APES 12.3 and 12.4Please take out module 25 for

check-off!Get a computer

Module 25 Multiple Choice

1. D- acid rain only causes chemical weathering. Erosion is a natural process

2. E- main soil formation factors are climate, parent material, topography, organisms, time

3. D- correct horizon order is OAEBC4. A- clay isn’t as permeable and won’t allow as much water

to seep out5. E- aluminum would lower the base saturation because (Al

and H are the main soil acids)6. E- tailings are the waste materials from mining

End of Chapter MC

1. D- heavier elements make up the earth’s core and lighter elements are towards the surface

2. C- after the core, the order of layers is mantle, asthenosphere, lithosphere, soil

3. E- all 3 are evidence of Pangaea4. E- subsurface mining is most dangerous to miners

because of build up of toxic gases and chance for collapses

5. E- each step up the richter scale is 10x more powerful (like the pH scale!)

End of Chapter MC

6. D- plate move laterally at transform plate boundaries7. C- subduction occurs at convergent boundaries8. B- seafloor spreading occurs at divergent boundaries9. E- an epicenter is the point above an earthquake10. E- fossils are found in sedimentary rock11. C- extrusive igneous rock comes from cooling of magma, so it must be on the ocean floor where magma comes up (best answer)12. A- soil DOES change constantly13. C- the B horizon is subsoil

Homework Accuracy Check

Module 24:a. From #19: what are some unique characteristics

of igneous rock?

Module 25:b. Write down your answer to #7 c. Define two different mining methods

Finish Rock Cycle Notes

Soil Formation and Properties

Soil Formation

•The type of soil found in an ecosystem is determined by:

1. Parent material (underlying rock)2. Climate (affects amount of decomp., types

of vegetation)3. Topography (losing/gaining sediment from

erosion)4. Organisms (decomposers, detritivores, etc.)5. Time (usually more time = more nutrients)

Soil Formation

•Soil’s profile is made up of several distinct horizontal layers called Horizons

O Horizon – “Organic” Layer, contains dead/decomposing plants & animals; supplies nutrients for the soil

A & E Horizon – Topsoil (darker brown); where majority of roots located, thickness dependent on amount of decomposed material

B Horizon – Subsoil (Lighter/Cinnamon) ; materials from A & O deposited, few roots

C Horizon – Parent material (gray); weathering of this horizon creates upper horizons

Leaching and Accumulation

•http://serc.carleton.edu/NAGTWorkshops/visualization/collections/soil_horizons.html•From the top Decomposition and the leaching of

water through the soil move nutrients•From the bottom Weathering causes the parent

material to break apart

Soil Profile

Eluviation/Zone of Leaching – water percolates down the soil, transporting materials. Happens in Horizons A & E

Illuviation/Zone of Accumulation – where transported materials are deposited. Happens in Horizon B.

O

A

B

C

E

Soil Analysis Lab

Which soil horizon will you be testing?

Soil Texture

•Find •40% Sand•45% Silt•15% Clay

•Loam •Mixture of all 3

•Loam?http://www.isa-arbor.com/education/onlineresources/CDDemos/triangle.swf

Soil Lab Steps

1. Read introduction and do pre-lab q’s2. Lab 1- Soil Texture a.(do the quantitative “feel” test and the quantitative soil triangle test) b. Answer the analysis q’s as homework!3. Lab 2- Soil Porosity (percent pore space)

a. Read the background and examine the rock samples first

b. Do the porosity procedure and calculation (see formula in the background)

Soil Lab Steps

Lab 3- Soil Percolationa. Read the background and answer the pre-

lab questionsb. Do the test using your phone for a timerLab 4- Soil pHc. Read the background and answer the pre-

lab questionsd. Use the pH probes instead of test strips

Eastern WA soil is more suited for farming than Western WA. Why?•Eastern WA•No glaciers sandy soil

that weathers easily•Hotter Speeds up

decomposition• Less dense canopy

more water hits soil and soaks in•Grasslands Easily

decompose

•Western WA•Glaciers Gravel and silt •Colder Slower

decomposition•Dense canopy A lot of

rain caught in trees•Conifers Needles very

acidic and don’t decompose

Due Next Time

•ALL of Soil Lab! (Pre-lab, data, analysis questions all in lab book!)