Namurian (Late Carboniferous) Depositional Systems of the Craven-Area, Northern England: Implications for Sequence-Stratigraphic Models
- Henry W. Posamentier3,
- Colin P. Summerhayes4,
- Bilal U. Haq5 and
- George P. Allen6
Published Online: 15 APR 2009
Copyright © 1993 The International Association of Sedimentologists
Sequence Stratigraphy and Facies Associations
How to Cite
Martinsen, O. J. (1993) Namurian (Late Carboniferous) Depositional Systems of the Craven-Area, Northern England: Implications for Sequence-Stratigraphic Models, 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.ch14
Plano, Texas, USA
Washington, DC, USA
St Remy les Chevreuses, France
- Published Online: 15 APR 2009
- Published Print: 17 NOV 1993
Print ISBN: 9780632035489
Online ISBN: 9781444304015
- Namurian (late Carboniferous) depositional systems - Craven-Askrigg area, northern England;
- EPR sequence-stratigraphic approach - reasonable predictor for basin-fill stratigraphy;
- sequence-stratigraphic models of Exxon Production Research (EPR);
- biostratigraphic framework;
- lithostratigraphic and sedimentary framework;
- early depositional patterns on block and in basin (‘block-margin’ phase);
- late depositional patterns on block and in basin (‘ramp’ phase);
- application of sequence-stratigraphic models;
- Exxon Production Research and Galloway sequence-stratigraphic models - Namurian Elc-H2c (Upper Carboniferous) sedimentary successions of Craven-Askrigg
Sequence-stratigraphic models of Exxon Production Research (EPR) and Galloway (1989a) have been applied to Namurian E1c-H2c (Upper Carboniferous) sedimentary successions of the Craven–Askrigg area, northern England. These sediments were deposited in an extensional setting characterized by a transition from a slowly subsiding basin margin fault block into a more rapidly subsiding initially deep basin. The basin margin fault block experienced reactivations which had impacts on sequence-stratigraphic development of the area. The basin fill is punctuated at several levels by goniatite-bearing marine bands which carry their own distinctive species, occur basin-wide and form excellent correlation markers. The goniatite bands were probably controlled by eustatic fluctuations in sea level.
While sedimentation on the basin margin fault block for the entire time period was dominated by shallow-marine and fluviodeltaic deposition, the basin was initially filled by turbidites which were followed by slope deposits and several subsequent deltaic episodes. In both areas the sedimentation was episodic with numerous progradations taking place punctuated by transgressions represented by the basin-wide marine bands and their correlatives. All of these progradational episodes are termed minor cycles in the traditional approach. The minor cycles form stacking patterns, which may be described as major cycles, separated by multi-minor cycle mudstone units.
Only in part does the EPR sequence-stratigraphic approach seem to be a reasonable predictor for the basin-fill stratigraphy, and it cannot account fully for lateral variability caused by tectonic influence on sedimentation patterns by reactivations of the basin margin fault block. In addition, evidence suggests that EPR type 1 sequences developed at more than one time scale and this severely constrains the potential of interregional correlations. Moreover, defining boundaries at unconformities within the basin fill is problematical since most ‘unconformable’ surfaces occur at the bases of channel sandstones which are localized and sometimes apparently linked genetically to the sediments below the erosion surfaces.
Galloway's (1989a) model provides a reasonable approach to the basin fill, at the scale of minor cycles. The goniatite bands form widely correlative genetic sequence boundaries, and appear to separate distinct phases of progradation and retreat of depositional systems. However, it does not predict deposits formed during lowstands of base level, which are present in several minor cycles. Moreover, at the larger scale of major cycles, the Galloway (1989a) model does not provide a satisfactory prediction of the basin fill.