Questions tagged [oceanic-crust]

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If the Pacific Ocean is 750 million years old, Why can't oceanic crust be older than 200 million years?

Since the first rocks of the pacific Ocean plates solidified from magma coming out of a rift 750 million years ago, shouldn't they be much older than the maximum age of oceanic crust (around 200 ...
Antozoa's user avatar
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3 votes
2 answers

If among oceanic crusts older means heavier, then why is old continental crust lighter than new oceanic crusts?

When we consider two oceanic crusts, the older oceanic crust is heavier and the newer oceanic crust is lighter. But when we consider two crusts, one continental and the other oceanic, continental ...
Koushik Sarkar's user avatar
2 votes
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Is the earth crust under the pacific ocean heavier than in the rest of the planet?

Please bear with me, since I don't know much about geography or geology. I was looking at an earth globe and noticed the pacific ocean covers virtually half of the planet (more or less). How is it ...
Joe DiNottra's user avatar
2 votes
0 answers

What caused the transverse "scarring" of the Atlantic Ocean floor [duplicate]

In Google Maps the floor of the Atlantic Ocean is shown as having much transverse "scarring". What are these crust formations? They're ~2,000 miles long. What caused them?
Tim's user avatar
  • 281
5 votes
2 answers

How is felsic magma produced at island arcs?

I previously believed that continental crust owes its lower density to the partial melting of oceanic crust; the mantle would partially melt at mid-ocean ridges to produce basaltic crust, and when ...
richard's user avatar
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