Weathering and Erosion Notes
Weathering
◦_________________________ of rock due to surface processes
◦Two types of weathering: ____________________ (Mechanical), _________________________
Physical (Mechanical) Weathering
Changes the physical _________________________ of the rock
1._________________________ - wind & water
2.Frost _________________________ - water expands when it freezes
3._________________________ or unloading – A rock breaks off into leaves or sheets along joints
which parallel the ground surface.
◦Caused by expansion of rock due to uplift and erosion; removal of pressure of deep burial
4.Thermal _________________________ -repeated daily heating (expansion) & cooling (contraction) of
rock
5.Plant _________________– break rocks apart as they grow
6._____________ Crystal Growth – evaporation, crystals grow between rocks
Chemical Weathering
Rock reacts with ____________________ , __________________&
_________________________
1. _________________________ (solution) - also includes leaching
2. Oxidation- reaction of __________________with other substances (minerals containing iron)
3. Hydrolysis- reaction of ____________________with other substances
4. __________________- Action
Dissolution
◦_________________________ topography forms on _________________________ terrain and is
characterized by: caves/caverns, sinkholes, disappearing streams, and springs
◦_________________________ or breaks down material
Weathering and Erosion Notes
◦Limestone and marble contain calcite and dissolve in limestone. _________________ and
_____________________typically form in limestone
◦_____________________ - cave formations; made of calcite
◦Form a rock called _____________________
◦_________________________ - from _________________________
◦_________________________ - on _________________________
Sinkholes
• A sinkhole is a _________________________ on the Earth’s surface
•
Can be caused by _________________________ of underlying rock, and overuse of
____________________________
•
Test soil composition before building
•
Treat underground limestone to resist water
•
Redirect surface water
•
Mitigation:
•
Use filters → Pump out water which dissolve underlying rock
•
Careful inspection of bedrock
Oxidation
◦____________________ combines with ________________-bearing silicate minerals causing
"_______________________"
◦Iron oxides are _____________, _____________________, or ___________________ in color
Hydrolysis-affected by H2O
•
_________________________ alters to _____________,
•
_________________ = stable at high temperatures and pressures.
•
_____________ are stable under conditions at the Earth's surface
•
______________________ turns to ____________________
Weathering and Erosion Notes
Biological Action
◦____________________, ____________________, and other
_________________________________
◦Chemically and physically change rock
Factors Affecting Weathering
◦Mineral ____________________
◦____________________ ___________________ –____________________particles=
____________________surface area, more available for chemical weathering
◦Type of ____________________
◦____________________- warm/rainy (____________________) and cold
(____________________)
Erosion
◦Process that ____________________Earth materials from one place to another
◦________________________: When materials are ____________________in another location
Erosion by Running Water
◦Has more ___________________to move large weathered particles, more material, and over a greater
______________________than wind
◦______________Erosion- erosion by running water in _________________channels, on the side of a
slope
◦____________________ Erosion- When a channel becomes deep and __________________ (more
than 3 meters deep)
◦Rivers entering large bodies of water (lakes, oceans, etc) deposit ____________________amounts of
______________________
◦These locations are also weathered and eroded constantly by ____________________,
____________________, and ____________________
◦Islands are also worn down by water
Glacial Erosion
◦They ____________________and ____________________out large sections of Earth
◦Because they are so dense, they can carry huge __________ and ____________ over great distances
Weathering and Erosion Notes
◦These particles are ____________________when glaciers ____________________proceeding
forward or recede backwards
Wind Erosion
◦Affect areas most with limited _________________________, high temperatures and little vegetation
◦Wind ____________________- When trees or other vegetation are planted __________________to
the direction of the wind to reduce the effects of wind erosion
Erosion by Plants, Animals & Humans
◦Earth’s surface materials are constantly relocated as everyday life processes are carried on
◦Examples: Animal’s ___________ into soil; Humans build __________, ____________________ and so on
Soil Formation
◦
Caused by ________________ and _______________
◦
The material that makes up soil is known as its ____________________material.
◦
__________________– dark colored substance in soil from decayed
____________________material
◦
_______________– soil that is made up of equal parts of _______________,
_______________, and _________________; best for growing most types of plants
◦
_____________________– measure of how well soil supports plant ____________________
◦
Soil formation continues over a long period and gradually develops layers called
________________________.
Soil Horizons
•soil horizon – layer of soil that differs in ________________and ___________________from the
layers above or below it
•______________________ – the “____” horizon or the top layer is crumbly, dark brown mixture of
_________________, ________________and other mineral
•_____________________ – the “____” horizon in below topsoil consisting of
________________and other particles washed down from top soil, but __________________humus
•“____” horizon – bottom layer containing partly _________________________rock
Weathering and Erosion Notes
•___________________ – the “__” horizon is _____________________layer of
________________beneath the soil; once exposed bed-rock gradually weathers in smaller particles that
are the basic material of soil
•Soil is full of living organisms – some are _______________________________that break down the
remains of dead organisms and others mix the soil, making space for air and water which help plants thrive.
Soil Types
•A soil’s _______________________, rate of
________________________and
__________________________are determined by its
_____________________
•_____________________ Soils-Have good drainage, very
_____________________,
__________________________often present
•________________________________ Soils___________________, _____________________soils,
can support diverse environments
•_____________________ Soils- Can only support limited vegetation, very ______________
_______horizon,
little to no _____________________ matter
•_____________________ Soils- Intensely weathered and _____________________soil, can contain
high grade iron ore for mining