Download Name Period ______ Date ______ Homework : Read chapter 7 and

Name __________________________ Period __________ Date __________
● Homework : Read chapter 7 and do 2 pages (front and back) of the blue
note-taking/reading study guide.
Weathering – process by which _______________ is broken down. Two types
1) ____________________ weathering – process of breaking rock by physical
forces. Also called physical weathering
2) ______________________ weathering – the break down of rock by
chemical reaction that change the rock's make up or composition.
Mechanical Weathering
Ice wedging – water seeps into the _________________ and pores of rocks. As it
freezes it ________________ causing the rocks to break.
______________ ________ – roots of plants enter the cracks in rocks,
________________ the pieces apart as they _______________.
Abrasion – particle carries by ________________ and _______________ scratch
the surface of rocks.
Exfoliation – as rock rise to the surface, __________________ is released. Rock
peels like an _____________
1) What are the four causes of Mechanical Weathering?
___________________
___________________
___________________
____________________
Chemical Weathering
Dissolving rock – _______________ is the main cause of weathering.
As water travels through the ___________________________ it picks up carbon
dioxide.
Water + carbon dioxide = _____________________ __________
As it travels through the ___________ it picks up more CO².
The acid breaks down minerals in the rock.
Oxidation – ________________ in the atmosphere combines with mineral containing
_____________ in the rock to produce iron oxide (rust) giving the soil or rock a
_____________ color.
Lichen – part ______________ part __________________.
Lichen attaches to rocks.
Lichens _______________ produce _____________ which dissolve rock.
Weathering Rates
Surface area – the greater the surface _______________ the faster the weathering.
Climate – rocks will chemically weather faster in ____________, _________ areas.
Rocks will mechanically weather faster in _____________, _________ areas
Rock composition – different rocks have ___________________ weathering rates.
Granite weathers more slowly than limestone.
2) How do water and air help cause chemical weathering?___________________
__________________________________________________________________
___________________________________________________________________
3) What 3 factors affect weathering rates? _____________________________,
_____________________________, ___________________________
4) How does the mechanical weathering affect the rate of chemical weathering?
___________________________________________________________________
___________________________________________________________________
5) Would weathering affect a marble statue in a museum?
____________________
6a. What is the surface area of each of the smaller rectangular prisms? __________
6b. How does the total surface area of the two smaller prisms compare with the
surface area of the larger prism? ________________________________________
___________________________________________________________________
6c. Will the rock weather more quickly in one piece or broken in half? ____________
____________________________________________________________________
Soil Formation
Soil is a mixture of __________________ materials
Weathered rock particles, soils differ depending on the ___________ of rocks
that the particles came from
Organic materials, (Humus) waste products of ______________, ___________
and other living organisms broken down by decomposers such as
_________________and ______________
Water, ________________% of soil volume
Air, ___________________% of soil volume
Animals make their homes in soil. Burrowing adds to the soil's _________content
The kind of soil depends on several factors
1. The kind of _______________in a in area
2. The area's __________________
3. The ____________________ in the area, mountains, valleys...
4. The ________________ ______________in the area
5. The __________________ and ________________ in an area
A ____________ __________________ is a layer of soil that is that is different from
the layers around it
Soil profile is all the ___________________ together
___________________soils – heavy rains wash away minerals leaving thin layer of
humus not suitable for crops
________________soils – have very small if any A horizon due to lack of vegetation.
Due to lack of rain weathering and soil formation occur slowly
Temperate soils – due to ___________ weather and rainfall soils are rich in
________________ and good for growing _____________. Usually dark in color
_______________ soils – due to lack of rainfall and constant cold little soil formation
occurs. Contains a lot of _______________ fragments
7) In which part of Australia are most of the crops grown?
__________________
__________________________________________________________________
8) Does northern Africa have much of an A horizon, why
___________________
_________________________________________________________________
9) In which areas would you find soils which contain many rock fragments?
_________________________________________________________________
_________________________________________________________________
Soil ________________________ is determined by the size of the weathered rock
_________________________ it contains
Sand – 0.05 – 2 mm, feels gritty
Does not hold ________________ well.
Water moves through _______________
Silt – 0.002 – 0.05mm
Need _______________________ to see
_________________ and _____________ when wet
Forms _______________ when dry
Holds more ______________ than sand
Clay – less than 0.002mm
____________________, need microscope to see
__________________ when wet
Forms hard clumps when dry
Absorbs _______________ water
Water moves through ___________________
Color
Soil may be red, black, brown, yellow, green or even white
Red soils contain ________________
Black or brown soils contain a lot of _______________
Color can indicate how well water will ______________ through the soil
_____________ ________________ is the spaces between soil particles
_______________ and ___________move through pore space
Soils range between 20 – 60% pore space
1) List the four main ingredients of soil
2) What is humus?
3) What helps humus form?
4) Which soil horizon contains the most humus?
5) Horizon A, B and C make up what?
6) How do animals help add air to the soil?
7) Which is the smallest soil particle?
8) Red soil contains what?