Rochester City School District



-605642-60564200UNIT XII: EROSION, DEPOSITION, AND LANDSCAPES NOTES PACKET4072255200734Picture: The Adirondack Mountains in northern New York State. Most rocks found here are metamorphic in origin and over 1 billion years old. The Grenville Orogeny was responsible for the observed changes recorded in the rocks.400000Picture: The Adirondack Mountains in northern New York State. Most rocks found here are metamorphic in origin and over 1 billion years old. The Grenville Orogeny was responsible for the observed changes recorded in the rocks.After UNIT XII you should be able to:Understand how sediments are transported in a stream, use the Relationship of Transported Particle Size to Water Velocity reference table chart, and recognize the characteristics of sediments that have been weathered in a streamUnderstand basic erosional and depositional features of a riverUnderstand the relationship between particle shape and settling rateUnderstand how climate impacts landscapes near riversMatch topographical features with stream drainage patternsRecognize differences between glacial and river sedimentsRecognize differences between valleys eroded by glaciers and riversRecognize common erosional and depositional features of glaciersUnderstand how erosion and deposition function within systems driven by wind, shoreline current, and mass movement and recognize common features of these systemsRecognize common landscape features of New York State and how they formedBe able to use the Generalized Landscape Regions of New York State map2388425171450MorainesOutwash plainCirqueAreteHornSand dunesLong-shore driftMass movementLandslideSlumpCreepMudflowMountainsFault-block mountainsFolded mountainsLandscape regionPlateauPlainValleysMorainesOutwash plainCirqueAreteHornSand dunesLong-shore driftMass movementLandslideSlumpCreepMudflowMountainsFault-block mountainsFolded mountainsLandscape regionPlateauPlainValleys-313880171450ErosionSedimentGravityVelocityParticleTransportBouldersCobblesSandSiltClayDissolved mineralsDepositionDiameterMorphologyTransectRiver channelMeanderOxbow lakeMeander scarRoundedSorted sedimentsSuspended sedimentSettling rateDeltaAlluvial fanDowncuttingStream drainage patternOrientationResistanceWeatheringLowlandsAridCanyonsHumidTopographyGlacierEscarpmentAccumulationUnsorted sedimentsAngularContinental glacierIce sheetValley glacierAlpine glacierAbrasionStriationsPolishingPluckingV-shaped valleyU-shaped valleyFinger lakesDrumlinsErraticsKettle lakesEskersKames00ErosionSedimentGravityVelocityParticleTransportBouldersCobblesSandSiltClayDissolved mineralsDepositionDiameterMorphologyTransectRiver channelMeanderOxbow lakeMeander scarRoundedSorted sedimentsSuspended sedimentSettling rateDeltaAlluvial fanDowncuttingStream drainage patternOrientationResistanceWeatheringLowlandsAridCanyonsHumidTopographyGlacierEscarpmentAccumulationUnsorted sedimentsAngularContinental glacierIce sheetValley glacierAlpine glacierAbrasionStriationsPolishingPluckingV-shaped valleyU-shaped valleyFinger lakesDrumlinsErraticsKettle lakesEskersKamesUNIT XII vocabulary you should be able to use and understand:Tying it together…You now have had significant experience learning about the variety of ways rocks form, and some unique formations associated with the study of plate tectonics. You are most familiar with what are known as uplifting forces. For example, the contribution of plate convergence to volcanic mountain ranges. New crust is formed, old crust is recycled back into the Earth. The focus of this unit seeks to broaden your understanding of leveling forces, those which contribute to transport of materials on the Earth’s surface in conjunction with your prior knowledge of weathering.55811473538700Our weathering unit taught us that rocks can be broken down by both physical and chemical means based on climate and bedrock type. Understanding how Earth materials erode, becomes the next step in truly understanding the dynamic nature of landscapes.Basic Principles of Erosion______________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________________________________________ ______________________________________________________________________________________There are 5 distinct agents of erosion:___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________347653639675700Erosion in moving water varies greatly within a river, and between rivers. Lighter, less dense sediment is first to be transported by moving water.Transport of Sediments in StreamsSediment transport is dependent on 2 variables:____________________________________________________________________________________________________Describing Rock Particle Size283889330953Increasing Size00Increasing SizeRock Particles are categorized into 6 types:______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________*Dissolved minerals are also transported, although they are not visible29768802476500797132247650039304773528800Sediment Transport Chart_________________________________________________________ _________________________________________________________ _________________________________________________________If water velocity falls below that level, sediment is deposited on the bottom of the riverUsing the Chart_________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________ _________________________________________________________Water Velocity and Stream MorphologyWater velocity is not a constant along a river nor is it constant across a transect39154105778500In other words, the stream is faster in some areas, slower in othersWater Velocity and Stream MorphologyWater, for the most part, flows in a straight line and will do so until redirected by the stream channel. Water also over time dictates how the channel changes.Because this is true, rivers have different channel shapes at different locationsIn a straight line path, rivers are fastest in the middle, leaving a channel deepest in the center__________________________________________________________ __________________________________________________________ ____________________________________________________________________________________________________________________ __________________________________________________________Stream MeandersOver time, erosion at the outside of the bend causes the stream channel to drift. When the old channel is cut off, an oxbow lake is formed.183978516129000-53384516129000420814518713500If the oxbow dries up, it becomes what is known as a meander scar394260715494800Sorting of SedimentsFaster moving water transports smaller sedimentsTherefore, a stream bottom will have larger particles on the bottom in faster moving water and smaller particles on the bottom in slower moving water______________________________________________________________________________________________________________________________________________________________________________________________48686276096000Shape and Density of Deposited SedimentsWhen water velocity slows, the shape and density of sediment suspended is important when it comes to the rate that the particles are deposited (settling rate)__________________________________________________________________________ ________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________50704755080000Using Principles of Deposition to Find GoldYou can pan for gold and find it in New York State streams, however a strange law prohibits you from keeping what you find. Most gold in the state was transported by glaciers and ground down into fine dust and then concentrated in streams, although nuggets are found on occasion.Since gold is high in density, it settles first when water slows. When panning for gold, focus on cracks or joints in bedrock within the stream, and on the inside of meanders.42608834454000Rivers Entering Lakes and OceansThe deposition of sediments at the mouth of a river results in the formation of a delta or alluvial fan_______________________________________________________________ ______________________________________________________________________________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________47377351225500Stream Valley Shape________________________________________________________________________ ________________________________________________________________________134908615983000464248514967000Drainage PatternsLooking at maps and examining rivers often tells us something about the rock strata beneath. Stream drainage patterns are dictated by:______________________________________________________________________ ____________________________________________________________________________________________________________________________________________ ____________________________________________________________________________________________________________________________________________ ______________________________________________________________________Differences in ElevationHigher elevations with steep slopes result in deep ‘V’ shaped valleys______________________________________________________________________________________________________________________________________________________________________________________________50942596815100Drainage Topography in Arid RegionsWeathering in dry regions is generally a very slow process. The majority of weathering and erosion takes place in the river channel.______________________________________________________________________________ ______________________________________________________________________________50821933122200Drainage Topography in Humid Regions_____________________________________________________________________________ _____________________________________________________________________________Common occurrence in NYS468614312140000Drainage Topography_______________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________Mate these with an overhead patternGlaciersNew York State owes its many unique landforms to the presence of glaciers in the past. Evidence of repeated glacial events surrounds us in western New York. Glaciers are responsible for both erosional and depositional features.___________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________Types of GlaciersFor our purposes, there are 2 types of glaciers that we are concerned with:_____________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________50704753683000Glacial Presence in NYSA massive glacier covered New York (most recently around 10,000 years ago), and it is important to understand how it shaped landforms in the areaThe glacial movement map (with gray arrows) shows directional flow of the recent surges of ice425069023641000Glacial WeatheringAbrasion is the dominant form of weathering underneath a glacier_______________________________________________________________ _______________________________________________________________ ______________________________________________________________________________________________________________________________ _______________________________________________________________ _______________________________________________________________This sediment may also result in the polishing of bedrockGlaciers also pluck rock masses in their base and carry them along453623410455200Glacial ErosionAs glaciers erode a valley, they leave evidence of having been there____________________________________________________________________ ____________________________________________________________________Finger Lakes42384908278900Glacial erosion can leave behind a variety of observable features_______________________________________________________________ _______________________________________________________________ _______________________________________________________________ _______________________________________________________________235267539941500Satellite image (right) of the Finger Lakes region of New York State and the inferred glacial movement that produced them (left)6868845350048686273538700DrumlinsElongated hills called drumlins are also found in areas that have undergone glaciation. The steeper end is on the side where the glacier approached, the tapered end is the side the glacier was moving.485603558270700__________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________ __________________________________________________________________________Our Chimney Bluffs field trip was to one of the thousands of drumlins found in central and western New York (image shows high lake level after glacial melt)ErraticsVery large boulders that do not match local bedrock type (transported) or are found in awkward elevations or places were likely transported there by a glacier.134112026606500This erratic is in Central Park sitting on top of striated bedrock, another piece of evidence for glaciation.527238813518000Kettle Lakes_________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________Devil’s Bathtub in Mendon Ponds Park is a kettle lake, one of a few that can be found thereEskersLong, winding hills of sediment deposited by streams beneath a glacier_________________________________________________________________________________ _________________________________________________________________________________ _________________________________________________________________________________1946778-4769670051538903582300KamesRocky debris that is deposited in crevasses within a glacier to form a hill. A kame in Mendon Ponds Park is the highest point in Monroe County.Kames, eskers, and kettles can all be found in Mendon Ponds Park.MorainesMoraines are long hills that are composed of material that a glacier has pushed or pulled along_______________________________________________________________________________ _______________________________________________________________________________The Valley Heads Moraine in the Finger Lakes Region represents the extent of the last glacial advance and prevents southward drainage of the lakes46735751711860060538632492200The Pinnacle Hills Range in Rochester – A series of hills caused by a sudden resurgence of ice depositing sediment and home to many radio and telecommunication towers439361526637900Outwash PlainAn outwash plain is where streams flow out of the glacier as it melts. The plain is relatively flat with sorted and rounded sediments due to abrasion in the streams.Cirques, Aretes, HornsAll features found in mountainous areas (such as the Adirondack region) once covered by glaciersHorn: Sharp point at mountain peakCirque: Bowl-shaped depression caused by abrasionArete: Sharp ridge carved out of the mountainside479425019729500Wind Erosion and Weathering________________________________________________________________________ ________________________________________________________________________________________________________________________________________________ ________________________________________________________________________46189901929700Wind Deposition_____________________________________________________________________ _____________________________________________________________________Wave Erosion and Weathering459486010242500Abrasion is the dominant form of weathering along beaches_____________________________________________________________________ _____________________________________________________________________ _____________________________________________________________________Long Shore CurrentLong shore currents flow parallel to the beach. This flow steadily drags sediments along the shore in what is called long shore drift.451231018459500Mass MovementThe final, though less substantial type of erosion is called mass movement.____________________________________________________________________ ____________________________________________________________________ ________________________________________________________________________________________________________________________________________ ____________________________________________________________________LandslideLandslide is a commonly used term for the movement of a mass of bedrock or loose soil and rock down the slope of a hill, mountain or cliff.459549511639500Creep_____________________________________________________________________ _____________________________________________________________________45927669174500SlumpBlocks of land that have tilted and moved downhill along a surface that curves into the slopeMudslides/Flows_____________________________________________________________________ _____________________________________________________________________Weathering, erosion, deposition, plate tectonics, folding and faulting all contribute to the beautiful landscapes around us, many of which can be found in New York.Landscapes Features of NYS__________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________401332423135500Mountains___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________ ___________________________________________________________NYS Example: Mount Marcy (Adirondack Mountains)440549038040700The Adirondack Mountains are part of an area which has been uplifted and domed upward and continues to do so. They are not volcanic in origin and are comprised mostly of metamorphic and intrusive igneous rocks.Other Types of MountainsFolded Mountains form when compression occurs typically during a tectonic collisionFault Block Mountains occur when faults (lines of breakage) allow rock on either side to move up or down relative to the opposite side47015403846300Plateau_______________________________________________________________________ ______________________________________________________________________________________________________________________________________________ _______________________________________________________________________ _______________________________________________________________________NYS Example: Allegheny PlateauPlains______________________________________________________________________________________________________________________________________________________________________________________________Example: Erie-Ontario Lowlands, City of RochesterValleysValleys can be formed from erosion by rivers, glaciers, in between folds in bedrock, or where a fault block has fallen down.______________________________________________________________________________________________________________________________________________________________________________________________RidgesA chain of mountains or hills that form a crest for some distanceFolded bedrock in Pennsylvania has formed ridges along the foldsRidges are sometimes lines of resistant bedrockEscarpmentsEscarpments are long cliffs formed by erosion or faultingLand is relatively flat on either side______________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________________12672701270000-356260369040040231213683000347891820891500NYS Landscape MapUse this map to identify major landscape regions in NYSFor example: Which landscape region is Rochester located in?Answer:__________________________ ................
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