Plate Tectonics is a result of Convection Currents in the Mantle. The plates cracked and continents drifted apart from the single Pangaea
Plate boundary- region where two plates meet
Fault is a crack- often the crack is on a plate boundary
Divergent boundaries- pull apart- go in opposite ways which leave open areas for magma to fill in (this explains the sea floor spreading)
Convergent plate boundaries- push together- sometimes one over powers the other and one ends up going under the other ( this is subduction)
Often when we have subduction, we find a track or trail for magma to find it’s way toward the surface
Transform boundaries are when two plates try to pass each other by sliding past one another
To determine the epi-center of an earthquake we need to use 3 seismograph readings and subtract the time difference between the p and s wave. Then use your ESRT to find the distance from the seismic station. Use your compass to draw a circle around the seismic station according to each distance. Triangulate the point by finding where the circles intersect for the exact epi-center.
The difference in arrival times for P- and S-waves from an
earthquake is 5.0 minutes. According to the Earth Science
Reference Tables, how far away is the epicenter of the
A) 2.6 x 103 km
B) 8.1 x 103 km
C) 3.5 x 103 km
D) 1.3 x 103 km
Natural Resources---- Substances that come from the Earth
What we can find in rocks and minerals
Green Movement- Conserving resources. Reasons to conserve have to do with the fact that certain kinds of resources can run out. Also, due to the fact that after we use resources, they often change, we have the issue of disposal. Where, How and what can we do with the used resources are all important questions.
Renewable Resources can be replaced- like trees. Not a big deal to use as long as we are aware of making sure that we re-plant more in it’s place. The problem is when we do not plant more, like when we cut down forests to build malls.
Nonrenewable Resources can not be replenished after they are used. It is possible to use all of them up and wait millions of years for them to come back, if they come back at all. Iron, gold and copper are all nonrenewable resources.
Fossil Fuels like coal and oil and natural gas are very important to us, but they are also nonrenewable. Because of the growth of industry and technology in the last 200 years, these resources have been severely cut down on Earth and of major concern to us.
Weathering- The breaking down of rock into smaller pieces----- gravity was the most common, but also wind and rain.
Erosion is the moving of this broken rock (sediment) again the most common way is gravity, but we can also always point to rain or water as a major source
Deposition is the depositing of the sediment in an area that eventually gets a build up of the sediment.
Compression is the build up of sediment that causes pressure pushing downward and compacting
Cementation is the natural sticking together that is caused by time and minerals combining.
Heating- This is when a rock is heated at extreme temperatures, but not melted because it is not in the magma
Re-crystallization- Due to heat crystals begin to grow again in the rock.
Folliation- Minerals line themselves up in layers or get pushed due to pressure into layers
Melting- The rock finds it’s way into magma and completely melts and the minerals mix with the other minerals in the “mineral soup”
Crystallization- As a new rock solidifies, mineral deposits begin to form on the rock. Remember, the longer this process takes, the bigger the crystals will be. If it is intrusive, the crystals will be bigger because the process of cooling would take longer due to the extreme temperatures of the magma.
If it is extrusive, the process is shorter because the rock will cool on the land or in water, therefore thecrystals are smaller or even absent.
The earth's surface is constantly being eroded. This means that rocks are broken up into smaller pieces by weathering agents such as wind, water, and ice. These small pieces of rock turn into pebbles, gravel, sand, and clay. They tumble down rivers and streams. These pieces settle in a new place and begin to pile up and the sediments form flat layers. Over a long period of time, the pieces become pressed together and form solid rock called sedimentary rock. Most sedimentary rocks form under water.
Sediments can harden into sedimentary rock in two ways.
cementing-Some sediments are glued together by minerals dissolved in water.
Igneous rock (from a latin word meaning fire) Igneous rock is formed in the mantle by magma or on the crust by lava (molten rock) being cooled and becoming solid. They may form with or without crystals either below the surface as Intrusive rocks or on the surface as extrusive or volcanic rocks. Intrusive rocks are formed inside the Earth. These rocks cook in the magma longer and cool much slower, as a result the crystals are bigger. Extrusive rocks form on the Earth's surface. They EXit the Earth, usually through a volcano. These rocks have smaller crystal grains because they cool faster. They don't cook as long. Sometimes these rocks cool so fast that they do not form crystals at all. Igneous rocks like Obsidian have a glassy look or Pumice have a rough texture and holes where crystals would have formed but gas took the place of the crystal.
By using the ESRT and following they graph downward and across, you can identify an Igneous rock.
Here is a podcast of an upstate teacher who can help you to review, as he explains rocks. The podcast explains all rocks, although we are just focusing on Igneous rocks right now.
By using the ESRT and your knowledge of how to identify minerals by their physical properties, you can now identify various popular minerals. Remember to look at hardness, streak, luster, cleavage, fracture and color in order to specify which mineral is which.