What are the 3 classifacations of sedimentary rocks?
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detritic (sand and pebbles glued together)\nchemical (salt in the water)\nbiochemical (squeletons of aquatic animals)
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Erosion breaks up igneous and metamorphic rocks, and the particles build up to create sedimentary rocks.  \n\nHope this is helpful.
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the types of fossils are:\n\n1.  body fossils - fossils of the actual body or body parts of an organism, whether altered or not\n2.  trace fossils - any evidence of past life that is not a body fossil.  Examples include tracks, trails, burrows, borings, impressions, molds, casts.\n3.  pseudofossils - are things that appear to be fossils but are not.  The most deceptive of these are the lacy dendrites of manganese dioxide.  Often, inorganic rock concentrations are thought to be fossilized soft parts of various animals. \n\nto form a fossil, there are important prerequisites:  there should bequick burial & there should be a hard part or parts of the organism. the the organixm is notquickly buried, bacteria or other animals may destroy it.  if the organism dies in an anaerobic environment (absence of oxygen) the soft tissues may also be preserved.
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Igneous rock becomes sedimentary rock by weathering and erosion which makes sediments. The sediments then is deposited and is cemented together to cause sedimentary rock.
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general characteristics of clastic sedimentary rocks:\n\nthey may...\ncontain layers\nbe dull & earthy in appearance\ncontain clastic material (small grains of rock)\ncontain fossils\nrub off easily b/t fingers\nloosely "glued" together w/ minerals such as iron oxide & calcite
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Stratigraphic columns give the geologic history of an area. Faults & folding give a tectonic history. By examining the types of rocks that have been deposited, intruded, folded, turned over, etc. geologists have a "relative" idea (pun intended) of the workings of the earth in the past.\n\nI spend about a week teaching my 9th grade earth science students about stratigraphy. They love figuring out strat cross-sections. For them it's like doing a puzzle.
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First off sedimentary rock is necessary for oil and gas formation. A known anticline (hill shaped folding),  is necessary for the entrapment of the oil and gas.  The rock needs to be old enough for the oil and gas forming to occur. Your not going to find alot of oil in gas in quaternary or tertiary rock. I live in an area known as the Bradford oil field and the rock age here is mainly Devonian. \n\nMany paleoentologists are being employed these days in this field of oil exploration. A core or test sample is drilled and brought to the surface and from the fossils found a determination can be made if this is a possible site for oil. (2 cent version)
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rock formed from layered sediments that pile up and squeeze together, providing clues to the earth's past. an example is sandstone.
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Sedimentary Rocks usually have layers and are made up of pieces of other rocks. The grain size that makes up the sedimentary rocks can be of any size. Microscopic as in silt, small as in sandstone and large as in conglomerate.
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A clastic rock is a sedimentary rock formed of particles deposited by water, wind, ice, gravity.  The particles themselves would give the rock texture--think of the gritty surface of a sandtone. Detrital texture is described by size, shape, and composition or the sorting of the redeposited particles. \n\nA chemical sedimentary rock is formed by precipitating from water solution. They precipate "in place", and are not formed by redeposited particles like clastic rocks. These include evaporites, opal, some carbonates, iron oxides, etc. Stalactites are examples. Dried up lake beds form flat layers of evaporites, another example. Chemical textures are usually crystalline with some special descriptions like pisolitic or  oolitic.\n\nThe category not mentioned is that of biological sedimentary rocks--composed largely of plant or animal material.
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There are three basic types of rocks: igneous, sedimentary, and metamorphic.\n\nIgneous rocks are formed from molten magma or lava. Igneous rocks vary greatly in grain structure and size, depending upon how quickly the magma or lava cooled. An example of an igneous rock is obsidian.\n\nSedimentary rocks are formed when layers of sediment are compacted by pressure. They are often composed of fragments of materials derived from other rocks and minerals, especially quartz.\n\nMetamorphic rocks occur when igneous, sedimentary, or previously-formed metamorphic rocks are submitted to extreme heat or pressure beneath the earth's surface, changing their structure and appearance. They often exhibit "foliation" or color banding when mineral crystals are elongated due to pressure. An example of a metamorphic rock is slate.
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Metamorphic rocks are already existing rocks that change under heat, pressure or in chemical reactions (usually underground). Examples are Gneiss (that froms from Granite), Slate (formed from Shale), and Quartzite (formed from Sandstone).\n\nSedimentary rocks are rocks made from sediment (haha makes sense, no?) which can be both organic (fossils!) or inorganic. They are formed into a solid rock through a variety of different forces, including erosion, deposition, compaction, and cementation. There are 3 major groups of sedimentary rocks, which are clastic (formed from the compression of rock fragments), organic rocks (Key word: ORGANIC, aka the remains of plants and animals), and chemical rocks (formed when a solution dissolves, & minerals are left behind). Examples:\nClastic: Shale, Sandstone, Conglomerate, and Breecia\nOrganic: Coal, Limestone\nChemical: Halite, Gypsum\n\nIgneous rocks are formed from magma or lava. They are classifed according to where they were formed-- extrusive rocks are formed from lava on Earth's surface, while intrusive rocks are formed from hardened magma beneath Earth's surface. Texture and mineral composition are also factors of classification. Examples include granite (which is extremely abundant), Rhyolite, Pegmatite, Porphyry, Basalt, Pumice, and Obsidian.
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Physical Science, Earth Science, and Life Science. I don't personally like this break down of the sciences, but I think it is what you are looking for. There are lots of different ways that you could classify the sciences.
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I am not sure I understand your question so I will answer it two ways. Fossils are found in sedimentary rock because they originate as living organisms, and their remains will be carried away or buried by the same processes that create sedimentary rocks. Windblown sand will build and move sand dunes, moving water will transport sediment, gravity will cause piles of rock to build up at the base of mountains, and all sorts of sediment and remains will settle to the bottom of the sea. All are possible sedimentary rocks. Since igneous rocks were once melted, and metamorphic rocks undergo chemical changes from heat and pressure, it is not possible to find fossils in these rocks. \n\nMy second answer is how sedimentary rocks (and fossils) end up in layers. Many of the processes that move the sediment, like wind, flowing water, and some gravity driven events, only happen periodically. Storms create windstorms, heavy rainfall causes rivers to flood, and often things like heavy rain will trigger a sudden landslide. These events are distinct, and each one will create a new layer of deposits somewhere. Another way these layers are created is that rivers will often change course due to changes in flow. This will cause areas that have accumulated sand to now be covered by silt or shale when the river overflows its new channel. As the river builds a delta outward into the ocean, the part of the delta where the river first meets the ocean will deposit sand, while clays and silt are carried further out into the ocean. This will create layers of shale that are later covered by sand. Within each of these layers fossils of any organism that died while those were being deposited will be trapped, and the fossils in turn can be used to calculate the age of those deposits. Every layer of a sedimentary rock represents some event in the history of the earth. \n\nIn limestone, which has a very high content of fossils, the reason for this is that the limestone is built by the accumulation of the body parts left behind by those organisms. The fossils in limestone may not be transported at all, and instead may be in same place the organism lived (in relation to the immediate rock). Layers in limestone are more often created by rising and falling of sea level. As sea level raises many organisms that end up as limestone will die off. They will then be covered by a layer of sediment falling from the overlying water, and if sea level drops again, new organisms will begin to colonize the shallower water and build another layer of limestone.
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Granite, forms deep underground\nObsidian, the really dark and smooth black rock\nBasalt, which forms from volcanoes mostly\nPumice, the really light rock that floats on water\n\nand a few others, listed in the source site
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Rocks can be divided into three key different groups, which you will need to know for chemistry and geography exams.\n\nThey are:\n- igneous\ne.g. volcanic rocks\n\n- sedimentary\ne.g. those laid down by the action of water, like limestone\n\n- metamorphic\ne.g. those that have been subject to many different processes within the earth and been changed as a result
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rocks are made up of minerals