UNIVERSE
PLANETARY INTERIORS
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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mafic, with a density of 3.0 g/cm3
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mafic, with a density of 2.7 g/cm3
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felsic, with a density of 3.0 g/cm3
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felsic, with a density of 2.7 g/cm3
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Detailed explanation-1: -The average density of oceanic crust is 3.0 g/cm3, while continental crust has an average of 2.7 g/cm3.
Detailed explanation-2: -Continental crust is broadly granitic in composition and, with a density of about 2.7 grams per cubic cm, is somewhat lighter than oceanic crust, which is basaltic (i.e., richer in iron and magnesium than granite) in composition and has a density of about 2.9 to 3 grams per cubic cm.
Detailed explanation-3: -Ocean crust is formed from molten material at the ocean ridge systems. Lava and intrusive rocks combine to form the crust. The molten material that solidifies to form new oceanic crust is mafic in composition. The rocks basalt and gabbro are the result.
Detailed explanation-4: -Oceanic crust is created as magma rises to fill the gap between diverging tectonic plates and is consumed in subduction zones. It is geologically young, with a mean age of 60 Ma, and is thin, averaging 6.5 km in thickness. Oceanic crust consists almost exclusively of extrusive basalt and its intrusive equivalents.