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M. Vacchi et al. / Earth-Science Reviews 155 (2016) 172–197 177
−0.5 mm a −1 (Fig. 2), although there is no robust information about tidal measurements (e.g. Morhange and Pirazzoli, 2005) or tidal model-
the elevation of the MIS 5e coastline in this region. The area is affected ing (e.g. Antonioli et al., 2015)were alsoused.
by historical seismicity up to M = 6.0 in the southern sector (Herak In the following section we describe the different types of index
et al., 1996). points used in the database.
The northwestern Adriatic region (#18) includes the southern part
of the Po Delta and the whole Romagna coastal plain. A major subsiding 3.1.1. Fixed biological index points
trend is documented across the area since the MIS 5e. High rates, up to Along the western Mediterranean coasts, the coralline rhodophyte
1mma −1 , occur near the Po Delta decreasing southwards to Lithophyllum byssoides build reef-like bioconstructions just above MSL
0.6 mm a −1 . GPS-derived vertical motion also indicates a clear pattern at the base of the mid-littoral zone (e.g., Pérès and Picard, 1964;
of subsidence, with rates higher than ~3 mm a −1 across the whole Laborel et al., 1994). Its lower limit is defined as the biological mean
region. sea level (i.e. the sharp transition between the midlittoral and the
We subdivided the central and southern Adriatic Sea into four re- infralittoral zone, Morri et al., 2004), which corresponds to the MSL
gions. The mid-eastern Adriatic Sea (Figs. 1 and 2; #19) includes data with reasonable accuracy (≤0.1 m) in microtidal environments
from Vis and Bisevo Islands, located in the eastern part of the central (e.g., Stiros and Pirazzoli, 2008; Schembri et al., 2005). L. byssoides
Adriatic Sea, in Croatia. Nearby GPS vertical velocities indicate zero mo- rims are almost absent in very sheltered areas; they usually develop
tion. In this region, medium to strong historical seismicity (such as the around the inlets of exposed coasts because the organic construction
1956 M = 5.7 earthquake) is reported (Herak et al., 1996). needs strong mixing of water but moderate wave impact to develop.
The mid-western Adriatic Sea (#20) includes data from the central Fossil rims of L. byssoides are accurate proxies for past RSL (e.g., Faivre
coast of Abruzzo, between Pescara and the Sangro coastal plain et al., 2013; Rovere et al., 2015) and have been used for high-
(Figs. 1 and 2). There is a paucity of long-term rates for vertical move- resolution (±0.1 to ±0.2 m of vertical uncertainty) RSL reconstructions
ments in this region. Furthermore, GPS-derived vertical velocities are in southern France and Croatia (e.g., Laborel et al., 1994; Faivre et al.,
contrasting in this region (Fig. 2). 2013). L. byssoides has a very narrow vertical living range and rims
The northern Apulia region (#21) includes the eastern Gargano prom- form at and slightly above the biological mean sea level (i.e. in the
ontory and the Gulf of Manfredonia (Figs. 1 and 2). To the west, the ele- upper midlittoral zone; Laborel and Laborel-Deguen, 1994; Laborel
vation of the MIS 5e shoreline on the Gargano promontory indicates et al., 1994). The indicative range associated with these samples is
moderate uplift. Contrasting GPS-derived vertical velocities range from from the Highest Astronomical Tide HAT to MSL (Fig. 3A, Table 1). The
zero movement down to moderate subsidence of ~0.5 mm a −1 . The database also includes four samples of fossil Vermetid reefs of
region was historically affected by intense seismicity (Mastronuzzi and Dendropoma petraeum collected in Sicily (region #12). The living
Sanso, 2002). As a consequence, the Holocene evolution of some sites range of these fixed Gastropoda is quite large (the lower intertidal to
on the western Gargano promontory (e.g., the Fortore River coastal the infralittoral zones, Rovere et al., 2015). However, on the basis of
plain and the Lesina Lake coastal barrier) have been strongly influenced the modern distribution of Vermetid reefs measured in Sicily
by strong seismic events which produced co-seismic vertical displace- (Antonioli et al., 1999; Lambeck et al., 2004a), we assigned an indicative
ments and devastating tsunamis (Mastronuzzi and Sanso, 2002, 2012). range of MSL to Mean Lower Water MLW to these samples (Fig. 3A,
The southern Apulia region (Figs.1,2; #22) represents the easternmost Table 1). This indicative range cannot be applied to other areas of the
areas of our database. Stability to weak subsidence since the last intergla- Mediterranean without a preliminary measurement of the local distri-
cial is reported for this region. This trend is corroborated by nearby GPS- bution of the living Vermetid reefs.
derived vertical velocities. Biological sea-level markers are not perfect horizontal lines but are
naturally warped, even over short distances, due to local variations in
hydrodynamics and morphology (Stiros and Pirazzoli, 2008; Faivre
3. Compilation of the RSL database et al., 2013). For this reason, we added an environmental error of
±0.2 m to the fixed biological indicators included in the database.
3.1. Indicators of former RSL
3.1.2. Marsh and lagoonal index points
In order to produce an index point, the following information is re- The majority of sea-level index points in previously published sea-
quired for each RSL indicator: (1) the location of the indicator; (2) the level databases are salt-marsh deposits (e.g., Shennan and Horton,
calibrated age of the indicator; and (3) the elevation of the indicator, 2002; Engelhart and Horton, 2012). However, due to the microtidal re-
corrected for the indicative meaning; (i.e. a known relationship be- gime of the Mediterranean, salt-marsh areas are less developed than on
tween the indicator and a contemporaneous tidal level, the Mean Sea oceanic coastlines and are usually concentrated around large deltas
Level (MSL) in our database Shennan et al., 2015; Hijma et al., 2015). (e.g., Somoza et al., 1998; Vella and Provansal, 2000) and downdrift
The indicative meaning is composed of a reference water level (RWL) coastal lagoons (e.g., Silvestri et al., 2005; Marco-Barba et al., 2013).
and the indicative range (IR). The IR is the elevational range over For salt marshes, the indicative meaning was estimated using the
which an indicator forms and the RWL is the midpoint of this range, present zonation of vegetation (e.g., Silvestri et al., 2005; Primavera
expressed relative to the same datum as the elevation of the sampled in- et al., 2011) and microfossil assemblages (e.g., Serandrei-Barbero
dicator (e.g., Hijma et al., 2015, Fig. 3). Where a suite of quality con- et al., 2006; Caldara and Simone, 2005). The indicative range associated
trolled sea-level index points exist for a locality or region, they with samples of salt-marsh origin is from the HAT to MSL (e.g., Hijma
describe changes in RSL through time and can be used to estimate the et al., 2015, Fig. 3B Table 1). In the Rhone Delta, Vella and Provansal
rates of change. If a sea-level indicator did not show a clear and reason- (2000) found that the modern distribution of freshwater peats is be-
ably established relationship with the MSL, we converted it into a limit- tween 0.1 and 0.6 m above the current MSL. This indicative range was
ing point (see Section 3.2). Although these data are not used to produce therefore applied to the samples from the Rhone and the Ebro deltas,
sea-level index points, they are extremely important in constraining the which present a similar geomorphic context (Somoza et al., 1998;
RSL above or below the terrestrial or limiting point (e.g., Shennan and Vella et al., 2005) and tidal range (Tsimplis et al., 1995).
Horton, 2002). The remaining freshwater peats of the database were conservatively
Tidal information was obtained from the National and International transformed into terrestrial limiting points (see Section 3.2).
networks of tidal stations (e.g. IGN-Red de Maréografos, Spain; Service Coastal lagoons are a very common feature of Mediterranean coast-
Hydrographique SHOM, France; ISPRA-Rete Mareografica Nazionale; lines. They are inland waterbodies, usually developing parallel to the
HHI; Hrvatski Hidrografski Institut; Admiralty Tide Tables, UK). Local coast, typically separated from the open sea by a sandy barrier