Page 6 - 15 New data on the Holocenic sea-level

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

Table 1
Radiometric datings of sampled speleothems, with indications of the correlative marine terrace and sector of provenance (see inset of Fig. 2)

Metres above m.s.l Sector Sample no. Terrace order Material Age (year BP) Dating method

+ 62 E ENEA1011 IIj speleothem 78,000 F 1950 Th/U

+ 42 E ENEA1012 IIIj speleothem >300,000 Th/U

+8 E ENEA1013 VIj speleothem 19,695 F 5300 Th/U

present sea level) were also found. The geomorpho- have developed during oxygen isotope stage 3, as
logical mapping of marine erosion surfaces was already hypothesized for analogous submerged ero-
improved by a spatial elaboration of altimetric data sional surfaces located at similar depths in the Tyr-
using the Arc/info GIS. rhenian sea (Antonioli and Ferranti, 1996; Antonioli
et al., 1994a; De Vita and Orsi, 1994) and in extra-
The marine forms were, thus, ascribed to the Mediterranean regions (Cann et al., 1988; Aharon and
Middle and Upper Pleistocene, by morphological Chappel, 1986).
and stratigraphic criteria. Dating trough U/Th method
on speleothems (Table 1), which locally coat marine 3.1. Eutyrrhenian erosional forms and deposits
notches, provide only the upper chronological limit
for the Terrace II (linked to the notch at + 62 m) Terrace VI and the associated deposits (Fig. 2)
modelled in a period before 78,000 F 1950 years ago were studied to verify their Eutyrrhenian age (see, for
and for the lower terrace of the emerged sequence example, Abate et al., 1993; Mauz et al., 1997) and
(Terrace VI, lying at 8 m a.s.l.) modelled before their present-day altimetric distribution.
19,695 F 5300 year BP, which means before the
LGM and, as suggested by other observations, in The palaeontological analysis of the marine sedi-
correspondence of the Last Interglacial. ments showed the presence of a ‘‘Senegalese’’ fauna,
with mollusks as S. bubonius in several bioclastic
Only the shallowest of presently submerged terra- lenses overlying the VI-order Terrace. Their occur-
ces (Terrace VII) shows a good lateral continuity and rence characterizes the base of the Eutyrrhenian sub-
ranges from À 15 to À 18 m b.s.l. This terrace could

Fig. 3. Triangular plot LMC – HMC – Ar of the sampled carbonatic deposits. The arrow indicates the trend in the mineralogical composition.