GEOLOGY 1500 FINAL EXAM
QUESTIONS WITH CORRECT
ANSWERS
Define Mechanical Weathering - Correct Answers -the physical breakdown or
disintegration of rocks and minerals into smaller and smaller pieces with no chemical
change
Define Chemical Weathering - Correct Answers -decomposition of rocks and minerals
into new minerals and substances due to the presence of water (H20), oxygen (O2),
and hydrogen ions (H+)
Role of Weathering in the Rock Cycle - Correct Answers -attacks any Earth materials
(minerals and rocks) that are exposed by Uplift and Erosion at/near the Earth's surface
What is the source of energy for weathering process? - Correct Answers -Solar
Energy/Radiation
One way in which the water molecule promotes both chemical and mechanical
weathering - Correct Answers --promotes chemical weathering because it dissolves
many substances due to the polar nature of the water molecule.
-promotes mechanical weathering because it expands by about 9% when it freezes thus
causing rocks to be broken into smaller pieces
5 mechanical weathering processes - Correct Answers -Frost Action or Wedging
Stress Release/Pressure Release
Salt Weathering-- Crystal Growth
Thermal Expansion and Contraction
Organic Activity or Bio-Mechanical Activity
Describe how Stress Release-Mechanical Exfoliation leads to Mechanical Weathering
and what type of landform results from Stress Release-Mechanical Exfoliation - Correct
Answers --opens large fractures in ricks and allows other processes to operate
-exfoliation domes
What is TALUS? - Correct Answers -coarse, angular rock material that accumulates at
the base of a slope or cliff--results from a combination of frost wedging and rock falls
, How and why does Mechanical Weathering enhance Chemical Weathering? - Correct
Answers -Mechanical Weathering breaks rocks and minerals down into smaller and
smaller pieces, which provides more surface area for chemical weathering to take place
on (work together to break down rocks)
5 factors that influence Chemical Weathering - Correct Answers -Climate
Rock Structure
Organic Activity
Time
Mineral and Rock Composition
(all other factors being equal) What global climate belt would you expect to observe the
fastest rates of Chemical Weathering? Why? - Correct Answers --Tropical Climate
Zone/Belt
What are the primary substances necessary for Chemical Weathering? - Correct
Answers -Water, Oxygen, and Hydrogen Ions
What is the primary source of hydrogen ions? - Correct Answers -dissociation of
carbonic acid that forms as a result of dissolution of carbon dioxide in water
List and define the 3 Chemical Weathering Processes or Reactions. What type of
rock(s) that each process/reaction breaks down. - Correct Answers --Dissolution: a
Chemical reaction whereby ions pass from a mineral into a solution; breaks down
Limestone, Dolostone, Marble, Rock Salt, and Rock Gypsum
-Hydrolysis: a Chemical Reaction in which Water dissociates into H+ (hydrogen cation)
and OH- (hydroxide anion); breaks down feldspars and micas in many types of Igneous
and Metamorphic Rocks
-Oxidation: a Chemical reaction in which oxygen as an oxidizing agent causes a loss of
electrons by an atom or ion and thus involves an increase in oxidation number; breaks
down Ferromagnesian minerals in Mafic Igneous Rocks and their Metamorphic
Equivalents.
For the following types of Chemical Weathering Reactions/Processes, what Gas is
removed from the atmosphere for each reaction/process, and what Substances are
needed for the reaction to take place? - Correct Answers --Dissolution: CO2; Water and
Hydrogen Ions
-Hydrolysis: NONE; Water and Hydrogen Ions
-Oxidation: O2; Oxygen
For the following types of Chemical Weathering Reactions/Processes, what New
Products (especially insoluble residues) are the result of each type of Reaction? -
Correct Answers --Dissolution: No Residue - All Soluble Ions-ultimately all material is
totally dissolved
-Hydrolysis: Insoluble Residue = Clay Minerals; some other material is dissolved
QUESTIONS WITH CORRECT
ANSWERS
Define Mechanical Weathering - Correct Answers -the physical breakdown or
disintegration of rocks and minerals into smaller and smaller pieces with no chemical
change
Define Chemical Weathering - Correct Answers -decomposition of rocks and minerals
into new minerals and substances due to the presence of water (H20), oxygen (O2),
and hydrogen ions (H+)
Role of Weathering in the Rock Cycle - Correct Answers -attacks any Earth materials
(minerals and rocks) that are exposed by Uplift and Erosion at/near the Earth's surface
What is the source of energy for weathering process? - Correct Answers -Solar
Energy/Radiation
One way in which the water molecule promotes both chemical and mechanical
weathering - Correct Answers --promotes chemical weathering because it dissolves
many substances due to the polar nature of the water molecule.
-promotes mechanical weathering because it expands by about 9% when it freezes thus
causing rocks to be broken into smaller pieces
5 mechanical weathering processes - Correct Answers -Frost Action or Wedging
Stress Release/Pressure Release
Salt Weathering-- Crystal Growth
Thermal Expansion and Contraction
Organic Activity or Bio-Mechanical Activity
Describe how Stress Release-Mechanical Exfoliation leads to Mechanical Weathering
and what type of landform results from Stress Release-Mechanical Exfoliation - Correct
Answers --opens large fractures in ricks and allows other processes to operate
-exfoliation domes
What is TALUS? - Correct Answers -coarse, angular rock material that accumulates at
the base of a slope or cliff--results from a combination of frost wedging and rock falls
, How and why does Mechanical Weathering enhance Chemical Weathering? - Correct
Answers -Mechanical Weathering breaks rocks and minerals down into smaller and
smaller pieces, which provides more surface area for chemical weathering to take place
on (work together to break down rocks)
5 factors that influence Chemical Weathering - Correct Answers -Climate
Rock Structure
Organic Activity
Time
Mineral and Rock Composition
(all other factors being equal) What global climate belt would you expect to observe the
fastest rates of Chemical Weathering? Why? - Correct Answers --Tropical Climate
Zone/Belt
What are the primary substances necessary for Chemical Weathering? - Correct
Answers -Water, Oxygen, and Hydrogen Ions
What is the primary source of hydrogen ions? - Correct Answers -dissociation of
carbonic acid that forms as a result of dissolution of carbon dioxide in water
List and define the 3 Chemical Weathering Processes or Reactions. What type of
rock(s) that each process/reaction breaks down. - Correct Answers --Dissolution: a
Chemical reaction whereby ions pass from a mineral into a solution; breaks down
Limestone, Dolostone, Marble, Rock Salt, and Rock Gypsum
-Hydrolysis: a Chemical Reaction in which Water dissociates into H+ (hydrogen cation)
and OH- (hydroxide anion); breaks down feldspars and micas in many types of Igneous
and Metamorphic Rocks
-Oxidation: a Chemical reaction in which oxygen as an oxidizing agent causes a loss of
electrons by an atom or ion and thus involves an increase in oxidation number; breaks
down Ferromagnesian minerals in Mafic Igneous Rocks and their Metamorphic
Equivalents.
For the following types of Chemical Weathering Reactions/Processes, what Gas is
removed from the atmosphere for each reaction/process, and what Substances are
needed for the reaction to take place? - Correct Answers --Dissolution: CO2; Water and
Hydrogen Ions
-Hydrolysis: NONE; Water and Hydrogen Ions
-Oxidation: O2; Oxygen
For the following types of Chemical Weathering Reactions/Processes, what New
Products (especially insoluble residues) are the result of each type of Reaction? -
Correct Answers --Dissolution: No Residue - All Soluble Ions-ultimately all material is
totally dissolved
-Hydrolysis: Insoluble Residue = Clay Minerals; some other material is dissolved
