Exam 1 Flashcards
Factors of soil formation
time, topography, parent material, climate and organisms
soil formation main processes
addition and losses, transformation, translocation
additions and losses
inputs water and organic matter and there are losses through weathering.
- change the soil overtime
transformation
weathering and decomposition change the nature of the soil
translocation
movement of material creates zones of depletion and enrichment, this creates vertical heterogeneity
O-Horizon
organic, decomposition, typically at the soil surface
A-Horizon
top mineral, organic matter accumulates and it is darkened by organic matter
E-Horizon
Lighter colored than A, Clay and organic matter have been leached , eluviation below A and O
B-Horizon
Where clay and organic matter from A and E accumulate, illuviation occurs
C-Horizon
Parent material, unconsolidated material below A and B
eluviation
removal, leaching
illuviation
accumulation
g
strong gleying - molting
h
illuvial accumulation of organic matter
k
accumulation of carbonates
n
accumulation of sodium
s
illuvial organic matter and iron, aluminum oxides
t
accumulation of silicate clays
o
accumulation of iron and aluminum oxides
p
plowing or other disturbances
glacial till
sediment deposited by a glacier
alluvium
transported by water (streams)
colluvium
gravity
aeolian/loess
transported by wind/wind blown dust
tephra
transported by volcanic eruption
lacustrine/marine
formed at bottoms of lakes, carried to oceans by rivers and streams
residual
formed in place - none
physical weathering
change in size of the rocks and minerals by atmospheric agents without chemical alteration
physical weathering examples
freezing/thawing, grinding and abrasion
chemical weathering
change in the chemical nature of the rocks/minerals by atmospheric agents
chemical reaction - hydrolysis
splitting H2O
chemical reaction - hydration
addition of intact water molecule
chemical reaction - carbonation
reaction with CO2 and H2Co3 solubilizing minerals
chemical reaction - oxidation
electron loss
reduction
electron gain
dissolution
water as a solvent, hydration cations and anions
Alfisols
argillic, natric and kandic horizon that has a high to medium base saturation
Alfisols
alf
andisols
from volcanic ejecta, dominated by allophane and al-humic complexes
andisols
and
aridisols
dry soil, ochric epipedon that is sometimes argillic or natric
aridisols
id
entisols
little profile development, ochric epipedon common
entisols
ent
gelisols
permafrost often with cryoturbation (frost churning)
gelisols
el
histosols
peat or bog >20% organic matter
histosols
ist
inceptisols
ept
inceptisols
embryonic soils with few diagnostic features, ochric/umbric epipedon, cambric horizon
mollisols
mollic epipedon, high base saturation, dark soils, argillic/natric horizons
mollisols
oll
oxisols
oxic horizon, no argillic horizon highly weathered
oxisols
ox