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class="interlanguage-link-target"><span>العربية</span></a></li><li class="interlanguage-link interwiki-ca mw-list-item"><a href="https://ca.wikipedia.org/wiki/Principi_de_l%27horitzontalitat_original" title="Principi de l'horitzontalitat original – Catalan" lang="ca" hreflang="ca" data-title="Principi de l'horitzontalitat original" data-language-autonym="Català" data-language-local-name="Catalan" class="interlanguage-link-target"><span>Català</span></a></li><li class="interlanguage-link interwiki-es mw-list-item"><a href="https://es.wikipedia.org/wiki/Horizontalidad_original" title="Horizontalidad original – Spanish" lang="es" hreflang="es" data-title="Horizontalidad original" data-language-autonym="Español" data-language-local-name="Spanish" class="interlanguage-link-target"><span>Español</span></a></li><li class="interlanguage-link interwiki-eu mw-list-item"><a href="https://eu.wikipedia.org/wiki/Hasierako_horizontaltasun_printzipioa" title="Hasierako horizontaltasun printzipioa – Basque" lang="eu" hreflang="eu" data-title="Hasierako horizontaltasun printzipioa" data-language-autonym="Euskara" data-language-local-name="Basque" class="interlanguage-link-target"><span>Euskara</span></a></li><li class="interlanguage-link interwiki-fa mw-list-item"><a href="https://fa.wikipedia.org/wiki/%D8%A7%D8%B5%D9%84_%D8%AE%D8%A7%D8%B3%D8%AA%DA%AF%D8%A7%D9%87_%D8%A7%D9%81%D9%82%DB%8C" title="اصل خاستگاه افقی – Persian" lang="fa" hreflang="fa" data-title="اصل خاستگاه افقی" data-language-autonym="فارسی" data-language-local-name="Persian" class="interlanguage-link-target"><span>فارسی</span></a></li><li class="interlanguage-link interwiki-id mw-list-item"><a href="https://id.wikipedia.org/wiki/Prinsip_horizontalitas_asli" title="Prinsip horizontalitas asli – Indonesian" lang="id" hreflang="id" data-title="Prinsip horizontalitas asli" 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-it mw-list-item"><a href="https://it.wikipedia.org/wiki/Principio_dell%27orizzontalit%C3%A0_originaria" title="Principio dell'orizzontalità originaria – Italian" lang="it" hreflang="it" data-title="Principio dell'orizzontalità originaria" data-language-autonym="Italiano" data-language-local-name="Italian" class="interlanguage-link-target"><span>Italiano</span></a></li><li class="interlanguage-link interwiki-he mw-list-item"><a href="https://he.wikipedia.org/wiki/%D7%A2%D7%A7%D7%A8%D7%95%D7%9F_%D7%94%D7%90%D7%95%D7%A4%D7%A7%D7%99%D7%95%D7%AA_%D7%94%D7%9E%D7%A7%D7%95%D7%A8%D7%99%D7%AA" title="עקרון האופקיות המקורית – Hebrew" lang="he" hreflang="he" data-title="עקרון האופקיות המקורית" data-language-autonym="עברית" data-language-local-name="Hebrew" class="interlanguage-link-target"><span>עברית</span></a></li><li class="interlanguage-link interwiki-nl mw-list-item"><a href="https://nl.wikipedia.org/wiki/Principe_van_oorspronkelijke_horizontaliteit" title="Principe van oorspronkelijke horizontaliteit – Dutch" lang="nl" hreflang="nl" data-title="Principe van oorspronkelijke horizontaliteit" data-language-autonym="Nederlands" data-language-local-name="Dutch" class="interlanguage-link-target"><span>Nederlands</span></a></li><li class="interlanguage-link interwiki-tr mw-list-item"><a href="https://tr.wikipedia.org/wiki/Orijinal_yatayl%C4%B1k_prensibi" title="Orijinal yataylık prensibi – Turkish" lang="tr" hreflang="tr" data-title="Orijinal yataylık prensibi" data-language-autonym="Türkçe" data-language-local-name="Turkish" class="interlanguage-link-target"><span>Türkçe</span></a></li><li class="interlanguage-link interwiki-zh mw-list-item"><a href="https://zh.wikipedia.org/wiki/%E5%8E%9F%E5%88%9D%E6%B0%B4%E5%B9%B3%E5%BE%8B" title="原初水平律 – Chinese" lang="zh" hreflang="zh" data-title="原初水平律" data-language-autonym="中文" data-language-local-name="Chinese" 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<div class="vector-body-before-content"> <div class="mw-indicators"> </div> <div id="siteSub" class="noprint">From Wikipedia, the free encyclopedia</div> </div> <div id="contentSub"><div id="mw-content-subtitle"></div></div> <div id="mw-content-text" class="mw-body-content"><div class="mw-content-ltr mw-parser-output" lang="en" dir="ltr"><div class="shortdescription nomobile noexcerpt noprint searchaux" style="display:none">Layers of sediment are deposited approximately horizontally under the action of gravity</div> <style data-mw-deduplicate="TemplateStyles:r1129693374">.mw-parser-output .hlist dl,.mw-parser-output .hlist ol,.mw-parser-output .hlist ul{margin:0;padding:0}.mw-parser-output .hlist dd,.mw-parser-output .hlist dt,.mw-parser-output .hlist li{margin:0;display:inline}.mw-parser-output .hlist.inline,.mw-parser-output .hlist.inline dl,.mw-parser-output .hlist.inline ol,.mw-parser-output .hlist.inline ul,.mw-parser-output .hlist dl dl,.mw-parser-output .hlist dl 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class="sidebar sidebar-collapse nomobile nowraplinks plainlist" style="border:2px solid #BFB4A2;"><tbody><tr><td class="sidebar-pretitle">Part of <a href="/wiki/Category:Geology" title="Category:Geology">a series</a> on</td></tr><tr><th class="sidebar-title-with-pretitle" style="background:#D8B982;font-size:175%;padding:0.2em;font-weight:normal;"><b><a href="/wiki/Geology" title="Geology">Geology</a></b></th></tr><tr><td class="sidebar-image"><span typeof="mw:File"><a href="/wiki/File:WikiProject_Geology.svg" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/e/e7/WikiProject_Geology.svg/100px-WikiProject_Geology.svg.png" decoding="async" width="100" height="100" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/e/e7/WikiProject_Geology.svg/150px-WikiProject_Geology.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/e/e7/WikiProject_Geology.svg/200px-WikiProject_Geology.svg.png 2x" data-file-width="327" data-file-height="328" /></a></span><div class="sidebar-caption"><b>Science of the solid Earth</b></div></td></tr><tr><td class="sidebar-above" style="display:block; margin-bottom:0.55em; background-color: #FFFBF4;"> <div class="hlist"> <ul><li><a href="/wiki/Index_of_geology_articles" title="Index of geology articles">Index</a></li> <li><a href="/wiki/Outline_of_geology" title="Outline of geology">Outline</a></li> <li><a href="/wiki/Category:Geology" title="Category:Geology">Category</a></li> <li><a href="/wiki/Glossary_of_geology" title="Glossary of geology">Glossary</a></li> <li><a href="/wiki/History_of_geology" title="History of geology">History</a> (<a href="/wiki/Timeline_of_geology" title="Timeline of geology">Timeline</a>)</li></ul> </div></td></tr><tr><td class="sidebar-content" style="background:#FFFBF4;"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="text-align:center;background:#D8B982;font-size:100%;;color: var(--color-base)">Key components</div><div class="sidebar-list-content mw-collapsible-content"><div class="hlist"> <ul><li><a href="/wiki/Mineral" title="Mineral">Minerals</a></li> <li><a href="/wiki/Rock_(geology)" title="Rock (geology)">Rock</a> (<a href="/wiki/Igneous_rock" title="Igneous rock">Igneous</a></li> <li><a href="/wiki/Sedimentary_rock" title="Sedimentary rock">Sedimentary</a></li> <li><a href="/wiki/Metamorphic_rock" title="Metamorphic rock">Metamorphic</a>)</li> <li><a href="/wiki/Sediment" title="Sediment">Sediment</a></li></ul> </div><div class="hlist"> <ul><li><a href="/wiki/Plate_tectonics" title="Plate tectonics">Plate tectonics</a></li> <li><a href="/wiki/Strata" class="mw-redirect" title="Strata">Strata</a></li> <li><a href="/wiki/Weathering" title="Weathering">Weathering</a></li> <li><a href="/wiki/Erosion" title="Erosion">Erosion</a></li> <li><a href="/wiki/Geologic_time_scale" title="Geologic time scale">Geologic time scale</a></li></ul> </div></div></div></td> </tr><tr><td class="sidebar-content" style="background:#FFFBF4;"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="text-align:center;background:#D8B982;font-size:100%;;color: var(--color-base)">Laws, principles, theories</div><div class="sidebar-list-content mw-collapsible-content"><hr /> <ul><li><b><a href="/wiki/Stratigraphy" title="Stratigraphy">Stratigraphic principles</a></b></li></ul> <hr /> <div class="hlist"> <ul><li><a class="mw-selflink selflink">Principle of original horizontality</a></li> <li><a href="/wiki/Law_of_superposition" title="Law of superposition">Law of superposition</a></li> <li><a href="/wiki/Principle_of_lateral_continuity" title="Principle of lateral continuity">Principle of lateral continuity</a></li> <li><a href="/wiki/Principle_of_cross-cutting_relationships" class="mw-redirect" title="Principle of cross-cutting relationships">Principle of cross-cutting relationships</a></li> <li><a href="/wiki/Principle_of_faunal_succession" title="Principle of faunal succession">Principle of faunal succession</a></li> <li><a href="/wiki/Law_of_included_fragments" title="Law of included fragments">Principle of inclusions and components</a></li> <li><a href="/wiki/Walther%27s_law" class="mw-redirect" title="Walther's law">Walther's law</a></li></ul> </div></div></div></td> </tr><tr><td class="sidebar-content" style="background:#FFFBF4;"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="text-align:center;background:#D8B982;font-size:100%;;color: var(--color-base)">Topics</div><div class="sidebar-list-content mw-collapsible-content" style="padding-bottom:0.2em;"><hr /> <ul><li><b>Composition</b></li></ul> <hr /> <div class="hlist"> <ul><li><a href="/wiki/Geochemistry" title="Geochemistry">Geochemistry</a></li> <li><a href="/wiki/Mineralogy" title="Mineralogy">Mineralogy</a></li> <li><a href="/wiki/Sedimentology" title="Sedimentology">Sedimentology</a></li> <li><a href="/wiki/Petrology" title="Petrology">Petrology</a></li> <li><a href="/wiki/Structure_of_Earth" class="mw-redirect" title="Structure of Earth">Structure of Earth</a></li></ul> </div> <hr /> <ul><li><b>Landform structures</b></li></ul> <hr /> <div class="hlist"> <ul><li><a href="/wiki/Geomorphology" title="Geomorphology">Geomorphology</a></li> <li><a href="/wiki/Glaciology" title="Glaciology">Glaciology</a></li> <li><a href="/wiki/Structural_Geology" class="mw-redirect" title="Structural Geology">Structural Geology</a></li> <li><a href="/wiki/Volcanology" title="Volcanology">Volcanology</a></li></ul> </div> <hr /> <ul><li><b>Geologic history</b></li></ul> <hr /> <div class="hlist"> <ul><li><a href="/wiki/Geological_history_of_Earth" title="Geological history of Earth">Geological history of Earth</a></li></ul> </div></div></div></td> </tr><tr><td class="sidebar-content" style="background:#FFFBF4;"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="text-align:center;background:#D8B982;font-size:100%;;color: var(--color-base)">Research</div><div class="sidebar-list-content mw-collapsible-content" style="border-top:1px solid #90db90;padding-top:0.15em;"> <ul><li><a href="/wiki/Outline_of_geology#Branches_of_geology" title="Outline of geology">Branches of geology</a></li> <li><a href="/wiki/Geologist" title="Geologist">Geologist</a> (<a href="/wiki/List_of_geologists" title="List of geologists">List)</a></li></ul> <hr /> <ul><li><b>Methods</b></li> <li><a href="/wiki/Geological_survey" title="Geological survey">Geological survey</a></li></ul></div></div></td> </tr><tr><td class="sidebar-content" style="background:#FFFBF4;"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="text-align:center;background:#D8B982;font-size:100%;;color: var(--color-base)">Applications</div><div class="sidebar-list-content mw-collapsible-content"><div class="hlist"> <ul><li><a href="/wiki/Engineering_geology" title="Engineering geology">Engineering</a></li> <li><a href="/wiki/Mining_geology" title="Mining geology">Mining</a></li> <li><a href="/wiki/Forensic_geology" title="Forensic geology">Forensics</a></li> <li><a href="/wiki/Military_geology" title="Military geology">Military</a></li></ul> </div></div></div></td> </tr><tr><td class="sidebar-content" style="background:#FFFBF4;"> <div class="sidebar-list mw-collapsible mw-collapsed"><div class="sidebar-list-title" style="text-align:center;background:#D8B982;font-size:100%;;color: var(--color-base)"><a href="/wiki/Planetary_geology" title="Planetary geology">Planetary geology</a></div><div class="sidebar-list-content mw-collapsible-content"> <ul><li><a href="/wiki/Lists_of_geological_features_of_the_Solar_System" title="Lists of geological features of the Solar System">Lists of geological features of the Solar System</a></li> <li><a href="/wiki/Geology_of_solar_terrestrial_planets" title="Geology of solar terrestrial planets">Geology of solar terrestrial planets</a></li></ul> <hr /> <ul><li><b>By planet and body</b></li></ul> <hr /> <div class="hlist"> <ul><li><a href="/wiki/Geology_of_Mercury" title="Geology of Mercury">Mercury</a></li> <li><a href="/wiki/Geology_of_Venus" title="Geology of Venus">Venus</a></li> <li><a href="/wiki/Geology_of_the_Moon" title="Geology of the Moon">Moon</a></li> <li><a href="/wiki/Geology_of_Mars" title="Geology of Mars">Mars</a></li> <li><a href="/wiki/4_Vesta#Geology" title="4 Vesta"> Vesta</a></li> <li><a href="/wiki/Geology_of_Ceres" title="Geology of Ceres">Ceres</a></li> <li><a href="/wiki/Io_(moon)#Structure" title="Io (moon)">Io</a></li> <li><a href="/wiki/Titan_(moon)#Surface_features" title="Titan (moon)">Titan</a></li> <li><a href="/wiki/Geology_of_Triton" title="Geology of Triton">Triton</a></li> <li><a href="/wiki/Geology_of_Pluto" title="Geology of Pluto">Pluto</a></li> <li><a href="/wiki/Geology_of_Charon" title="Geology of Charon">Charon</a></li></ul> </div></div></div></td> </tr><tr><td class="sidebar-below" style="padding:0.25em 0.25em 0.25em; display:block; margin-bottom:0.55em; background-color: #FFFBF4;"> <ul><li><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></li></ul></td></tr><tr><td class="sidebar-navbar"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1239400231">.mw-parser-output .navbar{display:inline;font-size:88%;font-weight:normal}.mw-parser-output .navbar-collapse{float:left;text-align:left}.mw-parser-output .navbar-boxtext{word-spacing:0}.mw-parser-output .navbar ul{display:inline-block;white-space:nowrap;line-height:inherit}.mw-parser-output .navbar-brackets::before{margin-right:-0.125em;content:"[ "}.mw-parser-output .navbar-brackets::after{margin-left:-0.125em;content:" ]"}.mw-parser-output .navbar li{word-spacing:-0.125em}.mw-parser-output .navbar a>span,.mw-parser-output .navbar a>abbr{text-decoration:inherit}.mw-parser-output .navbar-mini abbr{font-variant:small-caps;border-bottom:none;text-decoration:none;cursor:inherit}.mw-parser-output .navbar-ct-full{font-size:114%;margin:0 7em}.mw-parser-output .navbar-ct-mini{font-size:114%;margin:0 4em}html.skin-theme-clientpref-night .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}@media(prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .navbar li a abbr{color:var(--color-base)!important}}@media print{.mw-parser-output .navbar{display:none!important}}</style><div class="navbar plainlinks hlist navbar-mini"><ul><li class="nv-view"><a href="/wiki/Template:Geology_sidebar" title="Template:Geology sidebar"><abbr title="View this template">v</abbr></a></li><li class="nv-talk"><a href="/wiki/Template_talk:Geology_sidebar" title="Template talk:Geology sidebar"><abbr title="Discuss this template">t</abbr></a></li><li class="nv-edit"><a href="/wiki/Special:EditPage/Template:Geology_sidebar" title="Special:EditPage/Template:Geology sidebar"><abbr title="Edit this template">e</abbr></a></li></ul></div></td></tr></tbody></table><p> The <b>principle of original horizontality</b> states that layers of <a href="/wiki/Sediment" title="Sediment">sediment</a> are originally deposited horizontally under the action of <a href="/wiki/Gravity" title="Gravity">gravity</a>.<sup id="cite_ref-Levin_1-0" class="reference"><a href="#cite_note-Levin-1"><span class="cite-bracket">[</span>1<span class="cite-bracket">]</span></a></sup> It is a <a href="/wiki/Relative_dating" title="Relative dating">relative dating</a> technique. The principle is important to the analysis of <a href="/wiki/Fold_(geology)" title="Fold (geology)">folded</a> and tilted <a href="/wiki/Stratum" title="Stratum">strata</a>. It was first proposed by the Danish geological pioneer <a href="/wiki/Nicholas_Steno" class="mw-redirect" title="Nicholas Steno">Nicholas Steno</a> (1638–1686). </p><figure class="mw-halign-left" typeof="mw:File/Thumb"><a href="/wiki/File:SEUtahStrat.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/66/SEUtahStrat.JPG/300px-SEUtahStrat.JPG" decoding="async" width="300" height="170" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/66/SEUtahStrat.JPG/450px-SEUtahStrat.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/66/SEUtahStrat.JPG/600px-SEUtahStrat.JPG 2x" data-file-width="3161" data-file-height="1794" /></a><figcaption>The <a href="/wiki/Permian" title="Permian">Permian</a> through <a href="/wiki/Jurassic" title="Jurassic">Jurassic</a> stratigraphy of the <a href="/wiki/Colorado_Plateau" title="Colorado Plateau">Colorado Plateau</a> area of southeastern <a href="/wiki/Utah" title="Utah">Utah</a> is a great example of Original Horizontality. These strata make up much of the famous prominent rock formations in widely spaced protected areas such as <a href="/wiki/Capitol_Reef_National_Park" title="Capitol Reef National Park">Capitol Reef National Park</a> and <a href="/wiki/Canyonlands_National_Park" title="Canyonlands National Park">Canyonlands National Park</a>. From top to bottom: Rounded tan domes of the <a href="/wiki/Navajo_Sandstone" title="Navajo Sandstone">Navajo Sandstone</a>, layered red <a href="/wiki/Kayenta_Formation" title="Kayenta Formation">Kayenta Formation</a>, cliff-forming, vertically jointed, red <a href="/wiki/Wingate_Sandstone" title="Wingate Sandstone">Wingate Sandstone</a>, slope-forming, purplish <a href="/wiki/Chinle_Formation" title="Chinle Formation">Chinle Formation</a>, layered, lighter-red <a href="/wiki/Moenkopi_Formation" title="Moenkopi Formation">Moenkopi Formation</a>, and white, layered <a href="/wiki/Cutler_Formation" title="Cutler Formation">Cutler Formation</a> sandstone. Picture from <a href="/wiki/Glen_Canyon_National_Recreation_Area" title="Glen Canyon National Recreation Area">Glen Canyon National Recreation Area</a>, Utah.</figcaption></figure><p>From these observations is derived the conclusion that the Earth has not been static and that great forces have been at work over long periods of time, further leading to the conclusions of the science of <a href="/wiki/Plate_tectonics" title="Plate tectonics">plate tectonics</a>; that movement and <a href="/wiki/Orogeny" title="Orogeny">collisions</a> of large plates of the Earth's <a href="/wiki/Crust_(geology)" title="Crust (geology)">crust</a> is the cause of <a href="/wiki/Folded_strata" class="mw-redirect" title="Folded strata">folded strata</a>.<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> </p><p>As one of Steno's Laws, the principle of original horizontality served well in the nascent days of <a href="/wiki/Geology" title="Geology">geological science</a>.<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> However, it is now known that not all <a href="/wiki/Sedimentary_rock" title="Sedimentary rock">sedimentary layers</a> are deposited purely horizontally. For instance, coarser grained sediments such as <a href="/wiki/Sand" title="Sand">sand</a> may be deposited at angles of up to 15 degrees, held up by the internal friction between grains which prevents them slumping to a lower angle without additional reworking or effort. This is known as the <a href="/wiki/Angle_of_repose" title="Angle of repose">angle of repose</a>, and a prime example is the surface of <a href="/wiki/Sand_dune" class="mw-redirect" title="Sand dune">sand dunes</a>. </p><p>Similarly, sediments may drape over a pre-existing inclined surface: these sediments are usually deposited conformably to the pre-existing surface. Also, sedimentary beds may pinch out along <a href="/wiki/Strike_and_dip" title="Strike and dip">strike</a>, implying that slight angles existed during their deposition. Thus the principle of original horizontality is widely, but not universally, applicable in the study of <a href="/wiki/Sedimentology" title="Sedimentology">sedimentology</a>, <a href="/wiki/Stratigraphy" title="Stratigraphy">stratigraphy</a>, and <a href="/wiki/Structural_geology" title="Structural geology">structural geology</a>. </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=Principle_of_original_horizontality&action=edit&section=1" title="Edit section: See also"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <ul><li><a href="/wiki/Law_of_superposition" title="Law of superposition">Law of superposition</a></li> <li><a href="/wiki/Principle_of_cross-cutting_relationships" class="mw-redirect" title="Principle of cross-cutting relationships">Principle of cross-cutting relationships</a></li> <li><a href="/wiki/Principle_of_faunal_succession" title="Principle of faunal succession">Principle of faunal succession</a></li> <li><a href="/wiki/Principle_of_lateral_continuity" title="Principle of lateral continuity">Principle of lateral continuity</a></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=Principle_of_original_horizontality&action=edit&section=2" title="Edit section: References"><span>edit</span></a><span class="mw-editsection-bracket">]</span></span></div> <style data-mw-deduplicate="TemplateStyles:r1235681985">.mw-parser-output .side-box{margin:4px 0;box-sizing:border-box;border:1px solid #aaa;font-size:88%;line-height:1.25em;background-color:var(--background-color-interactive-subtle,#f8f9fa);display:flow-root}.mw-parser-output .side-box-abovebelow,.mw-parser-output .side-box-text{padding:0.25em 0.9em}.mw-parser-output .side-box-image{padding:2px 0 2px 0.9em;text-align:center}.mw-parser-output .side-box-imageright{padding:2px 0.9em 2px 0;text-align:center}@media(min-width:500px){.mw-parser-output .side-box-flex{display:flex;align-items:center}.mw-parser-output .side-box-text{flex:1;min-width:0}}@media(min-width:720px){.mw-parser-output .side-box{width:238px}.mw-parser-output .side-box-right{clear:right;float:right;margin-left:1em}.mw-parser-output .side-box-left{margin-right:1em}}</style><style data-mw-deduplicate="TemplateStyles:r1237033735">@media print{body.ns-0 .mw-parser-output .sistersitebox{display:none!important}}@media screen{html.skin-theme-clientpref-night .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}@media screen and (prefers-color-scheme:dark){html.skin-theme-clientpref-os .mw-parser-output .sistersitebox img[src*="Wiktionary-logo-en-v2.svg"]{background-color:white}}</style><div class="side-box side-box-right plainlinks sistersitebox"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1126788409"> <div class="side-box-flex"> <div class="side-box-image"><span class="noviewer" typeof="mw:File"><span><img alt="" src="//upload.wikimedia.org/wikipedia/commons/thumb/d/df/Wikibooks-logo-en-noslogan.svg/40px-Wikibooks-logo-en-noslogan.svg.png" decoding="async" width="40" height="40" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/d/df/Wikibooks-logo-en-noslogan.svg/60px-Wikibooks-logo-en-noslogan.svg.png 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/d/df/Wikibooks-logo-en-noslogan.svg/80px-Wikibooks-logo-en-noslogan.svg.png 2x" data-file-width="400" data-file-height="400" /></span></span></div> <div class="side-box-text plainlist">The Wikibook <i><a href="https://en.wikibooks.org/wiki/Historical_Geology" class="extiw" title="wikibooks:Historical Geology">Historical Geology</a></i> has a page on the topic of: <i><b><a href="https://en.wikibooks.org/wiki/Historical_Geology/Steno%27s_principles" class="extiw" title="wikibooks:Historical Geology/Steno's principles">Steno's principles</a></b></i></div></div> </div><figure typeof="mw:File/Thumb"><a href="/wiki/File:OrdOutcropTN.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/4/42/OrdOutcropTN.JPG/200px-OrdOutcropTN.JPG" decoding="async" width="200" height="234" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/4/42/OrdOutcropTN.JPG/300px-OrdOutcropTN.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/4/42/OrdOutcropTN.JPG/400px-OrdOutcropTN.JPG 2x" data-file-width="700" data-file-height="818" /></a><figcaption>A <a href="/wiki/Stratigraphic_section" title="Stratigraphic section">stratigraphic section</a> of <a href="/wiki/Ordovician" title="Ordovician">Ordovician</a> rock exposed in central <a href="/wiki/Tennessee" title="Tennessee">Tennessee</a>, US. The sediments composing these rocks were formed in an ocean and deposited in horizontal layers.</figcaption></figure> <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"><ol class="references"> <li id="cite_note-Levin-1"><span class="mw-cite-backlink"><b><a href="#cite_ref-Levin_1-0">^</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="CITEREFLevin2009" class="citation book cs1">Levin, H.L. (2009). <a rel="nofollow" class="external text" href="https://books.google.com/books?id=D0yl7Cqsu78C&q=principle+of+original+horizontality&pg=PA15"><i>The Earth Through Time</i></a> (9 ed.). John Wiley and Sons. p. 15. <a href="/wiki/ISBN_(identifier)" class="mw-redirect" title="ISBN (identifier)">ISBN</a> <a href="/wiki/Special:BookSources/978-0-470-38774-0" title="Special:BookSources/978-0-470-38774-0"><bdi>978-0-470-38774-0</bdi></a><span class="reference-accessdate">. Retrieved <span class="nowrap">28 November</span> 2010</span>.</cite><span title="ctx_ver=Z39.88-2004&rft_val_fmt=info%3Aofi%2Ffmt%3Akev%3Amtx%3Abook&rft.genre=book&rft.btitle=The+Earth+Through+Time&rft.pages=15&rft.edition=9&rft.pub=John+Wiley+and+Sons&rft.date=2009&rft.isbn=978-0-470-38774-0&rft.aulast=Levin&rft.aufirst=H.L.&rft_id=https%3A%2F%2Fbooks.google.com%2Fbooks%3Fid%3DD0yl7Cqsu78C%26q%3Dprinciple%2Bof%2Boriginal%2Bhorizontality%26pg%3DPA15&rfr_id=info%3Asid%2Fen.wikipedia.org%3APrinciple+of+original+horizontality" 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">Michael E. Brookfield, Principles of Stratigraphy, Blackwell Publishing, 2004, p. 116, ISBN 140511164X</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">Kardel, Troels, ed. (2013). Nicolaus Steno: Biography and Original Papers of a 17th Century Scientist. Berlin: Springer. ISBN 978-3-642-25078-1.</span> </li> </ol></div></div> <div class="navbox-styles"><link rel="mw-deduplicated-inline-style" href="mw-data:TemplateStyles:r1129693374"><style data-mw-deduplicate="TemplateStyles:r1236075235">.mw-parser-output .navbox{box-sizing:border-box;border:1px solid #a2a9b1;width:100%;clear:both;font-size:88%;text-align:center;padding:1px;margin:1em auto 0}.mw-parser-output .navbox .navbox{margin-top:0}.mw-parser-output .navbox+.navbox,.mw-parser-output .navbox+.navbox-styles+.navbox{margin-top:-1px}.mw-parser-output .navbox-inner,.mw-parser-output .navbox-subgroup{width:100%}.mw-parser-output .navbox-group,.mw-parser-output .navbox-title,.mw-parser-output .navbox-abovebelow{padding:0.25em 1em;line-height:1.5em;text-align:center}.mw-parser-output .navbox-group{white-space:nowrap;text-align:right}.mw-parser-output .navbox,.mw-parser-output .navbox-subgroup{background-color:#fdfdfd}.mw-parser-output .navbox-list{line-height:1.5em;border-color:#fdfdfd}.mw-parser-output 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href="/wiki/Principle_of_lateral_continuity" title="Principle of lateral continuity">Principle of lateral continuity</a></li> <li><a href="/wiki/Principle_of_cross-cutting_relationships" class="mw-redirect" title="Principle of cross-cutting relationships">Principle of cross-cutting relationships</a></li> <li><a href="/wiki/Principle_of_faunal_succession" title="Principle of faunal succession">Principle of faunal succession</a></li> <li><a href="/wiki/Law_of_included_fragments" title="Law of included fragments">Principle of inclusions and components</a></li> <li><a href="/wiki/Walther%27s_law" class="mw-redirect" title="Walther's law">Walther's law</a></li></ul> </div></td><td class="noviewer navbox-image" rowspan="4" style="width:1px;padding:0 0 0 2px"><div><figure class="mw-halign-right" typeof="mw:File"><a href="/wiki/File:Wallula-Gap-the-sisters.JPG" class="mw-file-description"><img src="//upload.wikimedia.org/wikipedia/commons/thumb/6/62/Wallula-Gap-the-sisters.JPG/50px-Wallula-Gap-the-sisters.JPG" decoding="async" width="50" height="67" class="mw-file-element" srcset="//upload.wikimedia.org/wikipedia/commons/thumb/6/62/Wallula-Gap-the-sisters.JPG/75px-Wallula-Gap-the-sisters.JPG 1.5x, //upload.wikimedia.org/wikipedia/commons/thumb/6/62/Wallula-Gap-the-sisters.JPG/100px-Wallula-Gap-the-sisters.JPG 2x" data-file-width="1339" data-file-height="1786" /></a><figcaption></figcaption></figure></div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Petrology" title="Petrology">Petrologic principles</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/Intrusive_rock" title="Intrusive rock">Intrusive</a></li> <li><a href="/wiki/Extrusive_rock" title="Extrusive rock">Extrusive</a></li> <li><a href="/wiki/Volcanic_rock" title="Volcanic 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title="Tectonic uplift">Tectonic uplift</a></li> <li><a href="/wiki/Subsidence" title="Subsidence">Subsidence</a></li> <li><a href="/wiki/Marine_transgression" title="Marine transgression">Marine transgression</a></li> <li><a href="/wiki/Marine_regression" title="Marine regression">Marine regression</a></li></ul> </div></td></tr><tr><th scope="row" class="navbox-group" style="width:1%"><a href="/wiki/Sediment_transport" title="Sediment transport">Sediment transport</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/Fluvial" class="mw-redirect" title="Fluvial">Fluvial processes</a></li> <li><a href="/wiki/Aeolian_processes" title="Aeolian processes">Aeolian processes</a></li> <li><a href="/wiki/Glacier" title="Glacier">Glacial processes</a></li> <li><a href="/wiki/Mass_wasting" title="Mass wasting">Mass wasting processes</a></li></ul> </div></td></tr><tr><td class="navbox-abovebelow" 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