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 Byii. 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 - definitionsi. Evaporation ii. Transpiration iii. Precipitation iv. Condensation c. Ground and Surface Water Processes i. Percolation ii. Runoff 2) 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 3) Drainage Basins – Definitions and Examples a. Continental Divides b. Local divides c. Mississippi River System 4) Typical Drainage Patterns – Controls and Characteristics a. Dendritic b. Radial c. Rentangular d. Trellis 5) 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 6) Stream Erosion a. Hydraulic Action Mechanisms i. Plucking ii. Eddy Formation iii. Abrasion b. Hydraulic Action Zones i. Cascades and waterfalls ii. Rapids 7) 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. Saltation8) 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 velocityd. 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 Ablationiii. Equilibrium Line iv. Advancing vs. Retreating systems 5) 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 6) Movement of Ice Sheets a. Plastic flow dominates b. Basal sliding may also be important