...Mauna Loa because of long-term increased seismicity rates and inflation of the summit (as measured by cross-caldera difference). This doesn't mean an eruption is imminent, but signs are consistent with magma entering the shallow part of the magmatic system at the volcano. Mauna Loa is a "shield volcano", which means it is a gently sloping mountain produced from a large number of generally very fluid lava flows. The volcano has been erupting for at least 100,000 years prom a primary volcanic centre that is presently manifested by Moku'aweoweo crater at the mountain's summit. It has produced both a'a and pahoehoe flows, and lesser amounts of pyroclastic deposits. The volcano is constructed of a rock type known as tholeiitic basalt http://www.bgs.ac.uk/research/volcanoes/changingEruptionStyles.html http://www.livescience.com/29824-why-eyjafjallajoekull-volcano-erupted.html Eyjafjallajökull last erupted between 1821–1823. There were also documented intrusion events in 1994 and 1999 but magma didn't reach the surface. In the weeks prior to the eruption intense seismicity and high rates of deformation...
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...Introduction: My investigation looks into how environmental characteristics change with an increase in altitude along a 750m transect of Dumyat. Dumyat is the frontier hill of the Ochill range, which lies on the north side of the fourth valley, approximately 3.5 miles north east of Stirling. It was formed from the build up of layers of basalt, ash and volcanic mud from the Lower Devonian period, some 410 million years ago. Dumyat is also composed of Andesite, a dark grey igneous rock. The distinctive south facing cliff, known as a scarp was formed when movement in the Ochill fault line caused land to the north to move upwards and land to the south to slip downwards. The Ochill fault is no longer visible today due to it being covered with top soil and glacial moraine. The formation of the scarp exposed areas of hard and soft rock. Millions of years later glaciers moved through the the Fourth Valley, in doing so they eroded the soft rock (e.g. Red Sandstone) by plucking, abrasion and freeze-thaw. Plucking is when the glacier freezes onto rocks on the sides and base, before pulling them out, creating moraine that will later be deposited. Abrasion occurs...
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...continental flood basalts, rifted continental margin volcanic sequences and oceanic plateaus. Many large igneous provinces can be associated with mantle plumes. Where plumes ascend beneath spreading ridges, their energy is transformed into a large melt volume, producing over-thickened plateau crust. Comparing the timing of mass extinctions with the formation age of large igneous provinces reveals a close correspondence in several cases. The Columbia River Basalt Group is a large igneous province, which covers parts of the western United States. There are significant landforms associated with this formation that provide evidence as to the age and controlling mechanisms of its emplacement. 1. Introduction Large igneous provinces (LIPs) are massive emplacements of extrusive and intrusive mafic rock. Processes other than seafloor spreading form these mass emplacements and they are the primary mechanism of terrestrial magmatism on earth. LIPs are distinguishable from mid-ocean ridge magmatism and arc magmatism on the basis of petrologic, geochemical, geochronological and physical volcanological data. Large igneous provinces occur in both continental and oceanic crust.(Coffin and Eldholm, 1991). The purpose of this review is to give an overview of the types of LIPs, their formation, and the possibility of their contribution to mass extinction events. 2. Types of Large Igneous Provinces LIPs are characterized by the attributes of their primary mafic rocks. Research has primarily...
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...The Jordan Craters volcanic field is located on the Owyhee-Oregon Plateau at the southeastern end of a series of young basalt fields extending from near Bend, Oregon, through Diamond Craters in south-central Oregon (Volcanoes of the World). The Jordan Craters field is limited to the northern most and youngest portion of a larger (250 square kilometers) Quaternary alkaline basalt field. There are three major vent areas aligned north to south along surficial and inferred expressions of the regional Basin and Range faulting (Hart, W.K., and Mertzmann, S.A.). Fluid pahoehoe basalt flows emanated from each of these sources, with pyroclastic activity confined to small scatter cones and to a larger crater-cone complex (Coffeepot Crater) at the northernmost edge of the Jordan Craters portion of this field (Volcanoes of the World). This entire Quaternary alkaline basalt field is part of a larger field (nearly 800 square kilometers) that includes Pleistocene and Pliocene olivine tholeiite to transitional basalt flows and vents. Jordan Craters is a wonderful sight mainly because of its well-preserved vents and striking flow features. Near Coffeepot Crater, the flow surfaces are vesicular shelly pahoehoe, which grade to massive tube-fed ropy pahoehoe in the distal regions. A 75-square-kilometer coffeepot Crater is a heart-shaped tephra cone constructed of numerous overlapping lobes of alternating densely to weakly welded scoriaceous lapilli and bombs (Volcanoes of the World). The walls...
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...McKenzie Mikesell Geology 102 Geological Time 17.1 A) The oldest rocks are at the bottom of the bunch. (Dirty Laundry effect). B) It would be the same because they build up over time and the layers at the bottom are older. 17.2 A) The incline beds in figure 17.2 are younger. B) Because the beds on top are older than the beds on the bottom and have not flipped over. C) Younger D) Younger E) Younger, You cannot deform a structure that is not there yet. F) Lava flow has smaller mineral crystals- extrusive Sill Display-Intrusive- Display larger crystals. 17.3 A) Xenolith is a clast of preexisting rock contained within an igneous rock. B) Its older, clasts are usually older than the rock in which it is included. 17.4 DIAGRAM A) Drawing B) Right side up because ripple marks point up towards the younger material D) 4 is the youngest 17.5 17.9 C – G – A – I – K – F – D – J – H – B Layers E, A, F and I were once horizontal layers that were deformed with tilt. 17.10. E – A – F – I – C – K – G – D – H – J formed sequentially then underwent angular conformity and experienced some erosion. 17.11. A – F – B – E – H – K – J – I – D – G – C 17.12 D – J – F – G – C – B – E – I – H – A 17.6 A) Chonetes ,cleiothyridina, neospirifer, petrocrania, schizophoria 2)Leptanea Atrypa, chonetes, petrocrania, platystrophia, schizophoria 3)Petroerania platystrophia, strophomena B1)youngest B2) significant gap that spans the Devonian...
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...January 2011 Plate Tectonics and Associated Hazards (25 marks) a) The Philippines are located on the Philippine plate which is largely involved in the tectonic activity of the Pacific Ring of fire where you can find volcanoes and earthquakes which are two primary tectonic hazards, this is due to its location and the fact that numerous trenches are a strong piece of evidence to the presence of the sub-duction of tectonic plates. This makes me think that there is a strong degree to which this area of the Philippines is subject to tectonic hazards. Another piece of evidence supporting a strong chance of tectonic activity is the sheer volume of active faults on the islands compared to the actual land area of the countries, these are were the land has sustained damage over the years of plate movement and the rocks beneath are trapped against each other and creating tension that can be released to create an earthquake of a strong magnitude. Also visible from the image is the location of 5 volcanoes nad if these were to become active most of the countries in the Philippines would be in serious danger from tectonic hazards both primary and secondary like volcanic bombs or lahars. b) Hot spots are points where convection plumes are focusing on a single point beneath the crust as hot magma rises from the super-heated mesosphere into the asthenosphere where it cools and then proceeds to sink back down again. As this magma rises it carries radioactive elements with it and these...
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...Associate Level Material Comparison Worksheet Use the following table to compare extrusive and intrusive rocks. Describe and compare each type in at least 150 words. Extrusive Rock Intrusive Rock Extrusive rock refers to igneous volcanic rock formation in which hot magma from inside the Earth flows out to the surface as lava or explodes violently into the atmosphere to fall back as pyroclastic. This is different from intrusive rock formation, in which magma does not reach the surface. The main effect of extrusion is that the magma can cool much more quickly in the open air or under seawater, and there is less time for the growth of crystals. Often, some of the lava fails to crystallize at all, becoming an interstitial natural glass or obsidian. If the magma contains abundant volatile components which are released as free gas, then it may cool with large or small vesicles (bubble-shaped cavities) like those found in pumice or scoria. These rocks form many kilometers below the Earth’s surface, as molten rock called magma flows into cracks or underground chambers. There, the magma cools very slowly over thousands to millions of years. As it cools, elements combine to form common silicate minerals, the building blocks of igneous rocks; the mineral crystals can grow quite large if space allows. Rocks that form in this way are called intrusive igneous or plutonic rocks. The mineral crystals within them are large enough to see without a microscope. There are many different...
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...MEDC MOUNT ETNA • Supports rich agricultural land and it is estimated that 35% of Sicily’s population live on its slopes. • The UN has classified it as a Decade Volcano due to its activity and nearby population. • There have been at least 16 flank eruptions, and many summit eruptions, since 1600s. Since 2001, it has seen an eruption every year. • It is well monitored and actively managed. NATURE OF THE VOLCANIC HAZARD: • Vineyards and orchards spread across the lower slopes and the Plain of Catania. • It is a composite stratovolcano which typically erupts basaltic lava (low viscosity). • Fissures also open up, releasing lava flows and ‘hornitos’ spatter lava from the side of the cone. OTHER POTENTIAL HAZARDS: o Seismic activity connecting with eruptive activity – potential damage to buildings and infrastructure. o Gas plume emission, volcanic dust and ashfalls – high-magnitude explosive events at summit craters can lead to the formation of eruptive columns of ash, the fallout from which presents problems for settlement and agriculture. o Flank collapse before or following – one of the most hazardous processes – can lead to a huge avalanche of volcanic debris, as once occurred at the Valle del Bove. o Phreatic eruptions – steam-driven explosions when water beneath the ground is heated by magma or lava. • In 1669 extensive lava flows engulfed Nicolosi, and in 1928 a large lava flow destroyed Mascali in just two days. • In 2002-3 the biggest eruptions for many...
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...“Disappointment is an inevitable consequence of discovery” To what extent is this true in Jean Spracklands poem International Year of the Oceans? Discovery is something that can be good or bad. The concept of disappointment being an inevitable consequence of discovery refers to discovery in a light that seems to ruin or denote something. This idea can be explored in Jean Spracklands poem International Year of the Oceans in which many this significant concept can be viewed. Discovery is able to disrupt the natural ways of the universe. The beauty of undisturbed nature is something that is able to provoke an emotional response from someone, especially if little is known about it. Immediately in the poem the audience is invited to imagine what it was like for the author’s grandparents. That is, “Our grandparents lived with a romantic moon.” Similarly, later the audience imagines where “a warm ocean sleeps.” Sprackland’s use of soft sounds in these two phrases reflects a peaceful and fully undisrupted moon and ocean, inviting the audience to imagine what it would be like. This is contrasted in the last stanza when Sprackland mentions “nuclear submarines”, suggesting abandonment, war and the eventual destruction of this sleeping ocean for our needs. The idea of disappointment being an inevitable consequence of discovery is supported throughout the poem. This disappointment is evident throughout the poem, thus being through harsh imagery (“Nuclear Submarines”) and intruding language...
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...Bay River) 3. Gabbro w/ Augite Group: Igneous Texture: Phaneritic Type: internal Augite Chemical Formula: (Ca,Na)(Mg,Fe,Al)(Si,Al)2O6 Collected: (Mammoth Bay River Bed) 4. Dacite Group: Igneous Texture: Aphanitic Type: internal Collected: (Along American River) 5. Slate Group: Metamorphic Texture: Foliated Type: Low-Grade Collected: (Grass Valley, Trinity River) 6. Shale Group: Sedimentary Type: Clastic Texture: Smooth Collected: (Mammoth Bay on Shore of River) 7. Andesite Group: Igneous Texture: Aphanetic Type: Extrusive Collected: (Mammoth Bay near River) 8. Limestone Group: Sedimentary Texture: Fine Grain Type: Chemical/Bio clactic Collected: (Mammoth Bay Shore of River) 9. Andesite/Basalt (Basaltic Andesite) Group: Igneous Texture: Aphanetic Type: Intermediate Collected: (Along American River) 10. Metaconglomerate Group: Metamorphic Texture: Non-Foliated Collected: (Grass Valley, Trinity River) 11. Serpentine Group: Metamorphic Texture: Non-Foliated Type: Orthoclase Collected: (Mammoth Bay River Bed) 12. Diorite Group: Igneous Texture: Phaneritic Type: Intermediate Collected: (Mammoth Bay, Near River) 13. Quartz Group: Igneous Chemical Formula: SiO2 Collected: (Mammoth Bay River) 14. Chert Group: Sedimentary Chemical Formula: SiO2 Collected: (Mammoth Bay Trail) 15. Sandstone Group: Sedimentary Texture: Fine Grain Type: Clastic Collected: (Mammoth Bay River Edge) 16. ...
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... Yellowstone is a national park that has many hot springs. Do you know what is powering all of those hot springs and geysers? There is a giant volcano, otherwise known as a supervolcano, under the surface of Yellowstone. This blog will cover what makes the supervolcano power the hot springs and geysers and what environmental effects the supervolcano will have if it goes off. The hot springs and geysers of Yellowstone are all powered by a supervolano under the surface. Scientist have discovered that the volcano goes 600 miles deep, but are predicting that it could go all the way down to 1,800 miles. That would be all the way to the outer core-mantel boundary of the earth. The magma comes up and rests in chambers called magma reservoirs. These reservoirs are "superheated, sponge like rock holding pockets of molten material called magma." These pockets are what power all of the Yellowstone geysers and hot springs. Since this volcano is so large it is making resurgent domes. These are land formations that are caused when the heat from the supervolcano pushes up against the crust and forces it up to make room for the magma. Since this volcano is so deep and cover nearly 30 miles by 40 miles it can have major effects on our environment when it goes off. It would cause a sheet of ash to cover the entire globe. This sheet of ash would not let any sunlight in to our planet. No sunlight would cause the plants to die and the food supply to plummet. Also, this will cause a very cold...
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...Sea-floor spreading, the theory of plate tectonics, and continental drift, are three different theories stating three different things. These theories have many aspects that they share, while they also have their own unique aspects. The theory of sea-floor sreading says that molten material is shot up from the mantle through mid-ocean ridges and cools, forming magnetic strips across the ocean floor. Then, as the molten material cools it gets heavier and sinks into trenches to start this process all over. sea-floor spreading is a proven theory. The theory of plate tectonics says that the earth is divided into many equal plates that are constantly moving, due to convection currents. The continental drift is the theory that all of the continents were once one supercontinent called Pangaea and have since moved to their current locations. These three theories were all developed and are now accepted to be true. In the following paragraphs, you will learn just how different these three theories are. Seafloor spreading, theory of plate tectonics, and continental drift are all very alike in certain ways. sea-floor spreading, like the theory of plate tectonics, is always happening. “.. Plate tectonic theory supposes that plates move very slowly - about 2 to 18 centimeters per year”(Nevins 1). The movement of plate tectonics is very slow and gradual. The movement of the continental drift is just as gradual if not more. “By about 200 million years ago, this supercontinent began...
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...Igneous rocks form in three main places: where lithospheric plates pull apart at mid-ocean ridges, where plates come together at seduction zones and where continental crust is pushed together, making it thicker and allowing it to heat to melting. There are two ideas about igneous rocks that are geologically important. The first idea is that igneous rocks evolve - they change from one kind of rock into another. The second idea is that rocks are not randomly distributed across the earth. Specific kinds of rocks are always found in specific places for specific reasons, all tied into plate tectonic processes. Igneous rocks begin as hot, fluid material, and the word "igneous" comes from the Latin for fire. This material may have been lava erupted at the Earth's surface, or magma (un-erupted lava) at shallow depths, or magma in deep bodies (plutons). People commonly think of lava and magma as a liquid, like molten metal, but geologists find that magma is usually a mush — a liquid carrying a load of mineral crystals. Magma crystallizes into a collection of minerals, and some crystallize sooner than others. Not just that, but when they crystallize, they leave the remaining liquid with a changed chemical composition. When a body of magma, as it cools, evolves, and as it moves through the crust, interacting with other rocks, it evolves further. This makes igneous petrology a very complex field. Tell the three types of igneous rocks apart by their texture, starting with the size of the...
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...Associate Level Material History of Rock Worksheet Leah Bechtel 12/09/2012 SCI/245 Robert Dillon Write a 500- to 750-word explanation regarding the role of plate tectonics in the origin of igneous rocks. The role of plate tectonics in the origin of igneous rock is extremely important. Igneous rock is formed from magma that reaches the continental and oceanic crust or through hot spots that are around the world. There are three different places where igneous rocks can form; where the lithospheric plates pull apart at mid ocean ridges, where plates come together at seduction zones, and where continental crust is pushed together making the crust thicker and allowing it to heat to a melting point. The word igneous comes from the Latin word for fire, igneous rocks start off as a hot, fluid material which is usually erupted from the Earth’s surface as lava, or magma at shallow depths or deep depths. Magma is a mush like material that can carry a load of minerals, but people often think of lava and magma as a liquid like material of molten metals. The three types of igneous rocks are extrusive, intrusive and platonic rocks. Extrusive rocks are rocks that form and cool on the crust of the Earth whether it is on the continental crust or the oceanic crust. Extrusive rocks cool quickly, within a few seconds to months and they have invisible or very small grains; extrusive rocks have an aphanitic texture. Intrusive rocks are rocks that form within already existing rocks causing...
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...History of Rocks As explained in Visualizing Geology, rocks are the words that tell the story of Earth’s long history and minerals are the letters that form the words. While this report will not be discussing minerals, it will introduce the history of rocks and how they are affected by plate tectonics. The focus of this report is on two of the three types of rocks, igneous and metamorphic rocks. Plate tectonics plays a key role in the life of these types of rocks. So let’s get started by first explaining igneous rocks. Next metamorphic rocks will be explained. Lastly, plate tectonics and the affect this theory has on both types of rock. Igneous rocks are rocks that form from magma that has been cooled and solidified. Igneous rocks have a structure that is made up of crystals. Igneous rocks are placed into to categories. As stated before, rocks are created by minerals. The process of a liquid forming into a solid is known as crystallization. The first category is extrusive or volcanic. These rocks are cooled on the top of the Earth’s surface. Extrusive rocks have microscopic crystals because it cools relatively quickly and the crystals do not have a chance to become as large as they could be. Extrusive rocks are formed by lava cooling. The second category is intrusive or plutonic. These rocks are cooled below the Earth’s surface. Intrusive rock is formed by the cooling of magma. Intrusive rocks have crystals that can be seen with the naked eye because the cooling process is relatively...
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