Page 2 - Morticelli_et_al2016

2 M. GASPARO MORTICELLI ET AL.
Downloaded by [Universita di Palermo] at 02:49 07 January 2016 Figure 1. Structural map of western Sicily and its offshore area. (a) Location map showing the Egadi Islands in the context of the
central Mediterranean area (modified from Catalano et al., 2013).
Adventura Bank, the Sicilian FTB structural setting has
been illustrated (Catalano, D’Argenio, & Torelli, 1989;
Sulli, 2000) as an eastward and southeastward verging,
about 10 km-thick, tectonic stack made up of several
tectonic units.
Marettimo Island represents the outcropping por-
tion of a tectonic unit (Marettimo Unit) which over-
rides southeastward the Miocene sedimentary cover
of the Favignana-Levanzo Unit (Figure 1; Catalano,
Infuso, Milia, & Sulli, 1993); the latter is made up of
the Meso-Cenozoic carbonate platform to pelagic sea-
mount succession (Trapanese domain; Catalano, Di
Stefano, Sulli, & Vitale, 1996).
The structural model of Marettimo Island depicted
by Hill and Hayward (1988) shows three main tectonic
units stacked along flat surfaces. This model differs
from those proposed by Giunta and Liguori (1973)
and Abate, Incandela, and Renda (1999). The latter
considered Marettimo Island as made-up of four tec-
tonic units, settled during a late Miocene compres-
sional event and a subsequent Pliocene NNE-SSW
transpressive to transcurrent event.
4. Stratigraphy
The overall stratigraphic setting of the Island is charac-
terized by middle-upper Triassic to lower Cretaceous
carbonate rocks (Mesozoic succession) covered, along
the coastal belt, by continental to marine Quaternary
deposits.
4.1 The Mesozoic succession
On the whole, the stratigraphic succession is represented
by Figure 2: limestone, dolomitic limestone and dolomites
(Marettimo Formation, middle-upper Triassic); dolomitic
breccias and dolostones (Monte Falcone Formation, Lias);
cherty limestone (Scaturro Formation, upper Lias–Dog-
ger); bedded cherts, marls and marly limestone (Argilliti
di Punta Troia, Malm–Lower Cretaceous). We distin-
guished two tectonic units (Falcone unit and Bassano
unit, top to bottom) characterized by (slightly) different
stratigraphic successions, named the ‘Falcone succession’
and ‘Bassano succession’ (Main Map).
4.1.1 Stratigraphy of the Falcone succession
From the bottom, it is formed by:
. Marettimo Formation: blackish bituminous stromato-
lites, stromatolitic limestone, blackish dolomitic lime-
stone to dolomites rich in organic matter (MARa),
microbial laminated fenestral limestone with tepee-
like desiccation structures, oolitic limestone (MARd;
Figure 2(e)–(h)); yellowish to brownish thin layers
of marls locally interbedded (MARb). This formation
crops out along the eastern side of Monte Falcone
and in the Pizzo Spirone area (Main Map).
. Monte Falcone Formation (MFA) composed of
three lithofacies with lateral and vertical transition:
(a) massive limestone conglomerates (MFA1, crop-
ping out at Punta Troia; Figure 2 (c); Main
Map); the clasts, cobbles or boulders, are light
grey to white stromatolitic limestone and lami-
nated fenestral limestone;
(b) breccias of shallow water dolomitic limestone,
white to pinkish dolomites (MFA2, cropping
out at Punta Troia; Main Map); poor rounded
clasts of stromatolitic limestone and black
microbial laminated limestone surrounded by
dolomitic matrix;