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Exfoliation identification and geology

A weathering process in which concentric sheets or slabs of rock peel away from an exposed rock surface, typically driven by pressure release unloading as overlying material is eroded away. As confining pressure decreases, the rock expands slightly and fractures develop parallel to the surface. Exfoliation is also promoted by thermal expansion and contraction cycles and is most prominent in massive, homogeneous rocks such as granite. Field: geomorphology. Example: Half Dome in Yosemite National Park owes its smooth, curved face to exfoliation—sheets of granite have progressively peeled away as glacial erosion removed overlying material and released confining pressure.. Related terms: Weathering, Pressure release, Sheeting joints, Inselberg.

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Sources, scope & corrections

These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.

Editorial owner
GeoMiner
Last updated
2026-03-30T15:19:41.999576+00:00
Review status
Published; not independently peer-reviewed
  • USGS Thesaurus — U.S. Geological Survey. Controlled earth-science terminology used to describe USGS information resources.
  • Glossary of Geologic Terms — U.S. National Park Service. Geologic definitions prepared by the NPS Geologic Resources Inventory.

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Common questions

What does Exfoliation mean in geology?
A weathering process in which concentric sheets or slabs of rock peel away from an exposed rock surface, typically driven by pressure release unloading as overlying material is eroded away. As confining pressure decreases, the rock expands slightly and fractures develop parallel to the surface. Exfoliation is also promoted by thermal expansion and contraction cycles and is most prominent in massive, homogeneous rocks such as granite.
What is an example of Exfoliation?
Half Dome in Yosemite National Park owes its smooth, curved face to exfoliation—sheets of granite have progressively peeled away as glacial erosion removed overlying material and released confining pressure.
Which earth-science field uses the term Exfoliation?
Exfoliation is used in geomorphology.
Which terms are related to Exfoliation?
Related terms in this reference are Weathering, Pressure release, Sheeting joints, Inselberg.

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