Unformatted text preview: National Parks formed by National Parks formed by Volcanic Activity (part 2)
Yellowstone National Park Sunset Crater Volcano National Monument Hawaii Volcanoes National Park Rhyolite Rhyolite Andesite Andesite Basalt Basalt Extrusive igneous rocks Different chemistry Volcanism Volcanism High Silica ~70% Rhyolite Moderate Silica ~60% Andesite Low Silica ~50% Basalt Chemistry controls viscosity Rhyolitic – very viscous Basaltic – very runny Pyroclastic material (based on size) Volcanic Rocks Volcanic Rocks
Tuff Ash Lapilli Blocks Lava Flows Aa Pahoehoe Pumice and Scoria Types of Volcanoes Types of Volcanoes Shield Volcano Composite cone Volcanic dome Cinder cone Shield vs Shield vs Composite Divergent plate boundaries Location of Volcanoes Location of Volcanoes Mid ocean ridges Continental rift zone Convergent plate boundaries OceanicOceanic Crust OceanicContinental Crust Hot spots Hot Spots Hot Spots Parks covered in this lecture are all sourced by hot spots, but in different settings Hot Spots Worldwide Hot Spots Worldwide Yellowstone National Park Yellowstone National Park Vital Statistics Vital Statistics Northwestern Wyoming + MT, ID 2,220,000 acres ~3500 square miles Grand Teton NP Human History Human History 11,000 ya evidence for Indigenous Americans 1700’s French Trappers in area “SheepEaters” (Shoshone), Blackfoot, Crow, Sioux, & Nez Perce Tribes 1806 Louis & Clark 1820’s1840’s trappers Human History (con’t) Human History (con’t) 1860’s Prospectors & Miners 1870 General Washburn, surveyer for Montana 1871 Hayden Expedition Late 1871, bill proposed 01 March 1872, bill to create first national park signed by President U.S. Grant. Geologic Features Geologic Features Geysers Hot Springs Fumaroles “Muddy” vents – Mud Pots, Mud Volcanoes, Mud Geysers, Paint Pots Lava Flows Geologic Features Geologic Features Pyroclasts Fossilized Forests Calderas Streams and Waterfalls Glaciations Landslides Geologic History Geologic History 2700 mya sedimentary and igneous rocks metamorphosed to schist and gneiss Pz & Mz 8,000 ft of sedimentary rocks 75 mya Cretaceous Uplift (Laramide Orogeny) Cz dominated by volcanic rocks and glaciation Geologic History Geologic History Cz dominated by volcanic rocks and glaciation 40 mya Eocene volcanism 5 mya uplift, faulting, erosion ~ 2 mya cycles of volcanic rocks and caldera collapse ~ 1.5 mya beginning of glacial cycles Sunset Crater Volcano National Monument Sunset Crater Volcano National Monument Vital Statistics Vital Statistics North Central Arizona ~3,000 acres 4.5 square miles surrounded by Coconino National Forest. Human History Human History AD 600 Sinagua culture farmed area Between 1040 and 1100 eruption ~1600 Spanish missionaries 1870’s John Wesley Powell Human History Human History In 1928 a company wishing to film a landslide for the movie “Avalanche” proposed blowing up Sunset Crater. 1930 proclaimed NM by President Herbert Hoover, to protect its geologic formations. 1990 name changed to Sunset Crater Volcano National Monument. Geologic Features Geologic Features Cinder cone Lava Flows Ice cave Lava Tube Geologic History Geologic History Early history – Colorado Plateau ~6 mya volcanism begins in area (WE) 10401100 eruption at Sunset Colorado Plateau’s most recent volcanic eruption Hawaii Volcanoes National Park Hawaii Volcanoes National Park Vital Vital Statistics Southwest side of island of Hawaii 333,000 acres ~500 square miles Human History Human History 2000 to 1600 years ago Polynesians 1400 isolation 1778 Captain Cook 1790’s Captain Vancouver – scientific 1820’s Missionaries Human History (con’t) Human History (con’t) 1900 Territory of US 1912 USGS Volcano observatory 1916 Hawaiian Volcanoes NP 1959 Hawaii became state 1960 Haleakala NP separated from Hawaii NP Geologic Features Geologic Features Shield Volcanoes Fault Scarps Lava Flows Lava Tunnels Five Volcanoes on Hawaii Five Volcanoes on Hawaii Geologic Features Geologic Features Tree Molds Foot Prints Erosional Features Mudflow and other Mass Wasting Greensand Beach Geologic History Geologic History 40 mya Hawaiian Islands begin to form 3 mya Island of Maui 2 mya Island of Hawaii ...
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- Spring '10
- Volcano, Geologic History Geologic, Andesite Andesite