{"id":65,"date":"2020-12-29T15:00:09","date_gmt":"2020-12-29T20:00:09","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/?post_type=chapter&#038;p=65"},"modified":"2021-01-26T16:06:11","modified_gmt":"2021-01-26T21:06:11","slug":"exercise-1-3-sedimentary-structures","status":"publish","type":"chapter","link":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/chapter\/exercise-1-3-sedimentary-structures\/","title":{"raw":"Exercise 1.3. Sedimentary Structures","rendered":"Exercise 1.3. Sedimentary Structures"},"content":{"raw":"Sedimentary rocks can have physical structures that give clues as to how or where the original sediments were deposited. The most common and important sedimentary structures form at the time of deposition and are referred to as<strong> primary sedimentary structures<\/strong>. Learning to identify sedimentary structures and to understand how they formed gives geoscientists a crucial tool for understanding past environments.\r\n<h1>What To Do<\/h1>\r\nRead through the descriptions of all structures below, then advance through the slide decks in the <a href=\"#samples\"><strong>Samples<\/strong><\/a> section to see specimens that demonstrate <strong>one or more<\/strong> of these features. Identify the sedimentary structures in each sample. Your worksheet has blanks where you can record the sample numbers in which each structure appears. You may need to list a sample number in more than one blank.\r\n\r\nFor ease of reference, the structure types visible are summarized in the linked list below:\r\n<h3>List of Structure Types<\/h3>\r\n<ul>\r\n \t<li><a href=\"#bedding\">Bedding<\/a>\r\n<ul>\r\n \t<li><a href=\"#pb\">Parallel bedding<\/a><\/li>\r\n \t<li><a href=\"#lb\">Laminated (laminar) bedding<\/a><\/li>\r\n \t<li><a href=\"#cb\">Cross-bedding<\/a><\/li>\r\n \t<li><a href=\"#ac\">Asymmetrical cross-beds<\/a><\/li>\r\n \t<li><a href=\"#sc\">Symmetrical cross-beds<\/a><\/li>\r\n \t<li><a href=\"#gb\">Graded bedding<\/a><\/li>\r\n<\/ul>\r\n<\/li>\r\n \t<li><a href=\"#mc\">Mud Cracks<\/a><\/li>\r\n<\/ul>\r\n<h1>Descriptions of Sedimentary Structures<\/h1>\r\n<h3><a id=\"bedding\"><\/a>Bedding<\/h3>\r\nSediments and sedimentary rocks can be separated into different beds of varying thickness. A <strong>bed<\/strong> is a layer of sediment that is distinct from sediments above and below because of differences in grain size, mineralogy, cementing agents, fossils, sedimentary structures, and other properties. There are several types of beds:\r\n<h6><a id=\"pb\"><\/a>Parallel Bedding<\/h6>\r\nBeds are parallel to one another. <strong><span style=\"color: #800000\"><em>Which samples display parallel bedding?\r\n<\/em><\/span><\/strong>\r\n<h6><a id=\"lb\"><\/a>Laminated (or Laminar) Bedding<\/h6>\r\nA type of parallel bedding, where the beds are very thin (mm scale). <strong><span style=\"color: #800000\"><em>Which samples display laminar bedding?<\/em><\/span><\/strong>\r\n<h6><a id=\"cb\"><\/a>Cross-bedding<\/h6>\r\nBeds are over 1 cm thick, and inclined at an angle to the original surface of deposition. (Cross-laminations are similar structures with thicknesses &lt; 1cm.)\r\n\r\nUnder flowing water or air (wind) the sediment surface will form ripples ranging from cm high up to dunes that are m high (Figures 1.5, 1.6).\r\n\r\n&nbsp;\r\n\r\n[caption id=\"attachment_147\" align=\"aligncenter\" width=\"652\"]<img class=\" wp-image-147\" src=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/Flow-over-ripple-11-Dec-18.jpg\" alt=\"An asymmetrical ripple with flow direction moving up the side with the gentler slope\" width=\"652\" height=\"270\" \/> <strong>Figure 1.5 |<\/strong> Formation and movement of ripple and cross-beds.[\/caption]\r\n\r\n&nbsp;\r\n\r\n[caption id=\"attachment_148\" align=\"aligncenter\" width=\"650\"]<img class=\" wp-image-148\" src=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-6.png\" alt=\"Ripples stacked on top of each other\" width=\"650\" height=\"301\" \/> <strong>Figure 1.6 |<\/strong> Pattern of multiple sets of cross-beds.[\/caption]\r\n\r\nThe flowing water or air speeds up when it climbs the upstream side and may pick up or erode some of the sediment there. When it passes over the crest, the water or air slows down and sediment will settle out of suspension on the downstream side of the ripple, adding layers to that side. Over time, the whole ripple or dune moves downstream as sediment is added to the downstream face. For sediments deposited in water, larger cross-beds indicate faster moving water or larger water waves. <span style=\"color: #800000\"><strong><em>Which samples display cross-bedding bedding?<\/em><\/strong><\/span>\r\n<h6><a id=\"ac\"><\/a>Asymmetrical Cross-beds<\/h6>\r\nThese cross-beds or cross-laminations form in a stream where flow is uni-directional (i.e., the water flows only in one direction). Material is removed from the upstream side and deposited on the downstream side (Figure 1.7a), and the resulting ripple has a steeper slope on the downstream side. <span style=\"color: #800000\"><strong><em>Which samples display asymmetrical cross-beds?<\/em><\/strong><\/span>\r\n<h6><a id=\"sc\"><\/a>Symmetrical Cross-beds<\/h6>\r\nSediments on or near beaches in lakes and at the ocean encounter wave action which reworks the sediment back and forth as the waves come on shore and off.\u00a0\u00a0 Cross-beds or cross-laminations form as sediment is added into this wave action. Some will be preserved going onshore, and some offshore (Figure 1.7b). The result is symmetrical cross-beds that form a herringbone pattern. These features indicate near-shore conditions in a lake or ocean. <span style=\"color: #800000\"><strong><em>Which samples display symmetrical cross-beds?<\/em><\/strong><\/span>\r\n\r\n[caption id=\"attachment_150\" align=\"aligncenter\" width=\"699\"]<img class=\" wp-image-150\" src=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-7.png\" alt=\"left- ripples with cross-beds tilted in the same direction. Right- ripples with cross-beds forming a cris-cross pattern\" width=\"699\" height=\"160\" \/> <strong>Figure 1.7 |<\/strong> Cross-sections show a) asymmetrical ripples with cross-bedding due to uni-directional flow, and b) symmetrical cross-bedding with herringbone texture due to oscillating currents.[\/caption]\r\n<h6><a id=\"gb\"><\/a>Graded Bedding<\/h6>\r\nGrain size may change through a bed and the trend is described from the bottom to the top (oldest to youngest). Normally grain size decreases upwards, indicating that a higher energy environment gradually slowed down and allowed finer sediments to settle out on top of coarser sediments. This might be typical of sediments deposited from a river where flow decreased over time, or at the beach following a big rainfall or storm event. This is referred to as a <strong>fining upward sequence<\/strong> (FUS). <strong>Coarsening upward sequences<\/strong> (CUS) are less commonly preserved in a bed. If energy was rising in a river or beach, then chances are, the higher energy later in time will erode and re-deposit any finer sediment. <span style=\"color: #800000\"><strong><em>Which samples display graded bedding?<\/em><\/strong><\/span>\r\n<h3><a id=\"mc\"><\/a>Mud Cracks<\/h3>\r\nMud cracks are formed by the drying and shrinking of mud exposed to air. Drying creates either polygonal shaped desiccation cracks or mud curls. They are common in desert (playa) lakes, tidal flats and the flood plains of rivers, where fine sediments are deposited at the edges of water bodies that then dry out or where water levels drop. <span style=\"color: #800000\"><strong><em>Which samples display mud cracks?<\/em><\/strong><\/span>\r\n<h1><a id=\"samples\"><\/a>Samples<\/h1>\r\nAdvance through each of the following slide decks to see one or more photographs of each sample. Some slides also include a short video of the sample being rotated. Videos do not have sound.<span style=\"color: #800000\"><em> If you can't see the slide decks, click on each sample name to open the slide deck in a new window.<\/em><\/span>\r\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=16\" target=\"_blank\" rel=\"noopener noreferrer\">SB15<\/a><\/h3>\r\n[h5p id=\"16\"]\r\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=17\" target=\"_blank\" rel=\"noopener noreferrer\">SB17<\/a><\/h3>\r\n[h5p id=\"17\"]\r\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=18\" target=\"_blank\" rel=\"noopener noreferrer\">SB18<\/a><\/h3>\r\n[h5p id=\"18\"]\r\n<h3>SC1A<\/h3>\r\n<h5><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=19\" target=\"_blank\" rel=\"noopener noreferrer\">Example A<\/a><\/h5>\r\n[h5p id=\"19\"]\r\n<h5><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=20\" target=\"_blank\" rel=\"noopener noreferrer\">Example B<\/a><\/h5>\r\n[h5p id=\"20\"]\r\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=21\" target=\"_blank\" rel=\"noopener noreferrer\">SC2B<\/a><\/h3>\r\n[h5p id=\"21\"]\r\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=22\" target=\"_blank\" rel=\"noopener noreferrer\">SC2BA<\/a><\/h3>\r\n[h5p id=\"22\"]\r\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=27\" target=\"_blank\" rel=\"noopener noreferrer\">SC7B<\/a><\/h3>\r\n[h5p id=\"27\"]\r\n<h3>SC7C<\/h3>\r\n<h5><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=23\" target=\"_blank\" rel=\"noopener noreferrer\">Example A<\/a><\/h5>\r\n[h5p id=\"23\"]\r\n<h5><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=24\" target=\"_blank\" rel=\"noopener noreferrer\">Example B<\/a><\/h5>\r\n[h5p id=\"24\"]\r\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=25\" target=\"_blank\" rel=\"noopener noreferrer\">SC7D<\/a><\/h3>\r\n[h5p id=\"25\"]\r\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=26\" target=\"_blank\" rel=\"noopener noreferrer\">SS6<\/a><\/h3>\r\n[h5p id=\"26\"]","rendered":"<p>Sedimentary rocks can have physical structures that give clues as to how or where the original sediments were deposited. The most common and important sedimentary structures form at the time of deposition and are referred to as<strong> primary sedimentary structures<\/strong>. Learning to identify sedimentary structures and to understand how they formed gives geoscientists a crucial tool for understanding past environments.<\/p>\n<h1>What To Do<\/h1>\n<p>Read through the descriptions of all structures below, then advance through the slide decks in the <a href=\"#samples\"><strong>Samples<\/strong><\/a> section to see specimens that demonstrate <strong>one or more<\/strong> of these features. Identify the sedimentary structures in each sample. Your worksheet has blanks where you can record the sample numbers in which each structure appears. You may need to list a sample number in more than one blank.<\/p>\n<p>For ease of reference, the structure types visible are summarized in the linked list below:<\/p>\n<h3>List of Structure Types<\/h3>\n<ul>\n<li><a href=\"#bedding\">Bedding<\/a>\n<ul>\n<li><a href=\"#pb\">Parallel bedding<\/a><\/li>\n<li><a href=\"#lb\">Laminated (laminar) bedding<\/a><\/li>\n<li><a href=\"#cb\">Cross-bedding<\/a><\/li>\n<li><a href=\"#ac\">Asymmetrical cross-beds<\/a><\/li>\n<li><a href=\"#sc\">Symmetrical cross-beds<\/a><\/li>\n<li><a href=\"#gb\">Graded bedding<\/a><\/li>\n<\/ul>\n<\/li>\n<li><a href=\"#mc\">Mud Cracks<\/a><\/li>\n<\/ul>\n<h1>Descriptions of Sedimentary Structures<\/h1>\n<h3><a id=\"bedding\"><\/a>Bedding<\/h3>\n<p>Sediments and sedimentary rocks can be separated into different beds of varying thickness. A <strong>bed<\/strong> is a layer of sediment that is distinct from sediments above and below because of differences in grain size, mineralogy, cementing agents, fossils, sedimentary structures, and other properties. There are several types of beds:<\/p>\n<h6><a id=\"pb\"><\/a>Parallel Bedding<\/h6>\n<p>Beds are parallel to one another. <strong><span style=\"color: #800000\"><em>Which samples display parallel bedding?<br \/>\n<\/em><\/span><\/strong><\/p>\n<h6><a id=\"lb\"><\/a>Laminated (or Laminar) Bedding<\/h6>\n<p>A type of parallel bedding, where the beds are very thin (mm scale). <strong><span style=\"color: #800000\"><em>Which samples display laminar bedding?<\/em><\/span><\/strong><\/p>\n<h6><a id=\"cb\"><\/a>Cross-bedding<\/h6>\n<p>Beds are over 1 cm thick, and inclined at an angle to the original surface of deposition. (Cross-laminations are similar structures with thicknesses &lt; 1cm.)<\/p>\n<p>Under flowing water or air (wind) the sediment surface will form ripples ranging from cm high up to dunes that are m high (Figures 1.5, 1.6).<\/p>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_147\" aria-describedby=\"caption-attachment-147\" style=\"width: 652px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-147\" src=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/Flow-over-ripple-11-Dec-18.jpg\" alt=\"An asymmetrical ripple with flow direction moving up the side with the gentler slope\" width=\"652\" height=\"270\" srcset=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/Flow-over-ripple-11-Dec-18.jpg 2195w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/Flow-over-ripple-11-Dec-18-300x124.jpg 300w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/Flow-over-ripple-11-Dec-18-1024x423.jpg 1024w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/Flow-over-ripple-11-Dec-18-768x317.jpg 768w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/Flow-over-ripple-11-Dec-18-1536x635.jpg 1536w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/Flow-over-ripple-11-Dec-18-2048x846.jpg 2048w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/Flow-over-ripple-11-Dec-18-65x27.jpg 65w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/Flow-over-ripple-11-Dec-18-225x93.jpg 225w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/Flow-over-ripple-11-Dec-18-350x145.jpg 350w\" sizes=\"auto, (max-width: 652px) 100vw, 652px\" \/><figcaption id=\"caption-attachment-147\" class=\"wp-caption-text\"><strong>Figure 1.5 |<\/strong> Formation and movement of ripple and cross-beds.<\/figcaption><\/figure>\n<p>&nbsp;<\/p>\n<figure id=\"attachment_148\" aria-describedby=\"caption-attachment-148\" style=\"width: 650px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-148\" src=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-6.png\" alt=\"Ripples stacked on top of each other\" width=\"650\" height=\"301\" srcset=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-6.png 952w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-6-300x139.png 300w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-6-768x355.png 768w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-6-65x30.png 65w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-6-225x104.png 225w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-6-350x162.png 350w\" sizes=\"auto, (max-width: 650px) 100vw, 650px\" \/><figcaption id=\"caption-attachment-148\" class=\"wp-caption-text\"><strong>Figure 1.6 |<\/strong> Pattern of multiple sets of cross-beds.<\/figcaption><\/figure>\n<p>The flowing water or air speeds up when it climbs the upstream side and may pick up or erode some of the sediment there. When it passes over the crest, the water or air slows down and sediment will settle out of suspension on the downstream side of the ripple, adding layers to that side. Over time, the whole ripple or dune moves downstream as sediment is added to the downstream face. For sediments deposited in water, larger cross-beds indicate faster moving water or larger water waves. <span style=\"color: #800000\"><strong><em>Which samples display cross-bedding bedding?<\/em><\/strong><\/span><\/p>\n<h6><a id=\"ac\"><\/a>Asymmetrical Cross-beds<\/h6>\n<p>These cross-beds or cross-laminations form in a stream where flow is uni-directional (i.e., the water flows only in one direction). Material is removed from the upstream side and deposited on the downstream side (Figure 1.7a), and the resulting ripple has a steeper slope on the downstream side. <span style=\"color: #800000\"><strong><em>Which samples display asymmetrical cross-beds?<\/em><\/strong><\/span><\/p>\n<h6><a id=\"sc\"><\/a>Symmetrical Cross-beds<\/h6>\n<p>Sediments on or near beaches in lakes and at the ocean encounter wave action which reworks the sediment back and forth as the waves come on shore and off.\u00a0\u00a0 Cross-beds or cross-laminations form as sediment is added into this wave action. Some will be preserved going onshore, and some offshore (Figure 1.7b). The result is symmetrical cross-beds that form a herringbone pattern. These features indicate near-shore conditions in a lake or ocean. <span style=\"color: #800000\"><strong><em>Which samples display symmetrical cross-beds?<\/em><\/strong><\/span><\/p>\n<figure id=\"attachment_150\" aria-describedby=\"caption-attachment-150\" style=\"width: 699px\" class=\"wp-caption aligncenter\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-150\" src=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-7.png\" alt=\"left- ripples with cross-beds tilted in the same direction. Right- ripples with cross-beds forming a cris-cross pattern\" width=\"699\" height=\"160\" srcset=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-7.png 1266w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-7-300x69.png 300w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-7-1024x235.png 1024w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-7-768x176.png 768w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-7-65x15.png 65w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-7-225x52.png 225w, https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-content\/uploads\/sites\/1224\/2020\/12\/F1-7-350x80.png 350w\" sizes=\"auto, (max-width: 699px) 100vw, 699px\" \/><figcaption id=\"caption-attachment-150\" class=\"wp-caption-text\"><strong>Figure 1.7 |<\/strong> Cross-sections show a) asymmetrical ripples with cross-bedding due to uni-directional flow, and b) symmetrical cross-bedding with herringbone texture due to oscillating currents.<\/figcaption><\/figure>\n<h6><a id=\"gb\"><\/a>Graded Bedding<\/h6>\n<p>Grain size may change through a bed and the trend is described from the bottom to the top (oldest to youngest). Normally grain size decreases upwards, indicating that a higher energy environment gradually slowed down and allowed finer sediments to settle out on top of coarser sediments. This might be typical of sediments deposited from a river where flow decreased over time, or at the beach following a big rainfall or storm event. This is referred to as a <strong>fining upward sequence<\/strong> (FUS). <strong>Coarsening upward sequences<\/strong> (CUS) are less commonly preserved in a bed. If energy was rising in a river or beach, then chances are, the higher energy later in time will erode and re-deposit any finer sediment. <span style=\"color: #800000\"><strong><em>Which samples display graded bedding?<\/em><\/strong><\/span><\/p>\n<h3><a id=\"mc\"><\/a>Mud Cracks<\/h3>\n<p>Mud cracks are formed by the drying and shrinking of mud exposed to air. Drying creates either polygonal shaped desiccation cracks or mud curls. They are common in desert (playa) lakes, tidal flats and the flood plains of rivers, where fine sediments are deposited at the edges of water bodies that then dry out or where water levels drop. <span style=\"color: #800000\"><strong><em>Which samples display mud cracks?<\/em><\/strong><\/span><\/p>\n<h1><a id=\"samples\"><\/a>Samples<\/h1>\n<p>Advance through each of the following slide decks to see one or more photographs of each sample. Some slides also include a short video of the sample being rotated. Videos do not have sound.<span style=\"color: #800000\"><em> If you can&#8217;t see the slide decks, click on each sample name to open the slide deck in a new window.<\/em><\/span><\/p>\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=16\" target=\"_blank\" rel=\"noopener noreferrer\">SB15<\/a><\/h3>\n<div id=\"h5p-16\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-16\" class=\"h5p-iframe\" data-content-id=\"16\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1-SB15\"><\/iframe><\/div>\n<\/div>\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=17\" target=\"_blank\" rel=\"noopener noreferrer\">SB17<\/a><\/h3>\n<div id=\"h5p-17\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-17\" class=\"h5p-iframe\" data-content-id=\"17\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1-SB17\"><\/iframe><\/div>\n<\/div>\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=18\" target=\"_blank\" rel=\"noopener noreferrer\">SB18<\/a><\/h3>\n<div id=\"h5p-18\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-18\" class=\"h5p-iframe\" data-content-id=\"18\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1-SB18\"><\/iframe><\/div>\n<\/div>\n<h3>SC1A<\/h3>\n<h5><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=19\" target=\"_blank\" rel=\"noopener noreferrer\">Example A<\/a><\/h5>\n<div id=\"h5p-19\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-19\" class=\"h5p-iframe\" data-content-id=\"19\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1-SC1A\"><\/iframe><\/div>\n<\/div>\n<h5><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=20\" target=\"_blank\" rel=\"noopener noreferrer\">Example B<\/a><\/h5>\n<div id=\"h5p-20\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-20\" class=\"h5p-iframe\" data-content-id=\"20\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1-SC1A-B\"><\/iframe><\/div>\n<\/div>\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=21\" target=\"_blank\" rel=\"noopener noreferrer\">SC2B<\/a><\/h3>\n<div id=\"h5p-21\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-21\" class=\"h5p-iframe\" data-content-id=\"21\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1-SC2B\"><\/iframe><\/div>\n<\/div>\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=22\" target=\"_blank\" rel=\"noopener noreferrer\">SC2BA<\/a><\/h3>\n<div id=\"h5p-22\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-22\" class=\"h5p-iframe\" data-content-id=\"22\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1-SC2BA-A\"><\/iframe><\/div>\n<\/div>\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=27\" target=\"_blank\" rel=\"noopener noreferrer\">SC7B<\/a><\/h3>\n<div id=\"h5p-27\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-27\" class=\"h5p-iframe\" data-content-id=\"27\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1-SC7B\"><\/iframe><\/div>\n<\/div>\n<h3>SC7C<\/h3>\n<h5><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=23\" target=\"_blank\" rel=\"noopener noreferrer\">Example A<\/a><\/h5>\n<div id=\"h5p-23\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-23\" class=\"h5p-iframe\" data-content-id=\"23\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1-SC7C-A\"><\/iframe><\/div>\n<\/div>\n<h5><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=24\" target=\"_blank\" rel=\"noopener noreferrer\">Example B<\/a><\/h5>\n<div id=\"h5p-24\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-24\" class=\"h5p-iframe\" data-content-id=\"24\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1-SC7C-B\"><\/iframe><\/div>\n<\/div>\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=25\" target=\"_blank\" rel=\"noopener noreferrer\">SC7D<\/a><\/h3>\n<div id=\"h5p-25\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-25\" class=\"h5p-iframe\" data-content-id=\"25\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1-SC7D\"><\/iframe><\/div>\n<\/div>\n<h3><a href=\"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-admin\/admin-ajax.php?action=h5p_embed&amp;id=26\" target=\"_blank\" rel=\"noopener noreferrer\">SS6<\/a><\/h3>\n<div id=\"h5p-26\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-26\" class=\"h5p-iframe\" data-content-id=\"26\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"1-SS6\"><\/iframe><\/div>\n<\/div>\n","protected":false},"author":1019,"menu_order":6,"template":"","meta":{"pb_show_title":"on","pb_short_title":"","pb_subtitle":"","pb_authors":[],"pb_section_license":""},"chapter-type":[],"contributor":[],"license":[],"class_list":["post-65","chapter","type-chapter","status-publish","hentry"],"part":3,"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-json\/pressbooks\/v2\/chapters\/65","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-json\/pressbooks\/v2\/chapters"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-json\/wp\/v2\/types\/chapter"}],"author":[{"embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-json\/wp\/v2\/users\/1019"}],"version-history":[{"count":16,"href":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-json\/pressbooks\/v2\/chapters\/65\/revisions"}],"predecessor-version":[{"id":370,"href":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-json\/pressbooks\/v2\/chapters\/65\/revisions\/370"}],"part":[{"href":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-json\/pressbooks\/v2\/parts\/3"}],"metadata":[{"href":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-json\/pressbooks\/v2\/chapters\/65\/metadata\/"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-json\/wp\/v2\/media?parent=65"}],"wp:term":[{"taxonomy":"chapter-type","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-json\/pressbooks\/v2\/chapter-type?post=65"},{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-json\/wp\/v2\/contributor?post=65"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/earthhistorylab\/wp-json\/wp\/v2\/license?post=65"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}