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WEATHERING &
EROSION
Chapter 4
Test 3 material
Begin
ASSIGNMENT


WRITE A 1-2
PAGE REPORT
ON HOW KARST
TOPOGRAPHY
HAS
INFLUENCED
LANDFORMS IN
THE MIDWEST
10 POINTS –
DUE IN 1 WEEK
WEATHERING

PROCESSES BY WHICH ROCKS
ARE CHEMICALLY ALTERED OR
PHYSICALLY BROKEN INTO
FRAGMENTS AS A RESULT OF
EXPOSURE TO THE ELEMENTS
MECHANICAL
WEATHERING




ROCK IS BROKEN INTO
SMALLER AND SMALLER
PIECES EACH RETAINING THE
CHARACTERISTICS OF THE
ORIGINAL MATERIAL
FROST WEDGING-FREEZE/THAW
UNLOADING - SHEETING
BIOLOGICAL ACTIVITY
spheroidal
CHEMICAL
WEATHERING


COMPLEX PROCESSES THAT
ALTER THE INTERNAL
STRUCTURES OF MINERALS BY
REMOVING AND/OR ADDING
ELEMENTS
WATER AND CARBONIC ACID OXIDATION
EROSION

THE
PROCESSES
THAT LOOSEN
SEDIMENT AND
MOVE IT FROM
ONE PLACE TO
ANOTHER
CYCLE OF EROSION
WILLIAM MORRIS DAVIS




YOUTH
MATURITY
OLD AGE
REJUVENATION
FACTORS OF
WEATHERING AND
EROSION


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CLIMATE
THE TYPE OF ROCK
THE AMOUNT OF VEGETATION
DIFFERENTIAL
WEATHERING/EROSION

DIFFERENT ROCKS WEATHER &
ERODE AT DIFFERENT RATES
LANDFORM FEATURES


PLATEAUS ERODE TO MESAS
MESAS ERODE TO BUTTES
buttes
DIFFERENTIAL
WEATHERING/EROSION



LIMESTONE BEST
ILLUSTRATES THIS
IN DRY CLIMATES LIMESTONE
PRODUCES MOUNTAINS
IN WET CLIMATES WITH ACIDIC
WATER QUALITY IT PRODUCES
FEATURES OF KARST
TOPOGRAPHY
KARST TOPOGRAPHY
FEATURES


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SINKHOLES/DOLINES
STALACTITES
STALAGMITES
COLUMNS
FOUND IN ILLINOIS, MISSOURI,
KENTUCKY, FLORIDA, INDIANA,
YUGOSLAVIA
KARST
SINKHOLE
VIRTUAL CAVE

http://www.goodearthgraphics.c
om/virtcave/virtmap.html
GRADATION



WEARS DOWN AREAS OF
GREAT RELIEF AND BUILDS UP
AREAS OF LOW RELIEF
CHIEF PHYSICAL AGENT OF
GRADATION IS WATER
TIME ALLOWS GRADATIONAL
PROCESSES TO WORK
EQUILIBRIUM



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PERFECT BALANCE IN NATURE
THRESHOLD
RESPONSE TIME
RELAXATION TIME
ANGLE OF REPOSE

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MAXIMUM ANGLE MATERIAL
STAYS STABLE BEFORE
MOVING DOWNSLOPE
FOR UNCONSOLIDATED
MATERIAL THIS IS BETWEEN 25
TO 40 DEGREES
Angle of repose
MASS WASTING


DOWNSLOPE MOVEMENT OF
ROCK AND SOIL UNDER THE
DIRECT INFLUENCE OF
GRAVITY
GRAVITY IS THE CONTROLLING
FORCE OF MASS WASTING
CLASSES OF MASS
MOVEMENTS

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FALL
SLIDE
FLOW
CREEP - MATERIAL MOVED BY
CREEP ACTION IS REFERRED
TO AS COLLUVIUM
FALL
Rock fall
slide
flow
creep
SLUMP

DOWNWARD SLIPPING OF A
MASS OF ROCK OR MATERIAL
MOVING AS A UNIT ALONG A
CURVED SURFACE
slump
WHY SLUMP OCCURS


OVERSTEEPENED - MATERIAL
REMOVED FROM BOTTOM OF
SLOPE
OVERLOADING - LESS
RESISTANT MATERIAL IN
UNDERLYING LAYERS