Geology 1304 Earth Science II

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Class 6 Fossils, Weathering, Erosion
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Class 6 Fossils, Weathering, Erosion

• Class updates
• Reading Section 3.3, 10.1-10.5
• Homework 1 due next Tuesday

• Todays topics
• Fossils
• Weathering
• Soils, erosion

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Fossils
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Hard-body Fossils
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Preserved-body Fossils
Otzi
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Petrified Wood
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Trace Fossils
Feeding tubes (burrows)
animal tracks
animal tracks
midden
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Fossils As Geologists Tools
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Index Fossils
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(No Transcript)
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The Rock Cycle
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Weathering
Arches Natl Park, Utah
Bryce Canyon Natl Park, Utah
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Mechanical Weathering
Sheet joints Sierra Nevada, CA
Talus
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Types of Mechanical Weathering

• Frost wedging
• Pressure-release fracturing
• Thermal expansion contraction
• Abrasion
• Organic activity

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Frost-Wedging
Talus
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Pressure-Release Fracturing
Sheet joints (exfoliation)
Exfoliated domes Yosemite Natl Park
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Thermal Expansion Contraction
Stone Mountain, GA
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Abrasion Organic Activity
Wind abrasion Arches Natl Park, Utah
Plant roots
Lichens, Irish Sea
Wind abrasion, Bolivia
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Mechanical Chemical Weathering
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Chemical Weathering
Georgia Red Clay Oxidation
Limestone Dissolution weathering Britain
Weathering pits
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Dissolution
Havasu Creek, Grand Canyon
Potassium feldspar dissolved rock
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Oxidation
Oxidized iron-rich rock Newfoundland
Rusted metal
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Hydrolysis
H2CO3 (acid)
Feldspar
Clay
anything
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Weathering Rates El Paso vs. San Antonio
(west)
(central)
El Paso
San Antonio
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Soil
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Soil Development
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Soil Development Climate Plants
Fig. 6-11, p. 149
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Soil Development Topography
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Erosion
water, wind, ice, gravity?