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Friday, March 11

  1. page Volcanoes edited ... {http://library.thinkquest.org/C0112681/images/erupt1.jpg} Hawaiian The least violent type of…
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    {http://library.thinkquest.org/C0112681/images/erupt1.jpg} Hawaiian
    The least violent type of eruption. Large amounts of runny lava erupt and produce large volcanoes with gentle slopes.
     
     
     
     
     
     
     
     
     
     
     
     

     
     
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    Strombolian
    Mild but fairly regular eruptions. Small sticky lava bombs, ash, gas and glowing cinders erupt.
     
     
     
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  5. page Volcanoes edited ... {http://library.thinkquest.org/C0112681/images/cone2.jpg} Shield volcanoes, like Mauna Loa o…
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    {http://library.thinkquest.org/C0112681/images/cone2.jpg}
    Shield volcanoes, like Mauna Loa on Hawaii in the Pacific Ocean, and Piton de la Fournaise on Reunion Island in the Indian Ocean, are made up of basalt-rich lava which is thin, runny and spreads a long way from the vent. As a result, shield volcanoes are very large but have very gently sloping sides. Shield volcanoes are mostly made up of lava and contain very little ash or cinder (approximately 95 per cent lava and 5 per cent ash).
    {http://library.thinkquest.org/C0112681/images/cone3.jpg}
    Composite cone volcanoes, also known as stratovolcanoes, make up more than 60 per cent of all volcanoes on earth. They are usually quite tall. They are formed by a cycle of quiet eruptions of runny lava followed by explosive eruptions of thick lava. Stratovolcanoes have more ash than shield volcanoes. This combination of high ash content and a thick, slow-moving lava means that their sides are much steeper than shield volcanoes. Mount St Helens in the USA, Pinatubo in the Philippines and Fuji in Japan are all examples of composite cone volcanoes.
    {http://library.thinkquest.org/C0112681/images/cone4.jpg}
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  6. page Minerals edited ... Vitreous- Glassy surface Ex. quartz Earthy-Very dull surface Ex. orthoclase, kaolinite Colo…
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    Vitreous- Glassy surface Ex. quartz
    Earthy-Very dull surface Ex. orthoclase, kaolinite
    Color- The physical color of the surface
    Streak-The color of a mineral when it is in powder form.
    Cleavage/Fracture- Breakage of a mineral along planes of weakness in crystal structue. If the mineral breaks with planes it has cleavage and if it breaks with no planes it has fracture.
    Specific Gravity- comparison of it's denisty to that of water. Found by displacing water.

    Mineral Identification
    Minerals can be identified throught
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  7. page Volcanoes edited Types of Volcanoes Volcanic Types There are three types of volcanoes and each are determined b…
    Types of Volcanoes Volcanic Types
    There are three types of volcanoes and each are determined by observing plate movements which formed them. They are hot spot, rift, and subduction.
    Simply rift volcanoes form along the boundary of two plates as they tear apart and are usually under water. Hot spots volcanoes are created by hot magma plumes rising to the surface from deep within the mantle. A observable result from hot spot volcanoes are the Hawaiin islands built up from rising and cooling magma overtime. Lastly there's subduction volcanoes that come from collisons between tectonic plates. Subduction are argueably the most important to understand due to there destructive power and abillity to change the fate of the world.
    Volcanic formsForms
    The shape and size of a volcano are determined by:
    The type of eruption
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    Acid lava cone volcanoes are made up of lava which is thick or viscous. This flows very slowly, like treacle, and does not extend very far from the vent. It forms cones that have steep sides. An example is Mount Ngauruhoe in New Zealand which last erupted in 1975.
    {http://library.thinkquest.org/C0112681/images/cone2.jpg}
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    cent ash).
    {http://library.thinkquest.org/C0112681/images/cone3.jpg}

    {http://library.thinkquest.org/C0112681/images/cone3.jpg}

    Composite cone volcanoes, also known as stratovolcanoes, make up more than 60 per cent of all volcanoes on earth. They are usually quite tall. They are formed by a cycle of quiet eruptions of runny lava followed by explosive eruptions of thick lava. Stratovolcanoes have more ash than shield volcanoes. This combination of high ash content and a thick, slow-moving lava means that their sides are much steeper than shield volcanoes. Mount St Helens in the USA, Pinatubo in the Philippines and Fuji in Japan are all examples of composite cone volcanoes.
    {http://library.thinkquest.org/C0112681/images/cone4.jpg}
    http://library.thinkquest.org/C0112681/Eng/Normal/Kids/cause.htm
    lava
    Types of Volcanic Eruptions
    Volcanoes can be divided according to the explosiveness of their eruptions. The least severe are known as Hawaiian eruptions – these generally produce shield volcanoes. The most severe are called Plinian eruptions – these often involve the collapse of the volcano’s cone and the formation of a caldera. Plinian eruptions were named after the Roman scholar Pliny the Elder, who lost his life, when Mount Vesuvius erupted in AD 79. His nephew, Pliny the Younger, wrote to Tacitus describing the eruption as it began.
    {http://library.thinkquest.org/C0112681/images/erupt1.jpg} Hawaiian
    The least violent type of eruption. Large amounts of runny lava erupt and produce large volcanoes with gentle slopes.
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
    {http://library.thinkquest.org/C0112681/images/erupt2.jpg}
    Strombolian
    Mild but fairly regular eruptions. Small sticky lava bombs, ash, gas and glowing cinders erupt.
     
     
     
     
     
     
     
     
     
     
     
     
     
    {http://library.thinkquest.org/C0112681/images/erupt3.jpg} Vulcanian
    Violent eruptions shoot out very thick lava and large lava bombs.
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
     
    {http://library.thinkquest.org/C0112681/images/erupt4.jpg}
    Peleean
    A violent type of eruption. Thick, sticky lava is accompanied by a burning cloud of ash, gas and pumice (a nuee ardente, which is French for ‘fiery cloud’).
    {http://library.thinkquest.org/C0112681/images/erupt5.jpg} Plinian
    The most violent type of eruption. Cinders, gas and ash are flung explosively high into the air. The volcano cone often collapses to form a caldera.
    Lava Domes
    In volcanology, a lava dome is a roughly circular mound-shaped protrusion resulting from the slow extrusion of viscous lava from a volcano.
    {http://upload.wikimedia.org/wikipedia/commons/thumb/0/0c/Volc%C3%A1n_Chait%C3%A9n-Sam_Beebe-Ecotrust.jpg/250px-Volc%C3%A1n_Chait%C3%A9n-Sam_Beebe-Ecotrust.jpg}
    {http://bits.wikimedia.org/skins-1.17/common/images/magnify-clip.png}
    Image of the rhyolitic lava dome of Chaitén Volcano during its 2008–2009 eruption.
    {http://upload.wikimedia.org/wikipedia/commons/thumb/f/f3/Mono_Crater_closeup-1000px.jpeg/250px-Mono_Crater_closeup-1000px.jpeg} {http://bits.wikimedia.org/skins-1.17/common/images/magnify-clip.png}
    One of the Mono Craters, an example of a rhyolite dome.
    {http://upload.wikimedia.org/wikipedia/commons/thumb/a/a4/MSH06_aerial_crater_from_north_high_angle_09-12-06.jpg/250px-MSH06_aerial_crater_from_north_high_angle_09-12-06.jpg} {http://bits.wikimedia.org/skins-1.17/common/images/magnify-clip.png}
    Lava
    domes
    types
    in the crater of Mount St. Helens
    http://en.wikipedia.org/wiki/Lava_dome
    Types of Lava Flows
    {http://library.thinkquest.org/17457/volcanoes/lava1.jpg} Pahoehoe
    (Fig. 2.46) Pahoehoe lavas. Credit: Dr. Duncan Heron
    Pahoehoe lavas are thin. They flow smoothly and are often formed by small volumes of hot, fluidbasalt. The higher the volume
    of lava emitted the faster the current. Pahoehoe flows
    Famous volcanoes: (Vesuvius)
    Supervolcanoes
    pyroclastic
    move forwards in tongues or lobes and are characterized by a glassy, plastic skin. They may embrace obstacles at a rate of about 50m an hour. When the pahoehoe lava flow cools, it often solidifies to a smooth surface.
    {http://library.thinkquest.org/17457/volcanoes/sheetlava.jpg} Sheet Lavas
    (Fig. 2.47) Sheet lavas. Credit: Mr.Mathot
    Sheet lavas emerge from fissure systems forming
    flows
    commonly ranging between 10m and 30m in thickness. They flow out so fast that vast volumes of basalt are discharged over an enormous area. Featureless lava plateaus are formed. During the eruption of Roza, Oregon, 14 million years ago, 1500km3 of sheet lavas were produced in about a week.
    {http://library.thinkquest.org/17457/volcanoes/lava3.jpg} Aa Flows
    (Fig. 2.48) Aa Flows. Credit: Dr. Duncan Heron
    Aa flows are emitted from the vent at high rates ranging to 50km an hour, often with much lava fountaining. They are characteristic of viscousmagmas. Aa flows are animated with sporadic bursts of energy. They may push down houses, walls and forests. However, the hallmark of aa lava flows is the very rough surface it produces when it cools and solidifies.
    {http://library.thinkquest.org/17457/volcanoes/lava4.jpg} Block Lavas
    (Fig. 2.49) Block Lavas. Credit: Dr. Duncan Heron
    Block-lavas are often emerged in a fairly viscous state. They tend to be both stronger and thicker than aa lava flows. The more silicic the magma, the shorter and stubbier is the flow. Block lavas move slowly at a rate ranging from 1 to 5 meter a day. When solidified, they are characterized by often cubic masses with relatively smooth faces. In comparison with aa lava flows the surfaces of block lavas are much less rough and pitted than aa lava flows.
    http://library.thinkquest.org/17457/volcanoes/hazards.lavaflow.php
    super volcanoes, famous volcanoes, pyroclastic flow

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  8. page Metamorphic Rocks edited ... Contact metamorphism: Contact metamorphism is basicly know as high heat low pressure metamor…
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    Contact metamorphism:
    Contact metamorphism is basicly know as high heat low pressure metamorphism. What essientally this means is that
    regional metamorphism. change take place when magma is injected into the surrounding solid rock causing it to change its structure. This is usually as more localized area.
    Metamorphism is restricted to the zone surrounding the intrusion. Rocks outside of the contact zone aren't affected by the intrusive event. The grade of metamorphism increases in all directions toward the intrusion. Due to the temperature contrast between the surrounding rock and the intruded magma contact metamorphism is often referred to as high temperature, low pressure metamorphism. The rock produced is often a fine-grained rock that shows no foliation, called a hornfels.
    Regional Metamorphism:
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    Types of Metamorphic Rocks:
    {ibcGetAttachment.jpg}
    metamorphicMetamorphic Rock Uses:
    Uses of common metamorphic rocks.
    SCHIST: A metamorphic uneven-granular, medium to coarse grained, crystalline with prominent parallel mineral orientation. Goes from silvery white to all shades of gray with yellow to brown tones depending on the mineral concentration. Some schists have graphite and some are used as building stones.
    GNEISS: A metamorphic uneven granular medium to coarse grained crystalline with more or less parallel mineral orientation. Colors are too variable to be of diagnostic value. Due to physical and chemical similarity between many gneisses and plutonic igneous rocks some are used as building stones and other structural purposes.
    QUARTZITE: A metamorphic or sedimentary
    rock with crystalline texture, consists of rounded quartz grains cemented by crystalline quartz, generally white, light gray or yellow to brown. Same uses as sandstone.
    MARBLE: A metamorphic even-granular grain to medium grained and may be uneven granular and coarse grained in calc-silicate rock. The normal color is white but accessory minerals act as coloring agents and may produce a variety of colors. Depending upon its purity, texture, color and marbled pattern it is quarried for use as dimension stone for statuary, architectural and ornamental purposes. Dolomite rich marble may be a source for magnesium and is used as an ingredient in the manufacture of refracting materials.

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  9. page Fossils edited ... What are Fossils? Fossils (Latin fossus, meaning "having been dug up") are the pres…
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    What are Fossils?
    Fossils (Latin fossus, meaning "having been dug up") are the preserved remains or traces of animals, plants, and other organisms from the remote past.
    Types of FossilsPreservation
    An organism trapped in amber: amberamber:Amber seals an
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    the organism
    Silicification: also

    Silicification:Also
    known as
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    decayed wood.
    Phosphatization
    In general, the cell structure of petrified wood is poorly preserved, but the presence of other minerals can produce color with the wood.
    Phosphatization: Bones and teeth that are fossilized in lage quantities of phosphate. This is a form of preservation that produces well-preserved fossils.

    Limstone Tomb
    Pyritization
    The fossil record
    Tomb: The casting of organisms in limestone.
    Pyritization: An imprint of an organism which is molded in iron pyrite. This is unstable in moist air, therefor it is advised to store the specimen in very dry conditions.
    Fossilization

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