{"id":298,"date":"2018-06-12T03:13:47","date_gmt":"2018-06-12T07:13:47","guid":{"rendered":"https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/part\/chapter-8-weathering-sediment-and-soils\/"},"modified":"2021-07-21T16:37:36","modified_gmt":"2021-07-21T20:37:36","slug":"chapter-8-weathering-sediment-and-soils","status":"publish","type":"part","link":"https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/part\/chapter-8-weathering-sediment-and-soils\/","title":{"raw":"Chapter 8. Weathering, Sediment, and Soil","rendered":"Chapter 8. Weathering, Sediment, and Soil"},"content":{"raw":"&nbsp;\r\n\r\n[caption id=\"attachment_297\" align=\"aligncenter\" width=\"675\"]<a href=\"https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/1304\/2018\/06\/hoodoos-2.jpg\" rel=\"attachment wp-att-2181\"><img class=\"wp-image-297\" src=\"https:\/\/pressbooks.bccampus.ca\/knowinghome\/wp-content\/uploads\/sites\/1304\/2018\/06\/hoodoos-2-1024x673.jpg\" alt=\"\" width=\"675\" height=\"444\" \/><\/a> <strong>Figure 8.1<\/strong> The Hoodoos, near Drumheller, Alberta, have formed from the differential weathering (weaker rock weathering faster than stronger rock) of sedimentary rock. Source: Steven Earle (2015), CC BY 4.0. <a href=\"https:\/\/opentextbc.ca\/geology\/wp-content\/uploads\/sites\/110\/2015\/07\/image002.png\" rel=\"noopener\">View source.<\/a>[\/caption]\r\n<h1>Chapter Goals<\/h1>\r\nComplete this chapter so you can:\r\n<ul>\r\n \t<li>Explain why rocks formed at depth in the crust are susceptible to weathering at the surface.<\/li>\r\n \t<li>Describe the main processes of mechanical weathering, and the materials that are produced.<\/li>\r\n \t<li>Describe the main processes of chemical weathering, and common chemical weathering products.<\/li>\r\n \t<li>Explain the characteristics used to describe sediments, and what those characteristics can tell us about the origins of the sediments.<\/li>\r\n \t<li>Discuss the relationships between weathering and soil formation, and the origins of soil horizons.<\/li>\r\n \t<li>Describe and explain the distribution of Canadian soil types.<\/li>\r\n \t<li>Explain how changing weathering rates affect the carbon cycle and the climate system.<\/li>\r\n<\/ul>\r\n<h1>What Is Weathering?<\/h1>\r\n<strong>Weathering<\/strong> occurs when rock is exposed to the \u201cweather\u201d\u2014to the forces and conditions that exist at Earth\u2019s surface. Rocks that form deep within Earth experience relatively constant temperature, high pressure, have no contact with the atmosphere, and little or no interaction with moving water. Once overlying layers are eroded away and a rock is exposed at the surface, conditions change dramatically. Temperatures vary widely, and pressure is much lower. Reactive gases like oxygen and carbon dioxide are plentiful, and in many climates, water is abundant.\r\n\r\nWeathering can be characterized as\u00a0<strong>mechanical\u00a0<\/strong>(or\u00a0<strong>physical<\/strong>), and\u00a0<strong>chemical<\/strong>. In mechanical weathering, physical processes break rock into smaller pieces. In chemical weathering, chemical reactions change minerals into forms that are less affected by chemical reactions that occur at Earth's surface. Mechanical and chemical weathering reinforce each other, because mechanical weathering provides new fresh surfaces for attack by chemical processes, and chemical weathering weakens the rock so that it is more susceptible to mechanical weathering. Together, these processes create the particles and ions that can eventually become sedimentary rock.\u00a0 They also create soil, which is necessary for our existence on Earth.\r\n\r\n&nbsp;\r\n<div class=\"textbox shaded\">\r\n\r\n<strong>Can You Tell the Difference Between Physical &amp; Chemical Weathering?\r\n<\/strong>\r\n\r\n[h5p id=\"187\"]\r\n\r\n<\/div>","rendered":"<p>&nbsp;<\/p>\n<figure id=\"attachment_297\" aria-describedby=\"caption-attachment-297\" style=\"width: 675px\" class=\"wp-caption aligncenter\"><a href=\"https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/1304\/2018\/06\/hoodoos-2.jpg\" rel=\"attachment wp-att-2181\"><img loading=\"lazy\" decoding=\"async\" class=\"wp-image-297\" src=\"https:\/\/pressbooks.bccampus.ca\/knowinghome\/wp-content\/uploads\/sites\/1304\/2018\/06\/hoodoos-2-1024x673.jpg\" alt=\"\" width=\"675\" height=\"444\" srcset=\"https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/1304\/2018\/06\/hoodoos-2-1024x673.jpg 1024w, https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/1304\/2018\/06\/hoodoos-2-300x197.jpg 300w, https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/1304\/2018\/06\/hoodoos-2-768x504.jpg 768w, https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/1304\/2018\/06\/hoodoos-2-1536x1009.jpg 1536w, https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/1304\/2018\/06\/hoodoos-2-65x43.jpg 65w, https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/1304\/2018\/06\/hoodoos-2-225x148.jpg 225w, https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/1304\/2018\/06\/hoodoos-2-350x230.jpg 350w, https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-content\/uploads\/sites\/1304\/2018\/06\/hoodoos-2.jpg 1600w\" sizes=\"auto, (max-width: 675px) 100vw, 675px\" \/><\/a><figcaption id=\"caption-attachment-297\" class=\"wp-caption-text\"><strong>Figure 8.1<\/strong> The Hoodoos, near Drumheller, Alberta, have formed from the differential weathering (weaker rock weathering faster than stronger rock) of sedimentary rock. Source: Steven Earle (2015), CC BY 4.0. <a href=\"https:\/\/opentextbc.ca\/geology\/wp-content\/uploads\/sites\/110\/2015\/07\/image002.png\" rel=\"noopener\">View source.<\/a><\/figcaption><\/figure>\n<h1>Chapter Goals<\/h1>\n<p>Complete this chapter so you can:<\/p>\n<ul>\n<li>Explain why rocks formed at depth in the crust are susceptible to weathering at the surface.<\/li>\n<li>Describe the main processes of mechanical weathering, and the materials that are produced.<\/li>\n<li>Describe the main processes of chemical weathering, and common chemical weathering products.<\/li>\n<li>Explain the characteristics used to describe sediments, and what those characteristics can tell us about the origins of the sediments.<\/li>\n<li>Discuss the relationships between weathering and soil formation, and the origins of soil horizons.<\/li>\n<li>Describe and explain the distribution of Canadian soil types.<\/li>\n<li>Explain how changing weathering rates affect the carbon cycle and the climate system.<\/li>\n<\/ul>\n<h1>What Is Weathering?<\/h1>\n<p><strong>Weathering<\/strong> occurs when rock is exposed to the \u201cweather\u201d\u2014to the forces and conditions that exist at Earth\u2019s surface. Rocks that form deep within Earth experience relatively constant temperature, high pressure, have no contact with the atmosphere, and little or no interaction with moving water. Once overlying layers are eroded away and a rock is exposed at the surface, conditions change dramatically. Temperatures vary widely, and pressure is much lower. Reactive gases like oxygen and carbon dioxide are plentiful, and in many climates, water is abundant.<\/p>\n<p>Weathering can be characterized as\u00a0<strong>mechanical\u00a0<\/strong>(or\u00a0<strong>physical<\/strong>), and\u00a0<strong>chemical<\/strong>. In mechanical weathering, physical processes break rock into smaller pieces. In chemical weathering, chemical reactions change minerals into forms that are less affected by chemical reactions that occur at Earth&#8217;s surface. Mechanical and chemical weathering reinforce each other, because mechanical weathering provides new fresh surfaces for attack by chemical processes, and chemical weathering weakens the rock so that it is more susceptible to mechanical weathering. Together, these processes create the particles and ions that can eventually become sedimentary rock.\u00a0 They also create soil, which is necessary for our existence on Earth.<\/p>\n<p>&nbsp;<\/p>\n<div class=\"textbox shaded\">\n<p><strong>Can You Tell the Difference Between Physical &amp; Chemical Weathering?<br \/>\n<\/strong><\/p>\n<div id=\"h5p-187\">\n<div class=\"h5p-iframe-wrapper\"><iframe id=\"h5p-iframe-187\" class=\"h5p-iframe\" data-content-id=\"187\" style=\"height:1px\" src=\"about:blank\" frameBorder=\"0\" scrolling=\"no\" title=\"Physical or chemical weathering (basic)\"><\/iframe><\/div>\n<\/div>\n<\/div>\n","protected":false},"parent":0,"menu_order":8,"template":"","meta":{"pb_part_invisible":false,"pb_part_invisible_string":""},"contributor":[],"license":[],"class_list":["post-298","part","type-part","status-publish","hentry"],"_links":{"self":[{"href":"https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/parts\/298","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/parts"}],"about":[{"href":"https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/types\/part"}],"version-history":[{"count":5,"href":"https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/parts\/298\/revisions"}],"predecessor-version":[{"id":1742,"href":"https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-json\/pressbooks\/v2\/parts\/298\/revisions\/1742"}],"wp:attachment":[{"href":"https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/media?parent=298"}],"wp:term":[{"taxonomy":"contributor","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/contributor?post=298"},{"taxonomy":"license","embeddable":true,"href":"https:\/\/pressbooks.bccampus.ca\/physicalgeologyh5p\/wp-json\/wp\/v2\/license?post=298"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}