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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Shallow/deep marine environments

• Shallow marine environments
• Shallow seas can be subdivided into clastic and
  carbonate-dominated systems, depending mainly on
  sediment supply and climatic setting
• Idealized models predict a general decrease of
  grain size with water depth (i.e., away from the
  shoreline) however, this simple picture is
  complicated by a large number of factors (e.g.,
  shelf bathymetry)

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Shallow/deep marine environments

• Shallow marine environments
• Storm-dominated clastic shelves ideally exhibit a
  transition from predominantly wave-rippled sands
  in the upper shoreface, to alternating sands and
  muds (tempestites with hummocky cross
  stratification) in the lower shoreface, to muddy
  facies below storm wave base
• Tide-dominated clastic shelves may exhibit
  erosional features, sand ribbons, and sand waves
  with decreasing flow velocities, commonly
  associated with mud-draped subaqueous dunes
  tidal sand ridges (tens of m high, many km
  across) are characteristic of shelves with a high
  supply of sand
• Bioturbation can obliterate many primary
  sedimentary structures in shelf environments

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Shallow/deep marine environments

• Shallow marine environments
• Shallow seas within the photic zone are the
  premier carbonate factories
• Carbonate platforms can cover continental shelves
  or epicontinental seas, when the conditions for
  carbonate production (temperature, salinity,
  light conditions) are favorable
• Isolated platforms (atolls) are found in shallow
  seas surrounded by deep water, like extinct
  volcanoes

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Shallow/deep marine environments

• Shallow marine environments
• Carbonate ramps exhibit processes and
  characteristics comparable to clastic shelves,
  with carbonate sands and muds ultimately
  producing a seaward transition from grainstone to
  mudstone, commonly with similar sedimentary
  structures
• Rimmed carbonate shelves consist of a coral reef
  or carbonate sand barrier at some distance from
  the mainland the shelf lagoon can be up to many
  tens of kilometers wide
• Boundstones dominate the reef facies
• Shelf lagoon facies are mostly fine-grained and
  ultimately lead to the formation of mudstones and
  wackestones

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Shallow/deep marine environments

• Deep marine environments
• The continental slope is a major source of
  sediment for the deep sea, and is a setting where
  slumps can occur
• Debris flows and turbidity currents are the main
  mechanisms of transport from the continental
  slope into the deep sea these processes can be
  triggered by external forcing (e.g., an
  earthquake) or by the slope reaching a critical
  state as a result of ongoing deposition
• Debris-flow deposits and turbidites are often
  genetically related
• Turbidites can be both clastic (commonly leading
  to the formation of wackes) or calcareous

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Shallow/deep marine environments

• Deep marine environments
• Submarine canyons at the shelf edge (commonly
  related to deltas) are connected to submarine
  fans on the ocean floor
• Contrary to debris flows, turbidites exhibit a
  distinct proximal to distal fining
• Submarine fans share several characteristics with
  deltas they consist of a feeder channel that
  divides into numerous distributary channels
  bordered by natural levees and are subject to
  avulsions
• Proximal fan (trunk channel)
• Medial fan (lobes)
• Distal fan

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Shallow/deep marine environments

• Deep marine environments
• Basal Bouma-divisions have the highest
  preservation potential updip upper
  Bouma-divisions are more common downdip
• Turbidite lobes characterize the medial fan and
  may exhibit the most complete Bouma sequences
• The Bouma-model is increasingly challenged,
  because many turbidites do not conform to it
  (e.g., high-concentration turbidites)
• Contourites are formed by ocean currents and
  commonly represent reworked turbidites

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Shallow/deep marine environments

• Deep marine environments
• Pelagic sediments primarily have a biogenic
  origin
• Calcareous ooze (e.g., foraminifera) forms above
  the calcite compensation depth (CCD) at 4000 m
  depth
• Siliceous ooze (e.g., radiolarians, diatoms)
  forms between the CCD and 6000 m depth where
  silica dissolves it lithifies into cherts
• Hemipelagic sediments consist of fine-grained
  (muddy) terrigenous material that is deposited
  from suspension
• Eolian dust is an important component (50) of
  hemipelagic (and pelagic) facies
• Black shales have a 1-15 organic-matter content
  and form in anoxic bottom waters