Midterm One Flashcards
(53 cards)
What is Pedology?
The study of natural bodies according to their origins, properties and classification.
Define Soil
A collection of natural bodies occupying portions of earth’s crust, capable of supporting plant life.
What are the 5 factors creating soil properties?
hint: clorpt
Climate, Vegetation + Organisms, acting on Parent Material, as conditioned by Relief, over periods of Time
S= f (cl, o, r, p, t)
What is the upper boundary of soil?
air
What is the lateral boundary of soil?
H2O bodies + rock outcrops
What is the lower boundary of soil?
rock/hard material
Define Pedon
The smallest 3D structure at the surface that is considered as soils.
Define Soil Horizon
A layer of soil approx. parallel to the surface and differs from other horizons in the soil profile
Define Landscape
a collection of 1 or more landforms
Define the O Horizon
Organic layers at the surface of the organic soils - not in all soil, only organic
Describe the A Horizon
layers nearest the surface, dominated by mineral particles, darkened by OM, has the most intense biological activity
Describe the Ae Horizon
intensely weathered + leached, has NOT accumulated OM.
e=eluviated
Describe the B horizon
less OM, has prominent silicate clays and oxides (secondary minerals), washed away from above or formed in situ by weathering
Describe the C horizon
mineral horizons below solum, least weathered
aka parent material - developed first
What are 5 ecological roles of the functions of soil?
- medium for plant growth
- recycling system of nutrients + wastes
- habitat ofr soil organisms
- engineering medium
- system for H20 supply + purification
What is the origin of soil?
non-soil material called rocks + vegetative material in bogs
What is the creation path of soil? (sequence)
rocks –> regolith –> parents material –> mature soil
Why does weathering occur more intensely on the surface?
rocks at depths are at equilibrium with their environment therefore there are no further changes. rocks are not at equilibrium with their environment on the surface
What is Pedogenesis?
all physical, chemical and biological alternations that give rise to different soils
What is Diagenesis?
all physical + chemical alterations that occur to rocks. Occur on primary rocks to get secondary rocks.
What are the 4 types of process surface rocks undergo during genesis?
- Addition to materials
- Subtraction of materials (breakdown)
- Movement within soil (translocation)
- Transformation from one mineral to another (chemical), change in size/formation
Define weathering
the action of the atmosphere, hydrosphere and biosphere on the surface of the lithosphere.
Define Landforms
Configurations of the land surfaces taking distinctive forms, produce by natural and/or un-natural processes.
Two types: Initial and Sequential
Define Initial Landforms - Primary
produced by internal (endogenic) earth forces
-such as tectonic activity, volcanoes, flat scarp
