Term
|
Definition
glassi thing in ejecta blanket.
Small, glassy, produced by heat impact (caused by a meteor), black/olive green, round or irregular shaped. |
|
|
Term
|
Definition
| a very hard, brittle, silvery-white transition metal - very rare and unusual element if found earth; dense, hard brittle silvery white transition metal can withstand high temperatures rare crust in the clay layer, found in meteorites. |
|
|
Term
|
Definition
| si, oxygen, strong precossion like meteorite impact;deformed quartz from a major impact event. when there is a meteorite. |
|
|
Term
| In what way are tektites, Iridium, and shocked quartz related to the K/T extinction event? |
|
Definition
| 65 m.y.a Louis and Walter Alvarez discovered clay layer in 1980's at the K/T extinction point and found large amount of the rare element iridium. They found that large amounts of iridium were also in meteorites. (this made them realize that the meteorites had came and killed all the dinosaurs and caused the extinction. They started to find other elements like micro-tektites, shock quartz and soot as well). |
|
|
Term
| In what way are the Deccan and Siberian flood basalt provinces related to mass extinction events? |
|
Definition
| the deccan flood was 65 m.y.a which the basalt covered position of india/himalayas. siberian flood was 248 m.y.a. they created basalt flood of lava which caused extinction right after the meteorite, 70% of all life died. |
|
|
Term
| Which of these is related to the Permian extinction (the greatest mass extinction event of all time)? |
|
Definition
| the siberian flood basalt in siberia and 95 % died. |
|
|
Term
| . which is related to the K/T extinction? |
|
Definition
| over 70% of things perished about 765 yrs ago; Deccan. |
|
|
Term
| What is the anti-podal hypothesis? |
|
Definition
| asteroid hits one side of the sphere and the opposite side will be affected to a point where lava will rise. |
|
|
Term
| What geologic time unit (Eon, Era, Period, Epoch) represents the greatest expanse of geologic time? |
|
Definition
|
|
Term
| What is the Era of Ancient Life called? |
|
Definition
|
|
Term
|
Definition
|
|
Term
|
Definition
|
|
Term
| the age of the Dinosaurs? |
|
Definition
|
|
Term
|
Definition
|
|
Term
| Know and be able to describe the impact events at Tunguska, Chicxulub, and Meteor Crater. Know the contributions of Eugene Shoemaker and Walter and Louis Alvarez in expanding our knowledge of meteorite impacts. What did Walter Alvarez find at the K/T boundary? |
|
Definition
Tunguska, Central SiberiaOccurred on June 30, 1908. This was the only extraterrestrial impact in the history of the earth. Impact was heard 1000km away and the impact from the shock destroyed forests up to 20 milles away. The impact produced an incandescent matter that rose to a height of 20km. The shock wave circled the globe twice. Tens of thousands of animals instantly perished and the settlements vanished.
Chicxulub, Yucatan Peninsula, MexicoThe diameter of the asteroid necessary to produce such a crater would be ~10 km. This was an asteroid impact that occurred 65 million years ago in Yuctan Pennisula, Mexico. The diameter 180km of the crater and the diameter of the asteroid was 10km.
Meteor Crater, Flagstaff and Winslow, ArizonaThe youngest crater, produced by an iron meterorite 50,000 years ago in Flagstaff/Winslow, Arizona. The crater was 1.2 km in diameter and the meteorite was 100m in diameter.
What did Walter Alvarez find at the K/T boundary?The clay layer that contained numerous impact features, including a high concentration of the element Iridium (common in meteorites), tektites produced by impact melt, shocked quartz produced by the precussion event, and soot derived from global wildfires. |
|
|
Term
| What are the three magma types? |
|
Definition
1.mafic
2.intermediate
3.Felsic |
|
|
Term
| What rocks do they produce? |
|
Definition
| basalt, andesite, rhyolite |
|
|
Term
| Which is more viscous, a basaltic (mafic) magma or a rhyolitic (felsic) magma? |
|
Definition
| Rhyoltitic, it has a higher viscosity |
|
|
Term
| Define viscosity. Know the relationship between viscosity and the explosive potential of an eruption. Is a basaltic magma more explosive or less explosive than a rhyolitic magma? |
|
Definition
The viscosity of a substance is a measure of its consistency. Viscosity is defined as the ability of a substance to resist flow. In a sense, viscosity is the inverse of fluidity. Cold molasses, for example, has a higher viscosity than water because it is less fluid. A magma's viscosity is largely controlled by its temperature, composition, and gas content (see downloadable programs at the bottom of this page). The effect of temperature on viscosity is intuitive. Like most liquids, the higher the temperature, the more fluid a substance becomes, thus lowering its viscosity.
A low-viscosity magma, like basalt, will allow the escaping gases to migrate rapidly through the magma and escape to the surface. However, if the magma is viscous, like rhyolite, its high polymerization will impede the upward mobility of the gas bubbles. As gas continues to exsolve from the viscous melt, the bubbles will be prevented from rapid escape, thus increasing the overall pressure on the magma column until the gas ejects explosively from the volcano. As a general rule, therefore, nonexplosive eruptions are typical of basaltic-to-andesitic magmas which have low viscosities and low gas contents, whereas explosive eruptions are typical of andesitic-to-rhyolitic magmas which have high viscosities and high gas contents. |
|
|
Term
| Are lava flows more likely to be composed of rhyolite or basalt (think about their viscosity). Is a lava dome generally composed of lava with a low viscosity, or a high viscosity? |
|
Definition
Basalt, lower viscosity.
High viscosity |
|
|
Term
| a low gas content or a high gas content? |
|
Definition
|
|
Term
| What is aa, pahoehoe, pillow lava, and a lava tube? |
|
Definition
ahi ahi----rugged, jagged, spiny. Thicker, more viscosity.
pahoehoe- smooth, billowy, ropey. Thinner, lower viscosity.
pillow lava --when lava is quenched by water or air into pillow shaped/sized balls.
lava tube---lava to travel extremely far from the volcano because the layer of hardened lava is protecting the liquid lava. Once the volcano stops the rest of the lava in the tube simply drains out. |
|
|
Term
| What type of magma/lava are these features usually associated with (basalt, andesite, or rhyolite)? |
|
Definition
|
|
Term
| What is obsidian? . . . pumice? . . .vesicles? |
|
Definition
Is a glassy volcanic rock. It does not contains crystals because it cooled quickly when it entered water.
Vesicular texture- once the magma becomes lava it de-gasses itself, the bubbles rise out of the lava and burst, it cools and crystallizes. Some of the bubbles don't make it to the surface of the lava and burst, it cools and crystallizes. Some of the bubbles don't make it to the surface of the lava before it cools so they get trapped inside (looks like swiss cheese).
These trapped bubbles are called vesicles.
PUMICE -- Frothy felsic rock formed by vigorous vesiculation (bubbling) due to rapid gas escape. Courtesy of W.E. Scott. |
|
|
Term
| What are pyroclastic deposits (i.e., tephra)? How do they differ from lava flows? |
|
Definition
Liquid fragments that cool in the air from an eruption, the accumulation of this is caused by huge eruption.
Tephra is airborne (ash, lapilli, blocks, bombs) while lava flows are liquid and flow on land (pahoehoe, a'a). |
|
|
Term
| Know the three types of tephra fragments based on particle size. What is a pyroclastic fall? . . . a pyroclastic flow? . . . a lahar? |
|
Definition
Ash is < 2mm
Lapilli is 2-64 mm
Bombs/blocks are <64 mm
Pyroclastic Fall ----Pyroclastic material (tephra) erupts from the earthquake. From a phinian eruption. Bombs/Blocks land closer to the site than ash does which can travel for miles.
pyroclastic flow----Mixture of very hot pyroclastic fragments and escaping gases. The releasing of gases in the mixture allows it to flow. *most dangerous of all phenomenas because it is
extremely hot
has high velocity
an abundence of toxic gases.
lahar---"volcanic mudflow" or landslide composed of pyroclastic material and water and hot gases.
it seeks about valle. |
|
|
Term
| Which of these played a greater role in the destruction of Pompeii? . . . of Herculaneum? . . . of St. Pierre? . . . of Armero? Which of these villages was destroyed by the eruption of Mt. Pele? . . . Nevado del Ruiz? . . . Mt. Vesuvius? |
|
Definition
Pyroclastic flows.
Pyroclastic flows.
Pyroclastic flows.
Lahars flows.
Martinique St. Pierre
Armero
Pompeii |
|
|
Term
| What is a volcanic vent? . . . a parasitic cone? . . . a fumarole? . . . the most abundant volcanic gas? |
|
Definition
A volcanic vent is an opening exposed on the earth's surface where volcanic material is emitted.
a parasitic cone?Such fractures may occasionally tap the magma source and act as conduits for flank eruptions along the sides of the volcanic edifice. These eruptions can generate cone-shaped accumulations of volcanic material, called parasitic cones.
fumarole?Fractures can also act as conduits for escaping volcanic gases, which are released at the surface through vent openings called fumaroles.
H20 (vapor) C02, S02 |
|
|
Term
| Know the three general types of volcanoes. How do they differ in size, shape, composition, and explosive potential. Which is more likely to produce a Plinian eruption? |
|
Definition
Scoria (cinder) Conessmall, steep, straight sides. They usually occur on the sides of other larger volcanoes. They are 100% basalt, pyroclastic (tephra) material. They are slightly more explosive than shield (but still considered non explosive) the volcano grows due to the accumulation of pyroclastic material.
Strato (composite) volcanoes---What we think of when we think of volcanoes. There is a small summit crater in the center. They are the most deadly and picturesque of all volcanoes. Composed of lava and pyroclastic (tephra) material. High gas pressure, high viscosity.
Strato |
|
|
Term
| a small pyroclastic eruption? . . . an extensive lava flow? . . . a lava dome? . . . a caldera? Know examples of all three volcano types. |
|
Definition
Scoria
shield
strato
strato or shield
example of scorio volcanoParicatin, Mexico.
example of Shield volcanoMauna Loa, Hawaii.
example of strato volcanoMt. Fiji, Mt. Rainer, Washington. |
|
|
Term
| What is spreading center volcanism? |
|
Definition
| mid ocean ridges spreading creating new basalt. |
|
|
Term
| subduction zone volcanism? |
|
Definition
| where you find convergent boundaries. andesite is produced here mostly around the pacific rim (andes, cascades, japan, phillipines) this is called the "ring of fire." ... A subduction zone is where one plate (usually the ocean plate) dives under another (continental) plate. Friction causes earthquakes along it and melts the rock. The molten rock may have enough pressure to break the surface to form volcanoes. |
|
|
Term
|
Definition
Means this type of volcano doesn't happen at a plate boundary, but within the plate itself.
It is caused by mantle plumes. This produces basalt.
Ex. Hawaii |
|
|
Term
| Which is associated with generation of stratovolcanoes? . . . the generation of andesite? . . . the generation of basalt? . . . a mantle hotspot? In what direction do the Hawaiian and Emperor volcanic chains become younger? |
|
Definition
Subduction volcanism.
Subduction volcanism.
Intraplate / spreading center volcanism.
hotspot---intraplate volcanism
further south east. |
|
|
Term
| Know the nature of giant explosive eruptions such as those that have occurred at Yellowstone and Long Valley (Mammoth), California. In what way do these caldera-forming eruptions differ from smaller caldera-forming eruptions such as occurred at Crater Lake, Oregon? Which produces voluminous pyroclastic sheetflows? |
|
Definition
Super volcano is too big to sit on earth surface, it would be subducted, so there are super eruptions. It is not a point source eruption, it comes from cracks in this large pancake shape, then a great volume of sheet flow comes out.
They form in a similar way to a standard caldera, but there was never a volcano there to begin with at Yellowstone or Long Valley, this is the difference between the two.
Giant resurgent calderas (a surge upwards) |
|
|
Term
| Have a comprehensive understanding of the volcanic processes and natural disasters associated with Lake Nyos, Mt. Pele, Mt. St. Helens, Nevado del Ruiz, Pompeii, Mt. Pinatubo, Kilauea, Herculeneum, Long Valley (Mammoth Mtn.), Mt. Rainier, Paricutin, and Yellowstone. |
|
Definition
dense cloud of c02.
Strato (lahars).
Strato (pyroclastic falls)
Strato (lahars)
Strato (pyroclastic falls)
Strato (huge c02 cloud)
Shield (fire fountains)
Strato (pyroclastic flows)
Caldera (possible super volcano)
Strato (lahars)
Scorio (cones)
Caldera (possible super volcano) |
|
|
