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(a) Bed deformation structure in Lungo Mare (b) Smaller scale dish-and-pillar deformation
at the north coast of Favignana, most likely as structures in Cala Azzurra, observed in the
a result of water escape or instability during yellowish deposits visible on the panel in fig-
deposition. Ruler of one metre for scale. ure B.5, appendix B. Chart for scale, which
is 10 centimetres wide.

Figure 7.1 – Water escape structures at two different scales.

The very high permeability of the Favignana calcarenite (30 to 100 D, with some outliers to little above 300
D) have to be interpreted carefully, because they might be caused by side effects of the test method, and
not by the matrix permeability itself. All samples show approximately the same variance in permeability
values (see porosity-permeability plot in figure 4.13). This implies that in the stratigraphical units where
the sampling was done no major flow barriers have been observed and/or sampled. The number of
samples, however, is too small to extrapolate this statement to the entire calcarenite complex. Very small
features like recrystallised fractures can have major implications on reservoir flow (see for example figure
4.7a). A set of plugs with a size as used in these experiments can never be representative of a such large
scale accumulation.

7.3 Location on shelf

Many examples of calcarenite complexes described in the Mediterranean area suggest that large foresets
as seen on Favignana usually indicate that the sedimentary system is prograding on a shelf edge, towards
the open sea. Multiple examples can be found in the literature. Below some of these examples will be
discussed:

1. Massari & Chiocci (2006) describe a cool-water carbonate body with large foresets in the central
part of Sicily. Pleistocene deposits can be found several hundreds of metres above present day sea
level, indicating that a substantial amount of uplift has occurred since deposition. Their conceptual
depositional model proposes a situation where bioclastic sediment is deposited on the shelf, partly
at depths lower than the storm-wave base. Storms and wave interaction reworks the sediment and
creates a wedge-type system that builds out towards the open sea.

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