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JOURNAL OF MAPS, 2016
http://dx.doi.org/10.1080/17445647.2015.1127858
SCIENCE
Sea–land geology of Marettimo (Egadi Islands, central Mediterranean sea)
M. Gasparo Morticelli, A. Sulli and M. Agate
Dipartimento di Scienze della Terra e del Mare, Università degli studi di Palermo, Palermo, Italy
ABSTRACT ARTICLE HISTORY
Received 24 July 2015
We present a 1:10,000 scale geological map of Marettimo Island and its offshore (Egadi Revised 1 December 2015
Archipelago, central Mediterranean Sea). The map was achieved by integrating a new Accepted 1 December 2015
geological survey with data from recent, marine, geological and geophysical surveys
acquired along the adjacent continental shelf. The island is composed of a Mesozoic, mostly KEYWORDS
carbonate platform succession, which is overlain by continental to coastal marine Quaternary Geological survey;
deposits. Extensional tectonics have affected the carbonate platform since the Late Triassic stratigraphy; tectonics; Egadi
producing an initial increase of accommodation space that was filled by interbed breccias, Islands
marls and calcareous marls. During the Jurassic, a NE-SW-directed normal fault-bounded
Downloaded by [Universita di Palermo] at 02:49 07 January 2016 structural lows where thick beds of megabreccias accumulated followed upwards by cherty
limestone and bedded cherts. During the building of the chain, the compressional tectonics
generated a southeast-verging tectonic wedge, displaced by subsequent transpression.
During the Quaternary, repeated sea-level changes shaped a rough erosional surface along
the inner shelf and controlled the lateral facies variation of the continental and marine
coastal deposits along the present day coastline.
1. Introduction Cartography) and GEBEC Sud (Agate, Catalano, Lo
Iacono, & Chemello, 2005) projects.
The stratigraphic and structural setting of the Maret-
timo Island (Italy) and its offshore are here illustrated The topographic basemap is the Section 604010, per-
with a detailed geological map at a scale of 1:10,000, taining to the Carta Tecnica Regionale, at a scale of
based on an integrated sea–land geological/geophysical 1:10,000 (vector file format .dwg, plane coordinates of
survey. Marettimo Island, belonging to the Egadi the East Zone of the Gauss-Boaga Italian national system
Archipelago and located in the western Sicily offshore geographical projection, datum Rome 1940, Monte
(central Mediterranean Sea, Figure 1(a)), represents Mario). The bathymetric basemap is Sheet 260 of the Isti-
the westernmost outcrop of the Sicilian Fold and tuto Idrografico della Marina, at a scale of 1:50,000. Both
Thrust Belt (FTB). A reliable understanding geological contour lines and isobaths are at a 10-m interval. To
evolution of Marettimo Island, a natural bridge improve the legibility of the geological map, the topo-
between the Sicilian and Tunisian sectors of the Apen- graphic vector file was cleaned of some toponyms as
ninic–Maghrebian FTB (Figure 1; see also the top-left well as cadastral and administrative boundaries.
regional map inset in the map), is a crucial contribution
to the regional geological framework of the central The marine geological map results from the overlay
Mediterranean. We also present the submerged coastal of different information layers:
zone (up to −50 m) to continue and correlate outcrop-
ping and submerged geological features. In doing this, . distribution of sediments based on different texture;
we note the stratigraphic relationships between conti- . outcrops of the late Quaternary depositional
nental and coastal marine sediments.
sequence and the underlying lithostratigraphic
units and
. outcropping and buried tectonic lineaments.
2. Data and methods 3. Geological background
The geological map of Marettimo is the result of a The geological setting of the Egadi Islands, located in
recent, detailed field survey reproduced at a scale of the western Sicily offshore (Figure 1) is due to the col-
1:10,000. The fieldwork included stratigraphic, sedi- lision between the Sardinia-Corsica micro-plate and
mentary facies and meso-structural analyses. We inte- the northern edge of the African continental margin,
grated the field data with results of previous marine starting from the early Miocene (Bellon, Coulon, &
geological and geophysical surveys, performed in the Edel, 1977; Channel, D’Argenio, & Horvath, 1979;
framework of the CARG (Italian official Geological Dercourt et al., 1986). From the Egadi Islands to
CONTACT M. Gasparo Morticelli maurizio.gasparo@unipa.it
© 2016 M. Gasparo Morticelli