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Test 1. Grades were “Fair”, But ADD 10 POINTS to Your Score (Don’t Count on it for Next Test!) Grades After “Curve” A/B = 88 B/C = 75 C/D = 62 D/F = 50. Evidence Why You Should Attend Class Regularly. 2000. 1999. # of Quizzes Taken Avg. Grade 3 69.23 71.05
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Test 1 • Grades were “Fair”, • But ADD 10 POINTS to Your Score • (Don’t Count on it for Next Test!) • Grades After “Curve” • A/B = 88 • B/C = 75 • C/D = 62 • D/F = 50
Evidence Why You Should Attend Class Regularly 2000 1999 # of Quizzes Taken Avg. Grade 3 69.23 71.05 2 60.36 59.88 1 58.46 57.16 0 56.17 59.33* Quiz Attendance (a proxy for overall attendance) explains a full letter grade difference in Test 1 scores! * Only 3 tests, so probably not Significant
Question of Time - Quiz • If you plotted all of geologic time on a time line as long as the circumference of the Earth (25,000 mi or 40,000 km), what distance would represent 1 year? • What distance would represent 75 years? • What distance would represent 1 semester (4 months)?
The Whole Earth Time Line • Circumference of the Earth is 25,000 mi (40,000 km) • What distance would represent 1 year? • Divide Distance by # of Years (4,600,000,000 yr) • Easiest if We Use Metric Units
The Whole Earth Time Line • 40,000 km / 4,600,000,000 yr = • distance represented by 1 year? • 40,000,000 m / 4,600,000,000 yr = • 4,000,000,000 cm / 4,600,000,000 yr = • 0.87 cm / yr (0.34 inch / year)
The Whole Earth Time Line • 0.87 cm / yr (0.34 inch / year) • X 75 yr = 65 cm • (Lifetime = 25.7 inches) • X 0.33 yr = 0.29 cm • (Semester = 0.7 inch)
Don’t Write This Down! • 40,000,000,000,000 microns / (4,600,000,000 yr X 365 day/yr X 24 hr/day) = 0.99 micron / hour • This Lecture would be just over 1 micron long on the Whole Earth Time Line. • The paper you are writing on is about 100 microns thick
Geology 1 (Kite) Quiz 4 15 Feb 2000 Fill out the landslide classification chart on the next slide: Put anext to the two most deadly types of landslides worldwide. Put a $ next to the most costly types of landslides in the Appalachians. Put a Flying WV next to all landslides common in the Appalachian region Which 2 States lead the US in Landslide damage per person? Which 2 States lead the US in Total Landslide Damage? What are the causes of Landslides? This Quiz MUST BE TURNED IN TODAY (15 February, 2000) for any credit.
“Soil” Landslides Rock Debris Earth Fall Topple Planar Slide Type of Motion Rotational Slide Flow Avalanche
Last Time We Learned...Best Way to Break Rock: • Create Tension Within.
Cement Leached Out by CaCO3 Dissolution • NOx or SO2 or CO2 + Water = Acid • Acid + Calcite = Ions in Solution
Cement Leached Out by CaCO3 Dissolution • NOx or SO2 or CO2 + Water = Acid • Acid + Calcite = Ions in Solution
Cement Leached Out by CaCO3 Dissolution • NOx or SO2 or CO2 + Water = Acid • Acid + Calcite = Ions in Solution
Role of Rock Type • Bedding, Foliation, Joints = Avenues for Weathering • Spheroidal Weathering .
Role of Rock Type • Porosity: % Void Space • Permeability: Ability for Fluid to Penetrate • Particle Size: • Volume v. Surface Area .
Temp Weathering“Facies” Strong Physical Very Slight Strong Chemical Rainfall
SOILS • Soils (Engineering): Unconsolidated Earthy Materials • Soils (Soil Science, Geology) Unconsolidated Earthy Materials that Support Life
Transported Soils vs.Residual Soils • Wind Depositsin Situ Weathering • Stream Depositsof Bedrock • Glacier Deposits • Beach Deposits
Soil-Forming Factors • Climate • Organisms • Relief (Topography) • Parent Material • Time .
Soils Vary a Great Deal From Region to Region Soil Orders - USA
Ye Olde Soil Horizons • A - Topsoil • B - Subsoil • C - Unaltered Unconsolidated Material .
Ye Olde Soil Horizons • A - Topsoil • B - Subsoil C - Unaltered Unconsolidated Material
Modern Soil Horizons • O - Organic Mat at the Surface • A - Topsoil: Removal of Clay, Iron, etc. • B - Subsoil: Accumulation of Clay, Iron, • Humus, etc. • C - Barely Altered Unconsolidated Material • R - Solid Bedrock .
Modern Soil Horizons O • A • B C R
Mass Movement = Mass Wasting • colluvial processes • slope processes • slope failures • LANDSLIDES
Strength of Slope = Cohesion + Strength of Material • Strength of Material Varies with Moisture • Poor Drainage: Slope Instability .
Angle of Internal Friction Stable Angle of Slope for a Material .
Angle of Internal Friction • Qtz Sandstone = 90o
Angle of Internal Friction • Shale = 45o • or 1:1 Slope
Angle of Internal Friction • Old Landslide Deposits = 5-25o
Angle of Internal Friction • Clay = 1-15o
Shear Strength/Shear Stress • Factor of Safety
“Soil” Landslides Rock Debris Earth Rock Fall Debris Fall Earth Fall Fall Topple Rock Topple Debris Topple Earth Topple Planar Slide Rock Slide Debris Slide Earth Slide Type of Motion Rotational Slide Rock Slump Debris Slump Earth Slump Flow Rock Flow Debris Flow Earth Flow Rock Avalanche Debris Avalanche Earth Avalanche Avalanche
Basic Landslide Classification Material “Soil” Rock Debris Earth Type of Motion
Material Rock: Bedrock Soil: Unconsolidated Material Debris: >20 % Big Stuff (>2 mm) Earth: <20 % Big Stuff (>2 mm)
“Soil” Landslides Rock Debris Earth Fall Topple Planar Slide Type of Motion Rotational Slide Flow Avalanche
Types of Landslides
“Soil” Landslides Rock Debris Earth Rock Fall Debris Fall Earth Fall Fall Fall Topple Topple Rock Topple Debris Topple Earth Topple Planar Slide Rock Slide Debris Slide Earth Slide Type of Motion Rotational Slide Rock Slump Debris Slump Earth Slump Flow Rock Flow Debris Flow Earth Flow Avalanche Rock Avalanche Debris Avalanche Earth Avalanche
Landslides Topple Fall
Landslides - Topple
“Soil” Landslides Rock Debris Earth Rock Fall Debris Fall Earth Fall Fall Topple Rock Topple Debris Topple Earth Topple Planar Slide Planar Slide Rock Slide Debris Slide Earth Slide Type of Motion Rotational Slide Rotational Slide Rock Slump Debris Slump Earth Slump Flow Rock Flow Debris Flow Earth Flow Avalanche Rock Avalanche Debris Avalanche Earth Avalanche
Landslides Planar Slide = “Slide” Rotational Slide = “Slump”
Landslides Planar Slide = “Slide” Rotational Slide = “Slump”
Landslides Planar Slide = “Slide” Rotational Slide = “Slump”