High-Resolution Sequence Architecture: A Chronostratigraphic Model Based on Equilibrium Profile Studies

  1. Henry W. Posamentier4,
  2. Colin P. Summerhayes5,
  3. Bilal U. Haq6 and
  4. George P. Allen7
  1. D. Nummedal,
  2. G. W. Riley and
  3. P. L. Templet

Published Online: 15 APR 2009

DOI: 10.1002/9781444304015.ch4

Sequence Stratigraphy and Facies Associations

Sequence Stratigraphy and Facies Associations

How to Cite

Nummedal, D., Riley, G. W. and Templet, P. L. (1993) High-Resolution Sequence Architecture: A Chronostratigraphic Model Based on Equilibrium Profile Studies, in Sequence Stratigraphy and Facies Associations (eds H. W. Posamentier, C. P. Summerhayes, B. U. Haq and G. P. Allen), Blackwell Publishing Ltd., Oxford, UK. doi: 10.1002/9781444304015.ch4

Editor Information

  1. 4

    Plano, Texas, USA

  2. 5

    Godalming, UK

  3. 6

    Washington, DC, USA

  4. 7

    St Remy les Chevreuses, France

Author Information

  1. Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, USA

  1. Amoco Production Corporation, PO Box 3092, Houston, TX 77253, USA

  2. Exxon Company USA, PO Box 4279, Houston, TX 77210, USA

Publication History

  1. Published Online: 15 APR 2009
  2. Published Print: 17 NOV 1993

ISBN Information

Print ISBN: 9780632035489

Online ISBN: 9781444304015

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Keywords:

  • high-resolution sequence architecture - chronostratigraphic model based on equilibrium profile studies;
  • wave-dominated strandplain and associated fluvial, deltaic and shelf systems;
  • profile adjustments to base-level change;
  • shoreface equilibrium concept and relative sea-level fall;
  • regressive fluvial/deltaic profile;
  • model stratigraphy;
  • flooding surface;
  • regressive surface of erosion - associated with phase of relative sea-level fall

Summary

The sequence-stratigraphic signature of a shoreline excursion is controlled by sediment accumulation rates relative to the distribution and rates of generation of accommodation space. Accommodation space, in turn, is controlled by slopes and rates of migration of the local equilibrium surfaces (‘base levels’). Based on forward modelling of the migrations of these equilibrium profiles, we demonstrate that the sediment package produced by a single cycle of relative sea-level change may contain as many as five separate diastems.

Regressions associated with sea-level fall produce two separate surfaces: exposure and bypass generate a subaerial erosion surface (first diastem) and decreasing water depth on the inner shelf creates a submarine erosion surface (second diastem). Regressions associated with sea-level stillstand or slow rise, in contrast, deposit conformable successions. During transgressions the flooding of the coastal plain produces a bypass surface (initial transgressive surface and third diastem), the erosion of the shoreface cuts a ravinement surface (fourth diastem) and outer-shelf environments which are depleted in clastic input form a starvation surface on top of the transgressive shelf strata (fifth diastem).

This model predicts the stratigraphy of a deposit resulting from a single regression and transgression of a shoreline. If no relative sea-level fall is associated with such a cycle, the resulting deposit is a parasequence, bounded by transgressive surfaces. If the cycle does include a relative fall, the resulting deposit becomes two half-sequences, separated by a regressive surface of erosion, which is the sequence boundary. The models highlight the observation that parasequences and sequences are simply two different ways of subdividing the stratigraphic record; parasequences are bounded by surfaces of deepening (transgressive surfaces) and sequences are bounded by surfaces of shallowing (sequence boundaries). Both may, and often do, represent the same thickness of rocks and increments of time.