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How the Age of Crustal Rocks relates to the theory of Plate
Transcript of How the Age of Crustal Rocks relates to the theory of Plate
the theory of Plate Tectonics
What are Crustal Rocks?
Our earth's crustal rocks form all of the earth's continental and oceanic crusts.
How Scientists Use this information to find plate movements:
The answer is a process called seafloor spreading.
Seafloor spreading causes divergent boundaries(Plates that move apart from each other).The process of seafloor spreading works like this: Plates move apart from each other, and when the plates move apart from each other the ocean floor is being split in the process repeatedly. To make up for this loss of oceanic crust, molten from inside the earth comes to the surface, and cools with the water to form a new crust. As this happens, the older crust spreads apart, and the oceanic crust is spread far enough till subduction happens. Subduction is when the Oceanic Crust goes under the Continental Crust. This process causes the Continental Crust to be pushed by the Oceanic Crust, and in the end contributes to plate tectonics.
Crustal Rocks are rocks that are found on the earth's crust. The continental crust is made up three different types of rocks. These rocks are Sedimentary, Metamorphic, and Igneous.
Now before I tell you how we can use crustal rocks to show evidence of plate tectonics actually existing, let me explain to you what the theory of plate tectonics really is...
In 1905, Alfred Wagner, a German meteorologist and geophysicist, couldn't help but notice that the continents, almost seemed like pieces in an enormous jigsaw puzzle, in the sense that some of them looked as if they may fit together. He then claimed that the continents were actually moving by some force of the ocean, and were not just motionless pieces of land, and also stated that a super continent known as Pangaea once existed.
These continents look as though they could very well fit like a jigsaw puzzle.
So how can the theory of plate tectonics be proven with the aging of crustal rocks?
Visual Example of the three types of crustal rocks found on the earth's continental crust:
There are two types of crusts on Earth. Continental, and oceanic. The Continental crust consists of the large land masses known a the continents such as Asia, North America, Europe, etc. And the Oceanic Crust is under the ocean, which makes up 70% of our earth's surface.
The Oceanic Crust is
compared to the
continential crust, but it is more dense
of the rocks that
consists of. These rocks are called
rocks. Examples of these
rocks are basalt and gabbro rocks. The Oceanic Crust is usually
because it's rocks are mostly made of iron and magnesium.
Oceanic Crustal Rocks Visual Examples:
There are many ways that we can prove the theory of continental drift, such as fossil locations, the earth's convection currents , and land masses such as the Himalayas give clues of plates converging together to form mountains like these. But for this presentation we'll only focus on the aging of crustal rocks to prove the theory of plate tectonics.
"Crust (geology)." Wikipedia. Wikimedia Foundation, 21 Feb. 2014. Web. 25 Feb. 2014. <http://en.wikipedia.org/wiki/Crust_(geology)>.
"Earth's Continental Plates - ZoomSchool.com." Earth's Continental Plates - ZoomSchool.com. N.p., n.d. Web. 24 Feb. 2014. <http://www.enchantedlearning.com/subjects/astronomy/planets/earth/Continents.shtml>.
"What is a tectonic plate? [This Dynamic Earth, USGS]." What is a tectonic plate? [This Dynamic Earth, USGS]. N.p., n.d. Web. 25 Feb. 2014. <http://pubs.usgs.gov/gip/dynamic/tectonic.html>.
Science. Nashville, Tenn.: Southwestern Co., 2011. Print.
MLA formatting by BibMe.org.
The Super Continent Pangaea
This video demonstrates the moving of continent over millions and millions of years till they form the continental lay out they're in today:
The Changes in the Continent positions over millions of years(image), due to continental drift.
These two diagrams show visually how seafloor spreading works:
This video will give you an in depth explanation of the sea floor spreading process
Scientists studied that the oceanic crust near the edges of the continental crust and away from the ridges that seafloor spreading creates, are much older than the crustal rock near the ridges itself. Scientists can look at the age of these crustal rocks, to show evidence of seafloor spreading occurring in an area, and then later come to the conclusion that the tectonic plates were diverging, or coming apart in that area.
That is how we can use the age of crustal rocks to relate to the theory of plate tectonics
A Link to My Earth Origin Prezi:http://prezi.com/repoepi_so9z/how-we-can-use-meteorites-and-planetary-surfaces-to-explain/