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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The Bible of stratigraphic classification

• Salvador, A. (Editor), 1994. International
  Stratigraphic Guide. A Guide to
• Stratigraphic Classification, Terminology, and
  Procedure.
• Geological Society of America, Boulder, 214 pp.

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Stratigraphic principles

• Lithostratigraphy subdivision of the
  stratigraphic record into sediments or rocks by
  means of lithologic characteristics and
  stratigraphic position
• Biostratigraphy subdivision of the
  stratigraphic record into sediments or rocks by
  means of fossil content
• Chronostratigraphy subdivision of the
  stratigraphic record into bodies of sediment or
  rock represented by a particular age, separated
  from underlying and overlying units by
  isochronous surfaces
• Geochronology subdivision of Earth history into
  time intervals

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Stratigraphic principles

• Type sections (stratotypes) constitute the
  standard of reference for definition and
  recognition of a stratigraphic unit or
  stratigraphic boundary they are defined where
  these are representative and well developed
• Stratigraphic relationships can be inferred from
  the principle of superposition, unconformities,
  cross-cutting relationships, included
  fragments, and way-up indicators

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Stratigraphic principles

• Type sections (stratotypes) constitute the
  standard of reference for definition and
  recognition of a stratigraphic unit or
  stratigraphic boundary they are defined where
  these are representative and well developed
• Stratigraphic relationships can be inferred from
  the principle of superposition, unconformities,
  cross-cutting relationships, included
  fragments, and way-up indicators

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Stratigraphic principles

• Lithostratigraphy
• The formation is the fundamental unit of
  lithostratigraphic classification just as the
  other lithostratigraphic ranks (groups, members,
  beds), it should be based on field description
  (i.e., fossil content and age do not play a role)
• Mode of deposition (genesis) is not a criterion
  in the distinction of lithostratigraphic units
  this requires interpretation and is therefore
  likely to undergo revision over time
• Lithostratigraphic units should have some degree
  of overall lithologic homogeneity, although
  diversity in detail may in itself characterize a
  lithostratigraphic unit

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Stratigraphic principles

• Lithostratigraphy
• Lithostratigraphic units are commonly
  diachronous, as opposed to chronostratigraphic
  units
• Detailed geologic mapping is usually strongly
  based on lithostratigraphy, whereas overview
  geologic maps usually show chronostratigraphic
  units
• Although objective lithostratigraphic
  classification should be as simple and
  straightforward as possible, reality demonstrates
  that this is not always the case as a result, in
  many areas revisions are frequently proposed
  which can lead to extremely complicated and
  confusing situations

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Stratigraphic principles

• Biostratigraphy
• Evolution forms the initial basis for
  biostratigraphic subdivision, either through the
  development of an increasing number of new
  species, or by means of evolution of one
  particular species
• In general, Earth history shows an increase of
  the number of taxa, but this process is
  punctuated by (mass) extinctions
• Depositional environments and geographic
  contrasts play an important role in determining
  the nature of fossil assemblages
• The biozone is the fundamental biostratigraphic
  unit
• Biozones are strictly diachronous in most cases
  however, over geological time scales their
  boundaries can commonly be considered to be
  isochronous, but their resolving power has
  limitations!

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Stratigraphic principles

• Biostratigraphy
• Evolution forms the initial basis for
  biostratigraphic subdivision, either through the
  development of an increasing number of new
  species, or by means of evolution of one
  particular species
• In general, Earth history shows an increase of
  the number of taxa, but this process is
  punctuated by (mass) extinctions
• Depositional environments and geographic
  contrasts play an important role in determining
  the nature of fossil assemblages
• The biozone is the fundamental biostratigraphic
  unit
• Biozones are strictly diachronous in most cases
  however, over geological time scales their
  boundaries can commonly be considered to be
  isochronous, but their resolving power has
  limitations!

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Stratigraphic principles

• Biostratigraphy
• A vast diversity of types of fossils exists the
  following criteria are important in determining
  how useful they are for strictly stratigraphic
  purposes of correlation
• Abundance and size
• Degree of dispersal
• Preservation potential
• Rate of speciation
• As a result, especially numerous marine
  microfossils (e.g., forams) are stratigraphically
  highly useful, whereas others are more valuable
  for paleoecologic purposes
• Numerous pitfalls exist in the correlation of
  biozones (e.g., Quaternary pollen zones)

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Stratigraphic principles

• Chronostratigraphy
• Chronostratigraphic classification of sediments
  or rocks involves the establishment of time lines
  (isochrons) this, in turn, forms the basis for
  paleogeographic reconstruction
• Traditionally, biostratigraphy has formed the
  most important basis for chronostratigraphic
  classification
• Numerical dating techniques are becoming
  increasingly important in defining
  chronostratigraphic units

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Stratigraphic principles

• Chronostratigraphy
• Radiometric dating methods are in essence based
  on the decay of radioactive isotopes
• Nnumber of daughter isotopes N0initial number
  of parent isotopes ?decay constant ttime
• Radiometric dating involves a large number of
  isotopes and decay series, with highly variable
  halflives and applications (age ranges from less
  than a century to billions of years)

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Stratigraphic principles

• Chronostratigraphy
• Mass spectrometry is the most commonly used
  technique to measure the ratio between different
  isotopes
• Many sediments and sedimentary rocks are not
  suitable for radiometric dating indirect ages
  can sometimes be obtained through dating of
  associated igneous rocks (e.g., volcanics)
• Luminescence dating is a relatively new technique
  that allows quartz and feldspar grains up to
  several 100 kyr to be dated it is based on the
  measurement of a minute light signal that can be
  released by these grains and that is proportional
  to time after burial

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Stratigraphic principles

• Magnetostratigraphy
• The Earths magnetic field is constantly subject
  to change
• Secular variations, continuous changes of the
  position of the magnetic poles, take place over
  time scales of 101 to 103 years
• Reversals from normal polarity to reversed
  polarity occur over time scales of 104 to 106
  years
• Fine-grained sediments deposited from suspension
  can align themselves according to the ambient
  geomagnetic field (the same applies to volcanics
  upon cooling below the Curie point)
• If paleomagnetic changes are independently
  numerically dated, a resulting magnetostratigraphy
  can be used to date sedimentary successions

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