{"id":5647,"date":"2020-01-13T22:45:06","date_gmt":"2020-01-13T22:45:06","guid":{"rendered":"https:\/\/course.oeru.org\/eths101\/?page_id=5647"},"modified":"2020-01-13T22:45:06","modified_gmt":"2020-01-13T22:45:06","slug":"sedimentary-structures","status":"publish","type":"page","link":"https:\/\/course.oeru.org\/eths101\/assessment\/assessment-resources\/sedimentary-structures\/","title":{"rendered":"Sedimentary Structures"},"content":{"rendered":"<div id=\"content\" class=\"mw-body container\" role=\"main\">\n<div class=\"row\">\n<div class=\"col-md-12\">\n<div class=\"panel\">\n<div class=\"panel-body\">\n<div id=\"bodyContent\">\n<div id=\"mw-content-text\" lang=\"en\" dir=\"ltr\" class=\"mw-content-ltr\">\n<h2><span class=\"mw-headline\" id=\"Sedimentary_Structures\">Sedimentary Structures<\/span><\/h2>\n<p>Sedimentary structures are features of or in beds, formed by physical, chemical and biological processes at or shortly after the time the sediment was laid down (deposited). They are useful large scale features (centimetres to metres) that can help us to understand about where the sediment was laid down.They can help answer questions such as:\n<\/p>\n<ul>\n<li>What was the agent carrying the sediment? Ice, water or wind?\n<\/li>\n<li>Did the water or wind move rapidly?\n<\/li>\n<li>Was the sediment dumped or did it lay down over longer periods of time?\n<\/li>\n<li>Were the sediment laid down in deep water or in shallow seas or in streams and rivers?\n<\/li>\n<\/ul>\n<p>Because we can see the processes that form sedimentary structures in action in various places today we can imagine the same processes happening in sediment laid down in the past.<br \/>\n<br style=\"clear:both\">\n<\/p>\n<p>\n<\/p>\n<p>\n<\/p>\n<div class=\"panel iDevice\">\n\t<div class=\"panel-heading idevice-heading\">\n\t\t<div>\n\t\t\t<img decoding=\"async\" class=\"pedagogicalicon\" alt=\"web resources\" src=\"https:\/\/course.oeru.org\/eths101\/wp-content\/themes\/oeru_course\/idevices\/Icon_inter.png\">\n\t\t<\/div>\n\t\t<div>\n\t\t\t<h2>Sedimentary structures: Cross bedding<\/h2>\n\t\t<\/div>\n\t<\/div>\n\t<div class=\"panel-body\">\n\t\t<div class=\"col-md-12\">\n\t\t\t<\/p>\n<p>Cross-bedding is formed by <a rel=\"nofollow\" class=\"external text\" href=\"https:\/\/www.youtube.com\/watch?v=2LU2DiMB0MA\">dune migration<\/a>. Sand bounces up the long side of the dune and then cascades down and deposits on the down current side of the dune.\n<\/p>\n<p>Dunes are common in deserts, rivers and in the shallow seas.\n<\/p>\n<div class=\"center\">\n<div class=\"floatnone\"><a href=\"https:\/\/wikieducator.org\/File:Cross_bedding.png\" class=\"image\" title=\"Beds marked in dark solid line, cross-bed marked in dashed line.\"><img loading=\"lazy\" decoding=\"async\" alt=\"Beds marked in dark solid line, cross-bed marked in dashed line.\" src=\"\/\/wikieducator.org\/images\/thumb\/9\/92\/Cross_bedding.png\/600px-Cross_bedding.png\" width=\"600\" height=\"329\" class=\"img-responsive\"><\/a><\/div>\n<\/div>\n<dl>\n<dt>Cross-bedding image<\/dt>\n<dd> Beds marked in dark solid line, cross-bed marked in dashed line.\n<\/dd>\n<\/dl>\n<h3><span class=\"mw-headline\" id=\"overturned_cross-bedding\">overturned cross-bedding<\/span><\/h3>\n<p>A variant on cross-bedding is <b>overturned cross-bedding<\/b>. This happens when the sand is saturated and sloppy and is caught up in a strong current so that it slides down the down current slope.\n<\/p>\n<div class=\"center\">\n<div class=\"floatnone\"><a href=\"https:\/\/wikieducator.org\/File:Overturned_Cross_bedding.png\" class=\"image\" title=\"Thick Black line shows beds. Arrows point to over-tuned cross bed\"><img loading=\"lazy\" decoding=\"async\" alt=\"Thick Black line shows beds. Arrows point to over-tuned cross bed\" src=\"\/\/wikieducator.org\/images\/thumb\/6\/61\/Overturned_Cross_bedding.png\/600px-Overturned_Cross_bedding.png\" width=\"600\" height=\"283\" class=\"img-responsive\"><\/a><\/div>\n<\/div>\n<dl>\n<dt>Overtuned cross bedding image<\/dt>\n<dd> Thick Black line shows beds. Arrows point to over-tuned cross bed\n<\/dd>\n<\/dl>\n<p>\n<\/p>\n<p>\n\t\t<\/div>\n\t<\/div>\n<\/div>\n<p>\n<\/p>\n<div class=\"panel iDevice\">\n\t<div class=\"panel-heading idevice-heading\">\n\t\t<div>\n\t\t\t<img decoding=\"async\" class=\"pedagogicalicon\" alt=\"web resources\" src=\"https:\/\/course.oeru.org\/eths101\/wp-content\/themes\/oeru_course\/idevices\/Icon_inter.png\">\n\t\t<\/div>\n\t\t<div>\n\t\t\t<h2>Sedimentary structures: Ripples<\/h2>\n\t\t<\/div>\n\t<\/div>\n\t<div class=\"panel-body\">\n\t\t<div class=\"col-md-12\">\n\t\t\t<\/p>\n<p>Ripples form in the same way as dunes, but are at a smaller scale so millimetre to centimetre layers. If you go to the link on dune formation, you can imagine the same process creating ripples. In water, high ripples form from coarse sand in deep water and low ripples form from fine sand in shallow water. Ripples can also form by wind action.\n<\/p>\n<p>Ripples form in deserts, rivers, on river flats, beaches, shallow seas and tidal flats\n<\/p>\n<div class=\"center\">\n<div class=\"floatnone\"><a href=\"https:\/\/wikieducator.org\/File:Ripple_marks_in_Moenkopi_Formation_rock_off_of_Capitol_Reef_Scenic_Drive2.jpeg\" class=\"image\"><img loading=\"lazy\" decoding=\"async\" alt=\"Ripple marks in Moenkopi Formation rock off of Capitol Reef Scenic Drive2.jpeg\" src=\"\/\/wikieducator.org\/images\/thumb\/1\/15\/Ripple_marks_in_Moenkopi_Formation_rock_off_of_Capitol_Reef_Scenic_Drive2.jpeg\/600px-Ripple_marks_in_Moenkopi_Formation_rock_off_of_Capitol_Reef_Scenic_Drive2.jpeg\" width=\"600\" height=\"398\" class=\"img-responsive\"><\/a><\/div>\n<\/div>\n<p>\n<\/p>\n<p>\n\t\t<\/div>\n\t<\/div>\n<\/div>\n<p>\n<\/p>\n<div class=\"panel iDevice\">\n\t<div class=\"panel-heading idevice-heading\">\n\t\t<div>\n\t\t\t<img decoding=\"async\" class=\"pedagogicalicon\" alt=\"web resources\" src=\"https:\/\/course.oeru.org\/eths101\/wp-content\/themes\/oeru_course\/idevices\/Icon_inter.png\">\n\t\t<\/div>\n\t\t<div>\n\t\t\t<h2>Sedimentary structures: Desiccation cracks (or mudcracks)<\/h2>\n\t\t<\/div>\n\t<\/div>\n\t<div class=\"panel-body\">\n\t\t<div class=\"col-md-12\">\n\t\t\t<\/p>\n<p>Removal of water by evaporation from waterlogged sediment forms desiccation cracks.\n<\/p>\n<p>These indicate that the area experienced wetting and drying, so was above water level at the time these features were forming. They are common on lakes, tidal zones and river flats.\n<\/p>\n<div class=\"center\">\n<div class=\"floatnone\"><a href=\"https:\/\/wikieducator.org\/File:Dried_mud_creeks_on_the_shores_of_the_Wash_-_geograph.org.uk_-_10669.jpg\" class=\"image\"><img loading=\"lazy\" decoding=\"async\" alt=\"Dried mud creeks on the shores of the Wash - geograph.org.uk - 10669.jpg\" src=\"https:\/\/upload.wikimedia.org\/wikipedia\/commons\/7\/75\/Dried_mud_creeks_on_the_shores_of_the_Wash_-_geograph.org.uk_-_10669.jpg\" width=\"510\" height=\"369\" class=\"img-responsive\"><\/a><\/div>\n<\/div>\n<p>\n<\/p>\n<p>\n\t\t<\/div>\n\t<\/div>\n<\/div>\n<p>\n<\/p>\n<p>\n<\/p>\n<div class=\"panel iDevice\">\n\t<div class=\"panel-heading idevice-heading\">\n\t\t<div>\n\t\t\t<img decoding=\"async\" class=\"pedagogicalicon\" alt=\"web resources\" src=\"https:\/\/course.oeru.org\/eths101\/wp-content\/themes\/oeru_course\/idevices\/Icon_inter.png\">\n\t\t<\/div>\n\t\t<div>\n\t\t\t<h2>Sedimentary structures: Nodules<\/h2>\n\t\t<\/div>\n\t<\/div>\n\t<div class=\"panel-body\">\n\t\t<div class=\"col-md-12\">\n\t\t\t<\/p>\n<p>Nodules form in sediments saturated by groundwater after burial. They do not indicate where the sediment was laid down, but are a later feature present in many sedimentary rocks. Minerals that make up the nodules will depend on the sediment and the composition of the groundwater.\n<\/p>\n<div class=\"center\">\n<div class=\"floatnone\"><a href=\"https:\/\/wikieducator.org\/File:Sedimentary_structures,_Nodules.png\" class=\"image\" title=\"White elongate oval-shaped area is a nodule\"><img loading=\"lazy\" decoding=\"async\" alt=\"White elongate oval-shaped area is a nodule\" src=\"\/\/wikieducator.org\/images\/thumb\/4\/48\/Sedimentary_structures%2C_Nodules.png\/600px-Sedimentary_structures%2C_Nodules.png\" width=\"600\" height=\"365\" class=\"img-responsive\"><\/a><\/div>\n<\/div>\n<p>\n<\/p>\n<p>\n\t\t<\/div>\n\t<\/div>\n<\/div>\n<p>\n<\/p>\n<div class=\"panel iDevice\">\n\t<div class=\"panel-heading idevice-heading\">\n\t\t<div>\n\t\t\t<img decoding=\"async\" class=\"pedagogicalicon\" alt=\"web resources\" src=\"https:\/\/course.oeru.org\/eths101\/wp-content\/themes\/oeru_course\/idevices\/Icon_inter.png\">\n\t\t<\/div>\n\t\t<div>\n\t\t\t<h2>Additional Resource<\/h2>\n\t\t<\/div>\n\t<\/div>\n\t<div class=\"panel-body\">\n\t\t<div class=\"col-md-12\">\n\t\t\t<\/p>\n<p>If you want to learn more:\n<\/p>\n<ul>\n<li> You are welcome to learn more this <a rel=\"nofollow\" class=\"external text\" href=\"http:\/\/www.indiana.edu\/~geol105\/images\/gaia_chapter_5\/sedimentary_structures.htm\">Sedimentary Structures site<\/a>. It is useful in terms of sedimentary images.\n<\/li>\n<li><a rel=\"nofollow\" class=\"external text\" href=\"http:\/\/www.thisoldearth.net\/Geology_Online-1_Subchapters.cfm?Chapter=5&amp;Row=3\">This Old Earth<\/a> is an online resource that delves a little deeper into Sedimentary structures. Really useful for providing you with more context about sedimentary structures.\n<\/li>\n<\/ul>\n<p>\n<\/p>\n<p>\n\t\t<\/div>\n\t<\/div>\n<\/div>\n<p><!-- \nNewPP limit report\nCPU time usage: 0.304 seconds\nReal time usage: 2.100 seconds\nPreprocessor visited node count: 576\/1000000\nPreprocessor generated node count: 1068\/1000000\nPost\u2010expand include size: 13569\/2097152 bytes\nTemplate argument size: 6318\/2097152 bytes\nHighest expansion depth: 7\/40\nExpensive parser function count: 0\/100\n--><\/p>\n<p><!-- Saved in parser cache with key we_en-mw_:pcache:idhash:185434-0!*!*!!*!2!* and timestamp 20200113224502 and revision id 1066180\n -->\n<\/div>\n<div class=\"visualClear\"><\/div>\n<\/p><\/div>\n<\/p><\/div>\n<\/div>\n<\/div>\n<\/div>\n<div class=\"row\">\n<div class=\"col-md-12\">\n<ul class=\"pager\">\n<li class=\"previous\">\n            <a href=\"\/eths101\/assessment\/assessment-resources\/sedimentary-rock-library\">\u2190 Previous<\/a>\n          <\/li>\n<li class=\"next\">\n            <a href=\"\/eths101\/assessment\/assessment-resources\/fossil-library\">Next \u2192<\/a>\n          <\/li>\n<\/ul><\/div>\n<\/p><\/div>\n<\/div>\n<footer>\n<br \/>\n<\/footer>\n","protected":false},"excerpt":{"rendered":"<p>Sedimentary Structures Sedimentary structures are features of or in beds, formed by physical, chemical and biological processes at or shortly after the time the sediment was laid down (deposited). They are useful large scale features (centimetres to metres) that can help us to understand about where the sediment was laid down.They can help answer questions [&hellip;]<\/p>\n","protected":false},"author":155,"featured_media":0,"parent":5643,"menu_order":0,"comment_status":"closed","ping_status":"closed","template":"","meta":{"footnotes":""},"class_list":["post-5647","page","type-page","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/course.oeru.org\/eths101\/wp-json\/wp\/v2\/pages\/5647","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/course.oeru.org\/eths101\/wp-json\/wp\/v2\/pages"}],"about":[{"href":"https:\/\/course.oeru.org\/eths101\/wp-json\/wp\/v2\/types\/page"}],"author":[{"embeddable":true,"href":"https:\/\/course.oeru.org\/eths101\/wp-json\/wp\/v2\/users\/155"}],"replies":[{"embeddable":true,"href":"https:\/\/course.oeru.org\/eths101\/wp-json\/wp\/v2\/comments?post=5647"}],"version-history":[{"count":1,"href":"https:\/\/course.oeru.org\/eths101\/wp-json\/wp\/v2\/pages\/5647\/revisions"}],"predecessor-version":[{"id":5648,"href":"https:\/\/course.oeru.org\/eths101\/wp-json\/wp\/v2\/pages\/5647\/revisions\/5648"}],"up":[{"embeddable":true,"href":"https:\/\/course.oeru.org\/eths101\/wp-json\/wp\/v2\/pages\/5643"}],"wp:attachment":[{"href":"https:\/\/course.oeru.org\/eths101\/wp-json\/wp\/v2\/media?parent=5647"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}