We use cookies to improve your experience, some are essential for the operation of this site.

How ocean crust is made.

How ocean crust is made.
How ocean crust is made.
How ocean crust is made.
How ocean crust is made.
Comments (0)
596786
Doucette, Jayne H.
How ocean crust is made.
Illustration
01/01/2003
Kelemen_scenarios.jpg
Date is approximate.
Caption from Oceanus magazine, Vol. 42, No. 2, Pg. 43:
The crust beneath oceans and continents is fundamentally different. Continental crust is made of light-colored rocks called andesite and granite. Ocean crust is composed of dark-colored rocks called basalt and gabbro. Ocean crust originates as a “melt” that forms in submicroscopic pores in rocks in Earth’s hot mantle and rises to the surface. Scientists have pieced together clues to discover: 1) how melt that forms over hundreds of kilometers in the mantle is focused into a five-kilometer volcanic zone beneath mid-ocean ridges, and 2) how oceanic crust is formed with a relatively uniform, three-tiered structure consisting of gabbro, sheeted dikes, and lava flows.
Illustration by Jayne Doucette
© Woods Hole Oceanographic Institution
Labels
This item includes these files
Collections