silt basins