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Exam 4
10-29 through 11-12
63
Geology
Undergraduate 1
11/10/2009

Additional Geology Flashcards

 


 

Cards

Term
Magma
Definition
Molten rock containing liquids, crystals, and dissolved gases that forms within the upper part of the Earth's mantle and crust.
Term
Lava
Definition
the term used for magma once it has erupted onto the Earth's surface. It cools quickly at the surface to form fine grained or porphyritic rocks.
Term
Shield Volcanoes
Definition
-Broad cones, gentle sloping sides, Low Si, High Fe & Mg, Basalt.
-Passive eruption, melt source=oceanic crust/mantle, low silica content, low viscosity, Hawaii.
Term
Composite Volcanoes (Stratovolcanes)
Definition
Narrow cones, steeply sloping sides, High Si, Low Fe & Mg, Andesites and rhyolites.
-Explosive reactions, Continental crust melt source, High melt source, high viscosity, Andesite/Rhyolite, Mount St. Helens.
Term
Eruptive Products of Composite Volcanoes
Definition
1. Tephra
2. Lava
3. Repeat
Term
Tephra
Definition
A catch-all term for solid material of all sizes explosively ejected from a volcano into the atmosphere.
Term
Pyroclastic
Definition
Pertaining to fragmented (clastic) rock material formed by a volcanic explosion or ejection from a volcanic vent.
Term
Ash
Definition
Fragments less than 2 mm in diameter of lava or rock blasted into the air by volcanic explosions.
Term
Plinian Eruption
Definition
A sustained explosive eruption which forms a high, jet-like column of pumice and ash in the atmosphere.
-Commonly last several hours
-Lay down thick layers of pumice as pyroclastic fall deposit.
-May reach well into the stratosphere.
Term
Pyroclastic Flow
Definition
A hot, dry, fast-moving and high-density mix of ash, pumice, rock fragments, and gas formed during explosive eruptions or from the collapse of a lava dome. (aka nuee ardente)
Term
Ash Flow
Definition
A pyroclastic flow consisting predominantly of ash-sized particles.
Term
Ash Fall
Definition
Ash falling from an eruption column or ash cloud.
Term
Lahar
Definition
A flowing mixture of water-saturated rock debris that forms on the slopes of a volcano, and moves downslope, sometimes referred to as debris flow or mudflow.
Term
Mount Rainier
Definition
Washington
Term
Mount St. Helens
Definition
Washington
Term
Seismology
Definition
Earthquakes commonly provide the earliest warning of volcanic unrest and earthquake swarms immediately precede most volcanic eruptions.
Term
Harmonic Tremor
Definition
A continuous rhythmic earthquake that indicates motion of magma below the surface.
Term
Typical earthquake
Definition
Occur when ground motion from upward moving magma displaces the land.
Term
Gas Geochemistry
Definition
Changes in gas composition or the emission rate may be related to the variation in magma supply rate, change in magma type, or modifications in the pathways of gas escape induced by magma movement.
Term
Ground movements
Definition
Measurement of the changing shape of the volcano surface caused by the pressure of magma moving underground.
Term
Crater Lake
Definition
Oregon
Term
Caldera
Definition
Large, usually circular depression at the summit of a volcano.
Term
Craters
Definition
Smaller, circular depressions created primarily by explosive excavation of rock during eruptions.
Term
Volcanic Bomb
Definition
Blobs of semi-solid of plastic lava that solidify in air.
Term
Columnar Joints
Definition
Joints that form as lava cools and contracts, occurring on the caldera walls.
Term
Lassen National Park
Definition
California
Term
Wrangell-St. Elias National Park
Definition
Alaska
Term
Katami NP
Definition
Alaska
Term
Lake Clark NP
Definition
Alaska
Term
Shield Volcano
Definition
A volcano shaped like an inverted warrior's shield with long gentle slopes produced by eruptions of low-viscosity basaltic lava. (Hawaii)
Term
Pahoehoe
Definition
is lava that in solidified form is characterized by a smooth, billowy, or ropey surface.
Term
Aa
Definition
Lava that has a rough, jagged, spiny, and generally clinkery surface. Dense interior.
Term
Fissure Eruption
Definition
a "Curtain of Fire" forms from eruptions out of rift zones.
Term
Lava Tube
Definition
A tunnel formed when the surface of a lava flow cools and solidifies, while the still-molten interior flows through and drains away.
Term
Breakout
Definition
A small lobe originating as an outbreak of lava from the molten interior of a previously formed lobe.
Term
Lobe
Definition
A single unit of lava that is surrounded by a chilled crust and can vary in size from 10 cm-km.
Term
Spatter Cone (hornito)
Definition
Form when lava comes up through a vent in a viscous or pre-hardened state.
Term
Skylight
Definition
Where a break in the solid lava surface allows a view of lava flowing below.
Term
Tree mold
Definition
Where lava flows around a tree.
Term
Littoral Explosion
Definition
Caused when sea water invades the hot lava-tube system and flashes to steam. The expanding steam blows a thin-walled bubble of lava through the roof of the tube and hurls spatter onto the bench.
Term
Fumarole
Definition
A vent that releases volcanic gases, including water vapor (steam).
Term
Yellowstone
Definition
Wyoming
Term
Resurgent Dome
Definition
a volcanic dome this is rising due to upward movement of magma in a magma chamber.
Term
4 Types of Geothermal Features in Yellowstone
Definition
Hot springs, Mudpots, Fumaroles, Geysers.
Term
Algae color reflects...
Definition
Water temperature
Term
Hot Springs
Definition
Ground water is heated by magma below the surface and flows to the surface.
Term
Mudpot
Definition
Steam rises through groundwater that has dissolved surrounding rocks into clay.
Term
Geyser
Definition
Intermittent fountain of hot water in which hot columns of water are ejected with great force.
Term
Travertine Terraces
Definition
calcium carbonate precipitates from the hot spring water building these.
Term
Geyserite
Definition
Composed of the mineral opal.
Term
Devils Tower
Definition
Wyoming
Term
Cinder Cones
Definition
built from blobs of congealed lava ejected from a single vent. As the gas charged lava is blown violently into the air, it breaks into fragments that solidify and fall as cinders around the vent to form a circular or oval cone.
Term
Cinders
Definition
Lava fragments about 1 cm in diameter. Erupted as fragmented blobs of lava and solidify in the air.
Term
Cinder Cone eruptions
Definition
1. Eruption
2. Formation of cone and crater
3. Lava flow
Term
Sunset Crater Volcano NM
Definition
Arizona
Term
Strombolian Eruption
Definition
Huge clots of molten lava burst form the summit crater. Lava clots combine to stream down the slopes in fiery rivulets.
Term
Squeeze-up
Definition
When hot, semi-solid plastic basalt lava squeezes up through a fracture. It scrapes the jagged, solid sides, creating grooves in the plastic-like mass.
Term
Spatter cone (hornito)
Definition
form when blobs spatter up through a vent in a viscous or pre-hardened state.
Term
Xenolith
Definition
a foreign crystal in an igneous rock. These rock fragments are brought up to the surface from depth by volcanic processes.
Term
Capulin Volcano NM
Definition
New Mexico
Term
Chiricahua NM
Definition
Arizona
Term
Spheroidal Weathering
Definition
occurs when the corners of a rock weather faster causing the rocks to become rounded.
Term
Bandelier NM
Definition
New Mexico
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