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Siliceous Ooze Deposition Pelagic Biogenous Deposits Pelagic Biogenous Deposits • Calcareous Ooze Pelagic Biogenous Deposits • Calcareous Ooze – Contains hard remains of calcareous-secreting organisms Pelagic Biogenous Deposits • Calcareous Ooze – Contains hard remains of calcareous-secreting organisms – Destruction varies at different depths in the ocean Calcareous Ooze and the CCD Calcareous Ooze and the CCD • Warm, shallow ocean saturated with calcium carbonate Calcareous Ooze and the CCD • Warm, shallow ocean saturated with calcium carbonate • Shells don’t dissolve any further Calcareous Ooze and the CCD • Warm, shallow ocean saturated with calcium carbonate • Shells don’t dissolve any further • Cool, deep ocean undersaturated with calcium carbonate Calcareous Ooze and the CCD • Warm, shallow ocean saturated with calcium carbonate • Shells don’t dissolve any further • Cool, deep ocean undersaturated with calcium carbonate • Shells begin to break down and dissolve Calcareous Ooze and the CCD • Warm, shallow ocean saturated with calcium carbonate • Shells don’t dissolve any further • Cool, deep ocean undersaturated with calcium carbonate • Shells begin to break down and dissolve – Lysocline – depth at which a significant amount of CaCO3 begins to dissolve rapidly Calcareous Ooze and the CCD • Warm, shallow ocean saturated with calcium carbonate • Shells don’t dissolve any further • Cool, deep ocean undersaturated with calcium carbonate • Shells begin to break down and dissolve – Lysocline – depth at which a significant amount of CaCO3 begins to dissolve rapidly • CCD – Calcite compensation depth Calcareous Ooze and the CCD • Warm, shallow ocean saturated with calcium carbonate • Shells don’t dissolve any further • Cool, deep ocean undersaturated with calcium carbonate • Shells begin to break down and dissolve – Lysocline – depth at which a significant amount of CaCO3 begins to dissolve rapidly • CCD – Calcite compensation depth – Depth where CaCO3 readily dissolves Calcareous Ooze and the CCD • Warm, shallow ocean saturated with calcium carbonate • Shells don’t dissolve any further • Cool, deep ocean undersaturated with calcium carbonate • Shells begin to break down and dissolve – Lysocline – depth at which a significant amount of CaCO3 begins to dissolve rapidly • CCD – Calcite compensation depth – Depth where CaCO3 readily dissolves – Rate of supply = rate at which the shells dissolve Calcareous Ooze and the CCD Calcareous Ooze and the CCD Calcareous Ooze and the CCD • Scarce calcareous ooze below 5000 meters (16,400 feet) in modern ocean Calcareous Ooze and the CCD • Scarce calcareous ooze below 5000 meters (16,400 feet) in modern ocean • Due to CCD Calcareous Ooze and the CCD • Scarce calcareous ooze below 5000 meters (16,400 feet) in modern ocean • Due to CCD • Ancient calcareous oozes can be found at greater depths Calcareous Ooze and the CCD • Scarce calcareous ooze below 5000 meters (16,400 feet) in modern ocean • Due to CCD • Ancient calcareous oozes can be found at greater depths • Moved by sea floor spreading, then covered by another deposits that is not affected by CCD Sea Floor Spreading and Sediment Accumulation Distribution of Modern Calcium Carbonate Sediments Hydrogenous Sediment Hydrogenous Sediment • hydro = water, generare = to produce Hydrogenous Sediment • hydro = water, generare = to produce • Derived from the dissolved materials in water Hydrogenous Sediment • hydro = water, generare = to produce • Derived from the dissolved materials in water • Small proportion of marine sediments Origin of Hydrogenous Sediments Origin of Hydrogenous Sediments • Minerals precipitate directly from seawater Origin of Hydrogenous Sediments • Minerals precipitate directly from seawater • Go from a dissolved to solid state Origin of Hydrogenous Sediments • Minerals precipitate directly from seawater • Go from a dissolved to solid state • Come from a variety of minerals and metals Composition of Hydrogenous Sediments – Metal sulfides – Evaporites Composition of Hydrogenous Sediments • Chemical compounds precipitate directly from seawater – Metal sulfides – Evaporites Composition of Hydrogenous Sediments • Chemical compounds precipitate directly from seawater • Go from a dissolved to solid state – Metal sulfides – Evaporites Composition of Hydrogenous Sediments • Chemical compounds precipitate directly from seawater • Go from a dissolved to solid state – Manganese nodules – Metal sulfides – Evaporites Composition of Hydrogenous Sediments • Chemical compounds precipitate directly from seawater • Go from a dissolved to solid state – Manganese nodules – Metal sulfides – Phosphates – Evaporites Composition of Hydrogenous Sediments • Chemical compounds precipitate directly from seawater • Go from a dissolved to solid state – Manganese nodules – Metal sulfides – Phosphates – Evaporites – Carbonates Manganese Nodules Manganese Nodules • Fist-sized lumps of manganese, iron, and other metals Manganese Nodules • Fist-sized lumps of manganese, iron, and other metals • Very slow accumulation rates Manganese Nodules • Fist-sized lumps of manganese, iron, and other metals • Very slow accumulation rates • Many commercial uses Manganese Nodules • Fist-sized lumps of manganese, iron, and other metals • Very slow accumulation rates • Many commercial uses • Unsure why they are not buried by seafloor sediments Manganese Nodules • Fist-sized lumps of manganese, iron, and other metals • Very slow accumulation rates • Many commercial uses • Unsure why they are not buried by seafloor sediments Phosphates and Carbonates Phosphates and Carbonates • Phosphates Phosphates and Carbonates • Phosphates – Contain phosphorus Phosphates and Carbonates • Phosphates – Contain phosphorus – Occur beneath areas iof very high biological productivity Phosphates and Carbonates • Phosphates – Contain phosphorus – Occur beneath areas iof very high biological productivity – Economically useful as fertilizer Phosphates and Carbonates • Phosphates – Contain phosphorus – Occur beneath areas iof very high biological productivity – Economically useful as fertilizer • Carbonates Phosphates and Carbonates • Phosphates – Contain phosphorus – Occur beneath areas iof very high biological productivity – Economically useful as fertilizer • Carbonates – Aragonite, calcite, oolites Phosphates and Carbonates • Phosphates – Contain phosphorus – Occur beneath areas iof very high biological productivity – Economically useful as fertilizer • Carbonates – Aragonite, calcite, oolites – Found in shallower, tropical waters Metal Sulfides • Zinc • Silver • Other metals Metal Sulfides • Metal sulfides • Zinc • Silver • Other metals Metal Sulfides • Metal sulfides – Contain: • Zinc • Silver • Other metals Metal Sulfides • Metal sulfides – Contain: • Iron • Zinc • Silver • Other metals Metal Sulfides • Metal sulfides – Contain: • Iron • Zinc • Nickel • Silver • Other metals Metal Sulfides • Metal sulfides – Contain: • Iron • Zinc • Nickel • Silver • Copper • Other metals Metal Sulfides • Metal sulfides – Contain: • Iron • Zinc • Nickel • Silver • Copper • Other metals – Associated with hydrothermal vents Metal Sulfides • Metal sulfides – Contain: • Iron • Zinc • Nickel • Silver • Copper • Other metals – Associated with hydrothermal vents – Found throughout the ocean floor Metal Sulfides • Metal sulfides – Contain: • Iron • Zinc • Nickel • Silver • Copper • Other metals – Associated with hydrothermal vents – Found throughout the ocean floor – Can be uplifted onto continents Evaporites Evaporites – “Salts” Evaporites – “Salts” – Minerals that form when seawater evaporates Evaporites – “Salts” – Minerals that form when seawater evaporates – Halite (NaCl - common salt) Evaporites – “Salts” – Minerals that form when seawater evaporates – Halite (NaCl - common salt) Evaporites – “Salts” – Minerals that form when seawater evaporates – Halite (NaCl - common salt) – Found in areas where open ocean circulation is minimal and evaporation rates are high Cosmogenous Sediments Cosmogenous Sediments • Macroscopic meteor debris • Microscopic iron-nickel and silicate spherules (small globular masses) – Tektites – Space dust • Overall, insignificant proportion of marine sediments Marine Sediment Mixtures Rate of Deposition of Marine Sediments Pelagic and Neritic Sediment Distribution Pelagic and Neritic Sediment Distribution • Distribution controlled by Pelagic and Neritic Sediment Distribution • Distribution controlled by – Proximity to sources of lithogenous sediments Pelagic and Neritic Sediment Distribution • Distribution controlled by – Proximity to sources of lithogenous sediments – Productivity of microscopic marine organisms Pelagic and Neritic Sediment Distribution • Distribution controlled by – Proximity to sources of lithogenous sediments – Productivity of microscopic marine organisms – Depth of water Pelagic and Neritic Sediment Distribution • Distribution controlled by – Proximity to sources of lithogenous sediments – Productivity of microscopic marine organisms – Depth of water – Sea floor features Pelagic and Neritic Sediment Distribution Pelagic Sediment Types Pelagic Sediment Types WHY ?!? Pelagic Sediment Types WHY ?!? Think about the marine provinces... Worldwide Marine Sediment Thickness Information from Marine Sediments Information from Marine Sediments • Fossil record Information from Marine Sediments • Fossil record • Geological record Information from Marine Sediments • Fossil record • Geological record • Level of productivity indicator Information from Marine Sediments • Fossil record • Geological record • Level of productivity indicator • Current concentrations in the ocean Information from Marine Sediments • Fossil record • Geological record • Level of productivity indicator • Current concentrations in the ocean • What else?? Resources from Marine Sediments Resources from Marine Sediments • Energy resources Resources from Marine Sediments • Energy resources – Petroleum Resources from Marine Sediments • Energy resources – Petroleum • Mainly from continental shelves; biogeneous sediment Resources from Marine Sediments • Energy resources – Petroleum • Mainly from continental shelves; biogeneous sediment – Gas hydrates Resources from Marine Sediments • Energy resources – Petroleum • Mainly from continental shelves; biogeneous sediment – Gas hydrates – Mostly methane; produced by bacteria Resources from Marine Sediments • Energy resources – Petroleum • Mainly from continental shelves; biogeneous sediment – Gas hydrates – Mostly methane; produced by bacteria • Sand and gravel Resources from Marine Sediments • Energy resources – Petroleum • Mainly from continental shelves; biogeneous sediment – Gas hydrates – Mostly methane; produced by bacteria • Sand and gravel • tin, gold, and so on Resources from Marine Sediments Resources from Marine Sediments • Evaporative salts Resources from Marine Sediments • Evaporative salts • Table salt, sodium hydroxide, others Resources from Marine Sediments • Evaporative salts • Table salt, sodium hydroxide, others • Phosphorite Resources from Marine Sediments • Evaporative salts • Table salt, sodium hydroxide, others • Phosphorite • Synthetic fertilizer production Resources from Marine Sediments • Evaporative salts • Table salt, sodium hydroxide, others • Phosphorite • Synthetic fertilizer production • Manganese nodules and crusts Resources from Marine Sediments • Evaporative salts • Table salt, sodium hydroxide, others • Phosphorite • Synthetic fertilizer production • Manganese nodules and crusts • Metal source Resources from Marine Sediments • Evaporative salts • Table salt, sodium hydroxide, others • Phosphorite • Synthetic fertilizer production • Manganese nodules and crusts • Metal source
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