over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods...
-
Upload
vivien-davidson -
Category
Documents
-
view
212 -
download
0
Transcript of over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods...
![Page 1: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/1.jpg)
WeatheringCHAPTER 3
HONORS EARTH SCIENCE
![Page 2: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/2.jpg)
Def: the breaking apart of rock over long periods of time and without obvious motion.
◦ Mechanical (Physical)- break into smaller pieces
◦ Chemical- chemical change in composition
Weathering
![Page 3: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/3.jpg)
Weathering occurs at a slower rate than erosion.
Erosion involves obvious motion when breaking down rock
WEATHERING vs. EROSION
![Page 4: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/4.jpg)
Cause by water freezing Common in high elevations and mid
latitudes (Michigan)
Physical Weathering1. FROST (ice)WEDGING
![Page 5: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/5.jpg)
![Page 6: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/6.jpg)
![Page 7: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/7.jpg)
Bryce Canyon, utah
![Page 8: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/8.jpg)
![Page 9: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/9.jpg)
Potholes
![Page 10: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/10.jpg)
![Page 11: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/11.jpg)
Removing overburden relieves pressure Outer layer peels off like onion skin
Occurs mainly in intrusive igneous rocks◦ batholiths
Exfoliation (sheeting)
![Page 12: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/12.jpg)
![Page 13: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/13.jpg)
Half-dome; Yosemite
![Page 14: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/14.jpg)
3. Mudcracks
When water evaporates- mud shrinks
Wet/dry climates
![Page 15: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/15.jpg)
Septarian nodule;
![Page 16: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/16.jpg)
BIOLOGIC ACTVITY
Lichen secrete aciddissolve rock
Tree roots- growth breaks rocks
Humid climates Usually sed. rock
![Page 17: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/17.jpg)
Change in composition (decomposition)
Chemical weathering
![Page 18: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/18.jpg)
Water + carbon dioxide = carbonic acid H2O + CO2 H2CO3
Acid reacts (dissolves) with calcite (limestone, marble)
May create caves and sinkholes
Dissolution
![Page 20: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/20.jpg)
Sinkhole formation
![Page 21: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/21.jpg)
Areas prone to sinkholes
![Page 22: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/22.jpg)
Sinkhole in Corvette Museum, 2014
![Page 23: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/23.jpg)
![Page 25: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/25.jpg)
Guatemala, Sinkhole
![Page 26: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/26.jpg)
MI sinkholes (near Alpena)
![Page 27: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/27.jpg)
Marble statue
Dissolution
![Page 28: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/28.jpg)
![Page 29: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/29.jpg)
![Page 30: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/30.jpg)
![Page 31: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/31.jpg)
where iron minerals produce iron oxide ("rust").
Often in ss from iron in groundwater OR mafic rocks
Fe + O2 (atm) Iron Oxide
Fe2O3
CHEMICAL WEATHERING
2. Oxidation
![Page 32: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/32.jpg)
Result- reddish stain
![Page 33: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/33.jpg)
Pictured Rocks, MI
![Page 34: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/34.jpg)
Hydrolysis Reaction with water
feldspar + carbonic acid +water clay + salt
common in granite
Result- holes in granite
CHEMICAL WEATHERING
![Page 35: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/35.jpg)
Water enters cracks in rock and weathers the edges and creates a rounded shape
Any rock type Result- rounded spheres
Spheroidal weathering
t
![Page 36: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/36.jpg)
Spherodial weathering
![Page 37: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/37.jpg)
Time- more time; more weatheringRock Type/Resistance
◦ Sedimentary least resistant- esp. calciteClimate
◦ Wet- chemical dominates◦ Freeze/thaw- physical dominates
Surface area
Factors that affect Weathering
![Page 38: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/38.jpg)
![Page 39: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/39.jpg)
Smaller pieces (more surface area)= more weathering
Surface area
![Page 40: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/40.jpg)
Climate
Cleopatra’s Needle
(Egypt)
3,000 years old
![Page 41: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/41.jpg)
Cleopatra’s Needle
(New York)
100 years old
![Page 42: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/42.jpg)
Not all rocks weather equally
Differential weathering
![Page 43: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/43.jpg)
Different rock types weather differently
OR
Different rates of weathering due to cracks
Differential weathering
![Page 44: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/44.jpg)
![Page 45: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/45.jpg)
Arches National Park
![Page 46: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/46.jpg)
Differential erosion
limestone shale
![Page 47: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/47.jpg)
Hoodoos-
![Page 48: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/48.jpg)
Tall spires of rock Often “balancing” Softer rock (shale) erodes faster than cap
rock
hoodoos
![Page 49: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/49.jpg)
![Page 50: over long periods of timewithout obvious motion Def: the breaking apart of rock over long periods of time and without obvious motion. ◦ Mechanical (Physical)-](https://reader037.fdocuments.us/reader037/viewer/2022110403/56649e5c5503460f94b54372/html5/thumbnails/50.jpg)
Thoughts?
Honeycomb weathering