Igneous rocks are formed by...?
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Igneous rocks are formed when molten rock (magma) cools and solidifies, with or without crystallization, either below the surface as intrusive (plutonic) rocks or on the surface as extrusive (volcanic) rocks. This magma can be derived from either the Earth's mantle or pre-existing rocks made molten by extreme temperature and pressure changes. Over 700 types of igneous rocks have been described, most of them formed beneath the surface of the Earth's crust. The word "igneous" is derived from the Latin ignis, meaning "fire".
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Sedimentary rocks can be divided into two major informal groups, referred to as clastics (or siliciclastics) and carbonates. Clastic rocks are formed by erosion of other rocks, igneous, metamorphic and sedimentary. These 'clasts' can be mud, silt, sand, cobbles, or boulders, and are transported by wind, water, or gravity and accumulate where they eventually are buried and pressure and temperature subject them to diagenesis, the process that makes them from unconsolidated clasts to one rock mass. Shale, sandstone, and conglomerate are examples of clastics.\n\nCarbonates can work much differently since they form primarily in the oceans. Many carbonates are made from reefs and other living organisms that grow in the ocean. As these organisms die and leave behind their carbonate skeletons, rocks are formed. Other carbonates are formed from small grains called ooids, small balls that form by precipitating out of sea water, possibly with the help of bacteria or algae. Some ocean algae even form carbonate 'mud' that eventually becomes hard rock. \n\nAnother unusual group of sedimentary rocks are called evaporites. These are rocks like gypsum and rock salt that are deposited by evaporation of water in confined basins. \n\nThe most fascinating part about sedimentary rocks is that they have a past, each one tells a story.
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woohoo geology... lets see if I remember anything...\n\nOkay here is a basic thing, the composition of rocks, especially it's silicate level, can tell us much about the molten/semimolten layers of Earth.... Okay I was enver very good in this subject, so look here...\nhttp://en.wikipedia.org/wiki/Geology
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the rock starts as magma turns into igneous then to sedimentary the metamorphic....extreamly siplified but i think u get the point\nheres what a more complex on looks like\nhttp://geologyonline.museum.state.il.us/tools/lessons/6.4/rockcycle.gif
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when a volano explodes it erupts lava.The lava is very hot but it still cant melt the volcano.The lava will cool off,forming a rock.Rocks that are formed when lava cools is called a Igneuse rock.It is very hard to melt a intire volcano.If the lava melts the volcano at all,only a little bit of the inside would be melted. the lava just dries up
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The answer is metamorphic. It literally translates to "change form".\n\nThe statement says "pressure & heat" but does not say anything about melting. If it had said melting then it would have been igneous.\n\nIn order for a rock to become igneous it has to have melted completely.\n\nHeat & pressure cause rocks to undergo changes in crystal structure in essence causing them to realign.\n\nExample: Marble is the metamorphic form of the sedimentary rock limestone. The heat & pressure changed the crystal structure but not the chemical formula. It is still CaCO3.
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The term comes from the Latin word "Ignis" which means fire. Igneous rocks are produced by melting within the earth and later cooling of the molten magma.\n\nThere are two major subdivisions of igneous rocks:\nExtrusive\nIntrusive\n\nExtrusive igneous rocks come from volcanic activity. They are "extruded' by being ejected from a volcano or being part of a slow moving lava flow on the surface of the earth.  Examples: basalt flows, pumice, obsidian, ash, scoria\n\nIntrusive igneous rocks are formed by these molten rocks as they cool within the earth. The slow cooling allows the rock to separate into different minerals and form grains. Large masses of intrusive rocks that harden within the earth are called batholiths and plutons, depending on the size.  Examples of intrusive igneous rocks are granite, gabbro, and monzonite. \n\nHere is a list with photos of examples:\nhttp://csmres.jmu.edu/geollab/Fichter/IgnRx/IgAlphabetical.html
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Water.\n\nWater is one of the key parts of the formation of magma in subduction zones. The water that is in the subducting plate lowers the melting point of the rock by a few hundred degrees C. The water in the subduction plate will boil and migrate upwards into the overlying wedge of mantle rock where it will reduce the melting point of the overlying mantle. This magma will migrate upwards and form a volcano. \n\nAnother part of this process is that within rock there are many different minerals, all with different melting points, so the ones that melt at the lowest temperatures tend to form magma first, so the resulting magma comes from a partial melt of the source rock.\n\nHere's another diagram (I'd draw you my own but I can't post anything but text here):\nhttp://earth.leeds.ac.uk/dynamicearth/subduction/cordillera_islandarc.htm
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Bowen's reaction series is what you're looking for.\n\nIn a nutshell, the rate of cooling, temperature, and magma composition determine which minerals form and the ultimate rock type.  The links provide more information.
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One way to distinguish between intrusive and extrusive igneous rocks is to observe the crystal size.\nRocks formed below groung (intrusive) have must longer to cool, resulting in a larger crystal size.\nOn the other hand, rocks formed above ground (extrusive) have a much smaller crystal size
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Geodes form by precipitation of minerals from solution. That would make it a chemical sedimentary rock. \n\nThey are not often found in intrusive igneous rocks because the geode needs a vug, or a cavity within the host rock in order to form. Intrusive igneous rocks rarely have vugs, but do sometimes have large fractures or joints that can be crystal lined similar to a geode. \n\nGeodes are more likely to be found in extrusive igneous rocks that have vugs formed by gas that comes out of solution as the rock cools rapidly (in comparison to intrusive igneous rocks). These vugs eventually may fill with fluid which carries dissolved calcite, quartz, and other minerals. As the fluid becomes oversaturated different minerals will drop out of solution forming layers of the geode and finally forming crystals within the center of the geode. \n\nThe similar things that form in sedimentary rocks are often referred to as concretions, and these are seldom hollow. They may be composed of calcite, chert, or other minerals, and will often have concentric rings within them. However, they do not form within a vug or cavity, but instead appear to grow outward. Septarian concretions have crystalline filled fractures inside them that makes them quite attractive. Concretions appear in most cases to form from a nucleus and grow outward, unlike a geode's growth inward.
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It depends on the volcano.\n\nIf magma - molten rock - is erupted it forms new formations when it cools. On the big island of Hawaii, the volcanic eruptions have added a lot of new land to the island.\n\nIf it is a pyroclastic flow - fast, hot gasses and volcanic debris -  like the one that destroyed Pompeii or Mt. St. Helens, there may not be any new land created and the existing land will be radically altered.\n\nIn general, when a land based volcano erupts, the lava and stone and ash build up around the eruption site into a cone shape.\n\nUndersea volcanos spweing lava also build up, but not in a cone shape. Once the hot rock hits water it starts to cool into large pillow-shaped forms.
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ok. i am giving u links which will help u find the right information fast and efficiently. since you have to write in ur words, its better that u deduce the answers urself. it should be quite simple and it will help you.\n\nbasically granite is an igneous rock which is formed due to the cooling down and crystallization of molten magma. here are the links which will help u. there is a file included which is quite informative.\n\nMost of the sites have overlapping information, so use the info u need. Have fun and do cite the links as the sources
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Both are igneous rocks, meaning they formed from molten rock (called magma when it is underground and lava when it is on the surface) and are pretty hard and dense, but the similarities trail off fast from there.\n\nGranite is an intrusive rock, which means it cooled off slowly well underground and crystals had time to grow relatively large.  If the crystals grow really large they call the rock a pegmatite; I've heard of a pegmatite in Russia with feldspar crystals the size of boxcars.\n\nBasalt is an extrusive rock, which means the molten rock flowed out onto the surface and cooled there quite quickly, leaving very little time for crystals to grow.  Some basalts do include some larger crystals that formed while the magma was still underground and moving up (and cooling) relatively slowly.  I've seen basalt from Hawai'i that contains pea-sized lumps of green olivine crystals.\n\nThe two differ chemically as well.  Granites contain more silica, and tend to be lighter in color than basalts.  Basalts tend to be more alkaline.\n\nGranites are associated with relatively low temperatures, around 800 degrees Celsius.  The minerals in basalt typically form at temperatures above 1300 degrees celsius.\n\nGranites are formed in continents , while basalts form at ocean spreading centers, like the mid-Atlantic Ridge, "hot spots", like the one that formed Hawai'i, and sometimes on continents.  Basalt also erupts on land; there are huge masses of basalt in the western United States (the Columbia River basalts) and in western India (the Deccan traps).
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granite....sand...\nhttp://images.google.com/imgres?imgurl=http://library.thinkquest.org/05aug/00461/images/igneous.jpg&imgrefurl=http://library.thinkquest.org/05aug/00461/igneous.htm&h=423&w=640&sz=262&hl=en&start=17&tbnid=1_Wjmt6u5ghPyM:&tbnh=91&tbnw=137&prev=/images%3Fq%3Digneous%2Brocks%26svnum%3D10%26hl%3Den%26lr%3D\n\n\nthe most common....basalt...\nhttp://images.google.com/imgres?imgurl=http://www.learner.org/channel/courses/essential/earthspace/images/show5-brit-with-igneous.jpg&imgrefurl=http://www.learner.org/channel/courses/essential/earthspace/session3/closer.html&h=300&w=300&sz=28&hl=en&start=14&tbnid=iEnzTA6MoGvW4M:&tbnh=116&tbnw=116&prev=/images%3Fq%3Digneous%2Brocks%26svnum%3D10%26hl%3Den%26lr%3D\n\n\npumice...\nhttp://images.google.com/imgres?imgurl=http://www.otago.ac.nz/geology/features/rocks-minerals/pumice.jpg&imgrefurl=http://www.otago.ac.nz/geology/features/rocks-minerals/rocks.html&h=667&w=800&sz=47&hl=en&start=6&tbnid=QxNtL7z7RM7VCM:&tbnh=119&tbnw=143&prev=/images%3Fq%3Dpumice%26svnum%3D10%26hl%3Den%26lr%3D\n\nobsidian...\nhttp://images.google.com/imgres?imgurl=http://faculty.icc.edu/easc111lab/labs/labb/rocks/ibox.jpg&imgrefurl=http://faculty.icc.edu/easc111lab/labs/labb/igneous.html&h=330&w=265&sz=59&hl=en&start=47&tbnid=6qFg9tv5UzEBnM:&tbnh=119&tbnw=96&prev=/images%3Fq%3Digneous%2Brocks%26start%3D40%26ndsp%3D20%26svnum%3D10%26hl%3Den%26lr%3D%26sa%3DN
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Igneous rocks make up approximately ninety five percent of the upper part of the Earth's crust, but their great abundance is hidden on the Earth's surface by a relatively thin but widespread layer of sedimentary and metamorphic rocks.
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You've been given exhaustive lists, copied directly from websites without giving proper citation I imagine. \n\nHere is how to think about this question so that you can recall and understand the answer, without just memorizing a bunch of rock names.\n\nUse the rock cycle. Igneous rocks are of two groups, those formed within the earth and those formed by volcanism.  The volcanic rocks will show signs of that volcanism and will be things like black columnar basalt found in massive flows. Obsidian (volcanic glass) that flowed as liquid, scoria and pumice which are like foam because the dissolved gases expanded and made them bubble as they hardened. The other igneous group formed under the earth's surface, and includes things like granite where you can see the crystals that formed as it cooled and solidified. \n\nSedimentary rocks are also in two major informal groups (and a minor third). The first group of sedimentary rocks is clastics. These are formed by weathering, transport and deposition. Weatherings breaks down rocks like igneous, metamorphic and even sedimentary rocks and transport by wind, water, or gravity deposits these rocks as accumulations of clasts, (thus clastics). They become sandstone, shale, and conglomerate. The other major sedimentary group is carbonates. These rocks are 'born' because they are formed by living things. Ocean environments (and lakes too) have many organisms that make shells, corals that make reefs, and algae that make fine carbonate sediments (known as carbonate mud). Even bacteria get into the act helping to precipitate carbonates in many ocean environments. The third group of sedimentary rocks is those that are dissolved by water and deposited by evaporation or precipitation. These include gypsum, halite, sylvite, and many more. \n\nMetamorphic rocks all start life as one of the previous groups. You can metamorphose a granite into a granitic gneiss by burial, pressure and heat. You can metamorphose a basalt into an amphibolite. You can make limestone into marble. Sandstone turns into quartzite.\n\nRemember the rock cycle, associate the rocks as they move through it, and you won't have trouble remembering examples of rock types. Also don’t get tripped up by the difference between a mineral and a rock. Geologists sometimes use the two terms identically, but there is a formal difference between a rock (which is an impure mixture) and a mineral that is chemically consistent.