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Earth Formation Formation of the Crust, Continents, Atmosphere, and Oceans
Earth FormationFormation of the Crust, Continents, Atmosphere, and Oceans
Formation of the Crust
What is Differentiation?
It is a process in which a planet becomes internally zoned, with the heavy materials sinking toward the center and the lighter materials accumulating near its surface.
Formation of the Crust
What are the differentiated zones of Earth?
Inner CoreOuter CoreLower MantleUpper MantleCrust
Formation of the Crust
Compare the proportions of elements in the Earth’s crust with the proportions of these elements in the Earth as a whole. What explains this difference?
Entire Earth Large percentage of Iron Large percentage of Oxygen A small amount of Silicon An equally as small amount of
Magnesium as there is silicon Very small amount of “other”
elements.
Earth’s Crust Very tiny percentage of Iron Very large percentage of Oxygen Medium percentage of Silicon Extremely low percentage of
Magnesium And a small to medium amount
of “other” elements.
Formation of the Crust
What became of the Earth’s earliest crust?
It was similar to the basaltic crust that underlies Earth’s oceans today; it is recycled at subduction zones.
Also, it is thought that pieces of the earliest crust were recycled in a process that does not occur on Earth today.
Formation of the Crust
Formation of the Crust
What material makes up much of the crust that forms Earth’s continents today?
Granite makes up most of the crust that forms Earth’s continents today.
Formation of the Crust
What is a craton? How is it like a continent’s root?
A Craton is the oldest and most stable part of a continent. It acts as a root because it’s attached to a part of the upper mantle that has a depth that can extend to 200 km .
Formation of the Crust
What is a Precambrian shield?
The Precambrian Shield is the top of a Craton exposed at the Earth’s surface.
What do we call the Precambrian shield in North America?
In North America we call the Precambrian Shield the Canadian Shield due to most of its exposure being in Canada.
Formation of the Crust
The Canadian Shield
