Overview
  Biogeochemical Cycles
  Spheres of B. Cycles
  Nitrogen Properties
  Simple Nitrogen Cycle
  Human Influences
  Spheres of the N Cycle
  Choose a Sphere




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Crust

The outermost solid layer of the Earth, between 10 and 40 kilometers thick, consisting of relatively light, low-melting-point materials. The continental crust consists largely of granite and granodiorite; the oceanic crust is mostly basalt.

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