WEATHERING & EROSION

Chapter 4Test 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 EROSIONWILLIAM MORRIS DAVIS

YOUTH MATURITY OLD AGE REJUVENATION

FACTORS OF WEATHERING AND EROSION

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

SINKHOLES/DOLINES STALACTITES STALAGMITES COLUMNS FOUND IN ILLINOIS, MISSOURI,

KENTUCKY, FLORIDA, INDIANA, YUGOSLAVIA

KARST

SINKHOLE

VIRTUAL CAVE

http://www.goodearthgraphics.com/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

PERFECT BALANCE IN NATURE THRESHOLD RESPONSE TIME RELAXATION TIME

ANGLE OF REPOSE

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

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