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  2. Relative dating - Wikipedia

    en.wikipedia.org/wiki/Relative_dating

    Relative dating by biostratigraphy is the preferred method in paleontology and is, in some respects, more accurate. [1] The Law of Superposition, which states that older layers will be deeper in a site than more recent layers, was the summary outcome of 'relative dating' as observed in geology from the 17th century to the early 20th century.

  3. Cross-cutting relationships - Wikipedia

    en.wikipedia.org/wiki/Cross-cutting_relationships

    Cross-cutting relationships can be used to determine the relative ages of rock strata and other structures. Explanations: A – folded rock strata cut by a thrust fault; B – large intrusion (cutting through A); C – erosional angular unconformity (cutting off A & B) on which rock strata were deposited; D – volcanic dike (cutting through A, B & C); E – even younger rock strata (overlying ...

  4. Law of included fragments - Wikipedia

    en.wikipedia.org/wiki/Law_of_included_fragments

    The law of included fragments is a method of relative dating in geology.Essentially, this law states that clasts in a rock are older than the rock itself. [1] One example of this is a xenolith, which is a fragment of country rock that fell into passing magma as a result of stoping.

  5. Principle of original horizontality - Wikipedia

    en.wikipedia.org/wiki/Principle_of_original...

    It is a relative dating technique. The principle is important to the analysis of folded and tilted strata. It was first proposed by the Danish geological pioneer Nicholas Steno (1638–1686). The Permian through Jurassic stratigraphy of the Colorado Plateau area of southeastern Utah is a great example of Original Horizontality.

  6. Chronological dating - Wikipedia

    en.wikipedia.org/wiki/Chronological_dating

    Relative dating methods are unable to determine the absolute age of an object or event, but can determine the impossibility of a particular event happening before or after another event of which the absolute date is well known.

  7. Obsidian hydration dating - Wikipedia

    en.wikipedia.org/wiki/Obsidian_hydration_dating

    Obsidian hydration dating (OHD) is a geochemical method of determining age in either absolute or relative terms of an artifact made of obsidian.. Obsidian is a volcanic glass that was used by prehistoric people as a raw material in the manufacture of stone tools such as projectile points, knives, or other cutting tools through knapping, or breaking off pieces in a controlled manner, such as ...

  8. Rubidium–strontium dating - Wikipedia

    en.wikipedia.org/wiki/Rubidium–strontium_dating

    The rubidium–strontium dating method (Rb–Sr) is a radiometric dating technique, used by scientists to determine the age of rocks and minerals from their content of specific isotopes of rubidium (87 Rb) and strontium (87 Sr, 86 Sr). One of the two naturally occurring isotopes of rubidium, 87 Rb, decays to 87 Sr with a half-life of 49.23 ...

  9. Lichenometry - Wikipedia

    en.wikipedia.org/wiki/Lichenometry

    The map lichen (Rhizocarpon geographicum), the lichen most used in lichenometry. Lichenometry can provide dates for glacial deposits in tundra environments, lake level changes, glacial moraines, trim lines, palaeofloods, [9] rockfalls, seismic events associated with the rockfalls, [2] talus stabilization and former extent of permafrost or very persistent snow cover. [10]