Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in...
-
Upload
andre-pomroy -
Category
Documents
-
view
219 -
download
1
Transcript of Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in...
![Page 1: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/1.jpg)
Fe/Ni
Fe/Mg
IncreasingFe toward
core
IncreasingSi towardsurface
There are certain trends in Earths chemistry.The crust is relatively depleted in Fe, Mg and enriched in Si, O
![Page 2: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/2.jpg)
Effect ofchemical differentiation
There are certain trends in Earths chemistry.The crust is relatively depleted in Fe, Mg and enriched in Si, O
![Page 3: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/3.jpg)
Earth’s magnetic fieldemanates from the core complex and surrounds the planet.
Magnetism gained from early nebula ismagnified by turbulentiron, nickel fluid of outer core.
Magnetic field envelops entire planet
Polarity + - tends to reverse
and fluctuate with time
![Page 4: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/4.jpg)
![Page 5: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/5.jpg)
MANTLE PLUMES warm rock rises,
cool rock descends
How will the lithosphere
respond to a plume?
![Page 6: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/6.jpg)
Earth is probably not built ofuniform layers, it is likely mixed
somewhat by convection
![Page 7: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/7.jpg)
The continental
rifting process
a
q
Kk
![Page 8: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/8.jpg)
Main Types of Plate MotionConvergentDivergentTransform
![Page 9: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/9.jpg)
![Page 10: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/10.jpg)
The role of partial melting
Granite
Basalt
Partial melting occurs when some minerals meltwhile others remain solid because their melting point has not been reached
![Page 11: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/11.jpg)
Subduction
ContinentalCrust
OceanicCrust
AccretionaryPrism
VolcanicArc
TrenchRifting SpreadingCenter
Granite
Basalt
PartialMelting
![Page 12: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/12.jpg)
3 Types of Plate
Boundaries
CONVERGENTOne plate dives beneath another (subduction) or two plates collide without either subducting.
DIVERGENTNew lithosphere forms as plates pull apart.
TRANSFORMPlates grind past each other. No change in Lithosphere
![Page 13: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/13.jpg)
Convergent boundary – 3 types
![Page 14: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/14.jpg)
Ocean-continent convergent boundary
Plate of oceanic crust collides with plate of continental crust. Oceanic crust is subducted (goes under) continental plate.
![Page 15: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/15.jpg)
Ocean-ocean convergent boundary
Two oceanic crust plates collide. Older, denser plate usually subducts, site of Island Arc
formation.
![Page 16: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/16.jpg)
MEGATHRUST EARTHQUAKEOCCURS WHEN “LOCKED” SUBDUCTION ZONE RUPTURES
1. Strain accumulates.
2. Crust shortens.3. Uplift occurs. 4. Plates unlock.5. Crust extends
rapidlyculminating in a
Megathrust Earthquake
![Page 17: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/17.jpg)
http://www.youtube.com/watch?v=QDqskltCixA
http://www.youtube.com/watch?v=WaUk94AdXPA
Some videos to consider giving in class.
![Page 18: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/18.jpg)
Continent-continent convergent boundaryOROGENESIS
![Page 19: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/19.jpg)
![Page 20: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/20.jpg)
Divergent BoundarySeafloor spreading leads to the formation of new crust that, compared to continental crust, is relatively enriched in iron and magnesium and depleted in silica (SiO2) (because it reflects thechemistry of the mantle).
As two plates continue to move apart, the rock in the seafloor grows older as its distance from the rift zone increases, and as it ages, it cools and becomes denser and is buried under marine sediments that are deposited on the seafloor.
![Page 21: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/21.jpg)
Mid-Ocean RidgeSpreading Center
![Page 22: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/22.jpg)
TRANSFORM BOUNDARY
(side-to-side plate movement)
FAULT “a place where the crust is broken and the broken edges
are offset relative to each other(either vertically or horizontally)”
![Page 23: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/23.jpg)
Transform Boundaries Connect
Two Spreading Centers
Occur where two plates slide past each other.
Motion called shearing.
Connect two spreading centers (less commonly, two subduction zones).
Probably the most famous transform boundary in the world is the San Andreas Fault.
![Page 24: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/24.jpg)
OCEANIC FRACTURE ZONE
Transform Boundary with INACTIVE (FRACTURE ZONE) and ACTIVE (TRANSFORM FAULT) portions.
![Page 25: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/25.jpg)
Lithospheric Plates Carry Continents and Oceans.
![Page 26: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/26.jpg)
Earthquakes Tend to Occur at Plate Boundaries.
![Page 27: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/27.jpg)
![Page 28: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/28.jpg)
MODERN CONTINENTS
EVOLVED FROM
PANGAEA
![Page 29: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/29.jpg)
![Page 30: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/30.jpg)
Plate Tectonics explainschains of volcanic islands
Hot Spots
![Page 31: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/31.jpg)
![Page 32: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/32.jpg)
Plates have divergent, convergent, and transform boundaries.
the “Ring of Fire” the most seismically and volcanically active zone in the world.
![Page 33: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/33.jpg)
Paleomagnetism confirms the seafloor spreading hypothesis
Geomagnetic field switches from reversed polarity to normal polarity on irregular basis
Iron crystals in magma incorporate Earth’s new magnetic orientation
Iron-rich sediment particles align with geomagnetic field like compass needles.
WHEN LITHIFIED, MAGMA AND SEDIMENTS PERMANENTLY RECORD ORIENTATION OF GEOMAGENTIC
FIELD AT THAT TIME!
![Page 34: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/34.jpg)
Paleomagnetism at Divergent Plate Boundaries
Two or more plates pull apart.
Molten material rises through Rift Zone
Newest magma on either side of rift.
Like conveyer belts, the newer crust travels away from the center on each side.
Oceanic crust records reversed and normal polarity episodes
![Page 35: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/35.jpg)
.
Magnetic striping on either side of oceanic
ridge.
RIDGE
Rocks can be divided into two groups: normal polarity, magnetic polarity same as today. reversed polarity.
![Page 36: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/36.jpg)
http://www.youtube.com/watch?v=ecGzjo73vUc
http://www.youtube.com/watch?v=GWSivxJ6IqM
Some videos to consider giving in class
![Page 37: Fe/Ni Fe/Mg Increasing Fe toward core Increasing Si toward surface There are certain trends in Earths chemistry. The crust is relatively depleted in Fe,](https://reader035.fdocuments.us/reader035/viewer/2022062407/56649c6d5503460f9491f178/html5/thumbnails/37.jpg)
Plate Movement Powers the Rock Cycle