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Exam #5-Soils
Soils
58
Geology
Undergraduate 1
11/24/2008

Additional Geology Flashcards

 


 

Cards

Term

 

 

 

Soils

Definition

 

 

 

fine material covering the earth's surface composed of both mineral & organic material;  dirt

Term

 

 

 

Soil formation & development happens by?

Definition

 

 

 

weathering

Term

 

 

 

Soil profile

Definition

 

 

 

 the array of soil layers; their sequence from top (surface) to bottom (bedrock)

 

Term

 

 

 

Soil horizon

Definition

 

 

 

 a distinct layer of soil within the soil profile

Term

 

 

 

Soil Properties

Definition
* color            * texture (clay, sand, silt)

* structure            * consistence (cohesion)

* porosity            * moisture
Term

 

 

 

Soil Formation

Definition

 

 

 

* an on-going process of a renewable resource, but
not an inexhaustible resource

 

Term

 

 

 

Components of Soil

Definition

 

 

 *Minerals

*Organic matter

*Water

*Air

 

Term

 

 

 

Minerals

Definition

 

 

 

elements or compounds with a crystalline structure; the building-blocks of rocks; found in all soils
 

Term

 

 

 

Organic matter

Definition

 

 

 

  that part originally from living matter; decaying matter of plants, animals & their waste products

 

Term

 

 

 

Water

Definition

 

 

 

 fills spaces in the soil or forms a thin film around particles

 

Term

 

 

 

Air

Definition

 

 

 

also fills pour spaces

Term

 

 

 

Parent Material

Definition

 

 

 

the type of rock & minerals the soil was formed from

Term

 

 

 

residual soil

Definition

 

 

 

made from the underlying rock

Term

 

 

 

transported soil

Definition

 

 

 

made from material not found in underlying rock

Term

 

 

 

Climate

Definition

 

 

 

if Temperature & precipitation (moisture) differ, will yield different soils, even from same parent material
 

Term

 

 

 

Biological Agents

Definition

 

 

 

decomposers, microorganisms, bacteria, fungi, type of humus or organic matter
 

Term

 

 

 

Topography

Definition

 

 

 

flat vs steep slopes;   windward vs leeward slopes;  sun exposure
 

Term

 

 

 

Time

Definition

 

 

 

for a given place, more time means more complete development & increased thickness of soil
 

Term

 

 

 

Factors involved in soil formation:

Definition

 

*Parent Material

*Climate

*Biological Agents

*Topography

*Time

 

Term

 

 

 

What are the 4 development processes of soil horizons?

Definition

 

 

*Addition

*Transformation

*Depletion

*Translocation

Term

 

 

 

Addition

Definition

 

 

grains of soil made by adding material to the soil already in place;  adding organic matter
 

Term

 

 

 

Transformation

Definition

 

 

 

weathering of rock, minerals, & soil particles already present;  physically or chemically changing them
 

Term

 

 

 

Depletion

Definition

 

 

 

particles are carried out of an area & downward thru soil by percolating water, the an area below
 

Term

 

 

 

Translocation

Definition

 

 

 

deposition of particles in a lower area from an area above
 

Term

 

 

 

Main Soil Horizons:

Definition

 

 

 

O, A, E, B, C, R

Term

 

 

 

'O' horizon

Definition

 

 

 

organic horizon, consisting entirely of organic material

Term

 

 

 

'A' horizon

Definition

 

 

 

upper most layer developed from parent material

Term

 

 

 

'E' horizon

Definition

 

 

 

lighter colored layer just below the 'A' horizon

Term

 

 

 

'B' horizon

Definition

 

 

 

created by translocation of particles from the 'A' & 'E' horizons above

Term

 

 

 

'C' horizon

Definition

 

 

 

where the parent material is transformed by weathering into soil particles to become future soil

Term

 

 

 

'R' horizon

Definition

 

 

 

where solid rock (bedrock) is first affected by weather

Term

 

 

 

Solum

Definition

 

 

the 'A', 'E', & 'B' horizons; those layers in which plant roots are most active

 

*sol:  used as a suffix in soil classification

Term

 

 

 

Pedon

Definition

 

 

column of soil, extending from the 'O' horizon into the 'C' horizon

 

*ped:  naturally occurring "clump" of soil

Term

 

 

 

Soil texture is:

Definition

 

 

*size of the particles in the soil

*an indication of the soils compactness & amount of pore space

Term

 

 

 

Largest to smallest:

Definition

 

 

 

Sand, silt, clay

Term

 

 

 

Loam

Definition

 

 

a term used to describe a soil, similar to a clay or sand, but based on the percent of sand, silt, & clay and NOT on particle size

Term

 

 

 

Field Capacity

Definition

 

 

 

ability of a soil to hold water against the downward pull of gravity

Term

 

 

 

Sand=

Definition

 

 

 

=low field capacity

Term

 

 

 

Clay=

Definition

 

 

 

=high field capacity

Term

 

 

 

Soil structure does what?

Definition

 

 

*  the type or arrangement of a soils' peds;
also plays a role in determing a soils field capacity
 

Term

 

 

 

Platy

Definition

 

 

 

layered peds, like flakes stacked horizontally

Term

 

 

 

Prismatic

Definition

 

 

 

peds arranged in columns

Term

 

 

 

Blocky or Angular

Definition

 

 

 

straight sided, irregularly shaped peds

Term

 

 

 

Spheroidal or Granular

Definition

 

 

 

small, rounded shaped peds

Term

 

 

 

 4 Basic Soil Structures

 

 

 

Definition

 

  • Platy
  • Prismatic
  • Blocky or Angular
  • Spheroidal or Granular
Term

 

 

 

How many soil orders?

Definition

 

 

 

12

Term

 

 

 

Entisols

Definition

 

 

 

soils of recent origin

Term

 

 

 

Inceptisols

Definition

 

 

 

show the beginnings of a weakly developed

'B' horizon  

 

 

Term

 

 

 

Vertisols

Definition

 

 

 

clay-rich soils which swell or shrink with moisture

Term

 

 

 

Andisols

Definition

 

 

 

developed from volcanic ash

Term

 

 

 

Histosols

Definition

 

 

 

water-saturated organic soils

Term

 

 

 

Aridisols

Definition

 

 

 

dry soils found in most desert areas; salinization common

Term

 

 

 

Mollisols

Definition

 

 

grassland soils of high agricultural value, such as under the Great Plains (US);  thick 'O' horizon

 

* very thick, sod houses made out of

Term

 

 

 

Alfisols

Definition

 

 

 

moderately weathered deciduous forest soils; moist, highly mineral-rich soils

Term

 

 

 

Spodosols

Definition

 

 

 

soils of coniferous (needle-leaf evergreen, pine) forests;  highly acidic soils
Term

 

 

 

Utisols

Definition

 

 

 

warm, wet climate soils with a high clay content in the 'B' horizon, as found in the SE US
 

Term

 

 

 

Oxisols

Definition

 


 

tropical areas with high rainfall;  rainforests; rich in FE & AL oxides; subject to laterization
 

Term

 

 

 

Gelisols

Definition

 

 

 

cold & frozen soils subject to crytoturbation

(frost churning); found in high latitudes & elevations
 

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