Basic Vocab Flashcards
Illuviation
Gains or Inputs of matter into a horizon. Illuviated into B horizons. Think immigration
Eluviation
Loss or exodus of matter from a horizon, often from A or E
Alluvium
Sediment deposition from water
Relict Soil
Ancient soils formed in environments different than todays
Buried soil
Soil covered by younger sediment and rock
Paleosols
Ancient souls that have been preserved in geological record
Exhumed soil
Soil brought to the surface from deeper
Polygenetic soil
Soils with multiple chemical, mineral, and morphological characteristics. Different parent materials
Primary minerals
Formed from cooling magma/lava or precipitated from water
Secondary minerals
Minerals formed by soil processes
CLORPT or CORPT
Climate, relief, parent materials, organisms, time
Humus
Dark, nutrient Rick organic material formed from composition of plants and animals… good for holding water
Toposequence
Soils that occur in a series of sites on the slope, with similar soils types and conditions
Physical weathering
Makes particles smaller
Freeze thaw, Exfoliation (cracks from erosion) Salt cristal growth (expand and break rock), abrasion (wind water ice loaded with sediment), roots and borrowing animals
Chemical weathering
Changes composition
Carbon dioxide (acids & chemical reactions)
Solution
Hyrodlisis
Oxidation
Diagenesis
Any weathering of geological materials after initials deposition. Not always at earth surface.
Pedogenesis
Soil formation, sub category of diagenesis that occurs at or near surface
Comminution
Breaking into small pieces
Physical weathering examples
Freeze thaw, Wet Dry, Insolation, Fire, Falls impacts bioturbation etc
Chemical weathering Processes
Dissolution, Oxidation/Reduction (redox), Hydrolysis, Ion exchange
Dissolution (Chem)
Joint sets can be enhanced by chemical weathering. Natural feature of many rocks
Redox (Chem)
Oxidation- Oxic environments above water table. Oxidized fe3+ usually red or brown
Reduction- anoxic environments, water saturated
-minerals usually grey
-Reduced Fe2+ minerals green to blue (gley)
Hydrolysis
H+ and OH ions break bonds with crystal lattices
-Dissociated water molecules
-removals of ions from lattice, replacement by H or OH
Breaks apart, distorts, forma new lattices
Ion exchange
Like hydrolysis, but with ions besides H+
-important with clay
-cation exchange capacity- estimate of number of charge sites available to exchange or bind to different cations
Saprolite
Chemically weathered rock “rotten rock” that retains original structure. Common in lower soil profiles
Regolith
Loose on consolidated rock and dust that sits atop a layer of bedrock. On earth includes soil
Felsic Rock
Igneous rocks that are high in silicon, aluminum, potassium, oxigen, and sodium. Lighter, less dense then magic rocks.
Granite
Rich in feldspar and quartz
More resistant to chemical weathering
Magic Rock
Igneous rock rich in magnesium and iron, dark in color
Basalt, gabbro
Weather faster than felsic because olivine and pyroxene are more susceptible to chemical weathering
Sedimentary rock
Forma from depositions preexisting rock and sediment, dead organisms.
Layering.
Sandstone, limestone
Igneous Rock
Formed when magma cools and solidifies
Can be intrusive (below ground) or extrusive (above ground)
Metamorphic Rocks
When other rocks are subjected to intense heat or pressure
Mesic
Soil with moderate amount of moisture, between wet and dry. Drains well but not completely
Prairies and savanna’s
Thermic
Between 15c and 22c
Not to hot or cold
Torric
Aridic moisture regime, dry and often requiring irrigation
Xeric
Dry soil, low moisture levels
Cryic
So cold it makes you cry
6 ecological functions of soils
1 medium for plant growth
2 water regulation
3 nutrient cycling
4 habitat for organisms
5 atmospheric modification
6 carbon storage
4 soil components
Mineral matter (45%)
Air (25%)
Water (25%)
Organic matter (5%)
