...formed and affect of plate tectonics on rocks. Sedimentary rocks are our best records today of how our earth is changing everyday and the best to describe to us why it is changing. Not only can geologists tell based on the shape, and deposits made of sediment but we can tell by the fossils that are made within the sediment rock. This allows us to know things about our earth from billions of years ago that we may have not known if h had not been for sediment. Where Sedimentary Rocks Originate Sedimentary rocks originate from the weathering and erosion of pre-existing rocks. When sediment is deposits it lithifies to create new rocks. Sedimentary rocks occur when sediments, weathered fragments from older rocks as well as biological debris like leaves, trees, and dead animals, are deposited and stay in place long enough for rock to form. It is known that sedimentary rocks contain sandstones, shale’s, and coal seams. Sedimentary deposits are a many key in economic geology for they include coal seams and oil deposits. There are ways to tell how deposits were made according to the rock beds they lie in. There are many ways they could have been created such as streams, wind and ocean waves. Depending on the way the sediment was deposited in these rocks beds, geologists can tell how they got there by the...
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...crystalline (igneous) rock overlain by Paleozoic sedimentary rock Ellesmere Island Appalachian Uplands- p.42 2% of Canada’s land mass Very old, heavily eroded mountains (Taconic mountains) Geologically complex (sedimentary, igneous, and metamorphic rocks, as a result of 2 periods of orogenesis (440 million years ago to 350 million years ago) Great Lakes-St Lawrence Lowlands- p 42-44 Less than 2% of landmass (1.8%) Smallest- 110 000 sq km 60% of all Canadians live here Underlain by Paleozoic sedimentary rocks Summary Given Canada’s enormous size- considerable variation in physical environment All of Canadian landscape influenced by glaciation Links between physical and human geographies Next- the Niagara Escarpment The Niagara Escarpment Dominant physiographic landform feature in Great Lakes-St Lawrence Lowlands Designated as a UNESCO World Biosphere Reserve in 1990 (12 total in Canada) 1st large scale environmental land use plan in Canada (The Niagara Escarpment Plan) Formation in 2 stages 1. Deposition of sediments by eperic (seas during Ordovician (435-400 mya) oldest sediments eroded from Taconic mountains. Then seas reappeared several times up to the end of the Paleozoic era (245 mya) 2. Erosion of eastern North America before Pleistocene ice ages Geologic Structure 1. Upper layers comprised of hard erosion resistant rocks (e.g. dolomite, limestone) 2. Lower layers comprised of softer rocks (less resistant to...
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...Associate Level Material Sedimentary Rock Worksheet Use the following table to describe and distinguish between the effects of weathering and erosion. Each response must be at least 200 words. |Effects of Weathering |Effects of Erosion |What are the Differences? | |Through mechanical and chemical weathering |Erosion is a term that describe the |Weathering involves two processes that | |of exposed rocks on Earth's surface chunks |transport of regolith from one place to |often work in concert to decompose rocks. | |of once embedded in bedrock are now exposed|another as oppose to weathering which |Both processes occur in place. No movement | |to the elements and over time they break |happens in place. Both processes can |is involved in weathering. Chemical | |down. Feldspar crystals in granite break |happen at the same time where weathering |weathering involves a chemical change in at| |down to form clay minerals. Other materials|can cause and rock to break down and then |least some of the minerals within a rock. | |such as quartz break down into sand which |materials from that are then transported |Mechanical weathering involves physically | |varies in grain sizes. "Seditment with |elsewhere by the wind in an erosion |breaking rocks into fragments without | |grain sizes between those of sand and clay |process. Fluids that cause the most erosion|changing...
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...weathering, rain, streamflow, erosion, or wind. The other forces that create sedimentary rock are generated from either chemical precipitation/crystallization or a process called lithification of what once was organic matter. This process involves the chemical breakdown of the source material that requires heat, dissolution, new minerals produced from the weathering process. The most significant characteristic of sedimentary rocks is the that are stratified. This means that sediments of any particular time period are arranged in a different layer that lays beneath and over equally different layers of time periods older and younger than itself. Detrital Detrital sedimentary rocks are a combination of conglomerate, sandstone, and shale/mudstone. These are primarily composed of other fragmented rocks. Based on the size they are subdivided into the various mentioned categories. Conglomerates are consolidated gravel deposits with variable amounts of sand and mud between the pebbles and are the least abundant of sediment type. They are primarily found in mountain streams, along margins of mountain ranges. The source rock of a conglomerate can be readily determined by examining the lithology of the pebble (Minerals, Rocks & Rock Forming Processes, n.d.). Sandstone comprise about 30% of all sedimentary rocks. It is much harder to identify the source rock of sandstone (as compared to conglomerate). The most abundant mineral found in sandstone is quartz since it is the hardest of the minerals...
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...crystalline form Rock-Aggregate of multiple grains of the same minerals Earth’s crust is made up of 8 elements oxygen 47% silicon 28% Al 8% Fe 5% Calcium 3.6% Sodium 2.8% Potassium 2.7% Magnesium 2% Every mineral has physical characteristics that aid in identification Hardness scale 1-10 chalk (1) and diamond (10) Luster-How shiny Cleavage-how it breaks Rocks are held together by a chemical bond Most common is oxygen and silica SiO2 which has 92% of the Earth’s crust. Granite is silicate. CaCO3 limestone forms in warm waters 3 types of rocks: Igneous- molten rock that has cooled and solidified Felsic- rock that is light color and light weight Mafic- heavy rocks are dark given it has a lot of metal Sedimentary-derive from accumulated sediment fragment of rocks ex: limestone, clay, silt, sand, gravel, and boulder Metamorphic- rock that has been changed and does not go into an igneous state Limestone=marble Sandstone-quartzite Fluvial process- River process Igneous(cools fast)- small crystal Igneous(cools slow)- large crystals Sedimentary- erodes, is transported, and later becomes rocks, sandstone and metamorphic (crystalline structure changed due to heat and pressure) Erosion- Process by which particles are separated from original site and deposit at a new site Arid and semiarid- wind and water are the main sources of erosion Geological Erosion- Sow uniform rate since the Earth was formed; wars down high places and builds up in low places A Slow uniform example...
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...that are used, and what are some uses of isotopic dating? Be sure to explain the calculation of the age of a rock. Relative dating is telling us the age of something compared to that of the substances around it, more plainly stated the sequence of events. Absolute dating tells how old something is, an amount of time can be associated with an object unlike in relative dating. There are four stratigraphy principles used to determine geologic history of a locality or a region: 1) original horizontally, 2) superposition, 3) lateral continuity, and 4) cross-cutting relationships. Original horizontally states that beds of sediment (sedimentary strata) deposited in water forms as horizontal or nearly horizontal layers. If rocks that are at inclined/folded have moved from their original position. The principal of superposition says that within deposition of sediment the oldest layer is at the...
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...Associate Level Material Sedimentary Rock Worksheet Use the following table to describe and distinguish between the effects of weathering and erosion. Each response must be at least 200 words. Effects of Weathering Effects of Erosion What are the Differences? Mechanical or physical weathering includes two main processes: fracturing and abrasion, which may be intense in wet and dry regions. Wind, rain, snow, ice and other geological events cause mechanical weathering. This type of weathering leads to splitting of rocks and minerals into fragments. Big and sudden changes in air temperature, which are very common in deserts or water temperature changes, always cause expansion or contraction of minerals. For example, when water enters a crack and freezes, it widens the crack and eventually leads to breaking of the surface. Plant roots have a similar effect when they grow so big that they reach the crack in the rock. At some point, the rock will fall apart. This type of weathering changes the mineral composition of rocks by chemical processes and it can sometimes lead to dangerous conditions. Water is the basic agent in chemical weathering because it initiates the whole process. Some of its effects are oxidation (rusting), hydration and carbonization. Chemical weathering also causes loss of chemical elements by solution in water. Caves, stalactites and stalagmites are created by different chemical processes of weathering Sheet erosion is soil movement from raindrop...
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...|types of weathering exist: chemical and |removed from one location, it is inevitably|causes effects at the site of the rock, | |mechanical. |placed somewhere else; this is called |erosion causes effects at a site other than| |Chemical weathering occurs when the rock |deposition. Both erosion and deposition are|that which was weathered. Weathering | |begins to break down and the chemical |natural processes. But when human |involves two processes that often work in | |composition changes as a result. These |activities substantially alter, increase or|concert to decompose rocks. Both processes | |chemical reactions break down the bonds |impede the natural movement of sediment, |occur in place. No movement is involved in | |holding the rocks together, causing them to|serious damage can occur. As stated, human |weathering. Chemical weathering involves a | |fall apart, forming smaller and smaller |involvement such as overgrazing, unmanaged |chemical change in at least some of the | |pieces. Chemical weathering tends to be |construction or building of roads can |minerals within a rock. Mechanical | |more common in locations where there is a |severely impact erosion. In...
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...AIM The aim of this field investigation was: 1. To investigate stream channel characteristic to see how they vary downstream. * Does the stream get wider and deeper downstream? * Does a rock sample vary downstream? 2. Examine the different erosional and depositional features of the river. 3. To investigate the impact of humans downstream. methodology On this field trip we went to Wag Water River. We use material such as rulers, stop watch, sketches and description of sites was made; method of observation was used to see how humans use the river for various reasons. Along the river channel group of student did the following at different points; Velocity: we measure the velocity of the river atleast three times to get an accurate measurement, we calculate the average. The velocity of the river was measured with a half filled bottle of water placed in the water at a given distance of 30m for some seconds (velocity=distance/time (seconds).The stream was also measured before and after tributary to show effect of tributaries, and deposit load which affects flow of the river stream and this was calculated by (cross section x velocity), then we compare the stream discharge at different sites and accounted for the differences. After we did that we also measured the depth of the river, we used the meter rule for this measurement, for every meter we measured the depth then we find the average. Rock samples were also taken to classified as: very angular, angular...
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...What they did was they mined large quantities of sand by pipeline, to raise the elevation of the entire City of Galveston above the previous land surface. The fill material was retrieved from several borrow areas including Offatts Bayou and East Lagoon. When the project was completed in 1911, over 9,900 acre-feet of material had been moved to help protect the city from future hurricanes. In 1931 despite the protests of oil, towing, and timber operations, the entrance to Lake Anahuac on the northern shore of Trinity Bay was closed to protect rice irrigation systems. The 6,000 acre lake was isolated from the Galveston Bay system and converted to a shallow freshwater lake. In 1966, the U.S. Army Corps of Engineers constructed a tidal floodgate, isolating Moses Lake from the bay which was once open to lower Galveston Bay. A levee system was also constructed on the southern shore of Moses Lake to protect the city from floodwaters. Other areas of impacted by isolation include the privately owned Delhomme hunting area and the impoundment used as part of the Reliant Energy Cedar Bayou Generating Station's cooling system. Shipping terminals impact shoreline through the dredging of channels, excavation of land for berths, and through the direct conversion of shoreline habitat to shipping terminal facilities. Some of the largest facilities in the Lower Galveston Bay watershed are the Port of Houston, which includes many private...
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...the reducing gradient. Upper course - the mountain stage of a river with steep gradients and much erosion. Confluence – where the tributary meet the main river channel Erosion – wearing away on land from hydraulic action , abrasion , attrition , solution. Attrition- The particles are knocked about as they are transported, and they gradually become more rounded and reduced in size. Abrasion- the pebbles being transported wear away the bed and banks of the river channel. Hydraulic Action: The sheer force of the water by itself can erode material from the bed and banks of the river channel. Solution: some rocks such as limestone are subject to chemical attack and slowly dissolve in the water. Velocity - the speed of the water Sediment – material that is broken down by erosion Deposition –the dropping off of the river load River channel – the course for the river water. It can either be a straight channel or a meandering channel River valley – is a low area between hills, with a river...
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...A glance at Cheney Lake Reservoir Ecosystem James Killion SCI/256 August 12, 2013 Mary Corrigan, Ph.D. As any lake Cheney Lake Reservoirs ecosystems begins with the sun, for without the sun there is no life. This is true because the sun is what provides the energy that is needed for the start of a food chain. At Cheney Lake Reservoir there is no difference than any other lake. Phytoplankton is the start food chain; it is mostly made of algae. Phytoplankton needs a sufficient amount of sunlight and temperature to grow, not only does it need sunlight it also requires phosphorous and nitrogen to flourish. In order to have an ecosystem that is productive and healthy there must a proper amount of phytoplankton at all times. If there is not enough phytoplankton there will not be enough to go around, if there is too much there not be enough light to support life. Phytoplankton is considered to be a producer. Zooplanktons are considered to be the animal in the free floating particles in the water. Their perpose is to eat algae, bacteria, and sometimes other zooplankton. Zooplanktons are considered to be a primary consumer in this food chain. Next to come is known as the secondary consumer....
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...Reaction Paper The documentary “China’s Water Challenges” is about the problems on water that China facing now. The problems they had is that they had more water, less water, dirty water and mud water. The main location of this problem is on the Yellow river. When it rains, the flow on the yellow river is turbulent that causes severe floods on the cities beside the river. When it is now raining, the river has less water and more sediments caused by the erosion of the soil. Drought was also a problem of China because some provinces do not rain often. Wastewater management causes problem to the community as it produces foul smell and contaminate the potable water of the city. China’s government, for me, has done a great job to solve these problems especially on the Yellow river. They relocate the people living on the side of the river to higher places to prevent damages from floods cause by the river. They also formed a committee that will monitor the condition of the whole river. They encourage people to build terraces and plant trees beside the river to prevent soil erosion. Their government is concerned to the well-being of the community. They really did what they are meant to do. The way they deal with the problem is something that we should learn from. We should take the China’s government as an example to take on our problem in water sources here in our country. We should work together to prevent and completely solve our problems...
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...River Landforms and Processes Processes and features in the sediment supply zone V shaped valleys and interlocking spurs As the spring of rivers are usually found high up in the mountains, they can flow quickly downhill eroding the landscape vertically (downwards). This is done by processes such as hydraulic action, corrasion, and corrosion, forming a deep notch into the landscape. As the river erodes vertically, the sides of the valley are exposed to various fors of weathering, for example freeze-thaw weathering which can cause sediment to fall into the river form the side of the valley, causing its steepness. This sediment is carried downstream causing the river to eventually become wider and deeper. Waterfalls Waterfalls again are found in the upper stages of a river where the water flows over various different bands of rock. With a waterfall, the soft rock found erodes more wuickly than the hard rock, this can cause the soft rock to undercut the hard rock which would eventuallt cause overhang. The overhang would soon collapse as it is not being supported, causing it to collpase into the plunge pool, which is the water below the overhang. The sediment will then swirl, casuing more erosion to the undercutted layer of rock, causing the process to repeat and the waterfall to move firther upstream. Mid Channel and alternate-bars A bar in a river is an elevated region of sediment built up of deposition such as sand a gravel which has been deposited by the flow of...
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...1.0 Introduction Soil erosion has been accelerated in many areas of the world especially Australia. It becomes a biggest problem in Australia which leads Australians have to confront it. Soil erosion means the removal or disappearance of soil by water or wind. It may due to the poor cultivation, overgrazing and stripping of the land. Today, soil erosion is one of the most critical environmental problems in Australia which threatening farmlands, streams and village. This report below is concentrate on the types, causes and preventing of soil erosion. 2.0 Types of soil erosion There have various types of soil erosion but the two major types of soil erosion that often occur in Australia which is water erosion and wind erosion. 2.1 Water erosion Water erosion is the most widespread erosion in Australia. There have several types of water erosion which is sheet, rill and gully erosion. Firstly, Raindrop can be a main problem for farmers when they strike bare soil. Rain can washes away seed and splashes soil into the air. If the fields are on a slope the soil is splashed downhill which causes deterioration of soil structure (Sydenham & Thomas, 2008). Hence, soil that has been separated by raindrops is more easily moved than soil that has not been separated. Sheet erosion is caused by raindrops whereas rill erosion and gully erosion caused by rainfall. Sheet erosion is defined as the uniform removal of soil in thin layers from sloping land. When rains run off the slope, without...
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