This document defines sequence stratigraphy and discusses its basic concepts. Sequence stratigraphy studies genetically related rock units bounded by unconformities. It is based on dividing strata into sequences bounded by sea level changes. Key concepts discussed include depositional sequences, parasequences, flooding surfaces, system tracts, accommodation space, and the importance of sequence stratigraphy for understanding basin evolution and resource exploration.

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

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

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

5.  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.

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

7.  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.

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

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

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

11.  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.

13.  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.

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

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

19.  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.

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

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

25.  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.

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

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

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

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

34.  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.

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