WEATHERING&

MASS WASTING

Weathering Processes  

• Factors Influencing Weathering Processes  • Physical Weathering Processes 

– Frost action– Crystallization (salt-crystal growth)– Pressure-release jointing 

• Chemical Weathering Processes  – Hydration and hydrolysis– Oxidation– Carbonation and solution

Regolith, Soil, and Parent Materials

Figure 10.4

Physical Weathering

Figure 10.6

Joint-block Separation

Figure 10.6

Physical Weathering in

Sandstone

Figure 10.8

Exfoliation in Granite

Figure 10.9

Exfoliation in Granite

Figure 10.9

Exfoliation in Granite

Figure 10.9

Chemical Weathering

Figure 10.10

Chemical Weathering

Spheroidal Weathering

Figure 10.11

Oxidation in Rock and Soil

Figure 10.12

Slope Mechanics and Form

Figure 10.3

Slope Mechanics and Form

Figure 10.3

Mass Movement Processes  

• Mass Movement Mechanics – The role of slopes 

• Classes of Mass Movements – Falls and avalanches – Landslide– Flow – Creep

• Human-Induced Mass Movements

Mass Movement Classes

Figure 10.19

Soil Creep

 

Soil Creep

Figure 10.23

Rockfall

Figure 10.7

Soil Creep, California

Madison River Landslide

Figure 10.18

Talus Slopes

Figure 10.20

Debris Avalanche,

Peru

Figure 10.21

Yungay, Peru, May 31, 1970

Colluvium, San Bernardino Mountains, California

Avalanche Chute, Colorado

Gros Ventre Slide, Wyoming

Figure 10.22

Figure 10.24

Scarification

Karst and Limestone Regions

Figure 10.13

Karst Topography

Figure 10.14

Sinkholes

Figure 10.15

Cavern Features

Figure 10.17

End of Chapter 10

Elemental Geosystems 5e

Robert W. ChristophersonCharles E. Thomsen

Mystery or Soil Creep?

Four Years’ Mass-Wasting, Bosnia

Four Years’ Mass-Wasting, Bosnia

• 100*40/2 cm2 = 2000 cm2 (4 years)

• = 500 cm2 /year

• Removed from 1 km slope per year = 500 cm2 /100,000 cm= 1 cm/200 yr= 5000 cm (50 m)/m.y. = 50m /m.y.

• A 1-m (100 cm) soil mantle yields 500 cm2 /year, so movement = 500 cm2 /year/100 cm= 5 cm/year

Mudflows, California

Urban Planning, San Diego

Avalanche Chute, Colorado

Landslide, Mount Saint Helens

Sherman Glacier, Alaska, March 27, 1964

Viaont, Italy, October 9, 1963

1800 people died.

Yungay, Peru, May 31, 1970

Yungay, Peru, May 31, 1970

Lituya Bay, Alaska, July 9, 1958

Lituya Bay, Before and

After

The Scour Line

The Highest Wave Ever Recorded