Contents

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Contents

• Introduction
• Sedimentology concepts
• Fluvial environments
• Deltaic environments
• Coastal environments
• Offshore marine environments

• Sea-level change
• Sequence stratigraphy concepts
• Marine sequence stratigraphy
• Nonmarine sequence stratigraphy
• Basin and reservoir modeling
• Reflection

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Sedimentology concepts

• Fluid flow and bedforms
• Unidirectional flow leads predominantly to
  asymmetric bedforms (two- or three-dimensional)
  or plane beds
• Current ripples
• Dunes
• Plane beds
• Antidunes
• Oscillatory flow due to waves causes
  predominantly symmetric bedforms (wave ripples)
• Combined flow involves both modes of sediment
  transport and causes low-relief mounds and swales

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Animation
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Sedimentology concepts

• Fluid flow and bedforms
• Unidirectional flow leads predominantly to
  asymmetric bedforms (two- or three-dimensional)
  or plane beds
• Current ripples
• Dunes
• Plane beds
• Antidunes
• Oscillatory flow due to waves causes
  predominantly symmetric bedforms (wave ripples)
• Combined flow involves both modes of sediment
  transport and causes low-relief mounds and swales

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Sedimentology concepts

• Fluid flow and bedforms
• Unidirectional flow leads predominantly to
  asymmetric bedforms (two- or three-dimensional)
  or plane beds
• Current ripples
• Dunes
• Plane beds
• Antidunes
• Oscillatory flow due to waves causes
  predominantly symmetric bedforms (wave ripples)
• Combined flow involves both modes of sediment
  transport and causes low-relief mounds and swales

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Sedimentology concepts

• Sedimentary structures
• Planar stratification is primarily the product of
  aggrading plane beds
• Cross stratification is formed by aggrading
  bedforms
• Planar and trough cross stratification are the
  result of straight-crested (2D) and linguoid (3D)
  bedforms, respectively
• Small-scale cross stratification (current
  ripples)
• Large-scale cross stratification (dunes)
• Wave cross stratification (wave ripples)
• Hummocky cross stratification (mounds and swales)
• A single unit of cross-stratified material is
  known as a set multiple stacked sets of similar
  nature form co-sets

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Animation
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Animation
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Sedimentology concepts

• Sedimentary structures
• Planar stratification is primarily the product of
  aggrading plane beds
• Cross stratification is formed by aggrading
  bedforms
• Planar and trough cross stratification are the
  result of straight-crested (2D) and linguoid (3D)
  bedforms, respectively
• Small-scale cross stratification (current
  ripples)
• Large-scale cross stratification (dunes)
• Wave cross stratification (wave ripples)
• Hummocky cross stratification (mounds and swales)
• A single unit of cross-stratified material is
  known as a set multiple stacked sets of similar
  nature form co-sets

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Sedimentology concepts

• The facies concept refers to the sum of
  characteristics of a sedimentary unit, commonly
  at a fairly small (cm-m) scale
• Lithology
• Grain size
• Sedimentary structures
• Color
• Composition
• Biogenic content
• Lithofacies (physical and chemical
  characteristics)
• Biofacies (macrofossil content)
• Ichnofacies (trace fossils)

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Sedimentology concepts

• Facies analysis is the interpretation of strata
  in terms of depositional environments (or
  depositional systems), commonly based on a wide
  variety of observations
• Facies associations constitute several facies
  that occur in combination, and typically
  represent one depositional environment (note that
  very few individual facies are diagnostic for one
  specific setting!)
• Facies successions (or facies sequences) are
  facies associations with a characteristic
  vertical order
• Walthers Law (1894) states that two different
  facies found superimposed on one another and not
  separated by an unconformity, must have been
  deposited adjacent to each other at a given point
  in time

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Sedimentology concepts

• Standardized facies codes have been proposed
  (e.g., by Andrew Miall), but they are frequently
  critized
• Sedimentary logs are one-dimensional
  representations of vertical sedimentary
  successions
• Architectural elements are the two- or
  three-dimensional building blocks of a sediment
  or a sedimentary rock
• The three-dimensional arrangement of
  architectural elements is known as sedimentary
  architecture
• Since the 1970s, facies analysis has evolved from
  a focus on one-dimensional data to
  three-dimensional data (architectural-element
  analysis, 3D seismic), recognizing that
  individual sedimentary logs can rarely provide
  detailed environmental interpretations

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Sedimentology concepts

• Standardized facies codes have been proposed
  (e.g., by Andrew Miall), but they are frequently
  critized
• Sedimentary logs are one-dimensional
  representations of vertical sedimentary
  successions
• Architectural elements are the two- or
  three-dimensional building blocks of a sediment
  or a sedimentary rock
• The three-dimensional arrangement of
  architectural elements is known as sedimentary
  architecture
• Since the 1970s, facies analysis has evolved from
  a focus on one-dimensional data to
  three-dimensional data (architectural-element
  analysis, 3D seismic), recognizing that
  individual sedimentary logs can rarely provide
  detailed environmental interpretations

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Sedimentology concepts

• Standardized facies codes have been proposed
  (e.g., by Andrew Miall), but they are frequently
  critized
• Sedimentary logs are one-dimensional
  representations of vertical sedimentary
  successions
• Architectural elements are the two- or
  three-dimensional building blocks of a sediment
  or a sedimentary rock
• The three-dimensional arrangement of
  architectural elements is known as sedimentary
  architecture
• Since the 1970s, facies analysis has evolved from
  a focus on one-dimensional data to
  three-dimensional data (architectural-element
  analysis, 3D seismic), recognizing that
  individual sedimentary logs can rarely provide
  detailed environmental interpretations

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Sedimentology concepts

• Sedimentary structures occur at very different
  scales, from less than a mm (thin section) to
  100s1000s of meters (large outcrops) most
  attention is traditionally focused on the
  bedform-scale
• Microforms (e.g., ripples)
• Mesoforms (e.g., dunes)
• Macroforms (e.g., bars)
• Bounding-surface hierarchies have been developed
  to distinguish different ranks of stratal
  discontinuity, from lamina to basin scale they
  are much more readily used in outcrops than in
  subsurface data

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Sedimentology concepts

• Sedimentary structures occur at very different
  scales, from less than a mm (thin section) to
  100s1000s of meters (large outcrops) most
  attention is traditionally focused on the
  bedform-scale
• Microforms (e.g., ripples)
• Mesoforms (e.g., dunes)
• Macroforms (e.g., bars)
• Bounding-surface hierarchies have been developed
  to distinguish different ranks of stratal
  discontinuity, from lamina to basin scale they
  are much more readily used in outcrops than in
  subsurface data

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Sedimentology concepts

• Allogenic (allocyclic) controls are external
  forces that exert a strong influence on
  depositional processes they include sea-level
  (base-level) change, climate change (e.g.,
  sediment supply), and tectonism (e.g.,
  subsidence, sediment supply)
• Autogenic (autocyclic) controls operate within a
  given depositional environment and cause changes
  while allogenic controls may remain constant
  (e.g., delta-lobe switching)
• The last few decades have seen an enormous shift
  in emphasis from autogenic to allogenic processes
  (sequence stratigraphy)

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Sedimentology concepts

• Accommodation is the space available, at any
  given point in time, for sediments to accumulate
  in marine environments accommodation is created
  or destroyed by relative sea-level changes
• The stratigraphic record is nearly always very
  incomplete due to a limited preservation
  potential, that decreases with increasing time
  scales
• Only an extremely small proportion of deposits
  that are initially formed actually survive and
  become preserved in the stratigraphic record
  (typical orders of magnitude 10-410-6)

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Sedimentology concepts

• Accommodation is the space available, at any
  given point in time, for sediments to accumulate
  in marine environments accommodation is created
  or destroyed by relative sea-level changes
• The stratigraphic record is nearly always very
  incomplete due to a limited preservation
  potential, that decreases with increasing time
  scales
• Only an extremely small proportion of deposits
  that are initially formed actually survive and
  become preserved in the stratigraphic record
  (typical orders of magnitude 10-410-6)

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Sedimentology concepts

• Facies models are schematic, three-dimensional
  representations of specific depositional
  environments that serve as norms for
  interpretation and prediction
• Facies models are static in the sense that they
  focus heavily on autogenic processes and
  deposits, following Walthers Law
• Modern processes must constitute the basis for
  interpreting ancient products (uniformitarianism
  works in many cases, but not always)
• Unconsolidated sediments (Quaternary) can
  provide the bridge between present-day processes
  and ancient sedimentary rocks (pre-Quaternary)
  Quaternary deposits are usually easy to interpret
  in terms of depositional environment and have
  great potential for studying 3D facies
  relationships and allogenic controls

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Sedimentology concepts

• Facies models are schematic, three-dimensional
  representations of specific depositional
  environments that serve as norms for
  interpretation and prediction
• Facies models are static in the sense that they
  focus heavily on autogenic processes and
  deposits, following Walthers Law
• Modern processes must constitute the basis for
  interpreting ancient products (uniformitarianism
  works in many cases, but not always)
• Unconsolidated sediments (Quaternary) can
  provide the bridge between present-day processes
  and ancient sedimentary rocks (pre-Quaternary)
  Quaternary deposits are usually easy to interpret
  in terms of depositional environment and have
  great potential for studying 3D facies
  relationships and allogenic controls

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Sedimentology concepts

• Facies models are schematic, three-dimensional
  representations of specific depositional
  environments that serve as norms for
  interpretation and prediction
• Facies models are static in the sense that they
  focus heavily on autogenic processes and
  deposits, following Walthers Law
• Modern processes must constitute the basis for
  interpreting ancient products (uniformitarianism
  works in many cases, but not always)
• Unconsolidated sediments (Quaternary) can
  provide the bridge between present-day processes
  and ancient sedimentary rocks (pre-Quaternary)
  Quaternary deposits are usually easy to interpret
  in terms of depositional environment and have
  great potential for studying 3D facies
  relationships and allogenic controls