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geochronology</span> </div> </a> <ul id="toc-Cosmogenic_nuclide_geochronology-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Luminescence_dating" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Luminescence_dating"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.4</span> <span>Luminescence dating</span> </div> </a> <ul id="toc-Luminescence_dating-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Incremental_dating" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Incremental_dating"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.5</span> <span>Incremental dating</span> </div> </a> <ul id="toc-Incremental_dating-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Paleomagnetic_dating" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Paleomagnetic_dating"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.6</span> <span>Paleomagnetic dating</span> </div> </a> <ul id="toc-Paleomagnetic_dating-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Magnetostratigraphy" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Magnetostratigraphy"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.7</span> <span>Magnetostratigraphy</span> </div> </a> <ul id="toc-Magnetostratigraphy-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Chemostratigraphy" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Chemostratigraphy"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.8</span> <span>Chemostratigraphy</span> </div> </a> <ul id="toc-Chemostratigraphy-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Correlation_of_marker_horizons" class="vector-toc-list-item vector-toc-level-2"> <a class="vector-toc-link" href="#Correlation_of_marker_horizons"> <div class="vector-toc-text"> <span class="vector-toc-numb">1.9</span> <span>Correlation of marker horizons</span> </div> </a> <ul id="toc-Correlation_of_marker_horizons-sublist" class="vector-toc-list"> </ul> </li> </ul> </li> <li id="toc-Geological_hierarchy_of_chronological_periodization" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Geological_hierarchy_of_chronological_periodization"> <div class="vector-toc-text"> <span class="vector-toc-numb">2</span> <span>Geological hierarchy of chronological periodization</span> </div> </a> <ul id="toc-Geological_hierarchy_of_chronological_periodization-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Differences_from_chronostratigraphy" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Differences_from_chronostratigraphy"> <div class="vector-toc-text"> <span class="vector-toc-numb">3</span> <span>Differences from chronostratigraphy</span> </div> </a> <ul id="toc-Differences_from_chronostratigraphy-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-See_also" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#See_also"> <div class="vector-toc-text"> <span class="vector-toc-numb">4</span> <span>See also</span> </div> </a> <ul id="toc-See_also-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-References" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#References"> <div class="vector-toc-text"> <span class="vector-toc-numb">5</span> <span>References</span> </div> </a> <ul id="toc-References-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-Further_reading" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#Further_reading"> <div class="vector-toc-text"> <span class="vector-toc-numb">6</span> <span>Further reading</span> </div> </a> <ul id="toc-Further_reading-sublist" class="vector-toc-list"> </ul> </li> <li id="toc-External_links" class="vector-toc-list-item vector-toc-level-1 vector-toc-list-item-expanded"> <a class="vector-toc-link" href="#External_links"> <div class="vector-toc-text"> <span class="vector-toc-numb">7</span> <span>External links</span> </div> </a> <ul id="toc-External_links-sublist" class="vector-toc-list"> </ul> </li> </ul> </div> </div> </nav> </div> </div> <div class="mw-content-container"> <main id="content" class="mw-body"> <header class="mw-body-header vector-page-titlebar"> <nav aria-label="Contents" class="vector-toc-landmark"> <div id="vector-page-titlebar-toc" class="vector-dropdown vector-page-titlebar-toc vector-button-flush-left" > <input type="checkbox" id="vector-page-titlebar-toc-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-vector-page-titlebar-toc" class="vector-dropdown-checkbox " aria-label="Toggle the table of contents" > <label id="vector-page-titlebar-toc-label" for="vector-page-titlebar-toc-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--icon-only " aria-hidden="true" ><span class="vector-icon mw-ui-icon-listBullet mw-ui-icon-wikimedia-listBullet"></span> <span class="vector-dropdown-label-text">Toggle the table of contents</span> </label> <div class="vector-dropdown-content"> <div id="vector-page-titlebar-toc-unpinned-container" class="vector-unpinned-container"> </div> </div> </div> </nav> <h1 id="firstHeading" class="firstHeading mw-first-heading"><span class="mw-page-title-main">Geochronology</span></h1> <div id="p-lang-btn" class="vector-dropdown mw-portlet mw-portlet-lang" > <input type="checkbox" id="p-lang-btn-checkbox" role="button" aria-haspopup="true" data-event-name="ui.dropdown-p-lang-btn" class="vector-dropdown-checkbox mw-interlanguage-selector" aria-label="Go to an article in another language. Available in 47 languages" > <label id="p-lang-btn-label" for="p-lang-btn-checkbox" class="vector-dropdown-label cdx-button cdx-button--fake-button cdx-button--fake-button--enabled cdx-button--weight-quiet cdx-button--action-progressive mw-portlet-lang-heading-47" aria-hidden="true" ><span class="vector-icon mw-ui-icon-language-progressive mw-ui-icon-wikimedia-language-progressive"></span> <span class="vector-dropdown-label-text">47 languages</span> </label> <div class="vector-dropdown-content"> <div class="vector-menu-content"> <ul class="vector-menu-content-list"> <li class="interlanguage-link interwiki-af mw-list-item"><a href="https://af.wikipedia.org/wiki/Geochronologie" title="Geochronologie – Afrikaans" lang="af" hreflang="af" data-title="Geochronologie" data-language-autonym="Afrikaans" data-language-local-name="Afrikaans" class="interlanguage-link-target"><span>Afrikaans</span></a></li><li class="interlanguage-link interwiki-ar mw-list-item"><a href="https://ar.wikipedia.org/wiki/%D8%B9%D9%84%D9%85_%D8%A7%D9%84%D8%B2%D9%85%D9%86_%D8%A7%D9%84%D8%AC%D9%8A%D9%88%D9%84%D9%88%D8%AC%D9%8A" title="علم الزمن الجيولوجي – Arabic" lang="ar" hreflang="ar" data-title="علم الزمن الجيولوجي" data-language-autonym="العربية" data-language-local-name="Arabic" class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-az mw-list-item"><a href="https://az.wikipedia.org/wiki/Geoxronologiya" title="Geoxronologiya – Azerbaijani" lang="az" hreflang="az" data-title="Geoxronologiya" data-language-autonym="Azərbaycanca" data-language-local-name="Azerbaijani" class="interlanguage-link-target"><span>Azərbaycanca</span></a></li><li class="interlanguage-link interwiki-ba mw-list-item"><a href="https://ba.wikipedia.org/wiki/%D0%93%D0%B5%D0%BE%D1%85%D1%80%D0%BE%D0%BD%D0%BE%D0%BB%D0%BE%D0%B3%D0%B8%D1%8F" title="Геохронология – Bashkir" lang="ba" hreflang="ba" data-title="Геохронология" data-language-autonym="Башҡортса" data-language-local-name="Bashkir" class="interlanguage-link-target"><span>Башҡортса</span></a></li><li class="interlanguage-link interwiki-be mw-list-item"><a href="https://be.wikipedia.org/wiki/%D0%93%D0%B5%D0%B0%D1%85%D1%80%D0%B0%D0%BD%D0%B0%D0%BB%D0%BE%D0%B3%D1%96%D1%8F" title="Геахраналогія – Belarusian" lang="be" hreflang="be" data-title="Геахраналогія" data-language-autonym="Беларуская" data-language-local-name="Belarusian" class="interlanguage-link-target"><span>Беларуская</span></a></li><li class="interlanguage-link interwiki-bg mw-list-item"><a href="https://bg.wikipedia.org/wiki/%D0%93%D0%B5%D0%BE%D1%85%D1%80%D0%BE%D0%BD%D0%BE%D0%BB%D0%BE%D0%B3%D0%B8%D1%8F" title="Геохронология – Bulgarian" lang="bg" hreflang="bg" data-title="Геохронология" data-language-autonym="Български" data-language-local-name="Bulgarian" class="interlanguage-link-target"><span>Български</span></a></li><li class="interlanguage-link interwiki-bs mw-list-item"><a href="https://bs.wikipedia.org/wiki/Geohronologija" title="Geohronologija – Bosnian" lang="bs" hreflang="bs" data-title="Geohronologija" data-language-autonym="Bosanski" data-language-local-name="Bosnian" class="interlanguage-link-target"><span>Bosanski</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Geocronologia" title="Geocronologia – Catalan" lang="ca" hreflang="ca" data-title="Geocronologia" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-cv mw-list-item"><a href="https://cv.wikipedia.org/wiki/%D0%93%D0%B5%D0%BE%D1%85%D1%80%D0%BE%D0%BD%D0%BE%D0%BB%D0%BE%D0%B3%D0%B8" title="Геохронологи – Chuvash" lang="cv" hreflang="cv" data-title="Геохронологи" data-language-autonym="Чӑвашла" data-language-local-name="Chuvash" class="interlanguage-link-target"><span>Чӑвашла</span></a></li><li class="interlanguage-link interwiki-cs mw-list-item"><a href="https://cs.wikipedia.org/wiki/Geochronologie" title="Geochronologie – Czech" lang="cs" hreflang="cs" data-title="Geochronologie" data-language-autonym="Čeština" data-language-local-name="Czech" class="interlanguage-link-target"><span>Čeština</span></a></li><li class="interlanguage-link interwiki-da mw-list-item"><a href="https://da.wikipedia.org/wiki/Geokronologi" title="Geokronologi – Danish" lang="da" hreflang="da" data-title="Geokronologi" data-language-autonym="Dansk" data-language-local-name="Danish" class="interlanguage-link-target"><span>Dansk</span></a></li><li class="interlanguage-link interwiki-de mw-list-item"><a href="https://de.wikipedia.org/wiki/Geochronologie" title="Geochronologie – German" lang="de" hreflang="de" data-title="Geochronologie" data-language-autonym="Deutsch" data-language-local-name="German" class="interlanguage-link-target"><span>Deutsch</span></a></li><li class="interlanguage-link interwiki-et mw-list-item"><a href="https://et.wikipedia.org/wiki/Geokronoloogia" title="Geokronoloogia – Estonian" lang="et" hreflang="et" data-title="Geokronoloogia" data-language-autonym="Eesti" data-language-local-name="Estonian" class="interlanguage-link-target"><span>Eesti</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Geocronolog%C3%ADa" title="Geocronología – Spanish" lang="es" hreflang="es" data-title="Geocronología" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%B2%D9%85%DB%8C%D9%86%E2%80%8C%DA%AF%D8%A7%D9%87%E2%80%8C%D8%B4%D9%86%D8%A7%D8%B3%DB%8C" title="زمین‌گاه‌شناسی – Persian" lang="fa" hreflang="fa" data-title="زمین‌گاه‌شناسی" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-fr mw-list-item"><a href="https://fr.wikipedia.org/wiki/G%C3%A9ochronologie" title="Géochronologie – French" lang="fr" hreflang="fr" data-title="Géochronologie" data-language-autonym="Français" data-language-local-name="French" class="interlanguage-link-target"><span>Français</span></a></li><li class="interlanguage-link interwiki-ga mw-list-item"><a href="https://ga.wikipedia.org/wiki/Geocroineola%C3%ADocht" title="Geocroineolaíocht – Irish" lang="ga" hreflang="ga" data-title="Geocroineolaíocht" data-language-autonym="Gaeilge" data-language-local-name="Irish" class="interlanguage-link-target"><span>Gaeilge</span></a></li><li class="interlanguage-link interwiki-gl mw-list-item"><a href="https://gl.wikipedia.org/wiki/Xeocronolox%C3%ADa" title="Xeocronoloxía – Galician" lang="gl" hreflang="gl" data-title="Xeocronoloxía" data-language-autonym="Galego" data-language-local-name="Galician" class="interlanguage-link-target"><span>Galego</span></a></li><li class="interlanguage-link interwiki-ko mw-list-item"><a href="https://ko.wikipedia.org/wiki/%EC%A7%80%EC%A7%88%EC%97%B0%EB%8C%80%ED%95%99" title="지질연대학 – Korean" lang="ko" hreflang="ko" data-title="지질연대학" data-language-autonym="한국어" data-language-local-name="Korean" class="interlanguage-link-target"><span>한국어</span></a></li><li class="interlanguage-link interwiki-hi mw-list-item"><a href="https://hi.wikipedia.org/wiki/%E0%A4%AD%E0%A5%82%E0%A4%95%E0%A4%BE%E0%A4%B2%E0%A4%BE%E0%A4%A8%E0%A5%81%E0%A4%95%E0%A5%8D%E0%A4%B0%E0%A4%AE" title="भूकालानुक्रम – Hindi" lang="hi" hreflang="hi" data-title="भूकालानुक्रम" data-language-autonym="हिन्दी" data-language-local-name="Hindi" class="interlanguage-link-target"><span>हिन्दी</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Geokronologi" title="Geokronologi – Indonesian" lang="id" hreflang="id" data-title="Geokronologi" data-language-autonym="Bahasa Indonesia" data-language-local-name="Indonesian" class="interlanguage-link-target"><span>Bahasa Indonesia</span></a></li><li class="interlanguage-link interwiki-is mw-list-item"><a href="https://is.wikipedia.org/wiki/Jar%C3%B0s%C3%B6guleg_t%C3%ADmatalsfr%C3%A6%C3%B0i" title="Jarðsöguleg tímatalsfræði – Icelandic" lang="is" hreflang="is" data-title="Jarðsöguleg tímatalsfræði" data-language-autonym="Íslenska" data-language-local-name="Icelandic" class="interlanguage-link-target"><span>Íslenska</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%92%D7%90%D7%95%D7%9B%D7%A8%D7%95%D7%A0%D7%95%D7%9C%D7%95%D7%92%D7%99%D7%94" title="גאוכרונולוגיה – Hebrew" lang="he" hreflang="he" data-title="גאוכרונולוגיה" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-kk mw-list-item"><a href="https://kk.wikipedia.org/wiki/%D0%93%D0%B5%D0%BE%D1%85%D1%80%D0%BE%D0%BD%D0%BE%D0%BB%D0%BE%D0%B3%D0%B8%D1%8F" title="Геохронология – Kazakh" lang="kk" hreflang="kk" data-title="Геохронология" data-language-autonym="Қазақша" data-language-local-name="Kazakh" class="interlanguage-link-target"><span>Қазақша</span></a></li><li class="interlanguage-link interwiki-ms mw-list-item"><a href="https://ms.wikipedia.org/wiki/Geokronologi" title="Geokronologi – Malay" lang="ms" hreflang="ms" data-title="Geokronologi" data-language-autonym="Bahasa Melayu" data-language-local-name="Malay" class="interlanguage-link-target"><span>Bahasa Melayu</span></a></li><li class="interlanguage-link interwiki-cdo mw-list-item"><a href="https://cdo.wikipedia.org/wiki/D%C3%AA-c%C3%A9k_ni%C3%A8ng-d%C3%B4%CC%A4i-h%C5%8Fk" title="Dê-cék nièng-dô̤i-hŏk – Mindong" lang="cdo" hreflang="cdo" data-title="Dê-cék nièng-dô̤i-hŏk" data-language-autonym="閩東語 / Mìng-dĕ̤ng-ngṳ̄" data-language-local-name="Mindong" class="interlanguage-link-target"><span>閩東語 / Mìng-dĕ̤ng-ngṳ̄</span></a></li><li class="interlanguage-link interwiki-mn mw-list-item"><a href="https://mn.wikipedia.org/wiki/%D0%93%D0%B5%D0%BE%D1%85%D1%80%D0%BE%D0%BD%D0%BE%D0%BB%D0%BE%D0%B3%D0%B8" title="Геохронологи – Mongolian" lang="mn" hreflang="mn" data-title="Геохронологи" data-language-autonym="Монгол" data-language-local-name="Mongolian" class="interlanguage-link-target"><span>Монгол</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Geochronologie" title="Geochronologie – Dutch" lang="nl" hreflang="nl" data-title="Geochronologie" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-ja mw-list-item"><a href="https://ja.wikipedia.org/wiki/%E5%9C%B0%E8%B3%AA%E5%B9%B4%E4%BB%A3%E5%AD%A6" title="地質年代学 – Japanese" lang="ja" hreflang="ja" data-title="地質年代学" data-language-autonym="日本語" data-language-local-name="Japanese" class="interlanguage-link-target"><span>日本語</span></a></li><li class="interlanguage-link interwiki-nn mw-list-item"><a href="https://nn.wikipedia.org/wiki/Geokronologi" title="Geokronologi – Norwegian Nynorsk" lang="nn" hreflang="nn" data-title="Geokronologi" data-language-autonym="Norsk nynorsk" data-language-local-name="Norwegian Nynorsk" class="interlanguage-link-target"><span>Norsk nynorsk</span></a></li><li class="interlanguage-link interwiki-uz mw-list-item"><a href="https://uz.wikipedia.org/wiki/Geoxronologiya" title="Geoxronologiya – Uzbek" lang="uz" hreflang="uz" data-title="Geoxronologiya" data-language-autonym="Oʻzbekcha / ўзбекча" data-language-local-name="Uzbek" class="interlanguage-link-target"><span>Oʻzbekcha / ўзбекча</span></a></li><li class="interlanguage-link interwiki-ps mw-list-item"><a href="https://ps.wikipedia.org/wiki/%D8%AC%DB%8C%D9%88%DA%A9%D8%B1%D9%88%D9%86%D9%88%D9%84%D9%88%DA%98%D9%8A" title="جیوکرونولوژي – Pashto" lang="ps" hreflang="ps" data-title="جیوکرونولوژي" data-language-autonym="پښتو" data-language-local-name="Pashto" class="interlanguage-link-target"><span>پښتو</span></a></li><li class="interlanguage-link interwiki-pl mw-list-item"><a href="https://pl.wikipedia.org/wiki/Geochronologia" title="Geochronologia – Polish" lang="pl" hreflang="pl" data-title="Geochronologia" data-language-autonym="Polski" data-language-local-name="Polish" class="interlanguage-link-target"><span>Polski</span></a></li><li class="interlanguage-link interwiki-pt mw-list-item"><a href="https://pt.wikipedia.org/wiki/Geocronologia" title="Geocronologia – Portuguese" lang="pt" hreflang="pt" data-title="Geocronologia" data-language-autonym="Português" data-language-local-name="Portuguese" class="interlanguage-link-target"><span>Português</span></a></li><li class="interlanguage-link interwiki-ro mw-list-item"><a href="https://ro.wikipedia.org/wiki/Geocronologie" title="Geocronologie – Romanian" lang="ro" hreflang="ro" data-title="Geocronologie" data-language-autonym="Română" data-language-local-name="Romanian" class="interlanguage-link-target"><span>Română</span></a></li><li class="interlanguage-link interwiki-ru mw-list-item"><a href="https://ru.wikipedia.org/wiki/%D0%93%D0%B5%D0%BE%D1%85%D1%80%D0%BE%D0%BD%D0%BE%D0%BB%D0%BE%D0%B3%D0%B8%D1%8F" title="Геохронология – Russian" lang="ru" hreflang="ru" data-title="Геохронология" data-language-autonym="Русский" data-language-local-name="Russian" class="interlanguage-link-target"><span>Русский</span></a></li><li class="interlanguage-link interwiki-sq mw-list-item"><a href="https://sq.wikipedia.org/wiki/Gjeokronologjia" title="Gjeokronologjia – Albanian" lang="sq" hreflang="sq" data-title="Gjeokronologjia" data-language-autonym="Shqip" data-language-local-name="Albanian" class="interlanguage-link-target"><span>Shqip</span></a></li><li class="interlanguage-link interwiki-simple mw-list-item"><a href="https://simple.wikipedia.org/wiki/Geochronology" title="Geochronology – Simple English" lang="en-simple" hreflang="en-simple" data-title="Geochronology" data-language-autonym="Simple English" data-language-local-name="Simple English" class="interlanguage-link-target"><span>Simple English</span></a></li><li class="interlanguage-link interwiki-sk mw-list-item"><a href="https://sk.wikipedia.org/wiki/Geochronol%C3%B3gia" title="Geochronológia – Slovak" lang="sk" hreflang="sk" data-title="Geochronológia" data-language-autonym="Slovenčina" data-language-local-name="Slovak" class="interlanguage-link-target"><span>Slovenčina</span></a></li><li class="interlanguage-link interwiki-sr mw-list-item"><a href="https://sr.wikipedia.org/wiki/%D0%93%D0%B5%D0%BE%D1%85%D1%80%D0%BE%D0%BD%D0%BE%D0%BB%D0%BE%D0%B3%D0%B8%D1%98%D0%B0" title="Геохронологија – Serbian" lang="sr" hreflang="sr" data-title="Геохронологија" data-language-autonym="Српски / srpski" data-language-local-name="Serbian" 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searchaux" style="display:none">Science of determining the age of rocks, sediments and fossils</div> <figure class="mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Geological_time_spiral.png" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/7/79/Geological_time_spiral.png/300px-Geological_time_spiral.png" decoding="async" width="300" height="265" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/7/79/Geological_time_spiral.png/450px-Geological_time_spiral.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/7/79/Geological_time_spiral.png/600px-Geological_time_spiral.png 2x" data-file-width="2424" data-file-height="2145" /></a><figcaption>An artistic depiction of the major events in the history of Earth</figcaption></figure> <p><b>Geochronology</b> is the <a href="/wiki/Science" title="Science">science</a> of <a href="/wiki/Chronological_dating" title="Chronological dating">determining the age</a> of <a href="/wiki/Rock_(geology)" title="Rock (geology)">rocks</a>, <a href="/wiki/Fossil" title="Fossil">fossils</a>, and <a href="/wiki/Sediment" title="Sediment">sediments</a> using signatures inherent in the rocks themselves. Absolute geochronology can be accomplished through <a href="/wiki/Radioactive_isotopes" class="mw-redirect" title="Radioactive isotopes">radioactive isotopes</a>, whereas relative geochronology is provided by tools such as <a href="/wiki/Paleomagnetism" title="Paleomagnetism">paleomagnetism</a> and <a href="/wiki/Stable_isotope_ratio" title="Stable isotope ratio">stable isotope ratios</a>. By combining multiple geochronological (and <a href="/wiki/Biostratigraphic" class="mw-redirect" title="Biostratigraphic">biostratigraphic</a>) indicators the precision of the recovered age can be improved. </p><p>Geochronology is different in application from biostratigraphy, which is the science of assigning sedimentary rocks to a known geological period via describing, cataloging and comparing fossil floral and faunal assemblages. Biostratigraphy does not <i>directly</i> provide an absolute age determination of a rock, but merely places it within an <i>interval</i> of time at which that fossil assemblage is known to have coexisted. Both disciplines work together hand in hand, however, to the point where they share the same system of naming <a href="/wiki/Strata" class="mw-redirect" title="Strata">strata</a> (rock layers) and the time spans utilized to classify sublayers within a stratum. </p><p>The science of geochronology is the prime tool used in the discipline of <a href="/wiki/Chronostratigraphy" title="Chronostratigraphy">chronostratigraphy</a>, which attempts to derive absolute age dates for all fossil assemblages and determine the geologic <a href="/wiki/History_of_the_Earth" class="mw-redirect" title="History of the Earth">history of the Earth</a> and <a href="/wiki/List_of_Solar_System_objects_by_size" title="List of Solar System objects by size">extraterrestrial bodies</a>. </p> <meta property="mw:PageProp/toc" /> <div class="mw-heading mw-heading2"><h2 id="Dating_methods">Dating methods</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=1" title="Edit section: Dating methods"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <table class="wikitable" style="float:right; font-size:100%; width:400px; margin-left:5px;"> <caption><a href="/wiki/Geologic_time_scale" title="Geologic time scale">Units in geochronology and stratigraphy</a><sup id="cite_ref-1" class="reference"><a href="#cite_note-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> </caption> <tbody><tr> <th>Segments of rock (<a href="/wiki/Stratum" title="Stratum">strata</a>) in <a href="/wiki/Chronostratigraphy" title="Chronostratigraphy">chronostratigraphy</a> </th> <th>Time spans in <a class="mw-selflink selflink">geochronology</a> </th> <th>Notes to<br />geochronological units </th></tr> <tr> <td style="text-align:center;"><a href="/wiki/Eonothem" title="Eonothem">Eonothem</a></td> <td style="text-align:center;"><a href="/wiki/Geologic_time_scale#Terminology" title="Geologic time scale">Eon</a></td> <td>4 total, half a billion years or more </td></tr> <tr> <td style="text-align:center;"><a href="/wiki/Erathem" title="Erathem">Erathem</a></td> <td style="text-align:center;"><a href="/wiki/Geologic_time_scale#Terminology" title="Geologic time scale">Era</a></td> <td>10 defined, several hundred million years </td></tr> <tr> <td style="text-align:center;"><a href="/wiki/System_(stratigraphy)" title="System (stratigraphy)">System</a></td> <td style="text-align:center;"><a href="/wiki/Geologic_time_scale#Terminology" title="Geologic time scale">Period</a></td> <td>22 defined, tens to ~one hundred million years </td></tr> <tr> <td style="text-align:center;"><a href="/wiki/Series_(stratigraphy)" title="Series (stratigraphy)">Series</a></td> <td style="text-align:center;"><a href="/wiki/Geologic_time_scale#Terminology" title="Geologic time scale">Epoch</a></td> <td>34 defined, tens of millions of years </td></tr> <tr> <td style="text-align:center;"><a href="/wiki/Stage_(stratigraphy)" title="Stage (stratigraphy)">Stage</a></td> <td style="text-align:center;"><a href="/wiki/Geologic_time_scale#Terminology" title="Geologic time scale">Age</a></td> <td>99 defined, millions of years </td></tr> <tr> <td style="text-align:center;"><a href="/wiki/Chronozone" title="Chronozone">Chronozone</a></td> <td style="text-align:center;"><a href="/wiki/Polarity_chron" class="mw-redirect" title="Polarity chron">Chron</a></td> <td>subdivision of an age, not used by the ICS timescale </td></tr></tbody></table> <div class="mw-heading mw-heading3"><h3 id="Radiometric_dating">Radiometric dating</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=2" title="Edit section: Radiometric dating"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1236090951">.mw-parser-output .hatnote{font-style:italic}.mw-parser-output div.hatnote{padding-left:1.6em;margin-bottom:0.5em}.mw-parser-output .hatnote i{font-style:normal}.mw-parser-output .hatnote+link+.hatnote{margin-top:-0.5em}@media print{body.ns-0 .mw-parser-output .hatnote{display:none!important}}</style><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Radiometric_dating" title="Radiometric dating">Radiometric dating</a></div> <p>By measuring the amount of <a href="/wiki/Radioactive_decay" title="Radioactive decay">radioactive decay</a> of a <a href="/wiki/Radioactive_isotope" class="mw-redirect" title="Radioactive isotope">radioactive isotope</a> with a known <a href="/wiki/Half-life" title="Half-life">half-life</a>, geologists can establish the absolute age of the parent material. A number of radioactive isotopes are used for this purpose, and depending on the rate of decay, are used for dating different geological periods. More slowly decaying isotopes are useful for longer periods of time, but less accurate in absolute years. With the exception of the <a href="/wiki/Radiocarbon_dating" title="Radiocarbon dating">radiocarbon method</a>, most of these techniques are actually based on measuring an increase in the abundance of a <a href="/wiki/Radiogenic" class="mw-redirect" title="Radiogenic">radiogenic</a> isotope, which is the decay-product of the radioactive parent isotope.<sup id="cite_ref-2" class="reference"><a href="#cite_note-2"><span class="cite-bracket">[</span>2<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-3" class="reference"><a href="#cite_note-3"><span class="cite-bracket">[</span>3<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-4" class="reference"><a href="#cite_note-4"><span class="cite-bracket">[</span>4<span class="cite-bracket">]</span></a></sup> Two or more radiometric methods can be used in concert to achieve more robust results.<sup id="cite_ref-5" class="reference"><a href="#cite_note-5"><span class="cite-bracket">[</span>5<span class="cite-bracket">]</span></a></sup> Most radiometric methods are suitable for geological time only, but some such as the radiocarbon method and the <sup>40</sup>Ar/<sup>39</sup>Ar dating method can be extended into the time of early human life<sup id="cite_ref-6" class="reference"><a href="#cite_note-6"><span class="cite-bracket">[</span>6<span class="cite-bracket">]</span></a></sup> and into recorded history.<sup id="cite_ref-7" class="reference"><a href="#cite_note-7"><span class="cite-bracket">[</span>7<span class="cite-bracket">]</span></a></sup> </p><p>Some of the commonly used techniques are: </p> <ul><li><a href="/wiki/Radiocarbon_dating" title="Radiocarbon dating">Radiocarbon dating</a>. This technique measures the decay of <a href="/wiki/Carbon-14" title="Carbon-14">carbon-14</a> in organic material and can be best applied to samples younger than about 60,000 years.<sup id="cite_ref-8" class="reference"><a href="#cite_note-8"><span class="cite-bracket">[</span>8<span class="cite-bracket">]</span></a></sup><sup id="cite_ref-9" class="reference"><a href="#cite_note-9"><span class="cite-bracket">[</span>9<span class="cite-bracket">]</span></a></sup></li> <li><a href="/wiki/Uranium%E2%80%93lead_dating" title="Uranium–lead dating">Uranium–lead dating</a>. This technique measures the ratio of two lead <a href="/wiki/Isotope" title="Isotope">isotopes</a> (lead-206 and lead-207) to the amount of uranium in a mineral or rock. Often applied to the trace mineral <a href="/wiki/Zircon" title="Zircon">zircon</a> in <a href="/wiki/Igneous_rock" title="Igneous rock">igneous rocks</a>, this method is one of the two most commonly used (along with <a href="/wiki/Argon%E2%80%93argon_dating" title="Argon–argon dating">argon–argon dating</a>) for geologic dating. <a href="/wiki/Monazite_geochronology" title="Monazite geochronology">Monazite geochronology</a> is another example of U–Pb dating, employed for dating metamorphism in particular. Uranium–lead dating is applied to samples older than about 1 million years.</li> <li><a href="/wiki/Uranium%E2%80%93thorium_dating" title="Uranium–thorium dating">Uranium–thorium dating</a>. This technique is used to date <a href="/wiki/Speleothem" title="Speleothem">speleothems</a>, <a href="/wiki/Coral" title="Coral">corals</a>, <a href="/wiki/Carbonate" title="Carbonate">carbonates</a>, and fossil <a href="/wiki/Bone" title="Bone">bones</a>. Its range is from a few years to about 700,000 years.</li> <li><a href="/wiki/Potassium%E2%80%93argon_dating" class="mw-redirect" title="Potassium–argon dating">Potassium–argon dating</a> and <a href="/wiki/Argon%E2%80%93argon_dating" title="Argon–argon dating">argon–argon dating</a>. These techniques date <a href="/wiki/Metamorphic_rock" title="Metamorphic rock">metamorphic</a>, <a href="/wiki/Igneous_rock" title="Igneous rock">igneous</a> and <a href="/wiki/Volcanic_rock" title="Volcanic rock">volcanic</a> rocks. They are also used to date <a href="/wiki/Volcanic_ash" title="Volcanic ash">volcanic ash</a> layers within or overlying <a href="/wiki/Paleoanthropology" title="Paleoanthropology">paleoanthropologic</a> sites. The younger limit of the argon–argon method is a few thousand years.</li> <li><a href="/wiki/Electron_spin_resonance" class="mw-redirect" title="Electron spin resonance">Electron spin resonance</a> (ESR) dating</li></ul> <div class="mw-heading mw-heading3"><h3 id="Fission-track_dating">Fission-track dating</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=3" title="Edit section: Fission-track dating"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Fission_track_dating" title="Fission track dating">Fission track dating</a></div> <div class="mw-heading mw-heading3"><h3 id="Cosmogenic_nuclide_geochronology">Cosmogenic nuclide geochronology</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=4" title="Edit section: Cosmogenic nuclide geochronology"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Cosmogenic_radionuclide_dating" class="mw-redirect" title="Cosmogenic radionuclide dating">Cosmogenic radionuclide dating</a></div> <p>A series of related techniques for determining the age at which a geomorphic surface was created (<a href="/wiki/Cosmogenic_dating" class="mw-redirect" title="Cosmogenic dating">exposure dating</a>), or at which formerly <a href="/wiki/Surficial_deposit" class="mw-redirect" title="Surficial deposit">surficial materials</a> were buried (burial dating).<sup id="cite_ref-10" class="reference"><a href="#cite_note-10"><span class="cite-bracket">[</span>10<span class="cite-bracket">]</span></a></sup> Exposure dating uses the concentration of exotic nuclides (e.g. <sup>10</sup>Be, <sup>26</sup>Al, <sup>36</sup>Cl) produced by cosmic rays interacting with Earth materials as a proxy for the age at which a surface, such as an alluvial fan, was created. Burial dating uses the differential radioactive decay of 2 cosmogenic elements as a proxy for the age at which a sediment was screened by burial from further cosmic rays exposure. </p> <div class="mw-heading mw-heading3"><h3 id="Luminescence_dating">Luminescence dating</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=5" title="Edit section: Luminescence dating"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Luminescence dating techniques observe 'light' emitted from materials such as quartz, diamond, feldspar, and calcite. Many types of luminescence techniques are utilized in geology, including <a href="/wiki/Optically_stimulated_luminescence" title="Optically stimulated luminescence">optically stimulated luminescence</a> (OSL), <a href="/wiki/Cathodoluminescence" title="Cathodoluminescence">cathodoluminescence</a> (CL), and <a href="/wiki/Thermoluminescence" title="Thermoluminescence">thermoluminescence</a> (TL).<sup id="cite_ref-11" class="reference"><a href="#cite_note-11"><span class="cite-bracket">[</span>11<span class="cite-bracket">]</span></a></sup> Thermoluminescence and optically stimulated luminescence are used in archaeology to date 'fired' objects such as pottery or cooking stones and can be used to observe sand migration. </p> <div class="mw-heading mw-heading3"><h3 id="Incremental_dating">Incremental dating</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=6" title="Edit section: Incremental dating"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Incremental_dating" title="Incremental dating">Incremental dating</a></div> <p><a href="/wiki/Incremental_dating" title="Incremental dating">Incremental dating</a> techniques allow the construction of year-by-year annual chronologies, which can be fixed (<i>i.e.</i> linked to the present day and thus <a href="/wiki/Calendar" title="Calendar">calendar</a> or <a href="/wiki/Sidereal_time" title="Sidereal time">sidereal time</a>) or floating. </p> <ul><li><a href="/wiki/Dendrochronology" title="Dendrochronology">Dendrochronology</a></li> <li><a href="/wiki/Ice_core" title="Ice core">Ice cores</a></li> <li><a href="/wiki/Lichenometry" title="Lichenometry">Lichenometry</a></li> <li><a href="/wiki/Varve" title="Varve">Varves</a></li></ul> <div class="mw-heading mw-heading3"><h3 id="Paleomagnetic_dating">Paleomagnetic dating</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=7" title="Edit section: Paleomagnetic dating"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>A sequence of <a href="/wiki/Paleomagnetic_pole" title="Paleomagnetic pole">paleomagnetic poles</a> (usually called virtual geomagnetic poles), which are already well defined in age, constitutes an <a href="/wiki/Apparent_polar_wander" title="Apparent polar wander">apparent polar wander</a> path (APWP). Such a path is constructed for a large continental block. APWPs for different continents can be used as a reference for newly obtained poles for the rocks with unknown age. For paleomagnetic dating, it is suggested to use the APWP in order to date a pole obtained from rocks or sediments of unknown age by linking the paleopole to the nearest point on the APWP. Two methods of paleomagnetic dating have been suggested: (1) the angular method and (2) the rotation method.<sup id="cite_ref-12" class="reference"><a href="#cite_note-12"><span class="cite-bracket">[</span>12<span class="cite-bracket">]</span></a></sup> The first method is used for paleomagnetic dating of rocks inside of the same continental block. The second method is used for the folded areas where tectonic rotations are possible. </p> <div class="mw-heading mw-heading3"><h3 id="Magnetostratigraphy">Magnetostratigraphy</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=8" title="Edit section: Magnetostratigraphy"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236090951"><div role="note" class="hatnote navigation-not-searchable">Main article: <a href="/wiki/Magnetostratigraphy" title="Magnetostratigraphy">Magnetostratigraphy</a></div> <p><a href="/wiki/Magnetostratigraphy" title="Magnetostratigraphy">Magnetostratigraphy</a> determines age from the pattern of magnetic polarity zones in a series of bedded sedimentary and/or volcanic rocks by comparison to the magnetic polarity timescale. The polarity timescale has been previously determined by dating of seafloor magnetic anomalies, radiometrically dating volcanic rocks within magnetostratigraphic sections, and astronomically dating magnetostratigraphic sections. </p> <div class="mw-heading mw-heading3"><h3 id="Chemostratigraphy">Chemostratigraphy</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=9" title="Edit section: Chemostratigraphy"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Global trends in isotope compositions, particularly carbon-13 and strontium isotopes, can be used to correlate strata.<sup id="cite_ref-13" class="reference"><a href="#cite_note-13"><span class="cite-bracket">[</span>13<span class="cite-bracket">]</span></a></sup> </p> <div class="mw-heading mw-heading3"><h3 id="Correlation_of_marker_horizons">Correlation of marker horizons</h3><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=10" title="Edit section: Correlation of marker horizons"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <figure class="mw-halign-right" typeof="mw:File/Thumb"><a href="/wiki/File:Icelandic_tephra.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/c/c3/Icelandic_tephra.JPG/250px-Icelandic_tephra.JPG" decoding="async" width="250" height="188" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/c/c3/Icelandic_tephra.JPG/375px-Icelandic_tephra.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/c/c3/Icelandic_tephra.JPG/500px-Icelandic_tephra.JPG 2x" data-file-width="3264" data-file-height="2448" /></a><figcaption>Tephra horizons in south-central <a href="/wiki/Iceland" title="Iceland">Iceland</a>. The thick and light-to-dark coloured layer at the height of the <a href="/wiki/Volcanologist" title="Volcanologist">volcanologist</a>'s hands is a marker horizon of <a href="/wiki/Rhyolitic" class="mw-redirect" title="Rhyolitic">rhyolitic</a>-to-<a href="/wiki/Basalt" title="Basalt">basaltic</a> <a href="/wiki/Tephra" title="Tephra">tephra</a> from <a href="/wiki/Hekla" title="Hekla">Hekla</a>.</figcaption></figure> <p><a href="/wiki/Marker_horizon" title="Marker horizon">Marker horizons</a> are stratigraphic units of the same age and of such distinctive composition and appearance that, despite their presence in different geographic sites, there is certainty about their age-equivalence. Fossil faunal and floral <a href="/wiki/Fossil" title="Fossil">assemblages</a>, both marine and terrestrial, make for distinctive marker horizons.<sup id="cite_ref-14" class="reference"><a href="#cite_note-14"><span class="cite-bracket">[</span>14<span class="cite-bracket">]</span></a></sup> <a href="/wiki/Tephrochronology" title="Tephrochronology">Tephrochronology</a> is a method for geochemical correlation of unknown volcanic ash (tephra) to geochemically fingerprinted, dated <a href="/wiki/Tephra" title="Tephra">tephra</a>. Tephra is also often used as a dating tool in archaeology, since the dates of some eruptions are well-established. </p> <div class="mw-heading mw-heading2"><h2 id="Geological_hierarchy_of_chronological_periodization">Geological hierarchy of chronological periodization</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=11" title="Edit section: Geological hierarchy of chronological periodization"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>Geochronology, from largest to smallest: </p> <ol><li><a href="/wiki/Supereon" class="mw-redirect" title="Supereon">Supereon</a></li> <li><a href="/wiki/Eon_(geology)" class="mw-redirect" title="Eon (geology)">Eon</a></li> <li><a href="/wiki/Era_(geology)" class="mw-redirect" title="Era (geology)">Era</a></li> <li><a href="/wiki/Period_(geology)" class="mw-redirect" title="Period (geology)">Period</a></li> <li><a href="/wiki/Epoch_(geology)" class="mw-redirect" title="Epoch (geology)">Epoch</a></li> <li><a href="/wiki/Age_(geology)" class="mw-redirect" title="Age (geology)">Age</a></li> <li><a href="/wiki/Polarity_chron" class="mw-redirect" title="Polarity chron">Chron</a></li></ol> <div class="mw-heading mw-heading2"><h2 id="Differences_from_chronostratigraphy">Differences from chronostratigraphy</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=12" title="Edit section: Differences from chronostratigraphy"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <p>It is important not to confuse geochronologic and chronostratigraphic units.<sup id="cite_ref-15" class="reference"><a href="#cite_note-15"><span class="cite-bracket">[</span>15<span class="cite-bracket">]</span></a></sup> Geochronological units are periods of time, thus it is correct to say that <i><a href="/wiki/Tyrannosaurus" title="Tyrannosaurus">Tyrannosaurus</a> rex</i> lived during the Late <a href="/wiki/Cretaceous" title="Cretaceous">Cretaceous</a> Epoch.<sup id="cite_ref-16" class="reference"><a href="#cite_note-16"><span class="cite-bracket">[</span>16<span class="cite-bracket">]</span></a></sup> Chronostratigraphic units are geological material, so it is also correct to say that fossils of the genus <i>Tyrannosaurus</i> have been found in the Upper Cretaceous Series.<sup id="cite_ref-17" class="reference"><a href="#cite_note-17"><span class="cite-bracket">[</span>17<span class="cite-bracket">]</span></a></sup> In the same way, it is entirely possible to go and visit an Upper Cretaceous Series deposit – such as the <a href="/wiki/Hell_Creek" class="mw-redirect" title="Hell Creek">Hell Creek</a> deposit where the <i>Tyrannosaurus</i> fossils were found – but it is naturally impossible to visit the Late Cretaceous Epoch as that is a period of time. </p> <div class="mw-heading mw-heading2"><h2 id="See_also">See also</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=13" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Astronomical_chronology" title="Astronomical chronology">Astronomical chronology</a> <ul><li><a href="/wiki/Age_of_Earth" title="Age of Earth">Age of Earth</a></li> <li><a href="/wiki/Age_of_the_universe" title="Age of the universe">Age of the universe</a></li></ul></li> <li><a href="/wiki/Chronological_dating" title="Chronological dating">Chronological dating</a>, archaeological chronology <ul><li><a href="/wiki/Absolute_dating" title="Absolute dating">Absolute dating</a></li> <li><a href="/wiki/Relative_dating" title="Relative dating">Relative dating</a></li> <li><a href="/wiki/Phase_(archaeology)" title="Phase (archaeology)">Phase (archaeology)</a></li> <li><a href="/wiki/Archaeological_association" class="mw-redirect" title="Archaeological association">Archaeological association</a></li></ul></li> <li>Geochronology <ul><li><a href="/wiki/Closure_temperature" title="Closure temperature">Closure temperature</a></li> <li><a href="/wiki/Geologic_time_scale" title="Geologic time scale">Geologic time scale</a></li> <li><a href="/wiki/Geological_history_of_Earth" title="Geological history of Earth">Geological history of Earth</a></li> <li><a href="/wiki/Thermochronology" title="Thermochronology">Thermochronology</a></li> <li><a href="/wiki/List_of_geochronologic_names" title="List of geochronologic names">List of geochronologic names</a></li></ul></li> <li>General <ul><li><a href="/wiki/Consilience" title="Consilience">Consilience</a>, evidence from independent, unrelated sources can "converge" on strong conclusions</li></ul></li></ul> <div class="mw-heading mw-heading2"><h2 id="References">References</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=14" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1239543626">.mw-parser-output .reflist{margin-bottom:0.5em;list-style-type:decimal}@media screen{.mw-parser-output .reflist{font-size:90%}}.mw-parser-output .reflist .references{font-size:100%;margin-bottom:0;list-style-type:inherit}.mw-parser-output .reflist-columns-2{column-width:30em}.mw-parser-output .reflist-columns-3{column-width:25em}.mw-parser-output .reflist-columns{margin-top:0.3em}.mw-parser-output .reflist-columns ol{margin-top:0}.mw-parser-output .reflist-columns li{page-break-inside:avoid;break-inside:avoid-column}.mw-parser-output .reflist-upper-alpha{list-style-type:upper-alpha}.mw-parser-output .reflist-upper-roman{list-style-type:upper-roman}.mw-parser-output .reflist-lower-alpha{list-style-type:lower-alpha}.mw-parser-output .reflist-lower-greek{list-style-type:lower-greek}.mw-parser-output .reflist-lower-roman{list-style-type:lower-roman}</style><div class="reflist"> <div class="mw-references-wrap mw-references-columns"><ol class="references"> <li id="cite_note-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-1">^</a></b></span> <span class="reference-text"><style data-mw-deduplicate="TemplateStyles:r1238218222">.mw-parser-output cite.citation{font-style:inherit;word-wrap:break-word}.mw-parser-output .citation q{quotes:"\"""\"""'""'"}.mw-parser-output .citation:target{background-color:rgba(0,127,255,0.133)}.mw-parser-output .id-lock-free.id-lock-free a{background:url("//upload.wikimedia.org/wikipedia/commons/6/65/Lock-green.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-limited.id-lock-limited a,.mw-parser-output .id-lock-registration.id-lock-registration a{background:url("//upload.wikimedia.org/wikipedia/commons/d/d6/Lock-gray-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .id-lock-subscription.id-lock-subscription a{background:url("//upload.wikimedia.org/wikipedia/commons/a/aa/Lock-red-alt-2.svg")right 0.1em center/9px no-repeat}.mw-parser-output .cs1-ws-icon a{background:url("//upload.wikimedia.org/wikipedia/commons/4/4c/Wikisource-logo.svg")right 0.1em center/12px no-repeat}body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-free a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-limited a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-registration a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .id-lock-subscription a,body:not(.skin-timeless):not(.skin-minerva) .mw-parser-output .cs1-ws-icon a{background-size:contain;padding:0 1em 0 0}.mw-parser-output .cs1-code{color:inherit;background:inherit;border:none;padding:inherit}.mw-parser-output .cs1-hidden-error{display:none;color:var(--color-error,#d33)}.mw-parser-output .cs1-visible-error{color:var(--color-error,#d33)}.mw-parser-output .cs1-maint{display:none;color:#085;margin-left:0.3em}.mw-parser-output .cs1-kern-left{padding-left:0.2em}.mw-parser-output .cs1-kern-right{padding-right:0.2em}.mw-parser-output .citation .mw-selflink{font-weight:inherit}@media screen{.mw-parser-output .cs1-format{font-size:95%}html.skin-theme-clientpref-night .mw-parser-output .cs1-maint{color:#18911f}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .cs1-maint{color:#18911f}}</style><cite id="CITEREFCohenFinneyGibbard2015" class="citation cs2">Cohen, K.M.; Finney, S.; Gibbard, P.L. (2015), <a rel="nofollow" class="external text" href="http://www.stratigraphy.org/ICSchart/ChronostratChart2015-01.pdf"><i>International Chronostratigraphic Chart</i></a> <span class="cs1-format">(PDF)</span>, International Commission on Stratigraphy</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=International+Chronostratigraphic+Chart&rft.pub=International+Commission+on+Stratigraphy&rft.date=2015&rft.aulast=Cohen&rft.aufirst=K.M.&rft.au=Finney%2C+S.&rft.au=Gibbard%2C+P.L.&rft_id=http%3A%2F%2Fwww.stratigraphy.org%2FICSchart%2FChronostratChart2015-01.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span>.</span> </li> <li id="cite_note-2"><span class="mw-cite-backlink"><b><a href="#cite_ref-2">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDickin2000" class="citation book cs1">Dickin, Alan P. (2000). <i>Radiogenic isotope geology</i> (1 ed.). Cambridge: Cambridge Univ. Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-521-59891-0" title="Special:BookSources/978-0-521-59891-0"><bdi>978-0-521-59891-0</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Radiogenic+isotope+geology&rft.place=Cambridge&rft.edition=1&rft.pub=Cambridge+Univ.+Press&rft.date=2000&rft.isbn=978-0-521-59891-0&rft.aulast=Dickin&rft.aufirst=Alan+P.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-3"><span class="mw-cite-backlink"><b><a href="#cite_ref-3">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFaure1986" class="citation book cs1">Faure, Gunter (1986). <i>Principles of isotope geology</i> (2 ed.). New York: Wiley. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-471-86412-7" title="Special:BookSources/978-0-471-86412-7"><bdi>978-0-471-86412-7</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Principles+of+isotope+geology&rft.place=New+York&rft.edition=2&rft.pub=Wiley&rft.date=1986&rft.isbn=978-0-471-86412-7&rft.aulast=Faure&rft.aufirst=Gunter&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-4"><span class="mw-cite-backlink"><b><a href="#cite_ref-4">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFaureMensingFaure2005" class="citation book cs1">Faure, Gunter; Mensing, Teresa M.; Faure, Gunter (2005). <i>Isotopes: principles and applications</i> (3 ed.). Hoboken, N.J: Wiley. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-471-38437-3" title="Special:BookSources/978-0-471-38437-3"><bdi>978-0-471-38437-3</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Isotopes%3A+principles+and+applications&rft.place=Hoboken%2C+N.J&rft.edition=3&rft.pub=Wiley&rft.date=2005&rft.isbn=978-0-471-38437-3&rft.aulast=Faure&rft.aufirst=Gunter&rft.au=Mensing%2C+Teresa+M.&rft.au=Faure%2C+Gunter&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-5"><span class="mw-cite-backlink"><b><a href="#cite_ref-5">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDalrympleGroveLoveraHarrison1999" class="citation journal cs1">Dalrymple, G. B.; Grove, M.; Lovera, O. M.; Harrison, T. M.; Hulen, J. B.; Lanphere, M. A. (1999). "Age and thermal history of the Geysers plutonic complex (felsite unit), Geysers geothermal field, California: a <sup>40</sup>Ar/<sup>39</sup>Ar and U–Pb study". <i>Earth and Planetary Science Letters</i>. <b>173</b> (3): 285–298. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1999E&PSL.173..285D">1999E&PSL.173..285D</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2FS0012-821X%2899%2900223-X">10.1016/S0012-821X(99)00223-X</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Earth+and+Planetary+Science+Letters&rft.atitle=Age+and+thermal+history+of+the+Geysers+plutonic+complex+%28felsite+unit%29%2C+Geysers+geothermal+field%2C+California%3A+a+%3Csup%3E40%3C%2Fsup%3EAr%2F%3Csup%3E39%3C%2Fsup%3EAr+and+U%E2%80%93Pb+study&rft.volume=173&rft.issue=3&rft.pages=285-298&rft.date=1999&rft_id=info%3Adoi%2F10.1016%2FS0012-821X%2899%2900223-X&rft_id=info%3Abibcode%2F1999E%26PSL.173..285D&rft.aulast=Dalrymple&rft.aufirst=G.+B.&rft.au=Grove%2C+M.&rft.au=Lovera%2C+O.+M.&rft.au=Harrison%2C+T.+M.&rft.au=Hulen%2C+J.+B.&rft.au=Lanphere%2C+M.+A.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-6"><span class="mw-cite-backlink"><b><a href="#cite_ref-6">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFLudwigRenne2000" class="citation journal cs1">Ludwig, K. R.; Renne, P. R. (2000). <a rel="nofollow" class="external text" href="https://archive.today/20130105085933/http://www3.interscience.wiley.com/journal/72000094/abstract?CRETRY=1&SRETRY=0">"Geochronology on the Paleoanthropological Time Scale"</a>. <i>Evolutionary Anthropology</i>. <b>9</b> (2): 101–110. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1002%2F%28sici%291520-6505%282000%299%3A2%3C101%3A%3Aaid-evan4%3E3.0.co%3B2-w">10.1002/(sici)1520-6505(2000)9:2<101::aid-evan4>3.0.co;2-w</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:83948790">83948790</a>. Archived from <a rel="nofollow" class="external text" href="http://www3.interscience.wiley.com/journal/72000094/abstract?CRETRY=1&SRETRY=0">the original</a> on 2013-01-05.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Evolutionary+Anthropology&rft.atitle=Geochronology+on+the+Paleoanthropological+Time+Scale&rft.volume=9&rft.issue=2&rft.pages=101-110&rft.date=2000&rft_id=info%3Adoi%2F10.1002%2F%28sici%291520-6505%282000%299%3A2%3C101%3A%3Aaid-evan4%3E3.0.co%3B2-w&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A83948790%23id-name%3DS2CID&rft.aulast=Ludwig&rft.aufirst=K.+R.&rft.au=Renne%2C+P.+R.&rft_id=http%3A%2F%2Fwww3.interscience.wiley.com%2Fjournal%2F72000094%2Fabstract%3FCRETRY%3D1%26SRETRY%3D0&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-7"><span class="mw-cite-backlink"><b><a href="#cite_ref-7">^</a></b></span> <span class="reference-text">Renne, P. R., Sharp, W. D., Deino. A. L., Orsi, G., and Civetta, L. 1997. <i>Science</i>, <b>277</b>, 1279-1280 <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite class="citation web cs1"><a rel="nofollow" class="external text" href="https://web.archive.org/web/20081030142813/http://www.pereplet.ru/gorm/dating/vesuvius.pdf">"<sup>40</sup>Ar/<sup>39</sup>Ar dating into the historical realm: Calibration against Pliny the Younger"</a> <span class="cs1-format">(PDF)</span>. Archived from <a rel="nofollow" class="external text" href="http://www.pereplet.ru/gorm/dating/vesuvius.pdf">the original</a> <span class="cs1-format">(PDF)</span> on 2008-10-30<span class="reference-accessdate">. Retrieved <span class="nowrap">2008-10-25</span></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=unknown&rft.btitle=%3Csup%3E40%3C%2Fsup%3EAr%2F%3Csup%3E39%3C%2Fsup%3EAr+dating+into+the+historical+realm%3A+Calibration+against+Pliny+the+Younger&rft_id=http%3A%2F%2Fwww.pereplet.ru%2Fgorm%2Fdating%2Fvesuvius.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-8"><span class="mw-cite-backlink"><b><a href="#cite_ref-8">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFPlastinoKaihola,_L.Bartolomei,_P.Bella,_F.2001" class="citation journal cs1">Plastino, W.; Kaihola, L.; Bartolomei, P.; Bella, F. (2001). <a rel="nofollow" class="external text" href="https://doi.org/10.1017%2FS0033822200037954">"Cosmic Background Reduction In The Radiocarbon Measurement By Scintillation Spectrometry At The Underground Laboratory Of Gran Sasso"</a>. <i>Radiocarbon</i>. <b>43</b> (2A): 157–161. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1017%2FS0033822200037954">10.1017/S0033822200037954</a></span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Radiocarbon&rft.atitle=Cosmic+Background+Reduction+In+The+Radiocarbon+Measurement+By+Scintillation+Spectrometry+At+The+Underground+Laboratory+Of+Gran+Sasso&rft.volume=43&rft.issue=2A&rft.pages=157-161&rft.date=2001&rft_id=info%3Adoi%2F10.1017%2FS0033822200037954&rft.aulast=Plastino&rft.aufirst=W.&rft.au=Kaihola%2C+L.&rft.au=Bartolomei%2C+P.&rft.au=Bella%2C+F.&rft_id=https%3A%2F%2Fdoi.org%2F10.1017%252FS0033822200037954&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-9"><span class="mw-cite-backlink"><b><a href="#cite_ref-9">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHajdasAscoughGarnettFallon2021" class="citation journal cs1">Hajdas, Irka; Ascough, Philippa; Garnett, Mark H.; Fallon, Stewart J.; Pearson, Charlotte L.; Quarta, Gianluca; Spalding, Kirsty L.; Yamaguchi, Haruka; Yoneda, Minoru (2021-09-09). <a rel="nofollow" class="external text" href="https://doi.org/10.1038%2Fs43586-021-00058-7">"Radiocarbon dating"</a>. <i>Nature Reviews Methods Primers</i>. <b>1</b> (1): 1–26. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<span class="id-lock-free" title="Freely accessible"><a rel="nofollow" class="external text" href="https://doi.org/10.1038%2Fs43586-021-00058-7">10.1038/s43586-021-00058-7</a></span>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/2662-8449">2662-8449</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature+Reviews+Methods+Primers&rft.atitle=Radiocarbon+dating&rft.volume=1&rft.issue=1&rft.pages=1-26&rft.date=2021-09-09&rft_id=info%3Adoi%2F10.1038%2Fs43586-021-00058-7&rft.issn=2662-8449&rft.aulast=Hajdas&rft.aufirst=Irka&rft.au=Ascough%2C+Philippa&rft.au=Garnett%2C+Mark+H.&rft.au=Fallon%2C+Stewart+J.&rft.au=Pearson%2C+Charlotte+L.&rft.au=Quarta%2C+Gianluca&rft.au=Spalding%2C+Kirsty+L.&rft.au=Yamaguchi%2C+Haruka&rft.au=Yoneda%2C+Minoru&rft_id=https%3A%2F%2Fdoi.org%2F10.1038%252Fs43586-021-00058-7&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-10"><span class="mw-cite-backlink"><b><a href="#cite_ref-10">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSchaeferCodileanWillenbringLu2022" class="citation journal cs1">Schaefer, Joerg M.; Codilean, Alexandru T.; Willenbring, Jane K.; Lu, Zheng-Tian; Keisling, Benjamin; Fülöp, Réka-H.; Val, Pedro (2022-03-10). <a rel="nofollow" class="external text" href="https://www.nature.com/articles/s43586-022-00096-9">"Cosmogenic nuclide techniques"</a>. <i>Nature Reviews Methods Primers</i>. <b>2</b> (1): 1–22. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2Fs43586-022-00096-9">10.1038/s43586-022-00096-9</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/2662-8449">2662-8449</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:247396585">247396585</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature+Reviews+Methods+Primers&rft.atitle=Cosmogenic+nuclide+techniques&rft.volume=2&rft.issue=1&rft.pages=1-22&rft.date=2022-03-10&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A247396585%23id-name%3DS2CID&rft.issn=2662-8449&rft_id=info%3Adoi%2F10.1038%2Fs43586-022-00096-9&rft.aulast=Schaefer&rft.aufirst=Joerg+M.&rft.au=Codilean%2C+Alexandru+T.&rft.au=Willenbring%2C+Jane+K.&rft.au=Lu%2C+Zheng-Tian&rft.au=Keisling%2C+Benjamin&rft.au=F%C3%BCl%C3%B6p%2C+R%C3%A9ka-H.&rft.au=Val%2C+Pedro&rft_id=https%3A%2F%2Fwww.nature.com%2Farticles%2Fs43586-022-00096-9&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-11"><span class="mw-cite-backlink"><b><a href="#cite_ref-11">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFMurrayArnoldBuylaertGuérin2021" class="citation journal cs1">Murray, Andrew; Arnold, Lee J.; Buylaert, Jan-Pieter; Guérin, Guillaume; Qin, Jintang; Singhvi, Ashok K.; Smedley, Rachel; Thomsen, Kristina J. (2021-10-28). <a rel="nofollow" class="external text" href="https://www.nature.com/articles/s43586-021-00068-5">"Optically stimulated luminescence dating using quartz"</a>. <i>Nature Reviews Methods Primers</i>. <b>1</b> (1): 1–31. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1038%2Fs43586-021-00068-5">10.1038/s43586-021-00068-5</a>. <a href="/wiki/ISSN_(identifier)" class="mw-redirect" title="ISSN (identifier)">ISSN</a> <a rel="nofollow" class="external text" href="https://search.worldcat.org/issn/2662-8449">2662-8449</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:240186965">240186965</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Nature+Reviews+Methods+Primers&rft.atitle=Optically+stimulated+luminescence+dating+using+quartz&rft.volume=1&rft.issue=1&rft.pages=1-31&rft.date=2021-10-28&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A240186965%23id-name%3DS2CID&rft.issn=2662-8449&rft_id=info%3Adoi%2F10.1038%2Fs43586-021-00068-5&rft.aulast=Murray&rft.aufirst=Andrew&rft.au=Arnold%2C+Lee+J.&rft.au=Buylaert%2C+Jan-Pieter&rft.au=Gu%C3%A9rin%2C+Guillaume&rft.au=Qin%2C+Jintang&rft.au=Singhvi%2C+Ashok+K.&rft.au=Smedley%2C+Rachel&rft.au=Thomsen%2C+Kristina+J.&rft_id=https%3A%2F%2Fwww.nature.com%2Farticles%2Fs43586-021-00068-5&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-12"><span class="mw-cite-backlink"><b><a href="#cite_ref-12">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFHnatyshinKravchinsky2014" class="citation journal cs1">Hnatyshin, Danny; Kravchinsky, Vadim A. (September 2014). <a rel="nofollow" class="external text" href="https://linkinghub.elsevier.com/retrieve/pii/S0040195114002613">"Paleomagnetic dating: Methods, MATLAB software, example"</a>. <i>Tectonophysics</i>. <b>630</b>: 103–112. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1016%2Fj.tecto.2014.05.013">10.1016/j.tecto.2014.05.013</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Tectonophysics&rft.atitle=Paleomagnetic+dating%3A+Methods%2C+MATLAB+software%2C+example&rft.volume=630&rft.pages=103-112&rft.date=2014-09&rft_id=info%3Adoi%2F10.1016%2Fj.tecto.2014.05.013&rft.aulast=Hnatyshin&rft.aufirst=Danny&rft.au=Kravchinsky%2C+Vadim+A.&rft_id=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0040195114002613&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-13"><span class="mw-cite-backlink"><b><a href="#cite_ref-13">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFBrasierSukhov1998" class="citation journal cs1">Brasier, M D; Sukhov, S S (1 April 1998). "The falling amplitude of carbon isotopic oscillations through the Lower to Middle Cambrian: northern Siberia data". <i>Canadian Journal of Earth Sciences</i>. <b>35</b> (4): 353–373. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/1998CaJES..35..353B">1998CaJES..35..353B</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1139%2Fe97-122">10.1139/e97-122</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Canadian+Journal+of+Earth+Sciences&rft.atitle=The+falling+amplitude+of+carbon+isotopic+oscillations+through+the+Lower+to+Middle+Cambrian%3A+northern+Siberia+data&rft.volume=35&rft.issue=4&rft.pages=353-373&rft.date=1998-04-01&rft_id=info%3Adoi%2F10.1139%2Fe97-122&rft_id=info%3Abibcode%2F1998CaJES..35..353B&rft.aulast=Brasier&rft.aufirst=M+D&rft.au=Sukhov%2C+S+S&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-14"><span class="mw-cite-backlink"><b><a href="#cite_ref-14">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFDemidov2006" class="citation journal cs1">Demidov, I.N. (2006). "Identification of marker horizon in bottom sediments of the Onega Periglacial Lake". <i>Doklady Earth Sciences</i>. <b>407</b> (1): 213–216. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2006DokES.407..213D">2006DokES.407..213D</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1134%2FS1028334X06020127">10.1134/S1028334X06020127</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:140634223">140634223</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Doklady+Earth+Sciences&rft.atitle=Identification+of+marker+horizon+in+bottom+sediments+of+the+Onega+Periglacial+Lake&rft.volume=407&rft.issue=1&rft.pages=213-216&rft.date=2006&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A140634223%23id-name%3DS2CID&rft_id=info%3Adoi%2F10.1134%2FS1028334X06020127&rft_id=info%3Abibcode%2F2006DokES.407..213D&rft.aulast=Demidov&rft.aufirst=I.N.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-15"><span class="mw-cite-backlink"><b><a href="#cite_ref-15">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFFastovskyWeishampel1996" class="citation book cs1">Fastovsky, David E.; Weishampel, David B. (1996). <i>The evolution and extinction of the dinosaurs</i>. Cambridge ; New York: Cambridge University Press. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-521-44496-5" title="Special:BookSources/978-0-521-44496-5"><bdi>978-0-521-44496-5</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+evolution+and+extinction+of+the+dinosaurs&rft.place=Cambridge+%3B+New+York&rft.pub=Cambridge+University+Press&rft.date=1996&rft.isbn=978-0-521-44496-5&rft.aulast=Fastovsky&rft.aufirst=David+E.&rft.au=Weishampel%2C+David+B.&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-16"><span class="mw-cite-backlink"><b><a href="#cite_ref-16">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFJacksonBatesAmerican_Geological_Institute1997" class="citation book cs1">Jackson, Julia A.; Bates, Robert Latimer; American Geological Institute, eds. (1997). <i>Glossary of geology</i> (4 ed.). Alexandria, Va: American Geological Institute. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-922152-34-6" title="Special:BookSources/978-0-922152-34-6"><bdi>978-0-922152-34-6</bdi></a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=Glossary+of+geology&rft.place=Alexandria%2C+Va&rft.edition=4&rft.pub=American+Geological+Institute&rft.date=1997&rft.isbn=978-0-922152-34-6&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> <li id="cite_note-17"><span class="mw-cite-backlink"><b><a href="#cite_ref-17">^</a></b></span> <span class="reference-text"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><cite id="CITEREFSmithLamannaLacovaraDodson2001" class="citation journal cs1">Smith, J.B.; Lamanna, M.C.; Lacovara, K.J.; Dodson, Poole; Jnr, P.; Giegengack, R. (2001). <a rel="nofollow" class="external text" href="http://doc.rero.ch/record/14792/files/PAL_E1924.pdf">"A Giant Sauropod Dinosaur from an Upper Cretaceous Mangrove Deposit in Egypt"</a> <span class="cs1-format">(PDF)</span>. <i>Science</i>. <b>292</b> (5522): 1704–1707. <a href="/wiki/Bibcode_(identifier)" class="mw-redirect" title="Bibcode (identifier)">Bibcode</a>:<a rel="nofollow" class="external text" href="https://ui.adsabs.harvard.edu/abs/2001Sci...292.1704S">2001Sci...292.1704S</a>. <a href="/wiki/Doi_(identifier)" class="mw-redirect" title="Doi (identifier)">doi</a>:<a rel="nofollow" class="external text" href="https://doi.org/10.1126%2Fscience.1060561">10.1126/science.1060561</a>. <a href="/wiki/PMID_(identifier)" class="mw-redirect" title="PMID (identifier)">PMID</a> <a rel="nofollow" class="external text" href="https://pubmed.ncbi.nlm.nih.gov/11387472">11387472</a>. <a href="/wiki/S2CID_(identifier)" class="mw-redirect" title="S2CID (identifier)">S2CID</a> <a rel="nofollow" class="external text" href="https://api.semanticscholar.org/CorpusID:33454060">33454060</a>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Ajournal&rft.genre=article&rft.jtitle=Science&rft.atitle=A+Giant+Sauropod+Dinosaur+from+an+Upper+Cretaceous+Mangrove+Deposit+in+Egypt&rft.volume=292&rft.issue=5522&rft.pages=1704-1707&rft.date=2001&rft_id=info%3Adoi%2F10.1126%2Fscience.1060561&rft_id=https%3A%2F%2Fapi.semanticscholar.org%2FCorpusID%3A33454060%23id-name%3DS2CID&rft_id=info%3Apmid%2F11387472&rft_id=info%3Abibcode%2F2001Sci...292.1704S&rft.aulast=Smith&rft.aufirst=J.B.&rft.au=Lamanna%2C+M.C.&rft.au=Lacovara%2C+K.J.&rft.au=Dodson%2C+Poole&rft.au=Jnr%2C+P.&rft.au=Giegengack%2C+R.&rft_id=http%3A%2F%2Fdoc.rero.ch%2Frecord%2F14792%2Ffiles%2FPAL_E1924.pdf&rfr_id=info%3Asid%2Fen.wikipedia.org%3AGeochronology" class="Z3988"></span></span> </li> </ol></div></div> <div class="mw-heading mw-heading2"><h2 id="Further_reading">Further reading</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=15" title="Edit section: Further reading"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li>Smart, P.L., and Frances, P.D. (1991), <i>Quaternary dating methods - a user's guide</i>. Quaternary Research Association Technical Guide No.4 <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-907780-08-3" title="Special:BookSources/0-907780-08-3">0-907780-08-3</a></li> <li>Lowe, J.J., and Walker, M.J.C. (1997), <i>Reconstructing Quaternary Environments</i> (2nd edition). Longman publishing <link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1238218222"><a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/0-582-10166-2" title="Special:BookSources/0-582-10166-2">0-582-10166-2</a></li> <li>Mattinson, J. M. (2013), <i>Revolution and evolution: 100 years of U-Pb geochronology</i>. Elements 9, 53–57.</li> <li><i>Geochronology bibliography</i> <a rel="nofollow" class="external text" href="http://www.talkorigins.org/origins/biblio/geochronology.html">Talk:Origins Archive</a></li></ul> <div class="mw-heading mw-heading2"><h2 id="External_links">External links</h2><span class="mw-editsection"><span class="mw-editsection-bracket">[</span><a href="/w/index.php?title=Geochronology&action=edit&section=16" title="Edit section: External links"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a rel="nofollow" class="external text" href="https://portal.ga.gov.au/persona/geochronology">Geochronology and Isotopes Data Portal </a></li> <li><a rel="nofollow" class="external text" href="http://stratigraphy.org/">International Commission on Stratigraphy </a></li> <li><a rel="nofollow" class="external text" href="http://data.bgs.ac.uk/home.html">BGS Open Data </a> <a rel="nofollow" class="external text" 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//upload.wikimedia.org/wikipedia/commons/thumb/e/e7/WikiProject_Geology.svg/100px-WikiProject_Geology.svg.png 2x" data-file-width="327" data-file-height="328" /></a></span><br /></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/History_of_geology" title="History of geology">History of geology</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a class="mw-selflink selflink">Geochronology</a></li> <li><a href="/wiki/Geological_history_of_Earth" title="Geological history of Earth">Geological history of Earth</a></li> <li><a href="/wiki/Timeline_of_geology" title="Timeline of geology">Timeline of geology</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Composition and structure</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Cosmochemistry" title="Cosmochemistry">Cosmochemistry</a></li> <li><a href="/wiki/Crystallography" title="Crystallography">Crystallography</a></li> <li><a href="/wiki/Geochemistry" title="Geochemistry">Geochemistry</a></li> <li><a href="/wiki/Mineralogy" title="Mineralogy">Mineralogy</a></li> <li><a href="/wiki/Petrology" title="Petrology">Petrology</a></li> <li><a href="/wiki/Sedimentology" title="Sedimentology">Sedimentology</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Historical_geology" title="Historical geology">Historical geology</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Stratigraphy" title="Stratigraphy">Stratigraphy</a></li> <li><a href="/wiki/Paleontology" title="Paleontology">Paleontology</a></li> <li><a href="/wiki/Paleoclimatology" title="Paleoclimatology">Paleoclimatology</a></li> <li><a href="/wiki/Palaeogeography" title="Palaeogeography">Palaeogeography</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Dynamic Earth</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Structural_geology" title="Structural geology">Structural geology</a></li> <li><a href="/wiki/Geodynamics" title="Geodynamics">Geodynamics</a></li> <li><a href="/wiki/Plate_tectonics" title="Plate tectonics">Plate tectonics</a></li> <li><a href="/wiki/Geomorphology" title="Geomorphology">Geomorphology</a></li> <li><a href="/wiki/Volcanology" title="Volcanology">Volcanology</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Water</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Glaciology" title="Glaciology">Glaciology</a></li> <li><a href="/wiki/Hydrogeology" title="Hydrogeology">Hydrogeology</a></li> <li><a href="/wiki/Marine_geology" title="Marine geology">Marine geology</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Geodesy" title="Geodesy">Geodesy</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Cartography" title="Cartography">Cartography</a></li> <li><a href="/wiki/Earth%27s_orbit" title="Earth's orbit">Earth's orbit</a></li> <li><a href="/wiki/Geodetic_astronomy" title="Geodetic astronomy">Geodetic astronomy</a></li> <li><a href="/wiki/Geomatics" title="Geomatics">Geomatics</a></li> <li><a href="/wiki/Gravity_of_Earth" title="Gravity of Earth">Gravity of Earth</a></li> <li><a href="/wiki/Planetary_science#Planetary_geodesy" title="Planetary science">Planetary geodesy</a></li> <li><a href="/wiki/Remote_sensing" title="Remote sensing">Remote sensing</a></li> <li><a href="/wiki/Geopositioning" title="Geopositioning">Geopositioning</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Geophysics" title="Geophysics">Geophysics</a></th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Geomagnetism" class="mw-redirect" title="Geomagnetism">Geomagnetism</a></li> <li><a href="/wiki/Geophysical_survey" title="Geophysical survey">Geophysical survey</a></li> <li><a href="/wiki/Planetary_science#Planetary_Geophysics_and_Space_Physics" title="Planetary science">Planetary geophysics</a></li> <li><a href="/wiki/Seismology" title="Seismology">Seismology</a></li> <li><a href="/wiki/Tectonophysics" title="Tectonophysics">Tectonophysics</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Applications</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Biogeology" title="Biogeology">Biogeology</a></li> <li><a href="/wiki/Economic_geology" title="Economic geology">Economic geology</a></li> <li><a href="/wiki/Engineering_geology" title="Engineering geology">Engineering geology</a></li> <li><a href="/wiki/Environmental_geology" title="Environmental geology">Environmental geology</a></li> <li><a href="/wiki/Planetary_geology" title="Planetary geology">Planetary geology</a></li> <li><a href="/wiki/Geobiology" title="Geobiology">Geobiology</a></li> <li><a href="/wiki/Geologic_modelling" title="Geologic modelling">Geologic modelling</a></li> <li><a href="/wiki/Forensic_geology" title="Forensic geology">Forensic geology</a></li> <li><a href="/wiki/Forensic_geophysics" title="Forensic geophysics">Forensic geophysics</a></li> <li><a href="/wiki/Meteoritics" title="Meteoritics">Meteoritics</a></li> <li><a href="/wiki/Mining_geology" title="Mining geology">Mining geology</a></li> <li><a href="/wiki/Mineral_physics" title="Mineral physics">Mineral physics</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Occupations</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Geologist" title="Geologist">Geologist</a></li> <li><a href="/wiki/Petroleum_geologist" title="Petroleum geologist">Petroleum geologist</a></li> <li><a href="/wiki/Volcanologist" title="Volcanologist">Volcanologist</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow hlist" colspan="3"><div> <ul><li><b><span class="nowrap"><span class="noviewer" typeof="mw:File"><a href="/wiki/File:WikiProject_Geology.svg" class="mw-file-description"><img alt="icon" src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e7/WikiProject_Geology.svg/16px-WikiProject_Geology.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e7/WikiProject_Geology.svg/24px-WikiProject_Geology.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e7/WikiProject_Geology.svg/32px-WikiProject_Geology.svg.png 2x" data-file-width="327" data-file-height="328" /></a></span> </span><a href="/wiki/Portal:Geology" title="Portal:Geology">Geology portal</a></b></li> <li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <b><a href="/wiki/Category:Geology" title="Category:Geology">Geology</a></b></li> <li><span class="noviewer" typeof="mw:File"><span title="WikiProject"><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/3/37/People_icon.svg/16px-People_icon.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/3/37/People_icon.svg/24px-People_icon.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/3/37/People_icon.svg/32px-People_icon.svg.png 2x" data-file-width="100" data-file-height="100" /></span></span> <b><a href="/wiki/Wikipedia:Geology" class="mw-redirect" title="Wikipedia:Geology">Geology</a></b></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"></div><div role="navigation" class="navbox" aria-labelledby="Time" style="padding:3px"><table class="nowraplinks hlist mw-collapsible autocollapse navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Time_topics" title="Template:Time topics"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Time_topics" title="Template talk:Time topics"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Time_topics" title="Special:EditPage/Template:Time topics"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Time" style="font-size:114%;margin:0 4em"><a href="/wiki/Time" title="Time">Time</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%">Key concepts</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Past" title="Past">Past</a></li> <li><a href="/wiki/Present" title="Present">Present</a></li> <li><a href="/wiki/Future" title="Future">Future</a></li> <li><a href="/wiki/Eternity" title="Eternity">Eternity</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Horology" class="mw-redirect" title="Horology">Measurement</a><br />and <a href="/wiki/Time_standard" title="Time standard">standards</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:6.5em;font-weight:normal; text-align:center;"><a href="/wiki/Chronometry" title="Chronometry">Chronometry</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Coordinated_Universal_Time" title="Coordinated Universal Time">UTC</a></li> <li><a href="/wiki/Universal_Time" title="Universal Time">UT</a></li> <li><a href="/wiki/International_Atomic_Time" title="International Atomic Time">TAI</a></li> <li><a href="/wiki/Unit_of_time" title="Unit of time">Unit of time</a></li> <li><a href="/wiki/Orders_of_magnitude_(time)" title="Orders of magnitude (time)">Orders of magnitude (time)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:6.5em;font-weight:normal; text-align:center;"><a href="/wiki/System_of_measurement" class="mw-redirect" title="System of measurement">Measurement<br />systems</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Italian_six-hour_clock" title="Italian six-hour clock">Italian six-hour clock</a></li> <li><a href="/wiki/Thai_six-hour_clock" title="Thai six-hour clock">Thai six-hour clock</a></li> <li><a href="/wiki/12-hour_clock" title="12-hour clock">12-hour clock</a></li> <li><a href="/wiki/24-hour_clock" title="24-hour clock">24-hour clock</a></li> <li><a href="/wiki/Relative_hour" title="Relative hour">Relative hour</a></li> <li><a href="/wiki/Daylight_saving_time" title="Daylight saving time">Daylight saving time</a></li> <li><a href="/wiki/Traditional_Chinese_timekeeping" title="Traditional Chinese timekeeping">Chinese</a></li> <li><a href="/wiki/Decimal_time" title="Decimal time">Decimal</a></li> <li><a href="/wiki/Hexadecimal_time" title="Hexadecimal time">Hexadecimal</a></li> <li><a href="/wiki/Hindu_units_of_time" title="Hindu units of time">Hindu</a></li> <li><a href="/wiki/Metric_time" title="Metric time">Metric</a></li> <li><a href="/wiki/Roman_timekeeping" title="Roman timekeeping">Roman</a></li> <li><a href="/wiki/Sidereal_time" title="Sidereal time">Sidereal</a></li> <li><a href="/wiki/Solar_time" title="Solar time">Solar</a></li> <li><a href="/wiki/Time_zone" title="Time zone">Time zone</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:6.5em;font-weight:normal; text-align:center;"><a href="/wiki/Calendar" title="Calendar">Calendars</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Calendar#Systems" title="Calendar">Main types</a> <ul><li><a href="/wiki/Solar_calendar" title="Solar calendar">Solar</a></li> <li><a href="/wiki/Lunar_calendar" title="Lunar calendar">Lunar</a></li> <li><a href="/wiki/Lunisolar_calendar" title="Lunisolar calendar">Lunisolar</a></li></ul></li> <li><a href="/wiki/Gregorian_calendar" title="Gregorian calendar">Gregorian</a></li> <li><a href="/wiki/Julian_calendar" title="Julian calendar">Julian</a></li> <li><a href="/wiki/Hebrew_calendar" title="Hebrew calendar">Hebrew</a></li> <li><a href="/wiki/Islamic_calendar" title="Islamic calendar">Islamic</a></li> <li><a href="/wiki/Solar_Hijri_calendar" title="Solar Hijri calendar">Solar Hijri</a></li> <li><a href="/wiki/Chinese_calendar" title="Chinese calendar">Chinese</a></li> <li><a href="/wiki/Hindu_calendar" title="Hindu calendar">Hindu Panchang</a></li> <li><a href="/wiki/Maya_calendar" title="Maya calendar">Maya</a></li> <li><i><a href="/wiki/List_of_calendars" title="List of calendars">List</a></i></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:6.5em;font-weight:normal; text-align:center;"><a href="/wiki/Clock" title="Clock">Clocks</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Clock#Types" title="Clock">Main types</a> <ul><li><a href="/wiki/Astronomical_clock" title="Astronomical clock">astronomical</a> <ul><li><a href="/wiki/Astrarium" title="Astrarium">astrarium</a></li></ul></li> <li><a href="/wiki/Atomic_clock" title="Atomic clock">atomic</a> <ul><li><a href="/wiki/Quantum_clock" class="mw-redirect" title="Quantum clock">quantum</a></li></ul></li> <li><a href="/wiki/Hourglass" title="Hourglass">hourglass</a></li> <li><a href="/wiki/Marine_chronometer" title="Marine chronometer">marine</a></li> <li><a href="/wiki/Sundial" title="Sundial">sundial</a></li> <li><a href="/wiki/Watch" title="Watch">watch</a> <ul><li><a href="/wiki/Mechanical_watch" title="Mechanical watch">mechanical</a></li> <li><a href="/wiki/Stopwatch" title="Stopwatch">stopwatch</a></li></ul></li> <li><a href="/wiki/Water_clock" title="Water clock">water-based</a></li></ul></li> <li><a href="/wiki/Cuckoo_clock" title="Cuckoo clock">Cuckoo clock</a></li> <li><a href="/wiki/Digital_clock" title="Digital clock">Digital clock</a></li> <li><a href="/wiki/Grandfather_clock" title="Grandfather clock">Grandfather clock</a></li> <li><i><a href="/wiki/History_of_timekeeping_devices" title="History of timekeeping devices">History</a></i> <ul><li><i><a href="/wiki/Timeline_of_time_measurement_inventions" title="Timeline of time measurement inventions">Timeline</a></i></li></ul></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><div class="hlist"><ul><li><a href="/wiki/Chronology" title="Chronology">Chronology</a></li><li><a href="/wiki/History" title="History">History</a></li></ul></div></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Astronomical_chronology" title="Astronomical chronology">Astronomical chronology</a></li> <li><a href="/wiki/Big_History" title="Big History">Big History</a></li> <li><a href="/wiki/Calendar_era" title="Calendar era">Calendar era</a></li> <li><a href="/wiki/Deep_time" title="Deep time">Deep time</a></li> <li><a href="/wiki/Periodization" title="Periodization">Periodization</a></li> <li><a href="/wiki/Regnal_year" title="Regnal year">Regnal year</a></li> <li><a href="/wiki/Timeline" title="Timeline">Timeline</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Philosophy_of_space_and_time" title="Philosophy of space and time">Philosophy of time</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/A_series_and_B_series" title="A series and B series">A series and B series</a></li> <li><a href="/wiki/B-theory_of_time" title="B-theory of time">B-theory of time</a></li> <li><a href="/wiki/Chronocentrism" title="Chronocentrism">Chronocentrism</a></li> <li><a href="/wiki/Duration_(philosophy)" title="Duration (philosophy)">Duration</a></li> <li><a href="/wiki/Endurantism" title="Endurantism">Endurantism</a></li> <li><a href="/wiki/Eternal_return" title="Eternal return">Eternal return</a></li> <li><a href="/wiki/Eternalism_(philosophy_of_time)" title="Eternalism (philosophy of time)">Eternalism</a></li> <li><a href="/wiki/Event_(philosophy)" title="Event (philosophy)">Event</a></li> <li><a href="/wiki/Perdurantism" title="Perdurantism">Perdurantism</a></li> <li><a href="/wiki/Philosophical_presentism" title="Philosophical presentism">Presentism</a></li> <li><a href="/wiki/Temporal_finitism" title="Temporal finitism">Temporal finitism</a></li> <li><a href="/wiki/Temporal_parts" title="Temporal parts">Temporal parts</a></li> <li><i><a href="/wiki/The_Unreality_of_Time" title="The Unreality of Time">The Unreality of Time</a></i></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><div class="hlist"><ul><li><a href="/wiki/Category:Time_in_religion" title="Category:Time in religion">Religion</a></li><li><a href="/wiki/Template:Time_in_religion_and_mythology" title="Template:Time in religion and mythology">Mythology</a></li></ul></div></th><td class="navbox-list-with-group navbox-list navbox-even" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Ages_of_Man" title="Ages of Man">Ages of Man</a></li> <li><a href="/wiki/Destiny" title="Destiny">Destiny</a></li> <li><a href="/wiki/Immortality" title="Immortality">Immortality</a></li> <li><a href="/wiki/The_Dreaming" title="The Dreaming">Dreamtime</a></li> <li><a href="/wiki/K%C4%81la" title="Kāla">Kāla</a></li> <li><a href="/wiki/Time_and_fate_deities" title="Time and fate deities">Time and fate deities</a> <ul><li><a href="/wiki/Father_Time" title="Father Time">Father Time</a></li></ul></li> <li><a href="/wiki/Wheel_of_time" title="Wheel of time">Wheel of time</a> <ul><li><a href="/wiki/Kalachakra" title="Kalachakra">Kalachakra</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Time_perception" title="Time perception">Human experience</a><br />and <a href="/wiki/Time-use_research" title="Time-use research">use of time</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Chronemics" title="Chronemics">Chronemics</a></li> <li><a href="/wiki/Generation_time" title="Generation time">Generation time</a></li> <li><a href="/wiki/Mental_chronometry" title="Mental chronometry">Mental chronometry</a></li> <li><a href="/wiki/Duration_(music)" title="Duration (music)">Music</a> <ul><li><a href="/wiki/Tempo" title="Tempo">tempo</a></li> <li><a href="/wiki/Time_signature" title="Time signature">time signature</a></li></ul></li> <li><a href="/wiki/Rosy_retrospection" title="Rosy retrospection">Rosy retrospection</a></li> <li><a href="/wiki/Tense%E2%80%93aspect%E2%80%93mood" title="Tense–aspect–mood">Tense–aspect–mood</a></li> <li><a href="/wiki/Time_management" title="Time management">Time management</a></li> <li><a href="/wiki/Yesterday_(time)" title="Yesterday (time)">Yesterday</a> – <a href="/wiki/Present" title="Present">Today</a> – <a href="/wiki/Tomorrow_(time)" title="Tomorrow (time)">Tomorrow</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Time in <a href="/wiki/Science" title="Science">science</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:6.5em;font-weight:normal; text-align:center;"><a href="/wiki/Geology" title="Geology">Geology</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Geologic_time_scale" title="Geologic time scale">Geological time</a> <ul><li><a href="/wiki/Age_(geology)" class="mw-redirect" title="Age (geology)">age</a></li> <li><a href="/wiki/Chronozone" title="Chronozone">chron</a></li> <li><a href="/wiki/Eon_(geology)" class="mw-redirect" title="Eon (geology)">eon</a></li> <li><a href="/wiki/Epoch_(geology)" class="mw-redirect" title="Epoch (geology)">epoch</a></li> <li><a href="/wiki/Era_(geology)" class="mw-redirect" title="Era (geology)">era</a></li> <li><a href="/wiki/Geological_period" class="mw-redirect" title="Geological period">period</a></li></ul></li> <li><a class="mw-selflink selflink">Geochronology</a></li> <li><a href="/wiki/Geological_history_of_Earth" title="Geological history of Earth">Geological history of Earth</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:6.5em;font-weight:normal; text-align:center;"><a href="/wiki/Time_in_physics" title="Time in physics">Physics</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Absolute_space_and_time" title="Absolute space and time">Absolute space and time</a></li> <li><a href="/wiki/Arrow_of_time" title="Arrow of time">Arrow of time</a></li> <li><a href="/wiki/Chronon" title="Chronon">Chronon</a></li> <li><a href="/wiki/Coordinate_time" title="Coordinate time">Coordinate time</a></li> <li><a href="/wiki/Instant" title="Instant">Instant</a></li> <li><a href="/wiki/Proper_time" title="Proper time">Proper time</a></li> <li><a href="/wiki/Spacetime" title="Spacetime">Spacetime</a></li> <li><a href="/wiki/Theory_of_relativity" title="Theory of relativity">Theory of relativity</a></li> <li><a href="/wiki/Time_domain" title="Time domain">Time domain</a></li> <li><a href="/wiki/Time_translation_symmetry" class="mw-redirect" title="Time translation symmetry">Time translation symmetry</a></li> <li><a href="/wiki/T-symmetry" title="T-symmetry">Time reversal symmetry</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:6.5em;font-weight:normal; text-align:center;">Other fields</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Chronological_dating" title="Chronological dating">Chronological dating</a></li> <li><a href="/wiki/Chronobiology" title="Chronobiology">Chronobiology</a> <ul><li><a href="/wiki/Circadian_rhythm" title="Circadian rhythm">Circadian rhythms</a></li></ul></li> <li><a href="/wiki/Chemical_clock" title="Chemical clock">Clock reaction</a></li> <li><a href="/wiki/Glottochronology" title="Glottochronology">Glottochronology</a></li> <li><a href="/wiki/Time_geography" title="Time geography">Time geography</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%">Related</th><td class="navbox-list-with-group navbox-list navbox-odd" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Leap_year" title="Leap year">Leap year</a></li> <li><a href="/wiki/Memory" title="Memory">Memory</a></li> <li><a href="/wiki/Moment_(unit)" title="Moment (unit)">Moment</a></li> <li><a href="/wiki/Space" title="Space">Space</a></li> <li><a href="/wiki/System_time" title="System time">System time</a></li> <li><i><a href="/wiki/Tempus_fugit" title="Tempus fugit">Tempus fugit</a></i></li> <li><a href="/wiki/Time_capsule" title="Time capsule">Time capsule</a></li> <li><a href="/wiki/Time_immemorial" title="Time immemorial">Time immemorial</a></li> <li><a href="/wiki/Time_travel" title="Time travel">Time travel</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" colspan="2"><div> <ul><li><span class="noviewer" typeof="mw:File"><span title="Category"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/16px-Symbol_category_class.svg.png" decoding="async" width="16" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/23px-Symbol_category_class.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/9/96/Symbol_category_class.svg/31px-Symbol_category_class.svg.png 2x" data-file-width="180" data-file-height="185" /></span></span> <a href="/wiki/Category:Time" title="Category:Time">Category</a></li> <li><span class="noviewer" typeof="mw:File"><span title="Commons page"><img alt="" src="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/12px-Commons-logo.svg.png" decoding="async" width="12" height="16" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/18px-Commons-logo.svg.png 1.5x, //upload.wikimedia.org/wikipedia/en/thumb/4/4a/Commons-logo.svg/24px-Commons-logo.svg.png 2x" data-file-width="1024" data-file-height="1376" /></span></span> <a href="https://commons.wikimedia.org/wiki/Category:Time" class="extiw" title="commons:Category:Time">Commons</a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"></div><div role="navigation" class="navbox" aria-labelledby="Chronology" style="padding:3px"><table class="nowraplinks mw-collapsible mw-collapsed navbox-inner" style="border-spacing:0;background:transparent;color:inherit"><tbody><tr><th scope="col" class="navbox-title" colspan="2"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1239400231"><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Chronology" title="Template:Chronology"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Chronology" title="Template talk:Chronology"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Chronology" title="Special:EditPage/Template:Chronology"><abbr title="Edit this template">e</abbr></a></li></ul></div><div id="Chronology" style="font-size:114%;margin:0 4em"><a href="/wiki/Chronology" title="Chronology">Chronology</a></div></th></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;">Key topics</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Archaeology" title="Archaeology">Archaeology</a></li> <li><a href="/wiki/Astronomy" title="Astronomy">Astronomy</a></li> <li><a href="/wiki/Geology" title="Geology">Geology</a></li> <li><a href="/wiki/History" title="History">History</a> <ul><li><a href="/wiki/Big_History" title="Big History">Big History</a></li></ul></li> <li><a href="/wiki/Paleontology" title="Paleontology">Paleontology</a></li> <li><a href="/wiki/Time" title="Time">Time</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;"><div class="hlist"><ul><li><a href="/wiki/Periodization" title="Periodization">Periods</a></li><li><a href="/wiki/Era" title="Era">Eras</a></li><li><a href="/wiki/Epoch_(reference_date)" class="mw-redirect" title="Epoch (reference date)">Epochs</a></li></ul></div></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;"><a href="/wiki/Calendar_era" title="Calendar era">Calendar eras</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Holocene_calendar" title="Holocene calendar">Human Era</a></li> <li><i><a href="/wiki/Ab_urbe_condita" title="Ab urbe condita">Ab urbe condita</a></i></li> <li><a href="/wiki/Anno_Domini" title="Anno Domini">Anno Domini</a> / <a href="/wiki/Common_Era" title="Common Era">Common Era</a></li> <li><a href="/wiki/Anno_Mundi" title="Anno Mundi">Anno Mundi</a></li> <li><a href="/wiki/Bosporan_era" title="Bosporan era">Bosporan era</a></li> <li><a href="/wiki/Bostran_era" title="Bostran era">Bostran era</a></li> <li><a href="/wiki/Byzantine_calendar" title="Byzantine calendar">Byzantine era</a></li> <li><a href="/wiki/Seleucid_era" title="Seleucid era">Seleucid era</a></li> <li><a href="/wiki/Era_of_Caesar_(Iberian_Peninsula)" class="mw-redirect" title="Era of Caesar (Iberian Peninsula)">Era of Caesar (Iberia)</a></li> <li><a href="/wiki/Before_present" class="mw-redirect" title="Before present">Before present</a></li> <li><a href="/wiki/Islamic_calendar" title="Islamic calendar">Hijri</a></li> <li><a href="/wiki/Egyptian_chronology" title="Egyptian chronology">Egyptian</a></li> <li><a href="/wiki/Sothic_cycle" title="Sothic cycle">Sothic cycle</a></li> <li><a href="/wiki/Hindu_units_of_time" title="Hindu units of time">Hindu units of time</a> (<a href="/wiki/Yuga" title="Yuga">Yuga</a>)</li> <li><a href="/wiki/Mesoamerican_calendars" title="Mesoamerican calendars">Mesoamerican</a> <ul><li><a href="/wiki/Mesoamerican_Long_Count_calendar" title="Mesoamerican Long Count calendar">Long Count</a></li> <li><a href="/wiki/Maya_calendar#Short_Count" title="Maya calendar">Short Count</a></li> <li><a href="/wiki/Tzolk%27in" class="mw-redirect" title="Tzolk'in">Tzolk'in</a></li> <li><a href="/wiki/Haab%27" class="mw-redirect" title="Haab'">Haab'</a></li></ul></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;"><a href="/wiki/Regnal_year" title="Regnal year">Regnal year</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Anka_year" title="Anka year">Anka year</a></li> <li><a href="/wiki/Canon_of_Kings" title="Canon of Kings">Canon of Kings</a></li> <li><a href="/wiki/Regnal_years_of_English_and_British_monarchs" title="Regnal years of English and British monarchs">English and British regnal year</a></li> <li><a href="/wiki/Category:Regnal_lists" title="Category:Regnal lists">Lists of kings</a></li> <li><a href="/wiki/Limmu" title="Limmu">Limmu</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;"><a href="/wiki/Regnal_year" title="Regnal year">Era names</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Chinese_era_name" title="Chinese era name">Chinese</a></li> <li><a href="/wiki/Japanese_era_name" title="Japanese era name">Japanese</a></li> <li><a href="/wiki/Korean_era_name" title="Korean era name">Korean</a></li> <li><a href="/wiki/Vietnamese_era_name" title="Vietnamese era name">Vietnamese</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;"><a href="/wiki/Calendar" title="Calendar">Calendars</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Pre-Julian / Julian</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Roman_calendar" title="Roman calendar">Pre-Julian Roman</a></li> <li><a href="/wiki/Julian_calendar" title="Julian calendar">Original Julian</a></li> <li><a href="/wiki/Proleptic_Julian_calendar" title="Proleptic Julian calendar">Proleptic Julian</a></li> <li><a href="/wiki/Revised_Julian_calendar" title="Revised Julian calendar">Revised Julian</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Gregorian</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Gregorian_calendar" title="Gregorian calendar">Gregorian</a></li> <li><a href="/wiki/Proleptic_Gregorian_calendar" title="Proleptic Gregorian calendar">Proleptic Gregorian</a></li> <li><a href="/wiki/Old_Style_and_New_Style_dates" title="Old Style and New Style dates">Old Style and New Style dates</a></li> <li><a href="/wiki/Adoption_of_the_Gregorian_calendar" title="Adoption of the Gregorian calendar">Adoption of the Gregorian calendar</a></li> <li><a href="/wiki/Dual_dating" title="Dual dating">Dual dating</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Astronomical</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Lunisolar_calendar" title="Lunisolar calendar">Lunisolar</a> (<a href="/wiki/Hebrew_calendar" title="Hebrew calendar">Hebrew</a>, <a href="/wiki/Hindu_calendar" title="Hindu calendar">Hindu</a>)</li> <li><a href="/wiki/Solar_calendar" title="Solar calendar">Solar</a></li> <li><a href="/wiki/Lunar_calendar" title="Lunar calendar">Lunar</a> (<a href="/wiki/Islamic_calendar" title="Islamic calendar">Islamic</a>)</li> <li><a href="/wiki/Astronomical_year_numbering" title="Astronomical year numbering">Astronomical year numbering</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Others</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Sexagenary_cycle" title="Sexagenary cycle">Chinese sexagenary cycle</a></li> <li><a href="/wiki/Geologic_Calendar" title="Geologic Calendar">Geologic Calendar</a></li> <li><a href="/wiki/Iranian_calendars" title="Iranian calendars">Iranian</a></li> <li><a href="/wiki/ISO_week_date" title="ISO week date">ISO week date</a></li> <li><a href="/wiki/Mesoamerican_calendars" title="Mesoamerican calendars">Mesoamerican</a> <ul><li><a href="/wiki/Maya_calendar" title="Maya calendar">Maya</a></li> <li><a href="/wiki/Aztec_calendar" title="Aztec calendar">Aztec</a></li></ul></li> <li><a href="/wiki/Winter_count" title="Winter count">Winter count</a></li> <li><a href="/wiki/New_Earth_Time" title="New Earth Time">New Earth Time</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;"><a href="/wiki/Astronomical_chronology" title="Astronomical chronology">Astronomic time</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0;background:#fff;"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Cosmic_Calendar" title="Cosmic Calendar">Cosmic Calendar</a></li> <li><a href="/wiki/Ephemeris" title="Ephemeris">Ephemeris</a></li> <li><a href="/wiki/Galactic_year" title="Galactic year">Galactic year</a></li> <li><a href="/wiki/Metonic_cycle" title="Metonic cycle">Metonic cycle</a></li> <li><a href="/wiki/Milankovitch_cycles" title="Milankovitch cycles">Milankovitch cycles</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;"><a href="/wiki/Geologic_time_scale" title="Geologic time scale">Geologic time</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Concepts</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Deep_time" title="Deep time">Deep time</a></li> <li><a href="/wiki/Geological_history_of_Earth" title="Geological history of Earth">Geological history of Earth</a></li> <li><a href="/wiki/Geologic_time_scale#Terminology" title="Geologic time scale">Geological time units</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Standards</th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Global_Standard_Stratigraphic_Age" title="Global Standard Stratigraphic Age">Global Standard Stratigraphic Age (GSSA)</a></li> <li><a href="/wiki/Global_Boundary_Stratotype_Section_and_Point" title="Global Boundary Stratotype Section and Point">Global Boundary Stratotype Section and Point (GSSP)</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;">Methods</th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Chronostratigraphy" title="Chronostratigraphy">Chronostratigraphy</a></li> <li><a class="mw-selflink selflink">Geochronology</a></li> <li><a href="/wiki/Isotope_geochemistry" title="Isotope geochemistry">Isotope geochemistry</a></li> <li><a href="/wiki/Law_of_superposition" title="Law of superposition">Law of superposition</a></li> <li><a href="/wiki/Luminescence_dating" title="Luminescence dating">Luminescence dating</a></li> <li><a href="/wiki/Samarium%E2%80%93neodymium_dating" title="Samarium–neodymium dating">Samarium–neodymium dating</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;"><a href="/wiki/Chronological_dating" title="Chronological dating">Chronological<br />dating</a></th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"></div><table class="nowraplinks navbox-subgroup" style="border-spacing:0"><tbody><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;"><a href="/wiki/Absolute_dating" title="Absolute dating">Absolute dating</a></th><td class="navbox-list-with-group navbox-list navbox-odd" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Amino_acid_dating" title="Amino acid dating">Amino acid racemisation</a></li> <li><a href="/wiki/Archaeomagnetic_dating" title="Archaeomagnetic dating">Archaeomagnetic dating</a></li> <li><a href="/wiki/Dendrochronology" title="Dendrochronology">Dendrochronology</a></li> <li><a href="/wiki/Ice_core" title="Ice core">Ice core</a></li> <li><a href="/wiki/Incremental_dating" title="Incremental dating">Incremental dating</a></li> <li><a href="/wiki/Lichenometry" title="Lichenometry">Lichenometry</a></li> <li><a href="/wiki/Paleomagnetism" title="Paleomagnetism">Paleomagnetism</a></li> <li><a href="/wiki/Radiometric_dating" title="Radiometric dating">Radiometric dating</a> <ul><li><a href="/wiki/Lead%E2%80%93lead_dating" title="Lead–lead dating">Lead–lead</a></li> <li><a href="/wiki/K%E2%80%93Ar_dating" title="K–Ar dating">Potassium–argon</a></li> <li><a href="/wiki/Radiocarbon_dating" title="Radiocarbon dating">Radiocarbon</a></li> <li><a href="/wiki/Uranium%E2%80%93lead_dating" title="Uranium–lead dating">Uranium–lead</a></li></ul></li> <li><a href="/wiki/Tephrochronology" title="Tephrochronology">Tephrochronology</a></li> <li><a href="/wiki/Luminescence_dating" title="Luminescence dating">Luminescence dating</a></li> <li><a href="/wiki/Thermoluminescence_dating" title="Thermoluminescence dating">Thermoluminescence dating</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:8.0em;font-weight:normal;background:#cc9;"><a href="/wiki/Relative_dating" title="Relative dating">Relative dating</a></th><td class="navbox-list-with-group navbox-list navbox-even" style="padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Fluorine_absorption_dating" title="Fluorine absorption dating">Fluorine absorption</a></li> <li><a href="/wiki/Nitrogen_dating" title="Nitrogen dating">Nitrogen dating</a></li> <li><a href="/wiki/Obsidian_hydration_dating" title="Obsidian hydration dating">Obsidian hydration</a></li> <li><a href="/wiki/Seriation_(archaeology)" title="Seriation (archaeology)">Seriation</a></li> <li><a href="/wiki/Stratigraphy_(archaeology)" title="Stratigraphy (archaeology)">Stratigraphy</a></li></ul> </div></td></tr></tbody></table><div></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;">Genetic methods</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Molecular_clock" title="Molecular clock">Molecular clock</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;">Linguistic methods</th><td class="navbox-list-with-group navbox-list navbox-even hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Glottochronology" title="Glottochronology">Glottochronology</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%;line-height:1.2em;background:#cc9;">Related topics</th><td class="navbox-list-with-group navbox-list navbox-odd hlist" style="width:100%;padding:0"><div style="padding:0 0.25em"> <ul><li><a href="/wiki/Chronicle" title="Chronicle">Chronicle</a></li> <li><a href="/wiki/New_Chronology_(Fomenko)" class="mw-redirect" title="New Chronology (Fomenko)">New Chronology</a></li> <li><a href="/wiki/Synchronoptic_view" title="Synchronoptic view">Synchronoptic view</a></li> <li><a href="/wiki/Timeline" title="Timeline">Timeline</a></li> <li><a href="/wiki/Year_zero" title="Year zero">Year zero</a></li> <li><a href="/wiki/Floruit" title="Floruit">Floruit</a></li> <li><a href="/wiki/Terminus_post_quem" title="Terminus post quem">Terminus post quem</a></li> <li><a href="/wiki/ASPRO_chronology" title="ASPRO chronology">ASPRO chronology</a></li></ul> </div></td></tr></tbody></table></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1236075235"><style 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