Question

what rocks makes up oceanic and continental crust

Answer 1

Short answer
- Oceanic crust: mostly mafic igneous rocks — basalt (extrusive) at the top and gabbro (intrusive) below.
- Continental crust: mostly intermediate to felsic rocks — granite, granodiorite, diorite and abundant metamorphic rocks (gneiss, schist), with a cover of sedimentary rocks (sandstone, shale, limestone).

A bit more detail
- Oceanic crust (~7 km thick) is produced at mid‑ocean ridges from partial melting of the mantle. It is dense (mafic, low SiO2) and typically shows a layered structure: pillow basalts and sheeted dikes at the top, gabbro in the lower part, underlain by peridotitic upper mantle.
- Continental crust (average ~35 km, up to ~70 km) is compositionally variable but generally lighter (felsic to intermediate, higher SiO2) and older. The upper crust is often granitic and covered by sedimentary rocks; the lower crust can be more mafic.

If you want, I can show simple diagrams, compare densities and compositions, or give examples of where each rock type is exposed.