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ARTICLE IN PRESS
38 L. Ferranti et al. / Quaternary International 145– 146 (2006) 30–54
few radiometric age constraints. Ecostratigraphy relies
on the index fossil S. bubonius and is less reliable when
only barren ‘‘senegalaise fauna’’, which includes species
still living today, occur. Many markers are ‘‘dated’’
using geomorphologic-stratigraphic criteria, and corre-
lations with adjacent sites where age estimates are
available.
Minor uncertainty sources are represented by correc-
tions for crustal loading due to eustatic changes and
ambiguity in marker identification due to tectonic
displacement. Crustal loading during 120 m of eustatic
sea-level variation is on the order of a few metres (e.g.
Lambeck et al., 2004b) and in most cases, given the
range of observed elevations up to over one hundred
metres, contributes little to the total uncertainty.
However, where the marker is close to the eustatic
elevation, lack of compensation for crustal loading
introduces a locally unknown error.
4.3. Database structure and uplift rate calculation
The complete dataset of the MIS 5.5 sea-level
highstand in Italy is listed in an Additional Table
provided on the web (.pdf file). Besides geographic
coordinates and marker specification, the dataset
includes the relevant faunal assemblage, the dating
technique and available radiometric ages, and the
derived uplift rate and its uncertainty.
Following Lambeck et al. (2004b), the uplift rate u
and its variance su2 are given by
DH sDH 2 2 on limestone promontories (Fig. 7). Inner margins are
u¼ DH
and su2 ¼ þ T 5:52
T 5:5
T 2
5:5
with eustatic and glacio-hydro-isostatic compensation
given by
DH ¼ H5:5 À dH5:5,
where H5:5 is the height of the observed MIS 5.5
shoreline above mean sea-level and dH5.5 is the height of
this shoreline in areas of tectonic stability.
T5:5 is the age of MIS 5.5 with the uncertainty sT5:5
and s2DH is the uncertainty of the tectonic uplift
s2 sd2H5:5 ).
(¼ þ We adopt the
H 5:5
T 5:5 ¼ 125 ka, sT5:5 ¼ 5 ka, dH5:5 ¼ 6 m, sdH5:5 ¼ 3 m,
the latter being the observational error of the Sardinia
site. sdH5:5 is deduced from the estimated uncertainty of
palaeo-sea-level, and mostly fall within 5 m (Table 1).
Radiometric ages are drawn from existing reports,
and additional ESR data are provided in this paper for
the Po Plain sites. Based on the combined uncertainties
derived from paleo sea-level positioning, age and
altitude measurement, a quality factor ranging from 1
to 3 is attributed to each marker. This datum is
presented in an Additional Table, available through
the Corresponding Author.
5. Occurrence of the MIS 5.5 markers in Italy
The spatial distribution of the MIS 5.5 markers in
Italy is shown in Fig. 3. Figs. 7–12 shows the altitude of
the most reliable indicators according to their quality
(indicated in the Additional Table). Sites, which lack
reliable chronological constraints (e.g. Sarno in Campa-
nia, Trieste in Friuli, Fortore in Puglia) and sites, for
which full consensus about their attribution to MIS 5.5
(e.g. Lipari and Taormina in Sicily, Crotone, Villa San
Giovanni and Capo Vaticano in Calabria) were not
achieved amongst the authors are listed in the Addi-
tional Table, but not included in Figures and in the
discussion.
The altitude of the most reliable markers varies from
À125 to +175 m with respect to modern sea-level.
Whereas the lowest altitudes are shown at the northern
Adriatic coast and at the large coastal plain in northern
Campania (Figs. 7 and 10), the highest altitudes are
recorded at the coasts of southern Calabria and eastern
Sicily, and at the Jonian coast of Basilicata (Figs. 11
and 12)
The significant differences in altitude of the indicators
originate from different regional tectonic settings
associated with segments of the orogenic belt. In the
following, the elevation pattern of the MIS 5.5 marker
in specific regions named in Fig. 4 is discussed in light of
the local tectonic processes, through a journey winding
counterclockwise along the shores of Italy. Where
Holocene deposits are present, we compare MIS 5.5
markers with Holocene markers to validate the tectonic
interpretation drawn from the MIS 5.5 markers.
5.1. Sardinia
From Sardinia an extensive number (58) of MIS 5.5
sites are reported, with marker distribution mainly
controlled by lithology since most notches are found
poorly identifiable at low laying coasts owing to the
sT 2 (1) thick continental cover, which was not eroded due to the
tectonically stable conditions of the island.
5:5
Sardinia is the only region in the Tyrrhenian Sea
where the marker elevation has a very low variability of
$10 m. The elevation of many sites lies between 5 and
6 m, and therefore it was chosen as our reference site for
the MIS 5.5 eustatic elevation.
Within this generally stable setting, minor but
consistent patterns of vertical motions at metre scale
may be recognized in local areas owing to the accurate
sea-level positioning and excellent lateral exposure of
the tidal notch (Fig. 7). For instance, at Capo Caccia,
located on the NW side of the island, the marker
altitude decreases from east to west across different rock
promontories from an eustatic elevation of 5.5 to 4 m
and 3.5 m (Fig. 7, inset). The subsidence towards the
following values: