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Volcanoes and Volcanism

Wildcat Mountain and Mt Washington. Kyle Migliorini. Rock Candy. 1 Glass jar or drinking ... Tie a short piece of cotton string to the middle of the pencil or stick. ...

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Volcanoes and Volcanism

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  1. Atwood Quarry, Port Clyde, ME Chelsea Sonksen

  2. Craters of the Moon NP Will Junkin

  3. Snake River, ID Hannah O’Brien

  4. Wildcat Mountain and Mt Washington Kyle Migliorini

  5. Rock Candy 1 Glass jar or drinking glass 1 Food coloring (optional) 1 Piece of cotton string 1 c Water 1 Pencil or stick 2 c Sugar 1 Paper clip Additional sugar Tie a short piece of cotton string to the middle of the pencil or stick. Attach a paper clip to the end of the string for a weight. Moisten the string very lightly, and roll in a bit of sugar (this will "attract" the sugar crystals from the syrup to the string). Place the pencil or stick over the top of the glass or jar with the string hanging down inside. Heat the water to boiling, and dissolve the 2 cups of sugar into it. For the biggest crystals FAST, heat the sugar-water solution a SECOND time, and dissolve as much additional sugar as you can into it. Add a few drops of food coloring to the solution if desired. Pour the solution into the prepared glass or jar and leave undisturbed for a couple of days. Depending on how much sugar you were able to dissolve into the water, you should start to see crystals growing in a few hours to a few days. Source: Karen Mintzias Just Recipes: http://www.melborponsti.com/index.htm

  6. IGNEOUS COMPOSITIONS IGNEOUS PROCESSES AND IGNEOUS ROCKS ULTRAMAFIC ROCKS MAFIC derived from Magnesium and Ferrum (iron). Dominated by Fe-Mg silicates, olivine and pyroxene. Contains very little silica < 40%. No feldspars or quartz. Form deep in the Earth’s surface. Very dark in color and dense. Found at converging continental plate boundaries. PERIDOTITE OR DUNITE

  7. IGNEOUS COMPOSITIONS IGNEOUS PROCESSES AND IGNEOUS ROCKS MAFIC ROCKS Silica content is 45-55%. Contains dark plagioclase feldspars, pyroxenes and possibly olivine. GABBRO - phaneritic BASALT - aphanitic SCORIA - aphanitic and porous (vesicular). BASALT is major constituent in oceanic crust.

  8. IGNEOUS COMPOSITIONS IGNEOUS PROCESSES AND IGNEOUS ROCKS INTERMEDIATE ROCKS Silica content is 55-65%. Contains dark plagioclase feldspars, pyroxenes, biotite and hornblende. Very little if any quartz. Lighter color than mafic rocks. ANDESITE - aphanitic 2nd most abundant volcanic rock in Earth’s crust. DIORITE - phaneritic

  9. IGNEOUS COMPOSITIONS IGNEOUS PROCESSES AND IGNEOUS ROCKS FELSIC ROCKS Felsic comes from Feldspar and Silica. Silica content is >65%. Rich in orthoclase, muscovite and quartz. Lighter color than intermediate rocks. Wide variety in texture in felsic rocks.

  10. PHANERITIC TEXTURE GRANITE

  11. APHANITIC TEXTURE RHYOLITE FELSITE

  12. GLASSY TEXTURE OBSIDIAN Forms when gas-poor felsic lava cools very quickly. PUMICE Forms when gas-rich felsic lava cools very quickly.

  13. IGNEOUS ROCK CLASSIFICATION IGNEOUS PROCESSES AND IGNEOUS ROCKS COMPOSITION PHANERITIC APHANITIC GLASSY

  14. CREATION OF MAGMA IGNEOUS PROCESSES AND IGNEOUS ROCKS Rocks are generally composed of several minerals. Consequently, rocks don’t just simply melt. Different minerals melt at different temperatures. Rocks undergo PARTIAL MELTING. Some of the rock stays solid. Generally those minerals with high melting point are last to melt. Those with lower melting points become liquid first. HEAT, PRESSURE and WATER CONTENT all affect the melting of rocks.

  15. CREATION OF MAGMA IGNEOUS PROCESSES AND IGNEOUS ROCKS HEAT Comes from: Radioactive Decay Heat produced from Earth’s formation still rising to be released. Frictional heat from plate movement. Temperature rises with depth in the Earth THERMAL GRADIENT. Increased temperature causes minerals to melt.

  16. CREATION OF MAGMA IGNEOUS PROCESSES AND IGNEOUS ROCKS PRESSURE High pressure on rocks acts to make the bonds stronger. Pressure increases -- melting point increases. If pressure is released quickly, melting will occur.

  17. CREATION OF MAGMA IGNEOUS PROCESSES AND IGNEOUS ROCKS WATER CONTENT Water, even in small amounts lowers melting point. Due to polarity of water molecules. Decreased pressure and water content greatly lowers melting point. Increases bond breaking ability of water. In subduction zones, wet oceanic crust is pushed down with increasing pressure causing increased melting.

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