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The thickness of Earth's crust (km). The continental crust consists of various layers, with a bulk composition that is intermediate (SiO 2 wt% = 60.6). [5] The average density of the continental crust is about, 2.83 g/cm 3 (0.102 lb/cu in), [6] less dense than the ultramafic material that makes up the mantle, which has a density of around 3.3 g/cm 3 (0.12 lb/cu in).
Continental crust is a tertiary crust, formed at subduction zones through recycling of subducted secondary (oceanic) crust. [18] The average age of Earth's current continental crust has been estimated to be about 2.0 billion years. [21] Most crustal rocks formed before 2.5 billion years ago are located in cratons.
Geothermal gradient is the rate of change in temperature with respect to increasing depth in Earth 's interior. As a general rule, the crust temperature rises with depth due to the heat flow from the much hotter mantle; away from tectonic plate boundaries, temperature rises in about 25–30 °C/km (72–87 °F/mi) of depth near the surface in ...
Abundance (atom fraction) of the chemical elements in Earth's upper continental crust as a function of atomic number; [ 5] siderophiles shown in yellow. Graphs of abundance against atomic number can reveal patterns relating abundance to stellar nucleosynthesis and geochemistry . The alternation of abundance between even and odd atomic number is ...
Plate tectonics (from Latin tectonicus, from Ancient Greek τεκτονικός (tektonikós) 'pertaining to building') [ 1] is the scientific theory that Earth 's lithosphere comprises a number of large tectonic plates, which have been slowly moving since 3–4 billion years ago. [ 2][ 3][ 4] The model builds on the concept of continental ...
Earth's crustal evolution involves the formation, destruction and renewal of the rocky outer shell at that planet 's surface. The variation in composition within the Earth's crust is much greater than that of other terrestrial planets. Mars, Venus, Mercury and other planetary bodies have relatively quasi-uniform crusts unlike that of the Earth ...
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 distinguished based on its phase (solid crust vs. liquid mantle).
The internal structure of Earth are the layers of the Earth, excluding its atmosphere and hydrosphere. The structure consists of an outer silicate solid crust, a highly viscous asthenosphere, and solid mantle, a liquid outer core whose flow generates the Earth's magnetic field, and a solid inner core . Scientific understanding of the internal ...