How Plates Create Rubric


Layers of the Earth



external image earthlayers.gif
external image earthlayers.gif



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external image 904278688.jpg?607


Geologist's Notebook: Digging Through the Earth (United Streaming) Video


The Earth's Interior Poster
Your task is to draw and label a picture of the Earth's Interior. Use the Inside the Earth Text and the wiki to gather your data (Pgs. 9-13). Make sure your picture is CLASSY, in color, and includes the following layers:
  • The Crust - Oceanic & Continental
  • The Mantle - Lithosphere, Asthenosphere & The Lower Mantle
  • The Core - Outer Core & Inner Core
For each layer you must:
  • Describe what it is made of
  • Record the thickness (in Kilometers)
  • Record the temperature (in degrees celcius)
  • Explain if the layer is a solid, liquid or gas.
  • make a poster of a interior poster

Inside the Earth Poster Rubric.

Convection Currents
Convection in Earth's Mantle
Convection currents in motion
Convection currents & the Hawaiin Islands

external image subduction.jpg
external image subduction.jpg





Continental Drift


external image tectonics-pangea.gif
external image tectonics-pangea.gif

Hypothesis proposed by Alfred Wegener (1910) says all the continents were once joined together in a single landmass called Pangaea.
He proposed that the continents slowly move over the Earth's surface. This idea was known asContinental Drift.

Evidence:
  • The Earth looks like a whole bunch of puzzle pieces. These pieces fit together
  • Fossils - Tropical plants were found in Arctic areas, freshwater reptiles found spread across salt water areas, warm land animals found spread out and in arctic areas, coal beds
  • Land Features - Folded mountains along South America & Africa
  • Climate - Glacier scratches spread across continents

Unfortunately, Wegener's Hypothesis was rejected because he could not provide a satisfactory explanation for the force that pushes or pulls the continents. In order for scientists to accept this idea they would need to change all their current ideas on how the world worked.

Continental Drift
Continental Drift - Pangea
Continental Drift Puzzle
Video - Discovery Learning (username: tb03bps & password: goblue)

external image Fossil-evidence-of-Continental-Drift.jpg
external image Fossil-evidence-of-Continental-Drift.jpg



external image Evidence_from_rock.jpg
external image Evidence_from_rock.jpg




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external image Module10-004.gif
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external image IMGete.jpg



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external image Evidence%20for%20Continental%20Drift.gif





Sea Floor Spreading

In the Mid-1900's scientists started using sonar to map the ocean floor. They soon discovered large mountain chains underwater. These mountains became known as the Mid-Ocean Ridges.


external image atlanticoceanfloor.png
external image atlanticoceanfloor.png



These mid-ocean are found in all of the oceans
external image wsci_03_img0352.jpg
external image wsci_03_img0352.jpg

Most of these mountains are hidden under the ocean water, but in a few places these mountains are so tall they rise above the ocean's waters. Iceland is an example of this.

external image Mid-ocean-ridge-of-North-Atlantic-showing-location-of-Iceland.jpg
external image Mid-ocean-ridge-of-North-Atlantic-showing-location-of-Iceland.jpg


In 1960, Harry Hess, an American geologist, carefully studies the mid-ocean ridge mountains. Hess then began to re-evaluate Alfred Wegener's idea of Continental Drift and decided that perhaps the continents are really moving! Hess proposed a radical idea called Sea-floor spreading. He proposed that at the mid-ocean ridge magma was rising from the mantle and pushing the sea floor apart. The sea floor would spread along both sides of the mid-ocean ridge as new crust is added in the middle. The result is that the ocean floor is moving away from the mid-ocean ridges like a conveyor belt, carrying the continents with them.

Sea-floor spreading in Motion

Harry Hess found several pieces of evidence to support his idea.
1. Evidence from molten material.
  • Scientists dived to the ocean floor in a small submarine to explore the mid-ocean ridge. There they found pillow shaped rocks that are only formed from molten material that cools quickly underwater.
2. Evidence from Magnetic stripes
  • Scientists discovered that the rock that makes up the ocean floor lies in a pattern of magnetized "stripes". Basalt on the ocean floor contains iron. When the magma rose up from underground the iron lined up with the Earth's magnetic poles. When the Earth's magnetic poles reversed, so did the direction the iron lines up in the rock. This left a permanent record of the Earth's magnetic field changes.
3. Evidence from drilling samples
  • A drilling ship took core samples of the ocean floor. From these core samples scientists could age the rock. The youngest rock is near the mid-ocean ridges and the oldest rocks are near the plate boundaries.




external image f-d%3Aeb24e5a8d8fe69770d810f644c2a785a04b7bc180e1534b4ffb6b5ae%2BIMAGE_THUMB_POSTCARD%2BIMAGE_THUMB_POSTCARD.1
external image f-d%3Aeb24e5a8d8fe69770d810f644c2a785a04b7bc180e1534b4ffb6b5ae%2BIMAGE_THUMB_POSTCARD%2BIMAGE_THUMB_POSTCARD.1


external image Ocean_ridges_spreading_rates.jpg
external image Ocean_ridges_spreading_rates.jpg


If the ocean floor is expanding, does that mean that the oceans will keep getting wider & wider?

The answer is NO. The ocean floor bends back down into the mantle at deep underwater canyons called deep-ocean trenches. Here, over millions of years part of the ocean floor will sink back down into the mantle.


external image cfd-1014_deepocean.jpg
external image cfd-1014_deepocean.jpg



The process of the ocean floor sinking back into the mantle is called subduction. Sea-floor spreading and subduction work together. As new molten rock rises at mid-ocean ridges it is hot and less dense than surrounding rock. As the rock moves away from the mid-ocean ridge and cools down it becomes more dense and eventually sinks back down into the mantle at the deep-ocean trench.


Subduction in Motion
The process of sea-floor spreading changes the size and shape of the oceans. Right now the Atlantic Ocean is expanding while the Pacific Ocean is shrinking. This is due to the location of the subduction zones.


Minerals


Mineral site for kids

United Streaming - What exactly are minerals?

Mineral Outline.DOC



Characteristics

1. Naturally Occuring

2. Inorganinc

3. Solid

4. Repeating crystal pattern

5. Definite chemical composition



How to identify

1. Streak

2. Luster

3. Color

4. Hardness

5. Density

6. Crystal Pattern

7. Special characteristics



How minerals are formed

1. Magma & Lava

2. Solutions that evaporate above ground

3. Hot water solutions below ground




Rocks


Rock Outline.doc

Pictures of each rock type

Types of Rocks








Rock Cycle

Rock Cycle
Rock Cycle Interactive
Rock Cycle Interactive