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