Some of these abraded reef flats can be observed in the
islands of insular arcs as for example in Vanuatu (Taylor
et al., 1987).
Coral terraces
Emerged coral reefs forming a series of terraces result over
long periods of time from both glacioeustatic sea-level
variation and from tectonic uplift (Figure 2a). These often
contain marine notches and are generally characterized by
typical reef morphological features including reef crest,
lagoon, etc. The most studied sequences are on Barbados
(Mesolella, 1967; Broecker et al., 1968) and on the Huon
Peninsula in Papua New Guinea (Bloom et al., 1974;
Chappell, 1974).
Uplift in island arc archipelagos and tectonically
active areas
The island arc archipelagos in tropical areas reveal the
presence of elevated coral terraces. Coral dating coupled
with morphological and paleoecological studies give information on both vertical motions and past sea-level variations over the Late Quaternary. Reconstruction of past sea
levels can be made from calculations using the radiometric
age of the emerged reef terraces and known rates of uplift
[e.g., from the present elevation of the last interglacial
(Stage MIS5e)]. Where rates of uplift are particularly high
and relatively steady, terraces, which were originally below
modern sea level (e.g., last glacial stadials and interstadials),
have now emerged and allow the accurate calculation of
these low sea levels.
Locations with intensive studies include Papua New
Guinea (Bloom et al., 1974; Chappell, 1974; Chappell
et al., 1996), Barbados (Broecker et al., 1968; Bender
et al., 1979), Indonesia (Pirazzoli et al., 1991; Bard et al.,
1995), Vanuatu (Neef and Veeh, 1977; Mitchell, 1968;
Coral terrace
Abraded
emerged reef
Modern
coral reef
Marine
notch
S.L.
S.L.
Coral terrace 1
Coral terrace 5
Coral terrace 4
Coral terrace 3
Coral terrace 2
Coral terraces (uplifting areas)
Abraded coral reefs
uplift
uplift
500 m
50 m
50 m
5 m
a
b
Emerged Reefs, Figure 2 Various types of emerged reef features. (a) Coral terraces; (b) abraded reefs.
Emerged Reefs, Figure 3 Remnants of slightly emerged reefs in
Vanuatu (photo G. Cabioch/IRD).
374
EMERGED REEFS
islands of insular arcs as for example in Vanuatu (Taylor
et al., 1987).
Coral terraces
Emerged coral reefs forming a series of terraces result over
long periods of time from both glacioeustatic sea-level
variation and from tectonic uplift (Figure 2a). These often
contain marine notches and are generally characterized by
typical reef morphological features including reef crest,
lagoon, etc. The most studied sequences are on Barbados
(Mesolella, 1967; Broecker et al., 1968) and on the Huon
Peninsula in Papua New Guinea (Bloom et al., 1974;
Chappell, 1974).
Uplift in island arc archipelagos and tectonically
active areas
The island arc archipelagos in tropical areas reveal the
presence of elevated coral terraces. Coral dating coupled
with morphological and paleoecological studies give information on both vertical motions and past sea-level variations over the Late Quaternary. Reconstruction of past sea
levels can be made from calculations using the radiometric
age of the emerged reef terraces and known rates of uplift
[e.g., from the present elevation of the last interglacial
(Stage MIS5e)]. Where rates of uplift are particularly high
and relatively steady, terraces, which were originally below
modern sea level (e.g., last glacial stadials and interstadials),
have now emerged and allow the accurate calculation of
these low sea levels.
Locations with intensive studies include Papua New
Guinea (Bloom et al., 1974; Chappell, 1974; Chappell
et al., 1996), Barbados (Broecker et al., 1968; Bender
et al., 1979), Indonesia (Pirazzoli et al., 1991; Bard et al.,
1995), Vanuatu (Neef and Veeh, 1977; Mitchell, 1968;
Coral terrace
Abraded
emerged reef
Modern
coral reef
Marine
notch
S.L.
S.L.
Coral terrace 1
Coral terrace 5
Coral terrace 4
Coral terrace 3
Coral terrace 2
Coral terraces (uplifting areas)
Abraded coral reefs
uplift
uplift
500 m
50 m
50 m
5 m
a
b
Emerged Reefs, Figure 2 Various types of emerged reef features. (a) Coral terraces; (b) abraded reefs.
Emerged Reefs, Figure 3 Remnants of slightly emerged reefs in
Vanuatu (photo G. Cabioch/IRD).
374
EMERGED REEFS