GEOLOGY 101

1
GEOLOGY 101

• Today Chapter 16
• Unsafe Ground
• Landslides and Other Mass Movements
• Part II

Course Website http//fouch101.asu.edu
2
NOTEToday we are finishing the lecture from
last Friday. These slides were therefore
already posted on the WWW site for the previous
lecture.
3

• Mass Wasting

4
3 Primary Influences onMass Movement

• Nature of slope materials
• Amount of water
• Angle of slope

5
Classification of Mass Movements

• Rock avalanche
• Debris avalanche
• Rockfall
• Rockslide
• Debris slide

• Debris flow
• Mudflow
• Earthflow
• Slump
• Creep
• Solifluction

6
Rock avalanche
7
Debris avalanche
8
Rockfalls
9
Rockslide
MASS WASTING
Blocks of bedrock break loose, slide down
slope if unconsolidated debris
slide usually where strata are inclined
causes
Fast, deadly
Base of slope is undercut Rain or melting snow
lubricates a sliding surface
10
(No Transcript)
11
(No Transcript)
12
(No Transcript)
13
Debris slide
14
Debris flow
MASS WASTING
15
Earthflow
MASS WASTING

• humid areas
• hillsides
• rich in clay/silt
• slow rates

16
(No Transcript)
17
(No Transcript)
18
Slump
MASS WASTING

• downward sliding of material
• moves as a whole section on curved surface
• usually slow, material doesnt travel far
• often involves multiple blocks
• commonly due to slope over-steepening

19
(No Transcript)
20
Slower movements
MASS WASTING

• Creep

Slow downhill movement of material. Usually
caused by alternate expansion/contraction of
material from freezing/thawing or wetting/drying
21
(No Transcript)
22
(No Transcript)
23
(No Transcript)
24
(No Transcript)
25
(No Transcript)