Physical Geology
GEOL 101 - Exam 2 Review
Study hints
The most important activity for you to do to prepare for examinations
is read and understand your class notes and required textbook. You should be able, without
referring to your notes, to answer all of the questions in this study guide.
Make sure that you are prepared to make connections between major concepts.
For reinforcement of the class notes, refer to the reading in your textbook.
I will not expect you to have memorized every detail presented in the book,
but your level of comprehension will increase with exposure to the reading.
Weathering
Erosion
Mechanical Weathering
- Frost wedging
- Crystal Growth (salt)
- Thermal expansion and contraction
- Exfoliation
- Biological (roots)
- Abrasion
Chemical Weathering
- Water
- Dissolution
- Oxidation
- Hydrolysis (clays)
Factors affecting weathering
- Climate
- Organisms
- Time
- Composition of minerals
Sedimentary Rocks
Sediments
Sediment transport and deposition (detrital and chemical)
Sediment Texture
- grain size
- grain shape
- sorting
Diagenesis
Lithification
Detrital Sedimentary Rocks
- Shale (>50% of all sedimentary rocks)
- Sandstone (~25% of all sedimentary rocks)
- Conglomerate
- Breccia
Chemical Sedimentary Rocks
- Limestone
- Chert
- Evaporites (e.g. salt)
- Coal
Metamorphism and Metamorphic Rocks
Metamorphism, foliation, and protolith
Factors controlling metamorphism
- Heat
- Pressure (confining pressure & directed pressure)
- Fluids (water)
Types of metamorphism
- Contact metamorphism
- Hydrothermal metamorphism
- Regional metamorphism (burial & convergent plate boundary)
- Subduction Zone metamorphism
Foliated metamorphic rocks
- Slate (regional metamorphism, relatively low temperature and pressure), protolith = shale
- Phyllite (regional metamorphism, intermediate-low temperature & pressure), protolith = shale
- Schist (regional metamorphism, intermediate-high temperature & pressure), protolith = shale
- Gneiss (regional metamorphism, high temperature and pressure)
Nonfoliated metamorphic rocks
- Marble (protolith = limestone, minerals arenŐt elongate so never foliated)
- Quartzite (protolith = sandstone or chert, minerals arenŐt elongate so never foliated)
- Hornfels (contact metamorphism, high temperature & low pressure), protolith = shale
Relative Dating
Principles of Relative Dating
- Principle of Original Horizontality
- Principle of Superposition
- Principle of Cross-cutting Relationships
- Principle of Inclusions
Unconformities
- Nonconformity
- Angular Unconformity
- Disconformity
Relative dating using weathering
- Weathering rinds
- Landscape and topography
- Soil development
Absoute Dating
Isotopes
- Parent isotope
- Daughter isotope
- Half Life
Types of Isotope Dating
- U-Th-Pb, Rb-Sr, K-Ar systems date metamorphic and igneous minerals
- Carbon 14 used to date organic carbon or detrital charcaol (things that used to be living)
Other Types of Dating
- Dendrochronology
- Lichenometry
- Varve chronology
Deformation, stress, folds and faults
Stress and strain
- Yield point and elastic limit
Types of stress
- Compression
- Tension
- Shear
Types of deformation
- Elastic
- Brittle
- Ductile/plastic
Factors affecting deformation
- Heat
- Pressure
- Time
- Rock type/composition
Faults
- Fractures, faults, & fissures
- Strike-slip faults (right- and left-lateral)
- Dip-slip faults (Normal and reverse)
- Hanging wall and foot wall
Climate Change
Greenhouse warming and Ozone in atmosphere
- How does the amount of CO2 in the atmosphere affect global climate?
- What is greenhouse warming? Has it occurred in the past? Why is it likely to increase in the future?
- How do CO2 concentrations in the atmosphere now relate to CO2 concentrations in the last several hundred years?
- The ozone layer
- Why is ozone layer important to us (what function it serves), and how human activities have impacted it.
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