Quantitative analysis of accommodation patterns in carbonate
platforms: an example from the mid-Cretaceous of SE Spain
Loading...
Download
Full text at PDC
Publication date
2003
Authors
Advisors (or tutors)
Editors
Journal Title
Journal ISSN
Volume Title
Publisher
Elsevier
Citation
Abstract
For sequence stratigraphic analysis of extensive carbonate platforms (hundreds of kilometres wide) developed in
greenhouse climates on broad, passive margins, less emphasis should be placed on large-scale seismic geometries, and
more attention paid to sequence stratigraphic correlation of stratigraphic sections based usually on isolated outcrops.
To this end, quantitative analysis of accommodation emerges as a simple, useful tool, that allows detailed
architectural reconstructions, regional chronostratigraphical correlation and systems tract interpretation. In this
paper, a quantitative analysis of accommodation was applied to the wide platforms that developed in the southern
passive continental margin of Iberia during the mid-Cretaceous (late Albian to early middle Cenomanian interval).
This analysis was based on several integrated techniques including: (1) construction of total accommodation curves
with the aid of backstripping techniques for calculating decompacted sedimentary accumulation through time, (2)
mathematical analysis of these curves and characterisation of second- and third-order accommodation patterns, and
(3) analysis of parasequence stacking patterns in peritidal cyclic successions by means of Fischer plots. By applying
these techniques to eight individual sections logged at the decimetre scale in outcrops of the External Zones of the
Betic orogenic belt, it was possible to characterise the second- and third-order accommodation signal for this interval
in the basin. The second-order curve defines a long-term sigmoidal pattern of nearly six million years, with low rates
of accommodation generation in the first and the last part of the interval, and high rates in the mid-interval. The
third-order signal defines six accommodation events of one million years average duration, which controlled the
development of six successive depositional sequences and their systems tracts. On the basis of this new sequence
stratigraphic framework, a high-resolution, 2-D platform transect, showing the spatial distribution of facies, was
erected and analysed. The results notably complete previous qualitative sequence stratigraphic data on the platform
and contribute to a better understanding of the nature of systems tracts and their boundaries in response to
overlapping of second- and third-order accommodation patterns.