Exam 1 Flashcards
What is the lithosphere primarily made up of?
Rocks
What is the pedosphere primarily made up of?
soil and its interactions with rocks, air, water, and living things
What are the six key roles of soil in the ecosystem?
- Supporting plant growth
- Recycling waste products of society and nature
- A modifier of the atmosphere (think carbon cycle)
- Providing habitat for an enormous diversity of organisms
- Functioning as construction material of support for buildings
- Controlling the flow of water through the hydrologic cycle
What is the Solum made of?
The O, A, E, and B horizons
What is the Regolith made of?
The Solum (O, A, E, B) and the C horizon
How long does it take for 1 inch of soil to form?
500 years
What is the ideal soil?
50% solid material (45% mineral and 5% organic) and 50% pore space (25% air and 25% water)
What are the different soil particle sizes?
Coarse fragments, Sand, Silt, Clay (CSSC)
How big is a coarse fragment?
> 2 mm
How big is a sand particle?
2-0.05mm
How big is a Silt fragment?
0.05-0.002mm
How big is a Clay fragment?
<0.002mm
What is Humus?
the portion of the soil organic matter that is well
decomposed, colloidal, and relatively
resistant to further microbial attack
How much of a soil’s dry weight is Soil Organic Matter?
1 to 6%
What greatly influences nearly all soil properties and uses?
Soil organic matter
Why is does water act differently in soil?
-the interactions with soil particles (Adhesion and cohesion)
-Water in soil has many substances dissolved in it
How many elements are considered to be essential to all plants?
17
How many of the essential elements to plants are supplied by soil water
14 of 17
How is soil air different from atmospheric air?
it is generally several times more concentrated in C)2 than normal air
How does soil support plant growth?
-deeper soils can allow for deep roots that stabilize a plant
-denser or compacted soils can limit root growth
-Aluminum is toxic to plants and can stunt growth
-soil texture can dictate water holding capacity, fertility, and treatability of conaminants
-porosity can allow for gas exchange
What is the law of the minimum?
if one growth factor is deficient a plant is limited to that growth factor even if all other factors are met.
What is Fauna?
Animal life
What is Flora?
plant life
What role do animals play in regards to soil?
They turn/plow the soil
What role do microorganisms play in regards to soil?
they regulate carbon in the soil and oceans
What are all of the Parent Materials?
-Residual materials (saprolite)
– Colluvial deposits
– Alluvial deposits
– Marine sediments
– Lacustrine sediments
– Glacially transported
– Wind transported (eolian)
– Organic deposits
– Volcanic Deposits
(Really Cool Animals Make Lively Gardens With Outstanding Vegetation)
What is saprolite?
-formed from
rocks weathering into a softer material
-Is the C horizon and often called “rotten rock”
What is crustal warping?
geologic forces,
acting over time, can result in
different parent materials being
pushed into the zone of weathering. (think about the layers of soil bending closer to the surface)
What are minerals?
-The eight major elements, combined with the trace amounts of other elements bond
to form minerals
How many minerals are there?
more than 3,000 minerals classified
What are the major classifications of minerals?
- Silicates
2.Precipitates
3.Secondar minerals
What are silicates?
-major classification of minerals
-minerals that crystallize from cooling magma [e.g. quartz (SiO2)].
Also referred to as primary minerals
What are precipitates?
-major classification of minerals
-minerals that
precipitate from fluids
o Evaporites such as halite (i.e.,
rock salt) precipitate from water
What are secondary minerals?
formed from the result of primary minerals weathering [e.g. hematite (Fe2O3]
What are rocks?
– crystals of different kinds of
minerals [or]
– broken pieces of crystals [or]
– broken pieces of rocks
What are the three rock classifications?
igneous
sedimentary
metamorphic
What is extrusive igneous rock?
when magma exits and cools outside of, or very near the Earth’s surface.
What is Intrusive igneous rock?
when great globs of molten rock rise but is trapped below the earth’s surface
What is sedimentary rock?
rocks formed
from sediment or organic deposits
What are the types of sedimentary rock?
Continental, Transitional, and marine
What are the different classifications of sedimentary rock?
Clastic, Chemical, and Biologic
What is lithification?
the process by which
sediments become compacted and
cemented together into a sedimentary
rock.
What is Clastic sedimentary rock?
formed from broken fragments of
pre-existing rocks or mineral
What is chemical sedimentary rock?
– Precipitation from an aqueous
solution (such as limestone or
dolostone)
– Evaporation of an aqueous
solution (such as halite or gypsum)
What is Biologic sedimentary rock?
biologic precipitation or
accumulation of organic material.
-Ex: Coal and limestone
What is marine sedimentary rock?
– This banded sedimentary rock
formed over 2.2 billion years ago in
ancient oceans.
– The banding is a geologic record of
our atmosphere during that
period.
What is metamorphic rock?
rocks that developed in environments where heat and pressure are intense and extreme.
What are the two types of metamorphic rocks?
- contact metamorphism
- regional metamorphism
What are contact metamorphic rocks?
-when
a rock is exposed to hot magma
inside the Earth.
-The intense heat of the magma alters
the rock, often causing its minerals to
recrystallize into new or larger
mineral crystals than the older rock.
What are regional metamorphic rocks?
occurs
during the formation of mountain
ranges.
What is metamorphism?
the
rearrangement of mineral crystals in
the original rock .
metamorphism results in what rock classifications?
- foliated and
- non-foliated
What are metamorphic foliated rocks?
rocks that have
minerals that have been flattened
and pushed down into parallel layers
What are metamorphic non-foliated rocks?
metamorphic rocks that don’t display layers
Sedimentary rocks are formed by:
a) Magma cooling at the earth’s surface
b) Magma cooling inside the earth’s crust
c) Sediments getting compacted and cemented together
d) Heat and pressure rearranging the chemical composition
c) Sediments getting compacted and cemented together
What are colluvial materials?
parent material that
moves downhill slopes by gravity
what is an alluvial deposit?
soil forming materials can be easily moved by water.
What are some examples of alluvial deposit landscapes?
Floodplains, Alluvial fans, oxbows, and terraces
What is an alluvial fan?
fan-shaped deposits of water-transported material.
What are marine sediments?
can be found on
land where ocean bottoms previously existed
(e.g., North Carolina Coastal Plain)
What is a lacustrine sediment?
sediments that are deposited in former lake bottoms.
What are glacially transported parent materials?
Glacially transported parent materials
are transported by the glaciers that once
covered much of the world’s northern
latitudes and result in Glacial Till and Glacial Outwash
What is glacial till?
a mixture of rocks and materials of varying sizes pushed in front of the glacier.
What is glacial outwash?
material transported from the original location by ice. It is deposited when the glacier melts and the sediment flows away
What are wind transported (eolian) parent materials?
wind blown materials resulting from cold air damming that produce dune sands and loess
What are dune sands?
medium to fine grains of sand “piled” into hills. Transport is over short distances.
What is loess?
fine sands, silt and course clays. Can be transported considerable distances.
What are organic deposit parent materials?
partially decomposed plant tissues in which organic soils form Bogs and Wetlands
What are volcanic parent materials?
Parent materials that are transported via a volcanic eruption
Alluvium parent material is transported by
a) Wind
b) Water
c) Ice
d) Gravity
b) water
What are the five factors of soil formation?
- climate (including water and temperature effects)
- Biota / organisms (macro- & micro-organisms)
- conditioned by topography (relief)
- acting on parent material
- over a period of time
CLORPT (CLimateOrganismsReliefParentmaterialTime)
What are the two types of weathering?
- Physical (mechanical) weathering
- Chemical weathering
What is Physical (mechanical) weathering?
the
breakdown of rock or mineral into
smaller pieces with no change in the
chemical composition of the rock of
mineral.
What is chemical weathering?
the breakdown
of rock or mineral by chemical agents or
reactions. The main chemical agent is
water.
What are some the methods of physical weathering?
-Expansion and contraction
-Frost Action
What is exfoliation?
– the process in which curved plates of rock are stripped from a larger
rock mass.
What is effective precipitation?
the amount
of water that moves through the
regolith.
What is soil aeration?
oxidation and reduction processes result in many soil developmental
characteristics.
- Well drained soil tend to be aerobic (oxidized)
- Poorly drained soils tend to be anaerobic (reduced).
What are the five soil forming factors?
a) Sand, silt, clay organic matter, gravel
b) Air, water, mineral matter, vegetation, climate
c) Climate, time, parent material, topography, organisms
d) Water, air, plants, wind, time
c) Climate, time, parent material, topography, organisms
What are the 4 soil forming processes?
- Additions
- Losses
- Translocation
- Transformation
What is addition?
movement of material into the profile from above or laterally.
What is loss?
when materials are completely
removed from the soil profile.
What is translocation?
The movement of soil-forming materials through the
developing soil profile. Material is
moving up and down the profile.
What is cryoturbation?
mixing of soil by freeze-thaw cycles.
What is Tree throw?
trees falling mixing the soil.
What is transformation?
the alteration of
materials within the soil profile.
Materials are moving side-to-side or
front-to-back in the soil profile.
What is Eluviation?
– the downward movement of material from a given horizon to a lower
horizon. Often thought of as “leaching.”
What is bioturbation?
physical mixing of soil material by organisms (humans) or tree-throw
What is synthesis?
– in-situ formation of secondary minerals and compounds from eluviated
materials.
What is reduction?
ionic change to a lower valence in response to microbial activity in
saturated conditions.
What is oxidation?
exposure of mineral and organic materials to O2 which can lead to ionic
change to a higher valence.
What process turns bedrock into saprolite?
a) Additions
b) Losses
c) Translocations
d) Transformations
d) Transformations
What are the 5 genetic horizons?
O,A,E,B,C
What is a transitional zone/horizon?
-
horizons
dominated by properties of one master
horizon but having subordinate
properties of another.
-two capital letters are used for these horizons, AB, EB, BE, or BC
What does the a subordinate horizon mean?
Highly decomposed organic material.
What does the c subordinate horizon mean?
– Concretions or nodules formed as the
result of cementation. C comes from
cementation.
What does the f subordinate horizon mean?
indicates that a horizon or layer
contains permanent ice. F comes from
frozen.
What does the g subordinate horizon mean?
Strong gleying. This symbol indicates
that iron has been reduced and removed
during soil formation. G comes from the
grey color of the soil
What does the h subordinate horizon mean?
Illuvial accumulation of organic
matter. H comes from humic matter.
What does the p subordinate horizon mean?
Indicates a disturbance of the surface
layer by mechanical means, pasturing, or
similar uses. P comes from plow.
What does the t subordinate horizon mean?
Accumulation of silicate clay. T comes
from translocated clay.
What does the w subordinate horizon mean?
“Weak” development of color or
structure. W comes from weak.
The A-horizon generally have the most
a) Organic matter content and biological activity
b) Fe and Al oxides
c) Clay accumulation and water
d) Rocks and minerals
a) Organic matter content and biological activity
The E-horizon is generally the last horizon to form.
a) True
b) False
a) true
What sequence of soil horizons results in the most mature soil?
a) O-A-Bt-C-R
b) A-E-Bt-C1-C2-R
c) Ap-C1-C2-R
b) A-E-Bt-C1-C2-R
What is a pedon?
soil characterized by a small three-dimensional hypothetical unit
What is a polypedon?
Contiguous and closely related pedons constitute a polypedon.
What are Gelisols?
Permanently frozen layers
-taxonomy prefix: el
What are Histosols?
Organic soils mainly formed in
wetland accumulations of plant
residues.
-Darker than mollisols
-Prefix: ist
What are Spodosols?
Are extremely acidic, sandy soils in
forested areas found in moist
(usually cold) regions
-Evidence of illuviated organic matter
(Bh horizon)
-Prefix: od
Which soil order is the Bh horizon?
spodosols
What are andisols?
Recent volcanic ash deposits and
subjected to only mild weathering.
-Prefix: andi
What are Oxisols
-The most highly weathered of the
soil orders.
-Subsurface horizons dominated by
oxides of iron and aluminum (give
the soil a red color).
prefix ox
What are vertisols?
Characterized by high levels of
shrink/swell clays.
-prefix: ert
What are Aridisols?
Dry soils of arid regions that contain
CaCO3
and exhibit subsurface horizon
development (clays, CaCO3
, silica,
salts, gypsum).
-prefix id
What are ultisols?
Presence of an Argillic (Bt)
subsurface horizon with less than
35% base saturation
Prefix: ult
What are mollisols?
Dark mineral soils common in
grasslands.
-prefix: ol
What are alfisols?
Presence of an Argillic (Bt)
subsurface horizon with 35% or
more base saturation.
-Prefix: Alf
What is the weather sequence order between Oxisols, alfisols, and ultisols
Alfisol to Ultisol to Oxisol
What are inceptisols?
-Few diagnostic features due to
minimal horizon development.
-Bw horizon
-Prefix: ept
What are Entisols?
Little if any profile development.
-no b horizon
-Prefix: ent
What is the soil development order between Mollisols, Entisols, and Inceptisols?
Entisols to Inceptisols to Mollisols
What is the possible weathering series between rock, Alfisol, Inceptisol, entisoi, ultisol, oxisol, and mollisol?
Rock to Entisol to Inceptisol, to mollisol, to alfisol to ultisol to oxisol
What soil has will most likely have a Bt horizon?
a) Vertisol
b) Inceptisol
c) Ultisol
d) Aridiso
c) Ultisol
Which of the following is a realistic soil profile progression?
a) Entisol – Vertisol – Inceptisol
b) Mollisol – Oxisol – Ultisol
c) Inceptisol – Ultisol – Oxisol
d) Ultisol – Alfisol – Oxisol
c) Inceptisol – Ultisol – Oxisol
What is a diagnostic horizon?
a layer or soil
zone whose properties meet certain
criteria specified for the purposes of
classification.
What are epipedons?
Eight of these diagnostic horizons are surface
diagnostic horizons, called epipedons
What is the mollic epipedon?
- A thick, dark, colored mineral horizon
(generally > 25 cm) at the surface. - The percent base saturation is greater than
50%.
What is the Umbric Epipedons?
colored mineral horizon
(generally > 25 cm) at the surface.
-base saturation
is less than 50% due to leaching of
basic cations (Ca, Mg & K).
What is the Melanic Epipedons?
-Characteristic of soils developed
from volcanic ash.
-Mineral horizon that is very black in
color due to its high organic matter
content.
What is the Histic Epipedons?
A layer of organic soil that is
naturally saturated with water.
What is the folistic epipedon?
A layer of organic soil that is not saturated with water for more
than 30 days
What is the ochric epipedon?
Fails to meet the definitions for any
of the other epipedons.
– Too light
– Too thin
– Too low in organic matter
What is the argillic horizon?
– A horizon that accumulates clay that has translocated from above.
– The Bt horizon identifies the argillic horizon.
What is the natric horizon?
– A horizon that accumulates clay that has translocated from above with the addition that sodium has accumulated and where there is >
15 % exchangeable sodium.
– The horizon will also have columnar soil structure.
What is the Kandic horizon?
– An accumulation of Fe and Al oxides and kaolinite clays.
– Low cation exchange capacities.
– Form in areas of intense weathering
What is the Oxic horizon?
– Highly weathered, very high in Fe and Al oxides.
– Only has 10% weatherable minerals in the sand, silt or clay sizes, as compared to
other soils which have weatherable minerals in the 50 to 90% range.
– Oxic horizons are found mostly in humid tropical and subtropical regions
What is the spodic horizon?
– An illuvial horizon characterized by the accumulation of colloidal organic matter,
aluminum oxide and iron.
– It is commonly found in highly leached forest soils of cool humid climate, on sandy
parent materials.
– The Bh horizon identifies the spodic horizon.
What is the Albic Horizon?
– A light colored eluvial horizon that is low in clay and other oxides which have been
removed by leaching (E horizon).
– The color of the horizon is often white or light tan.
What is the Calcic Horizon?
– An illuvial accumulation of carbonates (mostly CaCO3).
– The carbonates will react with HCl giving off CO2 or bubbles.
What is the Cambic Horizon?
– A slightly altered layer that has not undergone enough illuviation to become argillic.
– The Bw horizon identifies the cambic horizon.
What is the NONE horizon?
– Unlike the epipedon, not all soils need to have a diagnostic subsurface since they
may have not undergone very much soil development.
o Think of a thin A horizon sitting on the R horizon
All of the following diagnostic horizons are epipedons except for which one.
a) Argillic
b) Melanic
c) Ochric
d) Histic
a) Argillic
Which diagnostic horizon is characterized by having a Bh horizon?
a) Mollic
b) Spodic
c) Argilic
d) Folistic
b) Spodic
What parts of the soil taxonomic structure makes the last word of the name?
Order, suborder, and great group
What are the parts of a soil taxonomic name?
Order, suborder, great group, subgroup, subgroup, family, and series
What is the order of the following soil taxonomic name?
Fine, kaolinitic, thermic Typic Kanhapludults
a) Entisol
b) Ultisol
c) Histosol
d) Vertisol
b)ultisol
What is the great group of the following soil taxonomic
name?
Fine, kaolinitic, thermic Typic Kanhapludults
a) Typic Kanhapludults
b) Udults
c) Kanhapludults
d) Typic
c) Kanhapludults
What is the subgroup of the following soil taxonomic name?
Fine, kaolinitic, thermic Typic Kanhapludults
a) Typic Kanhapludults
b) Kanhapludults
c) Thermic
d) Fine, kaolinitic, thermic
a) Typic Kanhapludults
What is the family of the following soil taxonomic name?
Fine, kaolinitic, thermic Typic Kanhapludults
a) Typic
b) Kanhapludults
c) Fine, kaolinitic, thermic
d) Fine
c) Fine, kaolinitic, thermic
What is the thing to remember about soil map scale?
Small scale maps cover large areas and large scale maps cover small areas
