Geology Lab/Field Assignment

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Transcript of Geology Lab/Field Assignment

  • The Geological World Around Mt. Shasta, CA. By Kathryn Pimentel
  • Mount Shasta 14,179 ft. (4,322 m) Currently dormant Last eruption: 1786 Surrounding area contains igneous rocks from past eruptions Part of the Cascades (Volcano Discovery, 2012)
  • Mt. Shasta taken by me on July 7, 2013 from Montague, California
  • How Mt. Shasta Formed All of the volcanoes in the Cascade range have formed because of the movement of the Gorda crust moving under the North American Plate. This created a zone of subduction and formed Mt. Shasta (Siskiyous, 2001). (Siskiyous, 2001)
  • In the Surrounding Area... From molten rivers stemming from Mt. Shasta that, over time, broke down the rock in the surrounding area; creating Table Rock in Little Shasta, California (approx. 30 miles aways). Considering the molten river was much hotter than the existing rock, the rock was broken down to create a flat- topped mountain of sorts. Since then, Table Rock had been inhabited a by local Indian tribe, the Karuk, where many artifacts have been found (Obsidian arrowheads, etc.)
  • Table Rock in Little Shasta, CA. Taken by me on August 1, 2013. Mt. Shasta in the background.
  • A collection of Obsidian arrowheads found near Table Rock. Currently located at a local museum in Montague, CA. Picture taken by me, August 1, 2013.
  • The Rocks of Table Rock... The flat part of Table Rock is composed of Igneous rock that accumulated after the molten river flowed around original rock formation. The specific rock type over Table Rock is Basalt.
  • Another Life Form: The Shasta Daisy Classic perennial flower Grows in clusters of 2-3 ft tall and 1-2 ft wide Not considered intrusive (as some daisies are) They are native to the area and have not changed very much over time. (Old Farmers Almanac, 2012)
  • A small bloom of a Shasta Daisy in Montague, CA. Taken by me August 1. 2013.
  • The three rock samples I studied all turned out to be Igneous extrusive (meaning that they cooled quickly above ground) Picture 1: Pumice Picture 2: Granite Picture 3: Basalt Rocks Surrounding Table Rock
  • Pumice Super porous Probably spread from the last eruption of Mt. Shasta (1786). Broken down from natural weathering and human damage. Photo taken by me. August 1,2013.
  • Granite Very strong rock Easily polished Weathering was most likely done by humans Most likely found here from Mt. Shastas last eruption. Photo taken by me August 1, 2013.
  • Basalt The top of Table Rock is composed of Basalt Very, no crystal structures Found because of the molten river that stemmed from Mt. Shasta. Photo taken by me August 1, 2013.
  • References Mt. Shasta Volcano, nd. Retrieved from: http://www. August 4,2013. Geology of Mt. Shasta, nd. Retrieved from: http://www.siskiyous. edu/shasta/geo/fig4.htm. August 4, 2013 Old Farmers Almanac, June 5, 2012. Retrieved from: http://www. August 4, 2013. Sabalow,Ryan. How a Mount Shasta Eruption Might Occur, December 11, 2011. shasta-eruption-might-occur/. August 3, 2013.