Marine Geology 167 (2000) 391–411
www.elsevier.nl/locate/margeo
Alternating marine and lacustrine sedimentation during late
Quaternary in the Gulf of Corinth rift basin, central Greece
C. Perissoratis a,*, D.J.W. Piper b, V. Lykousis c
b
a
Marine Geology Department, Institute of Geology and Mineral Exploration, 70 Messoghion Street, 11527 Athens, Greece
Geological Survey of Canada (Atlantic), Bedford Institute of Oceanography, P.O. Box 1006, Dartmouth, N.S., Canada B2Y 4A2
c
Geological Oceanography Department, National Center of Marine Research, Greece
Received 8 December 1998; accepted 24 March 2000
Abstract
The Gulf of Corinth in central Greece has a maximum depth of about 900 m and is separated from the open sea by the Rion
Strait, with a sill depth of 62 m marked by an extensive submarine terrace. During eustatic sea-level lowstands, the Gulf of
Corinth was a lake. Under lacustrine conditions, stratified sediments accumulated in the deep-water basins and turbid underflows from rivers eroded the basin slopes. As the sea level rose, marine waters flooded the Gulf and deltas prograded across the
shelves. In shallow-water areas, two key reflectors termed Z and X are terrace surfaces, commonly erosional, which mark the
base of the overlying deltaic sequences. In deep-water basins, Z and X mark the top of the acoustically stratified sediments
interpreted as lacustrine turbidites; reflectors Y and W mark the base of these stratified intervals and overlie acoustically
transparent sections similar to the Holocene section. The last lacustrine conditions in the Gulf (Z to Y) were during isotopic
stage 2 and terminated about 12 000 yr ago. Age estimates based on sedimentation rates suggest that the X to W interval
corresponds to the stage 4 lowstand of sea level. In the western Gulf of Corinth, shoreline transgressive surfaces corresponding
to minor transgressions in stage 5 and to major transgression at the end of stage 6 are recognised. This seismic stratigraphy
permits a detailed interpretation of the history of the Gulf of Corinth in the past hundred thousand years. It also provides a
general model for sedimentation in rift basins in which marine and lacustrine sediments alternate. q 2000 Elsevier Science B.V.
All rights reserved.
Keywords: Sea-level changes; Stratigraphy; Sedimentation; Upper Quaternary; Central Greece
1. Introduction
1.1. Purpose and materials
Quaternary sea-level changes have left their imprint
on the sediment record on continental shelves, where
unconformities and hiatuses alternate with periods of
* Corresponding author. Tel.: 1 30-1-7795-093; fax: 1 30-17752-211.
E-mail address: cprs@mail.ariadne-t.gr (C. Perissoratis).
sedimentation. A complete record, however, can be
obscured in areas of insufficient sediment input
because of the presence of hiatuses, but can be imaged
better in areas where a barrier separates a bay or a
semi-enclosed marine area from the open sea. In
these cases, low sea-level stands result in lake formation, whereas during high sea-level stands open
marine conditions are established. Thus marine and
lacustrine conditions alternate and this is usually
depicted clearly in seismic records (e.g. Perissoratis
and Van Andel, 1988, 1991; Ryan et al., 1997).
0025-3227/00/$ - see front matter q 2000 Elsevier Science B.V. All rights reserved.
PII: S0025-322 7(00)00038-4
392
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
Fig. 1. Location map showing the geological setting of the Gulf of Corinth and the location of detailed study areas (boxes).
Chronostratigraphic markers distinguished in these
records can commonly be correlated with the standard
sea-level curves (Piper and Perissoratis, 1991).
Such an area is the Gulf of Corinth (Fig. 1), a
rapidly subsiding half graben in central Greece. The
Gulf is 105-km long, 30-km wide and has a maximum
depth of 900 m. Its connection with the Ionian sea is
via the Rion Strait between Rion and Antirion, which
is 2-km wide and about 60-m deep.
The data used in the following study are bathymetric and shallow penetration 3.5-kHz and Uniboom
seismic profiles collected from the eastern and
western parts of the Gulf. In most cases the quality
of the records was very good. The positioning system
was the ship’s radar or Motorola miniranger with an
accuracy of about 100 m to a few meters, respectively.
1.2. Previous studies
The Gulf of Corinth attracted early the interest of
the marine geologists due to its peculiar morphological characteristics (the presence of a shelf, slope, and
deep basin) which resemble those of a small-scale
ocean basin. Heezen et al. (1966) provided the first
modern understanding of the marine geology of the
Gulf, reporting the results of a RV Vema cruise and
identifying alternating marine and lacustrine sediments in a core. Detailed research throughout the
entire Gulf was carried out by RRS Shackleton in
1982 and RRS Discovery in 1983 (Brooks and Ferentinos, 1984; Higgs, 1988; Cramp et al., 1989). Anderson and Carmack (1973) and Poulos et al. (1996)
summarised the physical and chemical oceanographic
aspects of the Gulf. Bariagin (1972) provided tidal
data and Myrianthis (1984) some industrial multichannel seismic data. Detailed studies of parts of the
Gulf include work on sedimentation processes and the
impact of the 1981 earthquake in the eastern Gulf
(Perissoratis et al., 1984, 1986a; Papatheodorou and
Ferentinos, 1993), the impact of the 1995 earthquake
in the central Gulf (Papatheodorou and Ferentinos,
1997; Perissoratis et al., 1997), sediment instabilility
on steep slopes of the Gulf (Ferentinos et al., 1988;
Ferentinos, 1992), sediment distribution in Antikyra
Bay (Varnavas et al., 1986; Lykousis, 1990;
Papatheodorou, 1990), sediment distribution in the
western part of the Gulf (Piper et al., 1980) and
surveys of the Rion Strait for possible bridge
construction (Perissoratis et al., 1986b; Papanikolaou
et al., 1987).
The above studies have emphasised the structural
framework and the Holocene sediment distribution of
the Gulf, however only limited work has been done on
its Quaternary stratigraphic evolution due to the lack
of chronostratigraphy. The purpose of this paper is to
evaluate the existing data in order to develop such a
chronostratigraphic tool to reveal the sedimentation
conditions during Late Quaternary sea-level changes.
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
1.3. General setting
The Gulf of Corinth is the greater part of a discontinuous east–west trending graben that runs across the
Greek mainland. It is seismically very active and
shows a high rate of tectonic subsidence (Brooks
and Ferentinos, 1984). Multichannel seismic data
show 1.5–2 s of Neogene–Quaternary strata above
the alpine basement (Myrianthis, 1984). Neotectonic
studies on land (Doutsos et al., 1988; Doutsos and
Poulimenos, 1992; Armijo et al., 1996) and earthquake focal mechanism studies (McKenzie, 1978;
Jackson et al., 1982) suggest an approximate north–
south extension. The subsidence rates of the northern
margin of the Gulf of Corinth during the last 250 ka
was calculated as 0.9–1.3 m ka 21 and the differential
displacement between the north and the south margin
of Corinth graben is estimated to be about 2.8 m ka 21
(Lykousis et al., 1998). The land on the northern side
of the Gulf is occupied by Mesozoic limestones,
whereas the southern side is covered by Pliocene
marine and lacustrine strata overlain by Pleistocene
fluvial and lacustrine sediments (Fig. 1) (Doutsos and
Piper, 1990; Seger and Alexander, 1993; Gawthorpe
et al., 1994; Armijo et al., 1996).
393
recent fault offsets. Thus the absolute depth of the sill
is likely to have increased only slightly in the late
Pleistocene.
Based on published data on sea-level rise since the
latest sea-level lowering (Bard et al., 1989, 1996), a
60-m deep sill would have been flooded by the sea at
about 12 000–13 000 C-14 years before present, so
that during the last glacial maximum (of isotopic stage
2) the Gulf of Corinth would have been a lake. In
earlier low sea-level stands, during isotopic stages 4
and 6, the Gulf may also have been transformed into a
lake. The sea level during isotopic stage 3 is not well
defined (Chappell and Shackleton, 1986; Fairbanks,
1989; Skene et al., 1998), but during much of this
time the water level in the Gulf was higher than that
of a lake but lower than today, perhaps at times leading to brackish conditions.
2.2. River derived sediment input
The largest rivers draining into the Gulf are the
Mornos in the northwest and a series of short steep
rivers that enter the southern Gulf draining the mountains of the northern Paloponnese. From these, the
discharge data for the Selinous, Vouraikos, Krathis
and Asopos rivers are reported by Therianos (1974).
Rivers draining to the north-eastern part of the Gulf
2. Sedimentation and sub-bottom stratigraphy
21˚46 'E
2.1. Deltaic sedimentation and sea level changes in
the Gulf
20
Corinth
40
30
50
70
60
50
70
60
70
80
60
60
3b
38˚
19'N
3a
60
70
meters
60
50
60
Patras
0
50
30
Gulf of
500
20
The effect of sea-level change on the Gulf of
Corinth is influenced by the sill at the Rion Strait
(Fig. 2). The Strait has a maximum depth of 62 m,
and a prominent terrace is formed at a 60–62 m
water depth (Fig. 3a and b). This terrace is interpreted
as a coastal erosional terrace in a large lake with a
long fetch. A sinuous incised channel is present to the
west of the Strait (Figs. 2 and 3b), that can be interpreted as a fluvial outlet channel during low sea-level
stands.
On the sides of the Strait, Holocene sedimentary
wedges thin seawards and unconformably overlie
the terrace (reflector Z in Fig. 3a). Data from the
northeastern Gulf of Patras indicate a subsidence
rate of less than 1 mm a 21 (Chronis et al., 1991) and
the terraces at the Rion Strait sill show no evidence of
Gulf of
Antirion
Rion
Fig. 2. Bathymetric map of Rion Strait (from IGME suveys with
,300 m line spacing). The area shallower than 64 m is shaded.
394
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
Fig. 3. Boomer profiles from Rion Strait: (a) east of the Strait, showing prominent 60–64 m terrace forming reflector Z, overlain by Holocene
coastal and deltaic deposits; (b) central part of the Strait, showing the terrace and the outlet channel. Location in Fig. 2.
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
from predominantly limestone areas are relatively
small. Total mean discharge to the Gulf is estimated
at 40 m 3 s 21. There are no published sediment
discharge load data for these rivers, but if the relation
of water discharge to sediment load for the Acheloos
River to the west of Rion Strait (Piper and Panagos,
1981) can be applied to the Peloponnese, then the total
suspended sediment supply to the Gulf is about
0.85 × 10 6 ton/year. This corresponds to an average
sedimentation rate for suspended sediment of about
0.25 mm a 21; coarser sand deposition would increase
the overall sedimentation rate.
Changing sea level and the creation of a lake in the
Gulf of Corinth would have predictable effects on the
sedimentology of the Gulf. The Gulf of Corinth
receives large amounts of sediments through a
number of rivers that form either low gradient
(suspended load) deltas, such as the deltas of a number
of small rivers entering Corinth Bay, or deltas with
steep gradients (bed load), as is the case with most of
the rivers entering the Gulf on its southern side. In low
gradient deltas, the sediments are dispersed through
plumes but the coarse sediment load is trapped in the
coastal (shelf) zone (Piper and Panagos, 1981; Lykousis, 1990). In bed load deltas, channels extend down
the delta front from the river mouth (Piper et al.,
1990). Information from cable breaks (Heezen et al.,
1966; Ferentinos et al., 1988) shows that some coarse
sediment passes through the channels into deep water
where it is deposited as turbidites. Thus under conditions of high sea level, only the steep bed load deltas
deposit turbidites on the deep basin floor. When a lake
formed in the Gulf, all the rivers entering the lake
would form underflows and deposit turbidites on the
deep basin floor. These underflows would cause
erosion of the pro-delta slopes. When the sea level
rose again, underflow turbidite deposition would
cease. These differences are usually clearly depicted
in the examination of seismic profiles collected in
the various parts of the Gulf and are described in the
following sections on the stratigraphy in the shallow
and the deep areas of the Gulf (from east to west,
Fig. 1).
2.3. Corinth and Alcyonides bays
In Corinth Bay (Fig. 4), little sediment is supplied
from the north whereas modern suspended-load deltas
395
prograde from the south. The Holocene deltas consist
of wedge-like bodies that thin seaward (Fig. 5). The
upper part of the section consists of weakly reflective
clinoforms, locally obscured by shallow gas and in
places broken up into rotational slump blocks. Such
features are common in seismic reflection profiles of
suspended sediment deltas in the northeastern Mediterranean Sea (Chronis et al., 1991; Lykousis, 1990).
The lower part of the Holocene section consists of one
or more high amplitude reflections parallel to a planar
erosional surface, reflector Z, that cuts off the top of
older prograded clinoforms. Z is generally found at a
depth of about 80 msec.
The seaward end of the erosional surface Z appears
offset by normal faults and occurs at 290 msec
(68 m). Reflector Z forms an abrupt inflection at
about 80 msec depth and can be traced seawards as
a strong but irregular and clearly erosional reflector.
The underlying reflectors appear continuous into the
clinoforms beneath Z and the Holocene delta. Some of
these reflections are subparallel and of moderate
amplitude but other intervals have incoherent and
point source reflections or are transparent and appear
to be debris flow deposits. The section below Z is
locally offset by faults but these cannot be discerned
in the Holocene delta. At the eastern end of the bay,
the sequence below Z also passes into a deltaic
section.
A second regional reflector, Y, occurs generally 5–
10 msec below Z, but appears to pass beneath thick
clinoforms at the eastern end of the bay. It is a high
amplitude reflector overlying a thick, generally acoustically transparent unit that includes a few subparallel
moderate reflections. The depositional style is much
more continuous than between Y and Z and generally
resembles that of the section above Z.
In Alcyonides Bay, on the shelf, an erosional transgression surface correlative to Z can be recognised at
about 280 msec (e.g. profile B of Perissoratis et al.,
1986a). In places normal faulting has lowered this
reflector to as deep as 2120 msec (Fig. 6). The sediment thickness above this reflector is 7–15 msec.
Another more deeply buried erosional transgression
surface, termed X, occurs at 2220 msec in Fig. 6.
In the deep areas of Alcyonides Bay, near-surface
sediment is acoustically transparent, forming a seismic unit 3–10 msec thick, the base of which is correlated with the Z surface (Figs. 6 and 7). The unit is
396
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
22050'
23000'E
23010'
200m
Germeno Bay 380
10'
Fig.6
Fig.15
600
380
10'
m
Fig.7
KO-7
300m
0m
80
Central
Basin
- KO3
40
Alcyonides Bay
Psatha
Bay
30
0m
0m
1
30000m
m
20
10 0m
0m
380
00'
N
Fig.5
3.5 kHz profile
Corinth Bay
0
km
6
l
na
Ca
CORINTH
core
0
22 50'
23000'
Fig. 4. Bathymetric map of eastern Gulf of Corinth, showing 3.5-kHz track lines and cores with radiocarbon dates.
Fig. 5. 3.5-kHz profile from Corinth Bay showing seismo-stratigraphic interpretation.
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
Fig. 6. 3.5-kHz profile from northeastern Alcyonides Bay showing seismo-stratigraphic interpretation.
397
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
W
TWTT (msec.)
300
transparent
interval
between
Y and X
stratified
interval
between
X and W
stratified
interval
between
Z and Y
local erosion
at Y
transparent
interval
above Z
E
200
250
Z
350
Y
X
400
300
W
0
km
water depth (mbsl)
398
1
450
350
Fig. 7. 3.5-kHz profile from Alcyonides Bay showing acoustic stratigraphy. W, X, Y and Z are correlated reflectors described in text.
thickened locally by debris flows deposits (Perissoratis et al., 1986a, Fig. 6). The stratified sequence
below Z passes laterally into lowstand delta clinoforms. The base of the stratified sequence, reflector
Y, shows local erosion and channelling, probably
indicating sudden development of underflows.
Below reflector Y there is a second transparent
section, similar to but thicker than that between reflector Z and the surface, followed by a deeper stratified
section, floored by reflector W (Fig. 7), which locally
shows erosion at its base.
2.4. Antikyra and Itea bays
These two bays are located on the northern side of
the Gulf (Fig. 1). 3.5-kHz profiles (G. Ferentinos,
unpublished data, pers. commun.) clearly show a shallow transgression surface corresponding to reflector
Z, that terminates seaward at about 285 msec
(63 m). Long cores from these bays suggest a low
sedimentation rate, consistent with the small size of
the streams entering them. Core IS-82-37 from Antikyra Bay (Cramp et al., 1989) contains the Y-5 tephra
horizon (considered to be ca. 35 ka in age: St.
Seymour and Christanis 1995) at 1.13–1.17 m
depth. Core V-10-30 from Itea Bay (Heezen et al.,
1966) contains brackish faunas at 0.5–2.5, 5.0–6.5
and 8.5–9.0 m, interbedded with marine faunas.
2.5. Rion Strait
In the western part of the study area, Rion Strait is
subject to intense erosion by very strong currents of up
to 1 m s 21, which result in the absence of loose
surface sediments in the central part of the Strait:
only hard Pleistocene and Pliocene conglomerates
are present. At the sides of the Strait a Holocene
deltaic sequence is up to 20-msec thick (Fig. 3a).
The base of this prograding deltaic sequence lies at
about 80 msec (60 m) (Z in Fig. 3a) and is apparently
the same reflector as observed in the eastern part of
the Gulf described above.
2.6. Mornos Delta
Eastward of Rion Strait (Fig. 8), the Gulf of Corinth
consists of a central fault-bounded basin that slopes
gradually eastward to water depths of up to 500 m.
Sedimentation on the northern side is dominated by
the Mornos delta (Piper et al., 1980, 1990; Lykousis,
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
399
0
38
25'
Alluvium
3.5 kHz profile
core
50m
100m
NAVPAKTOS
Mornos
delta
Akra Marathias
Akra
Mornos
200m
Nisos
Trizonia
Fig.11
50
m
200
Fig.9
Akra Drepanon
380
20'
0m
on
Ri
m
m
Gulf of Corinth
Arahovitika
fan
10
50
m
ait
Str Fig.3
300
Fig.10
50m
PSATHOPIRGOS
0
km
Erineos
delta
6
30
0m
20
0m
21050'
21055'
22000'
Fig. 8. Bathymetric map of western Gulf of Corinth, showing 3.5-kHz track lines. Box at Rion Strait is area of detailed boomer survey by IGME
with ,300 m line spacing; the two lines within the box are illustrated in Fig. 3.
km
0.5
N
S
80
60
Z
erosion by
tidal
currents
100
TWTT (msec.)
80
120
T
100
water depth (mbsl)
0
140
160
120
Fig. 9. 3.5-kHz profile north of Arahovitika fan, showing reflectors Z and T.
400
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
Fig. 10. 3.5-kHz profile from southeast of Mornos delta showing stratified Holocene sediments overlying slump and channel fill deposits below
reflector Z.
1990), from which a subaqueous channel system
connects to the axis of the Gulf. Some fan deltas
have prograded from the south side that is marked
by a major fault.
On both sides of the Gulf, off the Mornos delta and in
the Psathopirgos area, a strong reflector (Z) occurs at
75–95 msec (Fig. 9), below which a deltaic sequence is
recognisable. Above the reflector the sediment sequence
is little more than 20 msec (15 m) thick on the upper
Mornos delta, thinning to about 10 msec in more
distal environments (Fig. 9). This horizon, corresponding to the lowstand terrace, continues eastward
into deeper water, where it marks the change from
stratified sediments to a sequence that includes
slump and channel fill deposits (Fig. 10) analogous
to the sequence in Corinth Bay.
In Navpaktos Bay (Fig. 8) reflector Z can be
traced from the Mornos delta to the bay in
water depths of 40–60 m (Fig. 11). The Holocene
sequence above Z is about 3-msec thick. Below Z
there is a 6-msec well stratified unit underlain by
a 20-msec transparent unit with a central more
stratified interval that is tentatively correlated with
the X to W section observed in the Alcyonides Bay.
Below the unit a series of erosive transgression
surfaces were identified (V, U, T, Fig. 11), the lowest
of which (horizon T) can be widely correlated
throughout the Mornos delta as a high amplitude
single or double reflector. This reflector appears to
Fig. 11. 3.5-kHz profile from Navpaktos Bay showing acoustic
stratigraphy. V, U and T are erosional transgression surfaces
discussed in text.
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
22˚05'E
401
22˚10'E
0
km
4
Egion
Bay
1
g.
Fi
4
EGION
38˚15'N
borehole
Fig.
13
Selinous
100m
50m
20m
ite
Ke
rin
ikos
a
Vour
s
38˚12'N
Fig. 12. Bathymetric map of southern shelf of western Gulf of Corinth between Selinous and Vouraikos deltas, showing boomer seismic track
lines.
have very little relief on its surface, except at fault
offsets.
2.7. Shelf area near Egion
The southern side of the Gulf of Corinth is very
steep and crossed by numerous channels that originate
in river mouths and carry sediments from the bed load
deltas to the basinal areas (Ferentinos et al., 1988;
Papatheodorou and Ferentinos, 1997). The shelf east
of Egion, between the Selinous and Vouraikos river
deltas (Fig. 12), is 1–2-km wide. Seismic profiles
show a prominent reflector terminating seaward at
about 280 msec and shallowing landward (Fig. 13),
Fig. 13. Boomer profile from shelf edge west of Selinous delta showing late Pleistocene erosional terrace (Z) at about 260 m overlain by
Holocene muds.
402
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
again correlated with reflector Z. On the outer shelf,
the reflector appears to overlay a prograded set of
clinoforms, whereas on the inner shelf it has higher
amplitude and appears to be an erosion surface. The
overlying sediments are predominantly acoustically
transparent and have a thickness from 5 msec at the
outer shelf to over 35 msec east of the modern
Selinous mouth. The age of reflector Z is confirmed
by two radiocarbon ages from silts immediately above
the reflector of 9450 ^ 160 and 10170 ^ 470 C-14
years BP, obtained from an offshore borehole
(Schwartz and Tsiavos, 1979) (Fig. 14).
Older channels of the Selinous are found immediately west of the present river course, with a Roman
channel identified from a bridge (Katsonopoulou,
1998). This outlet deposited a buried sandy interval
near the seaward continuation of the Egion fault (Fig.
14), which is marked by lines of pockmarks (Soter,
1999). More reflective sandy sediments up to 25 msec
thick occur off an apparently older (mid-Holocene?)
western channel of the Selinous (Fig. 14). Similar
sediments off the Vouraikos mouth are up to 12msec thick and a channel extends across the shelf
seaward of the mouth of Vouraikos. The transparent
character of the sediments off the modern Selinous
river mouth indicates that today fine-grained sediments are deposited there, suggesting that this channel
diversion is of recent age. Below reflector Z, lenticular
sediment bodies up to 20-msec thick, resting above
another erosion surface, are developed off the eastern
channel of the Selinous (Fig. 14) and off the Vouraikos.
These we interpret as Late Pleistocene alluvial fans.
They are similar in thickness to Holocene alluvial
fans at the southern side of the Gulf (Kontopoulos and
Stamatopoulos, 1991) and are acoustically rather incoherent, as would be expected from alluvial fan facies.
A similar stratigraphy is recognised in seismic
profiles in Egion Bay, where an upper weakly stratified unit overlies a lower well stratified unit, separated
by a transgressive horizon at a depth of about 80-msec
(60 m), which corresponds to the Z horizon observed
in the other areas. Boreholes show that the upper unit
consists of clayey mud, the transgressive surface of
silty sand and gravel, and the lower unit of silty sand
(Perissoratis et al., 1997).
The area between Selinous and Vouraikos deltas is
also of particular archaeological interest because it
was the site of the ancient city of Eliki, which was
reported to have been submerged by the sea during an
earthquake in 373 BC (Marinatos, 1960), although
recently reported sidescan and borehole data suggest
that the city is buried beneath the present coastal plain
(Soter and Katsonopoulou, 1998). Our data indicate
no evidence of either major slumping or active faults
on the shelf between these two rivers. The 1995 earthquake activity that caused large scale damage in the
city of Egion, produced abundant sediment liquefaction phenomena that were observed in the coastal
zone near the city, having a distinct NW–SE direction, parallel to the main earthquake fracture zone. In
the shelf area west of the Selinous river delta, extensive sediment creep was recognised in seismic profiles
(Perissoratis et al., 1997). If the city was flooded by
the sea following the earthquake, the suggestion of
Georgalas (1962) that it disappeared as a consequence
of tectonic subsidence and perhaps sediment liquefaction, seems more plausible.
2.8. Central basin of the Gulf
The large normal faults that exist all along at the
north and south side of the Gulf of Corinth graben
have formed the central basin and separate it from
the shelves and the perched basins at the eastern and
western ends of the Gulf. The central basin has a flat
floor with a slight gradient toward the east. 3.5-kHz
profiles collected in the eastern part of the central
basin indicate an accumulation of mass- and debris
flows at the basin slopes (our unpublished data;
Perissoratis et al., 1986a; Ferentinos, 1992; Poulos
et al., 1996). In the central part of the basin the
tails of these sediment masses, were deposited
together with turbidites and hemipelagic sediment
(Cramp et al., 1989; Varnavas et al., 1986).
High amplitude reflections in the basin pass laterally
into debris flow deposits. Reflectors Z and Y are
tentatively recognised as the top and bottom of a
packet of more reflective sediment layers (Fig.
15), with a deeper erosion surface perhaps corresponding to W.
3. Interpretation
3.1. Age of reflector Z
Interpretation of the age of reflector Z is based on
TWTT (msec.)
borehole
(projected)
0
late Pleistocene
alluvial fan
Holocene
muds
Z
Z
km
1
30
water depth
(mbsl)
Egion
fault
50
100
Sands ot Roman
mouth of Selinous
60
F
Fig. 14. Boomer profiles from shelf off Selinous delta showing Holocene prodelta deposits, late Pleistocene erosional terrace, and late Pleistocene Selinous fan delta. Site of borehole
dated by Schwartz and Tsiavos (1979) is projected into the profile.
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
SE
NW
sandy deposits
off mid Holocene
mouth of Selinous
403
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
N
S
passes laterally
on to debris flow
deposit
0
TWTT (msec.)
1.10
4
800
Z
Z
1.15
km
X
?W
Y
1.20
850
Y
X
F
F
900
water depth (mbsl)
404
1.25
950
Fig. 15. 3.5-kHz profile from the central Basin of the Gulf of Corinth showing offset of correlatable reflectors on faults.
both radiocarbon dating and consideration of eustatic
sea level at the sill at Rion Strait. Since the data from
the Rion area suggest that the Rion sill was relatively
stable at about 260 m during the late Pleistocene, the
last lacustrine condition in the Gulf of Corinth
occurred before about 12 000 years ago. This prominent transgressive surface of reflector Z is presumably
diachronous, starting at about 12 000 years ago and
continuing through the rather slow rise in sea level
between 12 and 10 ka.
The age of reflector Z is confirmed by radiocarbon
dating from cores. In the deep part of Alcyonides Bay,
two new radiocarbon dates were obtained from cores
collected during a survey in 1981 (Perissoratis et al.,
1986a). Core KO-3 (170-cm long) was taken in Psatha
Bay (Fig. 4) at a depth of about 320 m and contains a
upper mud section, 110-cm thick, that overlies a
faintly stratified sequence below. The seismic data
indicate that at this location the depth of reflector Z
is at about 3.5 m. Foraminiferal tests taken at the base
of the mud section (103–105 cm) give an age of about
Table 1
Radiocarbon dates from cores in Alcyonides Bay
Core
Depth
Material
Lab number
Age a
KO-3
KO-7
(cm)
102–105
138
Foraminifera
Mollusc shell
TO-3590
TO-3591
(yr BP)
3230 1 170
11 380 1 80
a
Ages in radiocarbon years are corrected for isotopic fractionation, but are not corrected for reservoir effect.
3000 yr (Table 1) which, assuming a constant Holocene sedimentation rate under the present open marine
sediment conditions, gives an age of about 12 000 yr
for reflector Z. The other date is from core KO-7 (230cm long) taken in a water depth of about 220 m on the
northern slope of the same basin (Fig. 4). The lower
100-cm core section is an intensively disturbed sandy
mud, probably a debris flow deposit, overlain by a
non-stratified bioturbated mud. In the seismic records,
the thickness of the Holocene section is about 1 m.
Dating of a mollusc shell taken from the top of the
sandy mud layer gave an age of about 11 000 yr, for
reflector Z in the area. The age of Z is also confirmed
by the dates in boreholes on the shelf near Egion,
discussed above (Schwartz and Tsiavos, 1979).
Piston cores (up to 7 m) from the deep central
basin, described by Heezen et al. (1966), Cramp et
al. (1989) and Poulos et al. (1996), did not penetrate
brackish or lacustrine sediments, implying that the top
7 m of sediments accumulated in less than 12 000 yr.
These cores, however, were obtained at the slopes of
the central basin where Holocene sediment thickness
is greater due to sediment deposition by mass movement processes. Varnavas et al. (1986) estimated sedimentation rates of 1–2 mm a 21 by studying bauxite
tailings discharge on the northern slope of the central
basin. We speculate that the penetration of piston
cores was stopped by sands corresponding to reflector
Z, in which case sedimentation rates in the central
basin average about 0.5 mm a 21. This is a little
lower than the rates estimated by Varnavas et al.
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
405
(1986) which may be artificially high due to recent
tailings discharge.
from slumps and other mass movement processes triggered in part by slope erosion.
3.2. Interpretation of sediment facies
3.3. Age of deeper reflectors and correlation with
eustatic sea level variations
The modern deltas on the inner shelf and the parallel continuous reflectors on the outer shelf above
reflector Z observed in Corinth, Egion and Alcyonides
bays and elsewhere apparently correspond to deposits of
the present highstand of sea level. The progradational
Holocene sequence is probably younger than 6500 yr,
when sea-level rise markedly decelerated, enhancing
progradation of marine deltas globally (Stanley and
Warne, 1994). The flat lying basal sequence is probably
older and formed during the early part of the latest
marine transgression. The erosional surface Z on the
shelf was formed by marine transgression after
12 000 years ago as sea level flooded the Rion Strait.
The deltaic section between Z and Y on the shelf
has clinoforms that are pinched off upwards at the
260 m Late Pleistocene lake level (Figs. 5 and 6).
The abundance of erosional features and debris
flows in this stratigraphic interval on the slope (Fig. 5)
is a consequence of erosion by underflows that in turn
produced over-steepening of channels and sediment
failure. The relatively thin stratigraphic section between
Z and Y on uneroded slopes (Fig. 6) suggests that much
of the sediment by-passed into the deeper basins.
In the deeper basinal areas, Z is interpreted to represent the change from marine conditions (transparent
section between Z and seabed, see also Piper and
Perissoratis, 1991; Perissoratis and Van Andel, 1991)
to lacustrine conditions (stratified sequence between Z
and Y). The beginning of the lacustrine sedimentation is
probably marked by the local erosional truncation of
reflectors observed at the base of this well structured
sequence (Fig. 7). With the same reasoning as above,
the transparent section between Y and X may also
represent open marine conditions while the X to W
stratified section with local erosion at its base represents
an earlier lacustrine interval.
During the open marine conditions, deltaic sediments were deposited on the shelf areas while finegrained sediments accumulated offshore in the basins,
intercalated with slumps and rare turbidites. During
lower water levels, the shelf areas underwent erosion
while the basinal areas received coarser sediments
originating from lacustrine turbidity currents, and
Two approximate methods can be used to independently estimate the age of reflectors below Z, which
are beyond the limit of sediment sampling and thus
radiocarbon dating. One is to assume that on timescales of tens of thousands of years, subsidence
rates along faults are relatively uniform. The other is
to base ages on sedimentation rates. We apply both of
these techniques to estimate the range of possible ages
for deeply buried reflectors. Then we compare these
ages with eustatic sea-level variations, as recently
summarised by Skene et al. (1998).
At the shelf break, in some cases more than one
deltaic sequence was noted below Z. In Germeno
Bay (Fig. 6), the Z reflector is at 2120 msec and
another truncation surface (correlated with X in the
deep basin) occurs at 2220 msec. The normal depth
of the Z reflector is 80–85 msec (see Figs. 3a, 5, 9 and
14), so that there has been 35–40 msec of subsidence
of Z in 12 000 yr. If the deeper truncation surface was
also graded to the level of the Rion Strait, it must have
subsided 140 msec and by assuming a constant subsidence rate, the age of reflector X is estimated to about
42 000 yr.
In the deep areas of the Gulf of Corinth, synsedimentary faulting produces increasingly large offsets
with depth (Figs. 7 and 15). If fault movement has
been approximately constant through time and assuming that reflector Y is about 32 000 yr, then reflectors
X and W would date around 45 000 and 75 000 yr,
respectively.
Order of magnitude estimates of the age of
reflectors can be made from sediment thicknesses in
any one location. Several assumptions are involved
here, notably that sedimentation rates were reasonably
constant and not strongly influenced by Late Quaternary climatic change, in which glacial stages were
times of greater aridity (Van Zeist and Bottema,
1982). Thus in Corinth Bay, the thickness of the Z
to Y deltaic sequence is about 1.5 times that of the
Holocene delta: it therefore probably took 10 000–
15 000 yr to accumulate, suggesting that reflector Y
dates from 22 000 to 27 000 years ago. In Alcyonides
406
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
Eustatic
sea-level
0 lacustrine
marine
Estimated
age of
reflectors
Age (thousand years)
2.2
50
RION SILL DEPTH
Z
Y
Basin
stratigraphy
Z
Y
Shelf
stratigraphy
deltaic
stratified
erosion
deltaic
X
W
4.2
X
stratified
erosion
W
5.1
5.2
100
5.3
5.4
deltaic
V
U
5.5
T
6.1
150
stratified
erosion
?
-100 -50
0
Relative sea-level (m)
Fig. 16. Correlation of Gulf of Corinth seismo-stratigraphy with global eustatic sea-level curve (from Chappell and Shackleton, 1986; Skene et
al., 1998), showing the effect of the Rion Strait sill. Age of reflector Z based on correlation with the sea level curve of Bard et al., 1989),
confirmed by radiocarbon dating. Age of Y, X and W based on rates of sedimentation discussed in text. Age of V, U and T based on correlation
with the eustatic sea level curve.
and Navpaktos bays, the transparent Y to X interval is
2–3 times thicker than the Z to surface interval,
suggesting that marine deposition lasted some
25 000–35 000 yr. This line of reasoning gives an
age of 47 000–62 000 years ago for reflector X. The
X to W lacustrine interval is thinner than the Z to Y
interval by a factor of 2, indicating a duration of
perhaps 5000 years.
By comparing these order of magnitude estimates
of the age of horizons Z, Y, X, and W with estimates
of global changes in eustatic sea level (Chappell and
Shackleton, 1986; Skene et al., 1998) it is clear that
reflector Z is correlated with isotopic stage 2–1 transgressive phase, and reflector Y probably correlates
with the isotopic stage 2–3 regressive phase (Fig.
16). The older estimates of the age of the lacustrine
X to W interval suggest that this interval corresponds
to isotopic stage 4 (65 000–75 000 years). Reflectors
V, U and T in Navpaktos Bay, which show transgressive erosional features, are interpreted as marine
transgressive shoreline deposits that have tectonically
subsided. Their sub-bottom depth in relation to the
overlying dated reflectors suggests that they may
correlate with the isotopic stage 5.2 to 5.1, 5.4 to
5.3, and 6.1 to 5.5 transgressions, respectively (Fig.
16). Reflector T represents a widespread erosional
surface in the area over which sediments of various
ages were deposited. A similar erosional surface was
noted in the adjacent Patraikos Gulf (profile F in
Chronis et al., 1991) and on the N. Aegean shelf
where it was associated with the large scale Eutyrrenian (isotopic stage 6) lowstand of sea level (Piper and
Perissoratis, 1991) which ended about 128 000 years
ago.
This chronology can be tentatively applied to the
seismic reflection profiles from the deep basin of the
Gulf of Corinth published by Brooks and Ferentinos
(1984) and Higgs (1988). These show intervals with
numerous strong reflections alternating with more
transparent intervals (Fig. 17). The more reflective
intervals show evidence of channel-like erosion near
the southern margin of the basin. Using a mean sedimentation rate of 0.5 mm a 21, reflectors, Z, Y, X, W
and T are identified, implying that reflector I3 of
Higgs (1988) dates from the last interglacial (isotopic
stage 5e).
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
Fig. 17. Part of seismic profile 15 of Higgs (1988) on the southern margin of the central basin of the Gulf of Corinth, showing interpretation of key reflections, acoustic facies and
chronology, e erosion.
407
408
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
a)MARINE
HIGHSTAND
low gradient
delta
high gradient
delta
SURFACE
PLUME
earthquake
-triggered
slope failure
RARE SANDY
HYPERPYCNAL
FLOW
suspension fallout of mud in deep water,rare turbidites
b)LACUSTRINE
LOWSTAND
high gradient
delta
low gradient
delta
SURFACE
PLUME
FREQUENT
HYPERPYCNAL
FLOW
FREQUENT
HYPERPYCNAL
FLOW
sediment failure
promoted by slope erosion
deep-water turbidite deposition
Fig. 18. Model showing contrasts in sedimentation processes between: (a) highstand fully marine conditions and (b) lowstand lacustrine or
brackish conditions.
4. Discussion and conclusions
Late Quaternary sedimentation in the Gulf of
Corinth has been controlled by two factors: the position of sea level relative to the Rion Strait sill, and the
sediment input from rivers. When the sea level fell
below the level of the Rion Strait sill (which is today
at 260 m), the Gulf was transformed into a lake or, if
the sea level was a few meters above the Rion Strait
sill, into a marine area with a high fresh water content.
When sea level was higher, normal open marine
conditions were restored. Low gradient (suspended
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
load) deltas, such as those entering Corinth Bay,
deposited most of their sediment on the shelf under
marine conditions, but supplied lacustrine turbidites
by underflow when the Gulf was a lake (Fig. 18).
Steep gradient (bed load) deltas like the Selinous
and Vouraikos supply turbidites to the basin floor
under both marine and lacustrine conditions, but the
importance of mass movement appears greater under
lacustrine conditions.
A distinct seismic stratigraphy was distinguished in
the shelf areas of the Gulf that was extended into the
deep-water areas. In the shallow areas, Z and X are
terrace surfaces, commonly erosional, which mark the
base of overlying deltaic sequences. In deep-water
basins, Z and X mark the top of acoustically stratified
sediments interpreted as lacustrine turbidites; reflectors Y and W mark the base of these stratified intervals
and overlie acoustically transparent sections similar to
the Holocene section.
According to standard eustatic sea-level curves
(Fig. 16), the last lacustrine conditions in the Gulf
were during stage 2. The lacustrine conditions terminated about 12 000 years ago when sea-level rise
overtopped the Rion Strait sill. Therefore reflector Z
is about 12 000 years old and corresponds to the
isotopic stage 2/1 transgression. During the initial
part of the transgression over the suspended load
deltas, a thin veneer of sediments was deposited at
the outer shelf due to the fast advance of the sea.
The maximum extent of the sea was reached about
6500 years ago and then Holocene deltaic sequences
began to prograde across the inner shelf (e.g. Corinth
and Egion bays). On the bed load deltas, only minor
changes were noted due to their steep gradient.
Age estimates based on sedimentation rates
suggest that the Z to Y lacustrine interval corresponds to the stage 2 lowstand of sea level and
the X to W interval to the stage 4 lowstand of sea
level. This correlation is also consistent with the relative duration of the two lacustrine phases. In the
western Gulf of Corinth, shoreline transgressive
surfaces corresponding to minor transgressions in
stage 5 are present, and the major transgression at
the end of stage 6 is recognisable as a reflector (T)
over a large area around the Mornos delta. T also
marks the top of a thick packet of acoustically wellstratified sediment about 120 m subbottom on the
basin floor of the Gulf of Corinth.
409
Acknowledgements
This paper was dedicated to the late Dr A.G.
Panagos, recently Professor of Geology at the Polytechnic University of Athens and former Professor
and Chancellor of Patras University. We thank the
Institute of Geology and Mineral Exploration and
the National Center of Marine Research of Greece
for permitting publication of the data. Geological
Survey of Canada contribution number 1999039.
References
Anderson, J.J., Carmack, E.C., 1973. Some physical and chemical
properties of the Gulf of Corinth. Estuarine and Coastal Marine
Research 1, 195–202.
Armijo, R., Meyer, B., King, G.C.P., Rigo, A., Papanastasiou, D.,
1996. Quaternary evolution of the Corinth rift and its implications for Late Cenozoic evolution of the Aegean. Geophys. J.
Int. 126, 11–53.
Bard, E., Fairbanks, R., Arnold, M., Maurice, P., Duprat, J., Moyes,
J., Duplessy, J.C., 1989. Sea level estimates during the last
deglaciation based on d 18O and AMSC14 ages measured in
Globigerina bulloides. Quaternary Research 31, 381–391.
Bard, E., Hamelin, B., Arnold, M., Montaggioni, L., Cabiochi, G.,
Faure, G., Rougerie, F., 1996. Deglacial sea-level record from
Tahiti corals and the timing of global meltwater discharge.
Nature 382, 241–244.
Bariagin, M.A., 1972. Tides and tidal data for Greek harbours.
Hydrographic Service, Athens (in Greek).
Brooks, M., Ferentinos, G., 1984. Tectonics and sedimentation in
the Gulf of Corinth and the Zakynthos and Kefallinia Channels,
western Greece. Tectonophysics 101, 25–54.
Chappell, J., Shackleton, N.J., 1986. Oxygen isotopes and sea level.
Nature 323, 137–140.
Chronis, G., Piper, D.J.W., Anagnostou, C., 1991. Late Quaternary
evolution of the Gulf of Patras, Greece: tectonism, deltaic sedimentation and sea level change. Mar. Geol. 97, 191–209.
Cramp, A., Vitaliano, C.J., Collins, M.B., 1989. Identification and
dispersion of the Campanian Ash layer (Y-5) in the sediments of
the Eastern Mediterranean. Geo-Mar. Lett. 9, 19–25.
Doutsos, T., Piper, D.J.W., 1990. Listric faulting, sedimentation and
morphological evolution of the Quaternary eastern Korinth rift,
Greece; first stages of continental rifting. GSA Bull. 102, 819–879.
Doutsos, T., Poulimenos, G., 1992. Geometry and kinematics of
active faults and their seismotectonic significance in the western
Corinth–Patras rift (Greece). J. Struct. Geol. 14, 689–699.
Doutsos, T., Kontopoulos, N., Poulimenos, G., 1988. The CorinthPatras rift as the initial stage of continental fragmentation
behind an active Island arc (Greece). Basin Res. 1, 177–190.
Fairbanks, R.G., 1989. A 17 000-year glacio-eustatic sea level
record: influence of glacial melting rates on the Younger
Dryas event and deep-ocean circulation. Nature 342, 637–642.
410
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
Ferentinos, G., 1992. Recent gravitative mass movements in a
highly tectonically active arc system: the Hellenic Arc. Mar.
Geol. 104, 93–107.
Ferentinos, G., Papatheodorou, G., Collins, M.B., 1988. Sediment
transport processes on an active submarine fault escarpment:
Gulf of Corinth, Greece. Mar. Geol. 83, 43–61.
Gawthorpe, R.L., Fraser, A.J., Collier, R.E.L.I., 1994. Sequence
stratigraphy in active extensional basins: implications for the
interpretation of ancient basin fills. Mar. Petrol. Geol. 11,
642–658.
Georgalas, G.C., 1962. Sur la submersion de l’ ancienne ville Helike
(Achaie). Prakt. Acad. Athinon 37, 232–247 (In Greek, French
summary).
Heezen, B.C., Ewing, M., Johnson, G.L., 1966. The Gulf of Corinth
floor. Deep Sea Res. 13, 381–411.
Higgs, B., 1988. Syn-sedimentary structural controls on basin
deformation in the Gulf of Corinth, Greece. Basin Res. 1,
155–165.
Jackson, J.A., Gagnepain, J., Houseman, G., King, G., Papadimitriou, P., Soufleris, C., Virieux, J., 1982. Seismicity, normal
faulting and the geomorphological development of the Gulf of
Corinth (Greece): the Corinth earthquakes of February and
March, 1981. Earth Planet. Sci. Lett. 57, 377–397.
Katsonopoulou, D., 1998. On the topography of Aigialeia (in Greek,
extended abstract in English). In: Katsonopoulou, D. (Ed.),
Proc. Second Int. Conf. on Ancient Helike and Aigeialeia,
Athens, ISBN 960-86377-0-8, pp. 31–66.
Kontopoulos, N.K., Stamatopoulos, L., 1991. A stream-flow
controlled “wet” late Quaternary alluvial fan, NW Peloponnese,
Greece. Il Quaternario 3, 61–72.
Lykousis, V., 1990. Prodeltaic deposits. Seismic stratigraphy–sedimentology-slope stability. PhD thesis (unpublished), University
of Patras, in Greek, 302p.
Lykousis, V., Sakellariou, D., Papanikolaou, D., 1998. Sequence
stratigraphy in the N. Margin of the Gulf of Corinth: implications to Upper Quaternary basin evolution. Bull. Geol. Soc.
Greece XXXII (2), 157–164.
Marinatos, S., 1960. Helice: a submerged town of classical Greece.
Archaeology 13, 186–193.
McKenzie, D.P., 1978. Active tectonics of the Alpine–Himalayan
belt: the Aegean Sea and surrounding areas. Geophys. J. R.
Astronom. Soc. 55, 217–254.
Myrianthis, M.L., 1984. Graben formation and associated seismicity in the Gulf of Corinth (Central Greece). Geological Society
of London Special Publication 17, pp. 701–707.
Papanikolaou, D., Chronis, G., Lykousis, V., Pavlakis, P., 1987.
Active tectonics in the Rion Antirion Strait, western Greece.
Abstracts, Fifth Meeting of European Geological Societies,
Dubrovnik, October, pp. 72–73.
Papatheodorou, G., 1990. Sedimentation in the Gulf of Corinth.
PhD thesis, University of Patras (in Greek).
Papatheodorou, G., Ferentinos, G., 1993. Sedimentation processes
and basin filling depositional architecture in an active graben:
Strava graben, Gulf of Corinth, Greece. Basin Res. 5, 235–253.
Papatheodorou, G., Ferentinos, G., 1997. Submarine and coastal
sediment failure triggered by the 1995, Ms 6.1 R Aegion
earthquake, Gulf of Corinth, Greece. Mar. Geol. 137, 287–304.
Perissoratis, C., Van Andel, Tj.H., 1988. Late Pleistocene unconformity in the Gulf of Kavalla, northern Aegean, Greece. Mar.
Geol. 81, 53–61.
Perissoratis, C., Van Andel, Tj.H., 1991. Tj.H., Sea level changes
and tectonics in the Quaternary extensional basin of South
Evvoikos Gulf, Greece. Terra Nova 3, 294–302.
Perissoratis, C., Mitropoulos, D., Angelopoulos, I., 1984. The role
of earthquakes in inducing sediment mass movements in the
eastern Corinthiakos Gulf: an example from the February 24–
March 4 activity. Mar. Geol. 55, 35–45.
Perissoratis, C., Mitropoulos, D., Angelopoulos, I., 1986a. Marine
geological research at the eastern Corinthiakos Gulf. I.G.M.E.
Geological and Geophysical Research, Special Issue, pp. 381–
401 (in Greek, English summary).
Perissoratis, C., Mitropoulos, D., Angelopoulos, I., 1986b. Marine
geological researches at the area of Rion-Antirrion. I.G.M.E.
Technical Report, 31p.
Perissoratis, C., Zacharaki, P., Zimianitis, E., Gazetas, G., 1997.
Contribution of marine geology to engineering projects: Maliakos submerged tunnel and Aegion harbour. In: Marinos, P.,
Koukis, G., Tsiambaos, G., Stournaras, G. (Eds.). Engineering
Geology and the Environment, Balkema, Rotterdam, pp. 2845–
2850.
Piper, D.J.W., Panagos, A.G., 1981. Growth patterns of the Archeloos and Evinos deltas, Greece. Sedim. Geol. 28, 111–132.
Piper, D.J.W., Perissoratis, C., 1991. Late Quaternary sedimentation
on the continental margin of Northern Greece. Am. Assoc.
Petrol. Geol. Bull. 75, 46–61.
Piper, D.J.W., Kontopoulos, N., Panagos, A.G., 1980. Deltaic,
coastal and shallow marine sediments of the western Gulf of
Corinth. Thalassographica 3, 5–14.
Piper, D.J.W., Kontopoulos, N., Anagnostou, C., Chronis, G., Panagos, A.G., 1990. Modern fan deltas in the Western Gulf of
Corinth, Greece. Geo-Mar. Lett. 10, 5–12.
Poulos, S., Collins, M., Pattiaratchi, C., Cramp, A., Gull, W., Tsimplis, M., Papatheodorou, G., 1996. Oceanography and sedimentation in the semi-enclosed, deep water gulf of Corinth (Greece).
Mar. Geol. 134, 213–235.
Ryan, W.B.F., Pitman III, W.C., Major, C.O., Shimkus, K., Moskalenko, V., Jones, G.A., Dimitrov, P., Gorur, N., Sakinc, M.,
Yuce, H., 1997. Abrupt drowning of the Black Sea shelf. Mar.
Geol. 138, 119–126.
Schwartz, M.L., Tsiavos, C., 1979. Geology in the search of ancient
Helice. J. Field. Arch. 6, 243–252.
Seger, M., Alexander, J., 1993. Distribution fo Plio-Pleistocene and
Modern coarse-grained deltas south of the gulf of Corinth,
Greece. Spec. Publ. Int. Assoc. Sediment. 1993), vol. 20, pp.
37–48.
Skene, K.I., Piper, D.J.W., Aksu, A.E., Syvitski, J.P.M., 1998.
Evaluation of the global oxygen isotope curve as a proxy for
Quaternary sea level by modeling of delta progradation. J.
Sedim. Res. 68, 1077–1092.
Soter, S., 1999. Macroscopic seismic anomalies and submarine
pockmarks in the Corinth–Patras rift, Greece. Tectonophysics
308, 275–290.
Soter, S., Katsonopoulou, D., 1998. The search for ancient
Helike, 1988–1995: geological, sonar and borehole studies.
C. Perissoratis et al. / Marine Geology 167 (2000) 391–411
In: Katsonopoulou, D. (Ed.), Proc. Second Int. Conf. on Ancient
Helike and Aigeialeia, Athens, ISBN 960-86377-0-8, pp. 67–116.
Stanley, D.J., Warne, A.G., 1994. Worldwide initiation of Holocene
marine deltas by deceleration of sea-level rise. Science 265,
228–230.
St. Seymour, K., Christanis, K., 1995. Correlation of a tephra layer
in western Greece with a Late Pleistocene eruption in the
Campanian Province of Italy. Quat. Res. 43, 46–54.
Therianos, A.D., 1974. The geographical distribution of river water
supply in Greece. Bull. Geol. Soc. Greece 11, 28–58.
411
Van Zeist, W., Bottema, S., 1982. Vegetational history of the
eastern Mediterranean and the near east during the last 20,000
years. In: Bintliff, J.L., Van Zeist, W. (Eds.), Paleoclimates,
Paleoenvironments and Human Communities in the Eastern
Mediterranean Region in Later Prehistory. British Archaeological Reports, International Series No. 133, pp. 277–321.
Varnavas, S.P., Ferentinos, G., Collins, M., 1986. Dispersion of
bauxitic red mud in the Gulf of Corinth. Mar. Geol. 70, 211–
222.