Page 11 - 15 New data on the Holocenic sea-level

F. Antonioli et al. / Global and Planetary Change 34 (2002) 121–140 133

Table 2
Results of the U/Th and 14C datings (AMS and conventional) performed on the collected samples

Metres b.s.l Sector Material Age (year BP) Dating method Laboratory sample no.

À 0.3 F speleothem 7912 – 7720 14C cal 1r R-2580 Rome
À 1.3 F speleothem 16,731 – 16,331 14C cal 1r R-2580 Rome
À 0.4 D Vermetid reef 461 – 400 14C cal 1r R-2580 Rome
À 0.3 D Vermetid reef 251 – 127 14C cal 1r R-2764 Rome
À 0.3 E Vermetid reef 232 – 106 14C cal 1r R-2741 Rome
À 0.3 E Vermetid reef 232 – 94 14C cal 1r R-2742 Rome
À 24 Marettimo Lithophaga 10,473 – 10,339 AMS 14C cal 1r 6810-Utrecht
À 24 Marettimo Lithophaga 9643 – 9485 AMS 14C cal 1r 7211-Utrecht
À 24 Marettimo speleothem 39,280 F 1500 1007-ENEA Rome
À 24 Marettimo speleothem 24,160 F 900 Th/U 1006-ENEA Rome

Th/U

We calibrated (1r) all the 14C data by using Stuiver et al. (1998) Intcal 98 radiocarbon age calibration. With respect to calibration, it must be
stressed that the regional effect was not taken into account (DR = 0).

that are very similar to those of limestone notches in Western Australian and the Central Mediterranean,
other nearly stable areas of Central –Southern Italy. there is an initial overshoot in relative sea level that
Notches can be solely observed in coastal zones decreases exponentially because the coastal margin is
subjected to uplifts not greater than 0.15 mm/year readjusting to the increased water load (hydroisostacy,
and with sea-level stillstand that lasted at least about a see McCulloch and Esat, 2000). It is likely that the
thousand years. These features are related to the marine terraces were formed during the following 10
maximum relative sea level, which was probably ka (Fig. 9). The different glacial –isostatic adjustments
reached at the beginning of stage 5e. Stage 5e lasted in the coastal areas should be taken into account since
about 10– 11 ka and was followed and preceded by an ‘‘the relation between height and age of shoreline
abrupt change in sea level (McCulloch and Esat, formed during last interglacial cannot be related
2000). In stable continental margins, such as the directly to changes in ocean volume because of the
effect of isostatic uplift’’ (Lambeck and Nakada,
1992). At present, there are no rebound models
availability for the Mediterranean coasts during the
Last Interglacial, therefore, it is not possible to
achieve an approximation of maximum sea level
better than 7– 8 m.

Fig. 9. Diagram showing the effects of hydroisostacy at a far-field 4. Holocenic sea-level rise curve
‘stable’ continental margin site such as the Western Australian. For
a step-function increase in eustatic sea level, there is an initial Reefs built by Vermetid Gastropods (Dendropoma
overshoot in the relative sea level that decays exponentially due to petraeum) and submerged speleothems sampled from
the coastal margin readjusting to the increased water load (replotted the Capo San Vito Promontory and Marettimo coastal
from McCulloch and Esat, 2000). zones allowed to reconstruct the sea-level rise through
the Holocene. Most carbonatic rocky shores of North-
western Sicily are bordered by intertidal reefs, the
frame of which results from the coalescence of the
tubular shells of the Gastropod Mollusc D. petraeum.
Midlittoral platforms have the potential to be good
environmental and climate indicators because: (1)
they are typical of warm-temperate areas, such as
the Mediterranean Sea; (2) the vertical growth of the