Seafloor Basalts Are Generally Oldest Near

More than 90 of all volcanic rock on earth is basalt and the eruption of basalt lava is observed by geologists at about 20.

Seafloor basalts are generally oldest near. 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. Where in the oceans is the oldest ocean crust generally found. The oldest seafloor is near the edges of continents or deep sea trenches and is less than 180 million years old figure above. 210 30 60 90 120 150 180 180 0 60 154 3 5 47 73 60 139 6 1319 126 7 120 4 83 5 67 7 55 9 47 9 40 1 20 1 9 7 0 0 2 210 270 150 180 select one.

In an oceanic trench where it s about to be subducted b. ˈ b æ s ɔː l t ˈ b æ s əl t is a mafic extrusive igneous rock formed from the rapid cooling of lava rich in magnesium and iron exposed at or very near the surface of a terrestrial planet or a moon. 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. On the continental shelf at passive margins c.

The oldest seafloor is near the edges of continents or deep sea trenches. Refer to the map of seafloor age below. The scientists also discovered that the seafloor was thinner at the ridge axis and grew thicker as the crust became older. The abyssal plain in the deepest ocean d.

B ə ˈ s ɔː l t ˈ b eɪ s ɒ l t uk. Since the oldest ocean crust is so much younger than the oldest continental crust scientists realized that seafloor was being destroyed in a relatively short time.