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GEOLOGY 12
CHAPTER 5 WORKSHEET
WEATHERING AND EROSION
KEY
1.
Silicate minerals that are most susceptible to chemical weathering at the earth's surface
a. must not be very dense (they have a low specific gravity)
b. form under conditions of high temperature and pressure, very different from conditions at
the surface .
c. form at the surface by means of other weathering processes
d. are all of the silicate minerals containing any iron or magnesium
2.
Warm, moist climates generally
a. favour chemical weathering
b. slow down chemical weathering
c. prohibit physical weathering
d. have no effect whatsoever on rates of weathering
3.
The process of mechanically breaking a rock into smaller pieces aids or facilitates processes
of chemical weathering because
a. the orderly arrangement of atoms in the minerals are disrupted when the rock is broken
b. more volume is provided in the initial rock
c. more surface are is available for chemical processes to attack
d. less surface are is available for chemical processes to attack
4.
The phenomenon of spheriodal weathering illustrates
a. how chemical weathering breaks down granite
b. the relationship of surface area to weathering rate
c. the mechanical process of unloading
d. the predominance of wedging in temperate climates
5.
The appropriate term for weathered particles being transported by a stream is
a. particles of regolith
b. soil
c. sediments
d. topsoil
6.
Which of the following weathering processes would be more effective in mountainous regions
at high altitudes?
a. dissolution of calcite by acidic rain
b. frost wedging
c. chemical leaching
d. wedging by plant roots
7.
The exfoliation of granite in Yosemite National Park illustrates the mechanical effect of
a. spheroidal weathering on a huge scale
b. differential weathering of soft and hard rocks
c. unloading of the granite as overlying rocks are eroded
d. freezing and thawing
8.
Industries in New England emit a lot of carbon dioxide which combines with water to produce
carbonic acid rain. As a result, limestone and marble in New England
a. are protected against weathering by a carbon dioxide coating
b. are likely to weather slowly if at all
c. are not affected by the amount of carbon dioxide in the air
d. are likely to weather rapidly by solution/dissolving
9.
SOIL is the surface accumulation of rock and mineral fragments, and some organic matter,
that covers the bedrock and is capable of supporting plant growth.
10.
A more general term than soil is REGOLITH, which includes all surface sediment
accumulations in place, regardless of their ability to support agriculture.
11.
Once particles of soil are transported and redeposited, they fall into the broader class of
SEDIMENT.
12.
The relative importance of different weathering processes depends largely on CLIMATE.
13.
Weathering processes that break up a rock or mineral physically into smaller pieces are
known collectively as PHYSICAL / MECHANICAL weathering
14.
Weathering processes which break down a rock or mineral by chemical reactions are known
collectively as CHEMICAL weathering.
15.
In the process of FROST SHATTERING / ICE WEDGING, water enters the cracks in rocks
and freezes, forcing the cracks to enlarge.
16.
The removal of overlying or confining stress from a rock sometimes causes layers of the rock
to flake off in sheets, a mechanical weathering process known as EXFOLIATION.
17.
The mineral calcite, found in the rock types limestone and marble, is most likely to weathering
chemically by SOLUTION / DISSOLVING.
18.
CLAY minerals are often the product of chemical weathering of silicate minerals.
19.
The susceptibility of silicate minerals to chemical weathering can be estimated from
BOWEN’S Reaction Series; those minerals that form early at high temperatures tend to be the
most unstable at the earth's surface.
20.
Most chemical weathering reactions proceed more rapidly in the presence of water and at
HIGHER temperatures.
21.
Mechanical weathering accelerates the rate of chemical weathering by increasing the amount
of SURFACE AREA exposed to air and water
22.
Angular chunks of rock are weathered into rounder shapes through the process known as
_________________ weathering.
23.
T
F
The term soil is a more inclusive term than regolith; regolith applies only to surface
material that has been transported to its present location.
24.
T
F
Calcite weathers chemically by dissolving, leaving no residue minerals behind.
25.
T
F
Minerals or rocks that form at high temperatures and pressures tend to be very
stable with respect to weathering at the earth's surface.
26.
T
F
The more water that is available, the slower the rate of chemical weathering.
Chapter 5 WS KEY
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