Learn about the Sierra Nevada in legend and science.
Read the full transcript »
Learn about the Sierra Nevada Floating along in the water world, they saw something like a birds nest. Earth maker said to metal ark; "It's very small, it would be good if it were bigger. I wonder how I may stretch it apart a little. What would be good to do? In what way could I make it a little bigger?" As he talked he transformed it. He stretched it out to where the day breaks. He stretched it out to the south; he stretched it out the place where the sun goes down. He stretched it out to the North Country. He stretched it out to the wind of the world. When earth maker has stretched it out, he said; "Good, you who solved this earth, this mud and made this nest sing. Telling all tales humans will say of you. In ancient times the beam who is metal ark, making the land and sticking it together and just that way built the nest from which the world was made." Then Metal Ark sang, sang a beautiful song about earth maker’s creation. People would call it "The basket world." There are many stories of how California’s great Valley came to resembled, the nest of the world. Scientist has their own version. So the weak diversion of the seer of the micro plate, appears to be a producing a very part. For 40 years Geologist Aldridge Morris has studied and thought California’s turbulent geology at UC Davis. Inspiring new generations of scientist, like Tasha Taylor. I love living here, I love working in the valley. It is a great big laboratory here for geologist. I mean the world geologist comes here to look at the San Andreas and the associated mountains and structures and things that occur because of motional San Andreas. And I get to live right here and drive 20 minutes and go look at it. We live on an active planet. Every time we drive from here to San Francisco, some of the stuff we drive over has moved a little bit from where it was the last time we drove over it. But very slowly, understanding the process requires turning back the calendar almost 150 million years. When then the place we now call California was just emerging from a vast deep ocean. Beneath that sea, 2 great tectonic plates the Theralon and the North American converge along a line and that would become the California coast. The Theralon plate begins diving beneath the North American, in the process that geologist call "subduction." A third plate, the Pacific. Riding a top the Theralon is pulling away from the North American, but not fast enough, pretending a 3 way collision on the earth's crust. To the east, heat and pressure from below begins pushing up a new range of mountains. And the ancestors of the sea earn Nevada rise above the sea as the mountains erode, sediments and lava flows from the eastern upland begging filling-in the thofth to the west. And 20 million years ago the residing waters finally exposed what we now know as the Central Valley. You have this heavy peace of ocean crust and mantel the heavy metal rock beneath it. Sitting as a slab at the edge on the edge of the North American continent, holding it down like you putting your foot on the edge of the board, that then has just filled up with sediment. Five to ten millions years ago, to the west, the sinking feralon plate continues to crumble beneath California. Portions of it are plowed up in a helter scalder jumble that will one day be the Coast Ranges. The pulling apart of the Feralon and the Pacific plates creates an eastward moving rift called the "San Andreas Fault." As it arrives at the edge of the continent, subduction grinds to a halt along most of the California coast allowing volcanic actions to push the Coast Ranges higher still. Hills become mountains. This melange of tectonic degree still causes mysteries today. The Coast Ranges are slowly pushing their way into the valley, and rumpling up the edge of the western side. And that's also an interesting thing which has only been recently discovered. That is in the last 20 years. And we don't really have yet a clear view of what is exact