1. Earth Systems

2. Earth’s Layers Liquid solid
Magma – slowly circulates in convection cells
Liquid
Core: nickel and iron
solid
Made up of plates
Semi-molten rock (flexible)

3. Theory of Plate Tectonics
Alfred Wegener – “Pangaea”
Plate Tectonics
a. earth’s lithosphere is divided into plates, most of
which are in constant motion
b. continental and oceanic plates
- movement driven by convection cells
Evidence of Pangaea – identical rock formations on both sides of the Atlantic Ocean, and fossil evidence
Continental plates are lighter (less dense) than oceanic plates and typically rise over the oceanic plates

4. - seafloor spreading (brings up important elements) b. Convergent
Plate Boundaries
a. Divergent
- beneath the oceans
- seafloor spreading (brings up important elements)
b. Convergent
- plates collide
- subduction (responsible for the Andes in SA)
- mountain formation (Himalayas in Asia)
c. Transform Fault
- plates slide past each other
- “San Andreas Fault”
Seafloor spreading – as oceanic crusts move apart, rising magma comes up and forms new oceanic crust on the seafloor (brings up copper, lead and silver)
Subduction – collision of oceanic and continental crust (oceanic goes underneath the continental crust)

5. Consequences of Plate Movement a. Earthquakes
- occurs when rocks of the lithosphere rupture
unexpectedly along a fault
- fault zones/seismic activity
- Richter Scale
* measurement of ground movement
* increases by a factor of 10
Plate movement is so slow, but the geologic activity provides evidence that the plates are in motion
Devastating earthquakes in Haiti and China

6. b. volcano - occurs as a plate moves over a hot spot and heat from the mantle melts the crust - as plate moves past the hot spot, leaves behind a trail of extinct volcanic islands (The Hawaiian Islands)

7. Rock Cycle “constant formation and destruction of rock”
Slowest of all Earth’s cycles
Rock: composed of one or more minerals
Mineral: solid chemical substance with uniform
composition

8. 3 types of rocks
a. Igneous
b. Sedimentary
c. Metamorphic

9. a. form directly from magma b. basaltic vs. granitic
Igneous Rocks
a. form directly from magma
b. basaltic vs. granitic
c. intrusive vs. extrusive
Baslatic – dark colored; dominant rock type of crust of oceanic plates
Granitic – lighter colored; dominant rock of continental plates
Intrusive – cooling magma below earth’s surface; cools slowly
Extrusive – cooling magma above earth’s surface; volcano, seafloor spreading; cools quickluy

10. a. form from sediments being compressed by other overlying sediments
Sedimentary Rocks
a. form from sediments being compressed by other
overlying sediments
b. typically uniform in composition
c. sink for phosphorus
d. fossil record

11. Metamorphic Rocks
a. formed when rocks are exposed to extreme
temperature and pressures
ex) collision of tectonic plates
b. structurally strong rocks

12. Weathering and erosion
a. occurs when rock is exposed to air, water,
chemical compounds, animals, etc.
b. 2 types
- physical
* mechanical breakdown of rocks
* water, wind, burrowing animals
Physical weathering: mechanical breakdown of rocks

13. - chemical. breakdown by chemical reactions
- chemical * breakdown by chemical reactions * acid deposition (“acid rain”)  S emitted into atmosphere, combines with O2 and forms SO2, SO2 reacts with water vapor to form sulfuric acid  rapid degradation of gravestones, marble, limestone

14. Erosion
a. “physical removal of rock from a landscape or
ecosystem”
b. wind, water, animals
c. deposition
d. acceleration of erosion
- deforestation, overgrazing, road building

15. Soil Benefits of soil a. plant growth b. primary filter of water
c. provides habitat
d. filters chemical compounds deposited by air
pollution
Soil formation is the third part to the geologic cycle (after tectonic and rock cycle)

16. a. result of physical and chemical weathering of
Soil Formation
a. result of physical and chemical weathering of
rocks and gradual accumulation of detritus from
the biosphere
b. mix of mineral and organic components
c. 5 factors
- parent material
- climate
- topography
- organisms
- time
“young” soil – poorly developed – less organic matter and fewer nutrients than a more developed soil
Parent material  rock material underlying it from which it inorganic components are derived
Climate  freezing weather results in poorly developed soil due to slow decomposition; humid environments, soil development is accelerated by rapid weathering and decomposition of organic material
Topography  arrangement of lanscape; steep slope = erosion
Organisms  animals mixing soil nutrients, plants removing nutrients and excreting acids that speed up chemical weathering
Time  as soil ages, they develop more characteristics

17. Soil Horizons
E Horizon: “zone of leaching” in acidic soils (found below O)
Organic material in various stages of decomposition
“topsoil”; zone of organic material and minerals mixed together
“subsoil”; zone of nutrients
Horizons – characteristic layers; composition of these layers depends on climate, vegetation and parent material
A horizon: in a mixed soil done naturally or by human practices, this is the top layer
Least weathered layer;
similar to parent material

18. * determined by percentage of sand, silt, and clay
Soil Properties
a. physical
- texture
* determined by percentage of sand, silt, and clay
* ex) 40% sand, 40% silt, 20% clay - __________
70% sand, 20% silt, 10% clay - __________

19. * porosity  determines water holding capacity of soil  depends on texture
Sand – largest of the three (sand, silt and clay)
* water can move through easily making soils high in sand content easy for roots to penetrate, but also quick to dry out
Clay – smallest of the three; less pore space therefore roots are not able to penetrate through making it less ideal for plant growth
Best agricultural soil is a mix of all three
Sand – too porous and not able to effeciently filter out pollutents
Clay – packed together tightly therefore better at filtering out pollutants; used in landfills to keep the contaminents from leaching into the soil

20. b. chemical - CEC. cation exchange capacity. nutrient holding capacity
b. chemical - CEC * cation exchange capacity * nutrient holding capacity * depends on amount of clay particles present - base saturation * soil bases to acids * bases (neutralizers)  Ca, K, Mg, Na acids (detrimental)  Al, H
Clay particles are the most important component of chemical properties because of their ability to attract positively charged cations since clay is negatively charged

21. c. biological - fungi, bacteria, protozoans - fix nitrogen (essential for plant growth)

22. a. loss of ability of soil to support plant growth
Soil Degradation
a. loss of ability of soil to support plant growth
b. due to overuse of land
c. one major cause = soil erosion (topsoil disturbed)
soil compaction/drying of soil – reduce amount of vegetation growth, increasing erosion
Intensive agriculture and irrigation – depletes soil nutrients
Pesticides – soil pollution

23. Mineral Resources Ores – concentrated accumulation of minerals from
which economically valuable materials can
be extracted
- characterized by presence of valuable metals
Metals – elements with properties that allow them to
conduct electricity and heat energy and
perform other functions
Reserve – known quantity of a resource that can be
economically recovered
Formation of ores
Magma coming in contact with water and water creating a precipitate (metal)
After deposition of igneous rock

24. a. extracting mineral resources b. Types of mining 1. strip mining
- removal of “strips” of soil and rock to expose ore
- “coal and sand”
- return tailing or spoils back to hole
2. open-pit mining
- creating of large hole visible from Earth’s surface
- “copper mines”
Mining the ore and separating any other minerals or elements away

25. 3. mountaintop removal - remove entire top of mountain with explosives - deposits tailings in lower elevation 4. placer mining - use of river water to separate heavier items - example: diamonds, gold 5. subsurface mining - below earth’s surface - “coal, diamonds, and goal”

26. - produces tailings which contaminate land and
Mining Safety
- produces tailings which contaminate land and
water with acids and metals
- subsurface mining
* acid mine drainage
* accidental burial
* inhalation of gases and particles (black lung disease)
* explosions
Mining can result in damage to waterways, habitat fragmentation, soil erosion

27. Mining Regulation
- Mining Law of 1872
* regulate mining of silver, copper, gold ore,
natural gas and oil on federal lands
- Surface Mining Control/Reclamation Act
* mandates that land disturbed must be
reclaimed after mining process