Introduction of sequence stratigraphy

 Presented to:
Dr. Kamran Mirza
 Presented by:
Muhammad Wajid Manzoor
Roll no. 09
Institute of Geology
University of the Punjab Lahore.

 Definition
 History
 Basic laws
 Fundamental principle
 Hierarchy
 Importance
 Applications

Study of sedimentary sequences, genetically
related strata bounded by unconformities or
their correlative conformities is known as the
sequence stratigraphy.

 James Hutton (1726-1797): Father of Modern
Geology, First described unconformity in
northern Scotland.
 In a paper entitled “Theory of The Earth”
(1785) Hutton recognized the importance of
unconformities.
 The term “ sequence” was introduced by
Sloss et al. (1949) to designate a
stratigraphic unit bounded by subaerial
unconformities.

There are three basic laws:
 Law of original horizontality.
 Law of superposition.
 Walther’s law of facies.

 Sequence stratigraphy is based on the premise
that sedimentary successions can be divided into
unconformity-bounded units (sequences) that
form during a cycle of sea-level change.

 Depositional Sequence.
 Depositional system.
 Parasequence.
 Flooding environment.
 Parasequence set.
 System tract.

 Genetically related strata bounded by surfaces of
erosion or non deposition or their correlative
conformities.

 A 3D assemblage of litho-facies genetically linked
and coexisting today (fluvial, deltaic,
barrier‐island) enclosed within sequence
boundaries.

 Parasequences are the smallest facies units of
depositional sequences and range in thickness from
about 10 to 100 m.
 A parasequence is a small-scale succession of beds or
bed sets bounded.
 Genetically related, relatively conformable successions
of beds and bedsets bounded by flooding surfaces and
their correlative surfaces.

 A surface that separates younger from older
strata, across which there is evidence of an
abrupt increase in water depth
 Surface marked by deeper‐water strata resting on
shallower‐water strata.

 Parasequence set is a succession of genetically
related parasequences that form a distinctive
stacking pattern that is bounded.

 Progradatioal .
(Step seaward)
 Retrogradational.
(Step landward)
 Aggradational.
(Build vertically)

 Accommodation space is the space available for
sediment to accumulate at any given time.
 Fundamentally, it is the space between a
conceptual equilibrium surface that separates
erosion from deposition in which potential
sediment can accumulate.

 Bed set, defined by discontinuities,
terminate against other bed sets and are
defined by the angular relationship between
the two.

 Genetically associated stratigraphic units
that were deposited during specific phases of
the relative sea‐level cycle.

 Four kinds of system tracts are recognized,
depending upon the sea-level conditions under
which they formed.
 High stand system tract.
 Falling stage system tract.
 Low-stand system tract.
 Transgressive system tract.

 Sediment deposited during high sea level,
(Alluvial and coastal plain sediments characterize
in high stand system tracts).

 Sediment deposited as sea level falls from high to
low.

 Sediments deposited during low sea level and early
rising sea level.

 Sediment deposited during rising sea level.
Transgressive system tract sediments may
contain alluvial and coastal plain sediments,
shallow-marine sediments and offshore marine
sediments.

 Sequence stratigraphy has geological time
significance, when compared to lithostratigraphy
which correlates similar rock type only on the
bases of lithology often irrespective of the
depositional environments.
 Sequence stratigraphy defines rock units based on
event significance of their bounding surfaces.

 Academic application:
Genesis and internal architecture of
sedimentary basin fill.
 Industrial application:
Exploration for hydrocarbons, coal and
mineral resources.

Introduction of sequence stratigraphy

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Introduction of sequence stratigraphy