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  2. Oceanic crust - Wikipedia

    en.wikipedia.org/wiki/Oceanic_crust

    Hence most oceanic crust is the same thickness (7±1 km). Very slow spreading ridges (<1 cm·yr −1 half-rate) produce thinner crust (4–5 km thick) as the mantle has a chance to cool on upwelling and so it crosses the solidus and melts at lesser depth, thereby producing less melt and thinner crust.

  3. Earth's crust - Wikipedia

    en.wikipedia.org/wiki/Earth's_crust

    Oceanic: 5 – 10 km (3 – 6 mi) thick [4] and composed primarily of denser, more mafic rocks, such as basalt, diabase, and gabbro. The average thickness of the crust is about 15 – 20 km (9 – 12 mi). [5] Because both the continental and oceanic crust are less dense than the mantle below, both types of crust "float" on the mantle.

  4. List of tectonic plates - Wikipedia

    en.wikipedia.org/wiki/List_of_tectonic_plates

    Tectonic plates are pieces of Earth's crust and uppermost mantle, together referred to as the lithosphere. The plates are around 100 km (62 mi) thick and consist of two principal types of material: oceanic crust (also called sima from silicon and magnesium) and continental crust (sial from silicon and aluminium).

  5. Internal structure of Earth - Wikipedia

    en.wikipedia.org/wiki/Internal_structure_of_Earth

    The thin parts are the oceanic crust, which underlies the ocean basins (5–10 km) and is mafic-rich [9] (dense iron-magnesium silicate mineral or igneous rock). [10] The thicker crust is the continental crust, which is less dense [11] and is felsic-rich (igneous rocks rich in elements that form feldspar and quartz). [12]

  6. Earth's mantle - Wikipedia

    en.wikipedia.org/wiki/Earth's_mantle

    Lithosphere underlying ocean crust has a thickness of around 100 km (62 mi), whereas lithosphere underlying continental crust generally has a thickness of 150–200 km (93–124 mi). [5] The lithosphere and overlying crust make up tectonic plates, which move over the asthenosphere. Below the asthenosphere, the mantle is again relatively rigid.

  7. Continental collision - Wikipedia

    en.wikipedia.org/wiki/Continental_collision

    Oceanic crust is thin (~6 km thick) and dense (about 3.3 g/cm 3), consisting of basalt, gabbro, and peridotite. Consequently, most oceanic crust is subducted easily at an oceanic trench. In contrast, continental crust is thick (~45 km thick) and buoyant, composed mostly of granitic rocks (average density about 2.5 g/cm 3).

  8. Crust (geology) - Wikipedia

    en.wikipedia.org/wiki/Crust_(geology)

    The internal structure of Earth. In geology, the crust is the outermost solid shell of a planet, dwarf planet, or natural satellite.It is usually distinguished from the underlying mantle by its chemical makeup; however, in the case of icy satellites, it may be defined based on its phase (solid crust vs. liquid mantle).

  9. Lithosphere - Wikipedia

    en.wikipedia.org/wiki/Lithosphere

    Young oceanic lithosphere, found at mid-ocean ridges, is no thicker than the crust, but oceanic lithosphere thickens as it ages and moves away from the mid-ocean ridge. The oldest oceanic lithosphere is typically about 140 kilometres (87 mi) thick. [ 3 ]