This idea played a pivotal role in the development of the theory of plate tectonics which revolutionized geologic thought during the last quarter of the 20th century.
Sea floor spreading drawing.
Learn more about sea floor spreading and how it works with this demo.
Earlier theories by alfred wegener and alexander du toit of continental drift postulated that.
Oceanic crust is the uppermost layer of the oceanic portion of a tectonic plate it is composed of the upper oceanic crust with pillow lavas and a dike complex and the lower oceanic crust composed of troctolite gabbro and ultramafic cumulates.
Next they cut out a round drawing of the earth added a fold tab folded that all in half and glued it half of it to the layers and half to the book page making a page within the page.
Sea floors cartoons.
The mid atlantic ridge for instance separates the north american plate from the eurasian plate and the south american plate from the african plate the east pacific rise is a mid ocean ridge that runs through the eastern pacific ocean and separates the pacific plate from the north american.
Seafloor spreading happens at the bottom of an ocean as tectonic plates move apart.
Sea floor spreading.
For students who finished early katy offered a model of sea floor spreading for them to experiment with for an extra page in their books.
Seafloor spreading is a process that occurs at mid ocean ridges where new oceanic crust is formed through volcanic activity and then gradually moves away from the ridge.
Sea floor drawing.
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This video goes over the process of sea floor spreading and the evidence that supports this theory.
The formation of the new crust is due to the rising of the molten material magma from the mantle by convection current.
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The oceanic crust is composed of rocks that move away from the ridge as new crust is being formed.
Seafloor spreading theory that oceanic crust forms along submarine mountain zones and spreads out laterally away from them.
At ridges in the middle of oceans new oceanic crust is created.
The seafloor moves and carries continents with it.
The mid ocean ridge is the region where new oceanic crust is created.
The motivating force for seafloor spreading ridges is tectonic plate pull rather than magma pressure although there is typically significant magma activity at spreading ridges.