GENERAL GEOLOGY 1113-005 Fall 2008
Partial Examination II – Study Guide
Dr. Glen S. Mattioli
Note that these are NOT questions, but rather are a list of topics that we have
covered either in class or are contained within the reading assignments. You should
use this list as a guide to help you review what topics are important for the exam.
Chapter 8: Time and Geology
1) Development of Geological Reasoning
a. Religious perspectives on the age of the Earth
b. Hutton & Lyell: “The Present is the Key to the Past”
c. Uniformitarianism – relationship to process and rate
2) Principles of Relative Time
a. Contacts and formations
b. Original Horizontality
c. Superposition
d. Lateral Continuity
e. Cross-cutting Relationships
f. Contact Metamorphism and Inclusions
3) Unconformities – definitions and differences
a. Disconformity
b. Angular Unconformity
c. Nonconformity
4) Correlation – principles and use in relative dating
a. Physical Continuity
b. Similarity of Lithology and Biofacies
c. Methods
i. Use of Index Fossils
ii. Faunal Succession
iii. Fossil Assemblages
5) The Standard Geological Time Scale
a. Eras, Periods, and Epochs
6) Numerical or Absolute Ages
a. Isotopic Principles and Radioactive Decay Mechanisms
b. Half-life and the Decay Constant
c. Exponential vs. Linear Decay: Rate Laws
d. The Rb/Sr Isochron method
e. Reliability of Isotopic Ages
7) Combining Relative and Numerical Ages
a. The Age of the Earth
i. Modern value of 4.55 By
ii. Early Methods and initial estimates
b. Revised Geological Time Scale with Numerical Ages
Chapter 9: Mass Wasting
1) Classification of Processes
a. Rate of Movement
b. Type of Material
c. Type of Movement
2) Major Divisions of Mass Wasting Movement
a. Flow
b. Fall
c. Slide
i. Rotational
ii. Translational
3) Factors Controlling Mass Wasting
a. Gravity (slope)
i. Shear force – role in block sliding
ii. Shear strength – role in debris flows
b. Water
4) Commons Types of Mass Wasting – Definitions and Characteristics
a. Creep
b. Debris Flow
i. Earthflow
ii. Solifluction/Permafrost
iii. Mudflow
iv. Debris Avalanche
c. Rockfalls and Rockslides
d. Debris slides and falls
5) Factors That Enhance or Mitigate Mass Wasting
a. Undercut slopes
b. Vegetation Removal
c. Mass Redistribution
d. Role of water
e. Engineering Methods
i. Roadcut design
ii. Drainage methods
iii. Anchoring methods
Chapter 10: Streams and Floods
1) The Hydrologic Cycle
a. Solar Energy
b. Atmospheric Processes - definitions
2)
3)
4)
5)
6)
7)
i. Evaporation
ii. Transpiration
iii. Precipitation
iv. Condensation
c. Ground and Surface Water Processes
i. Percolation
ii. Runoff
Channel and Sheet Flow
a. Idealized Longitudinal Stream Profile
i. Change in gradient along profile
ii. Change in channel shape along profiles
iii. Headwaters vs. Mouth
Drainage Basins – Definitions and Examples
a. Continental Divides
b. Local divides
c. Mississippi River System
Typical Drainage Patterns – Controls and Characteristics
a. Dendritic
b. Radial
c. Rentangular
d. Trellis
Factors Controlling Stream Erosion and Deposition
a. Velocity cross-sections
b. Velocity vs. Grain Size Diagram
i. Zone of Transportation
ii. Zone of Erosion
iii. Zone of Deposition
c. Gradient
d. Channel Shape and Roughness
e. Discharge: Definition and Calculation
Stream Erosion
a. Hydraulic Action Mechanisms
i. Plucking
ii. Eddy Formation
iii. Abrasion
b. Hydraulic Action Zones
i. Cascades and waterfalls
ii. Rapids
Stream Transportation
a. Sediment Load – Definitions and relative carrying capacity
i. Bed Load
ii. Suspended Load
iii. Dissolved Load
b. Bed Load Mechanisms
i. Traction: Rolling and Sliding
ii. Saltation
8) Stream Deposition
a. Bars: Location and Evolution
i. Placer Deposits
b. Braided Streams
c. Meandering Streams and Point Bars – Cross bedding
9) Mature Stream Features and Evolution
a. Flood Plains
b. Meander Loops and Oxbow Lakes
c. Natural Levees and Flood Stage
10) Delta Type and Structure
a. Controls
i. Waves, Tides, Streams
b. Internal Structure
i. Topsets-foresets-bottomsets
c. Alluvial Fans
11) Floods
a. Urbanization Effects
b. Recurrence Intervals and Prediction
c. Flash Floods
i. Causes and Consequences
ii. Common Locations
d. Controlled Floods
12) The Graded Stream Concept
a. Lateral vs. headward erosion
13) Fluvial Geomorphology: relationship to bedrock geology and tectonics
a. Stream Terraces
b. Incised Meanders
c. Superposed Streams
Chapter 11: Ground Water
1) World Distribution of Water
2) Porosity and Permeability
a. Definitions
b. Values for common rock types
3) The Water Table – Structure and Definitions
a. Vadose Zone
b. Capillary Fringe
c. Saturated Zone
d. Perched water tables
e. Change of position relative to rainfall
4) Movement of Ground Water
a. Definition of hydraulic head
b. Definition of hydraulic gradient
c. Darcy’s Law and ground water velocity
d. Potential and its effect on flow lines
5) Aquifers
a. Unconfined
b. Confined
c. Time for flow from various aquifers
6) Wells
a. Good vs. Bad wells
b. Drawdown and cones of depression
c. Recharge
d. Artesian Wells – Features and Controls
7) Springs and Streams
a. Graining
b. Losing
c. Dry Stream
8) Ground water contamination
a. Sources of pollution
b. Plumes
c. Aggravation by pumping wells
9) Recharge vs. Withdrawal
a. Ground subsidence effects
10) Effects of Ground water action
a. Karst features
b. Carbonate dissolution and precipitation
c. Geysers and Hydrothermal products
Chapter 12: Glaciers and Glaciation
1) Glacier Types
a. Continental Ice Sheets
b. Alpine Glaciers
2) Theory of Glacial Ages
a. Global changes in climate
b. Global changes in sea level
c. Pleistocene Glacial Maximum at 18 Ka
3) Glacier Basics
a. Global Distribution
b. Volume of water
c. Types of glaciers and their characteristics
i. Valley glaciers
ii. Ice Sheets
d. Glacier ice formation: snow, firn, and ice
4) Formation and Growth of Glaciers
a. Glacial ice budgets
i. Zone of Accumulation
ii. Zone of Ablation
5)
6)
7)
8)
9)
iii. Equilibrium Line
iv. Advancing vs. Retreating systems
Movement of Valley Glaciers - Mechanisms
a. Meltwater formation and basal sliding
b. Rigid zone vs. Zone of plastic flow
c. Velocity profile with depth
d. Formation and evolution of crevasses
Movement of Ice Sheets
a. Plastic flow dominates
b. Basal sliding may also be important
c. Erosion due to overburden of ice
Glacial Erosion
a. Bedrock grinding: formation of rock flour
b. Polished and striated surfaces: direction of flow indicators
c. Alpine features
i. V- vs. U-shaped valleys
ii. Aretes, Horns, spurs, and cirques – definitions
iii. Hanging valleys and streams
iv. Development of rock steps over fractured terrain
Glacial Deposition
a. Definition and development of till
b. Moraines: Location and types
i. Medial
ii. End
iii. Ground
iv. Drumlins
c. Glacial outwash
i. Eskers
ii. Kettles
iii. Braided streams
d. Glacial lakes and varved sediments: relationship to seasons
Effects of Past Glaciation
a. Glacial Ages
i. Glacial vs. Interglacial periods
ii. Northern Hemisphere peak glaciation at 18 Ka
iii. Antarctic glaciation > 20 Ma
b. Direct Effects
i. Rock flour -> loess
ii. Terminal moraines
iii. Great and Finger Lakes
iv. Scoured and polished bedrock
c. Indirect Effects
i. Pluvial Lakes
ii. Lowering of Sea Level
iii. Fiords
iv. Crustal Rebound
d. Evidence of Older Glaciation
i. Climate fluctuations
ii. Ancient Tillites
iii. Snowball Earth Hypothesis
Chapter 13: Deserts and Wind Action
1) Deserts
a. Annual rainfall
b. Vegetation type and abundance
2) Global Distribution
a. Earth’s wind systems
i. Latitudinal bands: Trade winds vs. Westerlies in the N hemisphere
ii. Hadley Cells related to thermal forcing at the equator
iii. Coriolis Force
b. Relationship of desert location to global wind systems
c. Rainshadows
3) Common Desert Features
a. Internal drainage
b. Flash Floods
c. Arroyos or Dry Washes
4) Desert Features of the SW United States
a. Tectonic provinces
i. Sierra Nevada
ii. Basin and Range
iii. Colorado Plateau
b. Plateaus, Mesas, Buttes
c. Monoclines: Hogbacks and Cuestas
d. Basin and Range Topography
i. Development of Horsts and Grabens
1. Symmetric, high angle faults
2. Listric normal faults
ii. Common landforms
1. Alluvial Fans
2. Playa Lakes
3. Bajadas
4. Pediment
5) Wind Action
a. Erosion and Transportation
i. Dust storms
ii. Ventifacts: features and mechanism of formation
iii. Deflation and Blowouts
6) Wind Deposition
a. Distribution of loess
b. Sand Dune Types: Structure and relationship to winds
i. Barchans
ii. Transverse
iii. Parabolic
iv. Longitudinal
Chapter 14: Waves, Beaches, and Coasts
1) Wave characteristics
a. Wave Height
b. Wavelength
c. Wave Period
d. Orbital particle motion
i. Wave Base – relationship to wavelength
2) Surf Zone
a. Changes in wave characteristics
b. Relationship to wave base
c. Formation of breakers
3) Near shore Circulation
a. Wave refraction
b. Longshore current
i. Relationship to wind
ii. Components of motion
c. Rip Currents
4) Beaches
a. Structure and relationship to tides
b. Seasonal effects on sediment distribution
5) Longshore Sediment Drift
a. Drift features
i. Baymouth bars
ii. Spits
iii. Tombolos
b. Anthropomorphic intervention
i. Jetties, Groins, and Breakwaters
ii. Implications for sand movement and distribution
c. Sand sources: relative abundance
i. Headwall erosion
ii. Onshore deposition
iii. River deposition and redistribution
6) Coasts and Coastal Features
a. Erosional Coasts
i. Wave focusing
ii. Coastal straightening
iii. Landforms
1. Wave cut platforms
2. Stacks
3. Arches
b. Depositional Coasts
i. Barrier islands
ii. Submerged tidal deltas
c. Drowned Coasts
i. Estuaries
ii. Fiords
iii. Relationship to glaciation
d. Uplifted or Emergent Coasts
i. Marine Terraces
ii. Relationship to active tectonics
e. Coasts shaped by Organisms
i. Carbonate platforms and barrier reefs
ii. Mangrove swamps
f. Coastal evolution
i. Long Term Issues
1. Sediment supply
2. Sea Level changes (rising)
3. Increased atmospheric instability due to global warming
ii. Short Term Issues
1. Surges related to severe storms and hurricanes