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  2. Unconformity - Wikipedia

    en.wikipedia.org/wiki/Unconformity

    A nonconformity exists between sedimentary rocks and metamorphic or igneous rocks when the sedimentary rock lies above and was deposited on the pre-existing and eroded metamorphic or igneous rock. Namely, if the rock below the break is igneous or has lost its bedding due to metamorphism, then the plane of juncture is a nonconformity.

  3. Great Unconformity - Wikipedia

    en.wikipedia.org/wiki/Great_Unconformity

    The unconformity between the Tonto Group and the Vishnu Basement Rocks is a nonconformity. The break between the Tonto Group and the Grand Canyon Supergroup is an angular unconformity. [2] [3] [4] Powell's Great Unconformity is part of a continent-wide unconformity that extends across Laurentia, the ancient core of North America.

  4. Hutton's Unconformity - Wikipedia

    en.wikipedia.org/wiki/Hutton's_Unconformity

    Hutton's Unconformity is a name given to various notable geological sites in Scotland identified by the 18th-century Scottish geologist James Hutton as places where the junction between two types of rock formations can be seen.

  5. Glossary of geology - Wikipedia

    en.wikipedia.org/wiki/Glossary_of_geology

    Also called Indianite. A mineral from the lime-rich end of the plagioclase group of minerals. Anorthites are usually silicates of calcium and aluminium occurring in some basic igneous rocks, typically those produced by the contact metamorphism of impure calcareous sediments. anticline An arched fold in which the layers usually dip away from the fold axis. Contrast syncline. aphanic Having the ...

  6. Nonconformity - Wikipedia

    en.wikipedia.org/wiki/Nonconformity

    Nonconformity or nonconformism may refer to: Culture and society ... A type of unconformity in geology; Nonconformity (Nelson Algren book), a 1950s essay published in ...

  7. Unkar Group - Wikipedia

    en.wikipedia.org/wiki/Unkar_Group

    Prior to the deposition of the Bass Formation, these rocks were uplifted to the Earth's surface from mid-crustal depths and eroded to form the surface of the nonconformity on which the Unkar Group lies. As these rocks were uplifted from mid-crustal depths, the timing of their cooling was recorded in cooling ages of feldspars and other minerals ...

  8. Contact (geology) - Wikipedia

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

    A geological contact is a boundary which separates one rock body from another. [1] A contact can be formed during deposition, by the intrusion of magma, [2] or through faulting or other deformation of rock beds that brings distinct rock bodies into contact.

  9. Sequence stratigraphy - Wikipedia

    en.wikipedia.org/wiki/Sequence_stratigraphy

    Sequence stratigraphy is a branch of geology, specifically a branch of stratigraphy, that attempts to discern and understand historic geology through time by subdividing and linking sedimentary deposits into unconformity bounded units on a variety of scales.