The Devonian–Boundary in Southern Belgium: Biostratigraphic Identification Criteria of Sequence Boundaries

  1. Henry W. Posamentier2,
  2. Colin P. Summerhayes3,
  3. Bilal U. Haq4 and
  4. George P. Allen5
  1. M. Van Steenwinkel

Published Online: 15 APR 2009

DOI: 10.1002/9781444304015.ch13

Sequence Stratigraphy and Facies Associations

Sequence Stratigraphy and Facies Associations

How to Cite

Van Steenwinkel, M. (1993) The Devonian–Boundary in Southern Belgium: Biostratigraphic Identification Criteria of Sequence Boundaries, 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.ch13

Editor Information

  1. 2

    Plano, Texas, USA

  2. 3

    Godalming, UK

  3. 4

    Washington, DC, USA

  4. 5

    St Remy les Chevreuses, France

Author Information

  1. Petroleum Development Oman, PO Box 81, Muscat, Sultanate of Oman

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:

  • Pre-Quaternary applications of sequence-stratigraphic concepts;
  • Devonian-carboniferous boundary in southern Belgium - biostratigraphic identification criteria of sequence boundaries;
  • biostratigraphic age determination at smallest possible scale;
  • relative sea-level changes;
  • depositional sequence of Belgian Devonian-carboniferous boundary;
  • eustasy and subsidence in relative sea-level curve of Dinant synclinorium

Summary

A biostratigraphic hiatus in the latest Devonian of the Dinant synclinorium, southern Belgium, is characterized by the extinction of several species, followed by a period in which index fauna are absent or scarce, and by a later, rapid diversification of evolved Carboniferous species.

This biostratigraphic hiatus is shown to be associated with a basinward facies shift. A relative sea-level fall in the latest Devonian is held responsible for both the biostratigraphic hiatus and the facies shift, causing the late-Devonian highstand sedimentation with its great faunal diversity to cease. This resulted in a period of non-deposition, expressed in the rock record as a hiatal sequence boundary. Sedimentation eventually resumed, but in a much shallower, lowstand depositional setting. These lowstand sediments do not contain the deep-water index species necessary to define the Devonian–Carboniferous boundary biostratigraphically. Deeper water environments were re-established only later, during a transgressive rise in relative sea level. These deeper water deposits contain newly evolved and diversified Carboniferous index fossils suitable for biostratigraphic subdivision.

Comprehending such geologic events by integration of bio- and lithostratigraphic data in a sequence-stratigraphic framework allows the correlation of small-scale flooding events (parasequence-bounding surfaces) within well-dated systems tract boundaries, and hence, lateral correlations in hiatal intervals can be significantly refined.