Contents

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Contents

• Introduction
• Unconsolidated clastic sediments
• Sedimentary rocks
• Diagenesis
• Sediment transport and deposition
• Sedimentary structures
• Facies and depositional environments
• Glacial/eolian/lacustrine environments
• Fluvial/deltaic/coastal environments
• Shallow/deep marine environments

• Stratigraphic principles
• Sequence stratigraphy
• Sedimentary basins
• Models in sedimentary geology
• Applied sedimentary geology
• Reflection

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Sedimentary rocks

• Clastic (siliciclastic) rocks (80-85 of the
  stratigraphic record)
• Carbonate sediments and rocks (10-15 of the
  stratigraphic record)
• Organic (carbonaceous) sediments and rocks
• Evaporites
• Volcaniclastic sediments and rocks

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Sedimentary rocks

• Clastic (siliciclastic) rocks
• Sandstones (20-25 of the stratigraphic record)
  can be subdivided according to the Pettijohn
  classification, based on texture and composition
  (relative proportions of quartz, feldspar, and
  lithic fragments)
• Quartz arenite quartz-dominated
• Arkosic arenite feldspar-dominated
• Lithic arenite dominance of lithic fragments
• Wacke significantly matrix-supported (gt15 mud)
• Quartz wacke
• Greywacke (feldspathic or lithic wacke)

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Sedimentary rocks

• Clastic (siliciclastic) rocks
• Mudstones (60 of the stratigraphic record) are
  also known as mudrocks or shales and commonly
  exhibit a distinct fissility
• Claystone
• Siltstone
• Conglomerates are consolidated gravels breccias
  are conglomerates with dominantly angular clasts
• Clast-supported conglomerates
• Matrix-supported conglomerates

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Sedimentary rocks

• Clastic (siliciclastic) rocks
• Mudstones (60 of the stratigraphic record) are
  also known as shales and commonly exhibit a
  distinct fissility
• Claystone
• Siltstone
• Conglomerates are consolidated gravels breccias
  are conglomerates with dominantly angular clasts
• Clast-supported conglomerates
• Matrix-supported conglomerates

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Sedimentary rocks

• Carbonate sediments and rocks
• Principal minerals calcite, aragonite
  (unstable), and dolomite (diagenetic)
• Principal rocks limestone (gt50 CaCO3) and
  dolomite (dolostone) (CaMg(CO3)2)
• Formation of carbonate sediments and rocks occurs
  by means of two main processes
• Biomineralization of CaCO3 by organisms
• Direct chemical precipitation

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Sedimentary rocks

• Carbonate sediments and rocks
• Biogenic carbonate formation occurs by a wide
  range of organisms (e.g., molluscs, corals,
  forams, algae, bacteria, and many others)
• Most organisms initially form unconsolidated
  carbonate sediments
• Coral reefs and microbial mats (e.g.,
  stromatolites) are examples of more solid
  carbonate structures
• Chemical precipitation produces non-skeletal
  carbonate grains of various sizes (e.g., ooids,
  pisoids, micrite)

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Sedimentary rocks

• Carbonate sediments and rocks
• Biogenic carbonate formation occurs by a wide
  range of organisms (e.g., molluscs, corals,
  forams, algae, bacteria, and many others)
• Most organisms initially form unconsolidated
  carbonate sediments
• Coral reefs and microbial mats (e.g.,
  stromatolites) are examples of more solid
  carbonate structures
• Chemical precipitation produces non-skeletal
  carbonate grains of various sizes (e.g., ooids,
  pisoids, micrite)

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Sedimentary rocks

• Carbonate sediments and rocks
• Carbonate sand usually consists either of
  (fragmented) skeletal remains or non-skeletal
  grains
• Carbonate mud (micrite) is commonly the product
  either of chemical precipitation or
  algal/bacterial activity
• Dunham classification of carbonate rocks
• Texturally-based subdivision (cf. clastics)
  mudstone, wackestone, packstone, grainstone,
  rudstone
• Organically bound framework during formation
  boundstone

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Sedimentary rocks

• Organic (carbonaceous) sediments and rocks
• Peat and organic-rich clastic sediments form in
  relatively anaerobic (reducing) environments
  (e.g., mires, lakes, oceans)
• Minerotrophic peat mostly nutrient-rich,
  groundwater-fed mires (e.g., floodplains, delta
  plains, coastal plains)
• Ombrotrophic peat mostly nutrient-poor,
  rainwater-fed mires (e.g., relatively high, flat
  terrains)
• Gyttja organic-rich lake sediment
• Sapropel organic-rich marine sediment

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Sedimentary rocks

• Organic (carbonaceous) sediments and rocks
• Coal consists primarily of solid organic matter
  the remainder is known as ash
• Carbonaceous shales have a lower proportion of
  solid organic matter
• Oil shales (may be formed in anaerobic lake and
  marine environments) contain organic matter that
  can be driven off as liquid or gas by heating

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Sedimentary rocks

• Evaporites
• Dissolved salts precipitate out of sea water due
  to concentration (brine formation) during
  evaporation (1 km of sea water --gt 12 m of
  evaporites)
• Evaporites commonly lithify into consolidated
  rocks upon formation
• Least soluble compounds precipitate first
• CaCO3 (calcium carbonate)
• CaSO4 (calcium sulphate gypsum or anhydrite)
• NaCl (halite rock salt)
• Other, less stable (highly soluble) chlorides

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Sedimentary rocks

• Evaporites
• Dissolved salts precipitate out of sea water due
  to concentration (brine formation) during
  evaporation (1 km of sea water --gt 12 m of
  evaporites)
• Evaporites commonly lithify into consolidated
  rocks upon formation
• Least soluble compounds precipitate first
• CaCO3 (calcium carbonate)
• CaSO4 (calcium sulphate gypsum or anhydrite)
• NaCl (halite rock salt)
• Other, less stable (highly soluble) chlorides

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Sedimentary rocks

• Volcaniclastic sediments and rocks
• Lava (cooled magma flows) produces volcaniclastic
  sediment upon weathering
• Pyroclastic material or tephra (ejected
  particulate material) can be subdivided into
  different compositional categories
• Mineral grains
• Lithic fragments
• Vitric material (volcanic glass or pumice)

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