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Sediment - particulate material transported and deposited by wind, water, or ice, chemically precipitated from solution, or secreted by organisms, that forms in layers in loose, unconsolidated form. Unconsolidated material - A sediment that is loosely arranged or unstratified, or whose particles are not cemented together, occurring either at the surface or at depth. Sedimentary rock - A layered rock resulting from the consolidation of sediment.
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Sedimentary Rocks Igneous Rocks Metamorphic Rocks Magma Sediment Pressure And Cementation Erosion Heat and Pressure Cooling Heat Pressure Erosion
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Material (such as gravel, sand, mud, and lime) that is transported by wind, water, ice, or gravity; Material that is precipitated from solution; Deposits of organic origin (such as coal and coral reefs).
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Rock formed by the accumulation and consolidation of sediment.
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- unconsolidated particles created by 1. The weathering of rock 2. The secretions of organisms or decomposition of organic matter 3. Chemical precipitation
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Composed of lithified sediments - by compaction y cementation Two Classifications - clastic -nonclastic
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Clastic Sedimentary Rocks Organic Sedimentary Rocks Chemical Sedimentary Rocks Skeletal (Bioclastic) Sedimentary Rocks
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From: “Sedimentary Rocks”
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1. Clastic 2. Biogenic 3. Chemical
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1. Clastic – broken fragments of rock produced by weathering. Range in size from largest boulder to smallest clay particle. Classified according to size. Found everywhere on the Earth.
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Texture - Size, shape, and distribution of particles that collectively make up a rock Size Rounding Sphericity Sorting
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Roundness – the shape of sediment grains. Related to the distance a sediment has been transported. Sphericity - how close to a spherical shape a grain is or will be.
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Sorting – separation of sediments by grain size and density. Poorly sorted – sediment with a wide range of grain sizes. Well sorted – sediment with a small range of grain sizes.
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Sorting - a function of transported 1. Water 2. Wind 3. Glaciers
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Udden-Wentworth Scale
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Fluid Dynamics
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Modes of Transport Suspended Load Bed Load Saltation
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Progressive Sorting
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Graded Beds
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Fining up
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Compaction Compaction - reduction in bulk volume or thickness of fine-grained sediments, owing to increasing weight of overlying material that is continuously being deposited, or to pressures resulting from earth movements. Tighter packing of sedimentary particles results in a decrease in porosity.
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Cementation Cementation - the process by which clastic sediments are converted into rock by precipitation of a mineral cement among the grains of the sediment. Cement - chemically precipitated mineral material that occurs in the spaces among the grains of a sedimentary rock, thus binding the grains into a rigid mass. The most common cements are silica, carbonates, and iron oxides.
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Crystallization Crystallization - the development and growth of crystals by precipitation from solution at or near the Earth's surface.
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Bioclastic and Chemical Sedimentary Rocks CarbonatesEvaporites
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Organic Sedimentary Rocks
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Clastic Sedimentary Rocks - Examples Conglomerate Breccia Sandstone Graywacke Siltstone Shale
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Bedforms
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Mudcracks
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In general, as transport distance increases, rounding and sorting increase. Examples: Breccia – cemented close to source Conglomerate – transported then cemented
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Size and Mode of Transport
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Transport-Related Properties
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Cross-Bedding
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Stream Deposit Tidal Flat Deposit
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Large ClastsSmall Clasts
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Sedimentary rocks made of silt- and clay- sized particles are collectively called mudrocks, and are the most abundant sedimentary rocks. Rock TypeSedimentGrain Size ShaleClayless than 0.001 mm SiltstoneSilt.001-0.1 mm SandstoneSand.01-1 mm ConglomerateGravel1mm +
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Strata Stratum Stratigraphy Stratigraphic Formation – smallest mappable unit
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Almost Always Present in Sedimentary Rocks Originally Horizontal Tilting by Earth Forces Later Variations in Conditions of Deposition Size of Beds (Thickness) Usually 1-100 Cm Can Range From Microscopic to 50m
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Evaporites -Water Soluble Halite Gypsum Calcite Precipitates Example: Ca(sol'n) + SO 4 (Sol'n) = CaSO 4 Gypsum Limestone Iron Formations Alteration After Deposition Dolomite Biogenic Sediments Limestone - Shells, Reefs, Etc. Organic Remains Coal Petroleum
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Chemical Sedimentary Rocks - Evaporites Rock salt NaCl Anhydrite CaSO 4 Rock gypsum CaSO 4. H 2 O
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Bioclastic Sedimentary Rocks - Carbonates (Limestones) Chalk Coraline limestone Coquina
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2. Biogenic – composed of remains of plants or animals.
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Corals - Large components of reefs. Bivalves, Gastropods, Foraminifers - Whole or partial skeletons form sand and gravels. Algae, Crinoids, Echinoderms, Bryozoans - disintergrate to form some sand particles and lime mud. Diatoms, Radiolaria – Bedded chert SiO 2 Terestrial Sediments - mainly plant matter Marine Sediments - mainly carbonates
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3. Chemical – formed by minerals precipitating from solution. Inorganic process, no biological activity involved.
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1. Terestrial - Evaporites: Gypsum - CaSO 4. H 2 O Anhydrite - CaSO 4 Halite - NaCl 2. Marine - Carbonates - CaCO 3
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Clastic Rock – composed of fragments of pre-existing rocks. Nonclastic Rock – composed of chemical precipitates or biogenic matter.
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Inorganic theories carbides of iron, calcium etc.. When contacted with water action of hot water on limestone, CaCO 3 and gypsum Organic theories Animal theories: due to decomposition of marine animals - fishes, oysters, other microscopic organisms. Vegetal theories: due to decomposition of plants – seaweeds Land plants such as those in swamps: coal beds, oil Microscopic plants: Diatoms and Non-fossil organisms - planktons
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Likely scenario: oil ancient animal + plants: paraffinic base - vegetal origin asphaltic base - animal origin = Flow of sediments Plants and animals SEA/FRESH WATER Water prevents rapid oxidation of organic material
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Source rock – mostly shales Final accumulation of oil – sandstones, limestones, fractured shales Regional flow of water Trapped hydrocarbons Shale Limestone/sandstone primary Secondary 10’s – 100’s km
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Anticlines Faults StratigraphicSalt domes
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Combination Anticlinal/fault traps Overlap on beds flanking the basement rock
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SEA LEVEL RECEDING Flow of sediments Coarse grain sediments Offshore/Deep Marine Near shore/Shallow Marine Shoreface Offshore Shore Fine grain sediments Coarse grain with clay Fine grains with clay SEA LEVEL ADVANCING
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Sedimentary rocks: Source rock: old sedimentary + igneous Broken down sediments Wind + water + organisms + chemical action Deltas, shore face, valley fills Compaction/ Cementation: Sandstones Sandstones: compacted quartz sands – fragments of rock crystals Limestones: Skeletons of lime-secreting organisms, corals etc.. Diatomaceous shales: Diatoms and other microscopic plants Gypsum/Anhydrides/Limestones: Chemical dissolution of rocks, followed by evaporation and crystallization
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Conglomerates: Loose aggregate of rounded pebbles – gravels when cemented – conglomerates. Porosity due to differential cementation Oil fields in Pennsylvania, Texas, Oklahoma Sand, Sandstones: Finer sediments – yet noticeable, angular Sands cemented by calcite – sandstones silica – quartzite Porosity due to voids and inter-grain spaces also differential cementation Pools in California, Alberta, Gulf Coast, Texas
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Clays, shales: Fine grained particles – aluminous materials, trapped water Deep ocean sediments : Compaction yields shales Porosity in cracks and fissures Some pools in Santa Maria Basin, California, Gas in Kentucky Limestone: Principally CaCO 3, hard and crystalline rock, Marl, chalk, dolomites – other forms Porosity due to weathering and solution – vugs Many pools in mid-continent, Alberta, Middle east, Saudi Arabia
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Cherts: Chemically pure silica – cryptocrystalline – crystals visible only under magnification Occurrence as small nodules or large masses parallel to bedding plane Porosity due to fractures Major pool – Offshore California, Monterey cherts
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Grain Size - Power of Transport Medium Grading - Often Due to Floods Rounding Sorting Cross-bedding - Wind, Wave or Current Action } Transport, Reworking
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Fossils Salt Water - Corals, Echinoderms Fresh Water - Insects, Amphibians Terrestrial - Leaves, Land Animals Color And Chemistry Red Beds - Often Terrestrial Black Shale - Oxygen Poor, Often Deep Water Evaporites – Arid Climates
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Dimension stone can be defined as natural rock material quarried for the purpose of obtaining blocks or slabs that meet specifications as to size (width, length, and thickness) and shape. Color, grain texture and pattern, and surface finish of the stone are normal requirements. Durability is mainly based on mineral composition and hardness and past performance.
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Although a variety of igneous, metamorphic, and sedimentary rocks are used as dimension stone, the principal rock types are granite, limestone, marble, sandstone, and slate. Other varieties of dimension stone may be used. They are normally considered to be special minor types which include alabaster (massive gypsum), soapstone (massive talc), and various products fashioned from natural stone.
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may be defined as: the extraction of building stone or slate from an open surface quarry.Quarrying plays a very important role in the use of dimension stone. Dimension stone is stored in a ‘quarry’ until it is needed by it’s manufacturer. Dimension stone may be used for many purposes. It can be, and often times is used in the construction of buildings and cemeteries.
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Sedimentary rocks is the most abundant type of rocks in Canada. Also, Hamilton and surrounding area lay mostly on sedimentary rocks. Natural Resources Canada, 2004
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