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a
b

Figure 3.1 – The principle of the apparent dip. By definition, β ≤ α for an apparent dip β
and a real dip α.

geological model. A good three-dimensional insight is crucial in order to make a reliable subdivision.
Generally an outcrop face exposing only one orientation does not provide sufficient information to
extract the transport direction. The fact that the quarries on Favignana provide outcrop walls in
almost all orientations, often perpendicular to each other, makes interpolation and reconstruction of
transport directions easier. Thus, for each sedimentary structure in an outcrop, an attempt to obtain the
palaeotransport direction was made. In some cases — for reasons described earlier — the outcrop quality
was too bad to make reliable observations. For those parts of the section the sedimentary structures and
transport directions are unknown.

The square character of the outcrops introduce the principle of apparent dips. A dip direction and/or
angle of a bed, lamina or other sedimentary feature as observed on a single wall will hardly ever be its real
orientation. Instead, it is more likely that one observes the so-called apparent dip. Figure 3.1 illustrates
this principle. By definition, the apparent dip is always smaller than or equal to the real dip.

3.2 Sampling

During the fieldwork, eight samples were taken in order to 1) test the rock for reservoir properties; and
2) describe the microfacies; of the Favignana calcarenite. A rock hammer and chisel were used to cut the
samples out of the outcrop walls. The size of the samples was kept large - cubes of around 20 cm - to
ensure that enough cores could be drilled back in the TU Delft core drilling facilities. Moreover, the size
also prevents the samples from breaking during chiselling.

In the core drilling laboratory, the sides of each sample were trimmed to be able to expose a fresh rock
face. Without weathering and debris that was present on the samples, the grain orientation and/or size
is easier to examine. Where possible, a number of horizontal and vertical cores were drilled from the
large samples. Finally, the obtained cores were cut to a length of about 3 cm, creating the plugs for

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