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.
Is granite oceanic crust.
The difference in composition between the mantle and the two layers of the crust is maintained by.
Oceanic crust is about 6 km 4 miles thick.
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.
The topmost layer about 500 metres 1 650 feet thick includes lavas made of basalt that is rock material consisting largely of plagioclase and pyroxene oceanic crust differs from continental crust in several ways.
It is thinner denser younger and of different.
On the other hand continental crust remains where it is for billions of years and it is much older than oceanic crust.
This is made up of basaltic rocks in the shape of pillows and sheets.
The lower layer of oceanic.
By contrast the continental crust is made up of light colored granite rocks full of substances like oxygen and silicon.
Composition of oceanic crust.
Continental crust is typically 40 km 25 miles thick while oceanic crust is much thinner.
Oceanic crust is made up of several layers with the topmost layer being just 500 meters thick.