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4 M. Antonellini et al. / Marine and Petroleum Geology xxx (2013) 1e16

Figure 2. (a) The conjugate strike-slip compactive shear bands exposed in the studied outcrops, the field mini-permeameter is also recognizable. (b) Detail of a strike-slip
compactive shear band, the zones I, II and III composing the structure are shown.

3.2. Fault permeability New England Research. The employed permeameter provides
1
reliable permeability values from 10 4 to 10 Darcy. Sampling sites
Permeability measurements were carried out in the field on were carefully scraped with a putty knife to remove weathering
carbonate grainstone host rock, as well as on diagenetic/struc- effects, and gently brushed to take off dust that could likely influ-
tural zones I, II, and III associated with single compactive shear ence the permeability measurements. A silicon ring (5 mm of
bands (CSB), zones of compactive shear bands (ZB), and well- diameter) was used to avoid air leaking from the mini-
developed faults (DF), with slip surface and cataclasis (see permeameter nozzle, which is smaller than most ZB widths and
Figs. 3 and 4). A total of 56 measurements was collected in the of the same order of magnitude of CSB in coarse grainstones.
different domains: 33 measurements in the host rock, 12 mea- Despite the permeability has been measured in the single zones
surements in zone III, and 11 measurements in zones I and II of (zones I, II and III), due to the diameter size of nozzle, it was not
the structures (as for definition, zone I is present only in well- possible to distinguish between permeability measurements car-
developed faults). ried out in zones I and II. For this reason, all measurements per-
Measurements were performed by using the TinyPerm II taining to those zones are grouped together in the general class
Portable Air Permeameter (mini-permeameter) manufactured by “zones IeII”.

Figure 3. (a) Map of strike-slip faults in porous grainstone at San Vito Lo Capo that was used to build the reservoir/aquifer model, showing points (red circles) where the
permeability was measured in the field with a portable permeameter. (b) Detail of the map in (a). (For interpretation of the references to color in this figure legend, the reader is
referred to the web version of this article.)

Please cite this article in press as: Antonellini, M., et al., Fluid flow numerical experiments of faulted porous carbonates, Northwest Sicily (Italy),
Marine and Petroleum Geology (2013), http://dx.doi.org/10.1016/j.marpetgeo.2013.12.003