{"id":173,"date":"2006-05-16T20:58:24","date_gmt":"2006-05-17T04:58:24","guid":{"rendered":"http:\/\/www.bluebison.net\/content\/?p=173"},"modified":"2012-01-07T19:21:51","modified_gmt":"2012-01-08T03:21:51","slug":"how-yosemite-valley-was-formed-2","status":"publish","type":"post","link":"http:\/\/www.bluebison.net\/content\/2006\/how-yosemite-valley-was-formed-2\/","title":{"rendered":"how yosemite valley was formed"},"content":{"rendered":"<p><a href=\"http:\/\/bluebison.net\/yosemite\/valley\/1.jpg\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/1_small.jpg\" \/><\/a><\/p>\n<p><a href=\"http:\/\/bluebison.net\/teaching-materials\/how-yosemite-valley-was-formed\/how-yosemite-valley-was-formed-bluebison.pps\"><img decoding=\"async\" src=\"http:\/\/bluebison.net\/books\/monkey-pirate\/pps\/powerpoint.jpg\"><\/a> (click here for a <a href=\"http:\/\/bluebison.net\/teaching-materials\/how-yosemite-valley-was-formed\/how-yosemite-valley-was-formed-bluebison.pps\">powerpoint slide show<\/a>)<\/p>\n<p>470 &#8211; 220 million years ago:<\/p>\n<p>Layered sediments covered the sea floor west of the North American continent.<\/p>\n<p><a href=\"http:\/\/www.bluebison.net\/content\/?p=173\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/icon\/1_icon.jpg\" ><\/a> <a href=\"http:\/\/www.bluebison.net\/content\/?p=173\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/icon\/2_icon.jpg\" ><\/a> <a href=\"http:\/\/www.bluebison.net\/content\/?p=173\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/icon\/3_icon.jpg\" ><\/a> <a href=\"http:\/\/www.bluebison.net\/content\/?p=173\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/icon\/5_icon.jpg\" \/><\/a> <a href=\"http:\/\/www.bluebison.net\/content\/?p=173\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/icon\/7_icon.jpg\" \/><\/a> <a href=\"http:\/\/www.bluebison.net\/content\/?p=173\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/icon\/8_icon.jpg\" \/><\/a> <a href=\"http:\/\/www.bluebison.net\/content\/?p=173\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/icon\/9_icon.jpg\" \/><\/a> <a href=\"http:\/\/www.bluebison.net\/content\/?p=173\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/icon\/99_icon.jpg\" \/><\/a><\/p>\n<p><!--more--><\/p>\n<p><a href=\"http:\/\/bluebison.net\/yosemite\/valley\/2.jpg\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/2_small.jpg\" \/><\/a><\/p>\n<p>220 &#8211; 80 million years ago:<\/p>\n<p>Masses of molten magma rose from deep in the earth, pushing the layers of sediment up into mountains and breaking through as volcanoes.<\/p>\n<p><a href=\"http:\/\/bluebison.net\/yosemite\/valley\/3.jpg\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/3_small.jpg\" \/><\/a><\/p>\n<p>80 &#8211; 25 million years ago:<\/p>\n<p>Uplift and erosion stripped away most of the sedimentary layers, leaving the cooled magma (granite) exposed.<\/p>\n<p><a href=\"http:\/\/bluebison.net\/yosemite\/valley\/4.jpg\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/4_small.jpg\" \/><\/a><\/p>\n<p>25 million years ago:<\/p>\n<p>Rolling hills and valleys covered the current Yosemite area, the Merced river flowed through a shallow valley. <\/p>\n<p><a href=\"http:\/\/bluebison.net\/yosemite\/valley\/5.jpg\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/5_small.jpg\" \/><\/a><\/p>\n<p>25 to 10 million years ago:<\/p>\n<p>The mountains were pushed up higher from an increase in activity below the earth&#8217;s surface, causing the Merced river to dig deeper (erode) into its valley. <\/p>\n<p><a href=\"http:\/\/bluebison.net\/yosemite\/valley\/6.jpg\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/6_small.jpg\" \/><\/a><\/p>\n<p>10 &#8211; 2 million years ago:<\/p>\n<p> The land continued to push up, the water continued to erode down.  The V-shaped valley got deeper. <\/p>\n<p><a href=\"http:\/\/bluebison.net\/yosemite\/valley\/7.jpg\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/7_small.jpg\" \/><\/a><\/p>\n<p>2 million years ago:<\/p>\n<p>An ice age occurred.  Glaciers from the highest parts of the Sierra Nevada grew so big that they flowed down through Yosemite Valley, widening and cutting the Merced river&#8217;s path. <\/p>\n<p><a href=\"http:\/\/bluebison.net\/yosemite\/valley\/8.jpg\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/8_small.jpg\" \/><\/a><\/p>\n<p>20,000 years ago:<\/p>\n<p>The glaciers melted out of Yosemite Valley. <\/p>\n<p><a href=\"http:\/\/bluebison.net\/yosemite\/valley\/9.jpg\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/9_small.jpg\" \/><\/a><\/p>\n<p>10,000 years ago:<\/p>\n<p>The glaciers melted and created Lake Yosemite, which filled the Valley.  But the Merced river and small creeks were filling the lake with sediment&#8230; <\/p>\n<p><a href=\"http:\/\/bluebison.net\/yosemite\/valley\/99.jpg\"><img decoding=\"async\" border=\"0\" alt=\"Glacial Geologic formation of Yosemite Valley in Yosemite National Park\" src=\"http:\/\/bluebison.net\/yosemite\/valley\/99_small.jpg\" \/><\/a><\/p>\n<p>Today:<\/p>\n<p>The sediment eventually filled Lake Yosemite and turned it into the meadows and forests of today. <\/p>\n","protected":false},"excerpt":{"rendered":"<p>(click here for a powerpoint slide show) 470 &#8211; 220 million years ago: Layered sediments covered the sea floor west of the North American continent.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[24,82,23],"tags":[],"class_list":["post-173","post","type-post","status-publish","format-standard","hentry","category-glaciers","category-school","category-yosemite"],"_links":{"self":[{"href":"http:\/\/www.bluebison.net\/content\/wp-json\/wp\/v2\/posts\/173","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/www.bluebison.net\/content\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.bluebison.net\/content\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.bluebison.net\/content\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/www.bluebison.net\/content\/wp-json\/wp\/v2\/comments?post=173"}],"version-history":[{"count":1,"href":"http:\/\/www.bluebison.net\/content\/wp-json\/wp\/v2\/posts\/173\/revisions"}],"predecessor-version":[{"id":1761,"href":"http:\/\/www.bluebison.net\/content\/wp-json\/wp\/v2\/posts\/173\/revisions\/1761"}],"wp:attachment":[{"href":"http:\/\/www.bluebison.net\/content\/wp-json\/wp\/v2\/media?parent=173"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.bluebison.net\/content\/wp-json\/wp\/v2\/categories?post=173"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.bluebison.net\/content\/wp-json\/wp\/v2\/tags?post=173"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}