What type of rock makes up oceanic crust?

Question

i gotta exam tomorow and i need to know

Answer 1

Layer 1 consists of unconsolidated or semiconsolidated sediments, usually thin or even not present near the mid-ocean ridges but thickens farther away from the ridge. Near the continental margins sediment is terrigenous, meaning derived from the land, unlike deep sea sediments which are made of tiny shells of marine organisams, usually calcareous and siliceous, or it can be made of volcanic ash and terrigenous sediments transported by turbidity currents. [1]

Layer 2 could be divided into two parts: layer 2A – 0.5 km thick uppermost volcanic layer of glassy to finely crystaline basalt usually in form of pillow basalt, and layer 2B – 1.5 km thick layer composed of diabase dikes.

Layer 3 is formed by slow cooling of magma beneath the surface and consists of coarse grained gabbros and cumulate ultramafic rocks. It constitutes over two-thirds of oceanic crust volume with almost 5 km thickness.

Answer 2

You asked about rock, right? So ignore the ooze on the surface. The layer beneath the ooze is composed of pillowed basalt flows and underlying, steeply dipping basaltic dikes. It is thought the dikes were the feeders that supplied the lava for the overlying flows. This layer is about 2 kilometers thick. The bottom layer is about 5 kilometers thick and thought to consist of swarms of basalt dikes and sill-like gabbro intrusions. This bottommost section of oceanic crust lies on top of the mantle.

So to answer your question- BASALT

Answer 3

ingenues and ,metamorphic, and sedimentary rocks

Answer 4

Basalt