Weathering/Erosion Refresher
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Transcript of Weathering/Erosion Refresher
Weathering/Erosion Refresher
• Geomorphology– study of the changing shape of the earth
• Weathering– the breakdown of rock “in situ” (in place)
• Erosion– the transport of weathered material
• Weathering is the beginning to changing the shape of the earth
• Chemical
• Physical
• Biological– Either physical
stress or chemical decay
Physical Geography Refresher: Weathering
Physical Geography Refresher: Basic Rocks: Igneous
Basalt(Andesite)
Granite: lava cooled at great depth
Physical Geography Refresher: Basic Rocks: Igneous
Sandstone: notice bedding fissures
Graduation Rock
Physical Geography Refresher: Basic Rocks: Sedimentary
rock
coa
tings
Physical Geography Refresher: Forming New Minerals
rock coatings
What is an Index?
• A way to Quantify the Unquantifiable
Examples of Indices
• From everyday Life?– Ranking movies, ranking hotels, ranking
restaurants, best schools, best cities
• From schooling?– SAT, your GPA, grading scales in classes
• From geography?– Palmer Drought Severity index, sand mobility
index, soil development index
Another Example:Grading This Lab
Element of your grade Ranking ScaleWeighting(total pts)
Notebook: analysis of RASI training 0 1 2 3 x 2 (6)Notebook: evaluation of major RASI elements 0 1 2 3 x 3 (9)Notebook: observations of specific RASI elements 0 1 2 3 x 10 (30)Notebook: retrospective analysis 0 1 2 3 x 4 (12)
0 - blew it off1 - minimal job2 - many details3 - thoughtful withquestions and drawing
Scoring sheets 0 1 2 3 x 15 (45)0 - blew it off1 - obvious outlier (i.e.spent most of timesocializing & just filled inrandom pattern)2 - not an option3 - filled all sheetscarefully and thoughtfully
Grading Scale 90 - A80 - B70 - C60 - D
• Out of how many?– A possible score of 10? 100?
• Elements:– What scale?
• 1 - 10? 1-5? 0-3?
– Do you want to weight elements– What are you missing?
• How to score
Selecting Index Elements
How to Score Index Elements
• List elements of scoring:– Fissures
• What scale?
How to Score Index Elements
• Fissures– 0 not present– 1 present– 2 obvious– 3 dominant
Analyst Discretion
• May be concerned about specific environmental factors
• One parameter might be extremely dominant
• Choose a multiplication factor for any of the parameters
• Example:– Extreme fissures