MEDITERRANEAN MEGATURBIDITE TRIGGERED BY THE AD 365
CRETAN EARTHQUAKE AND TSUNAMI
Polonia A.* (1), Bonatti E. (1,2), Camerlenghi A. (3), Gasperini L. (1), Lucchi R. (3) and Panieri G. (1)
(1) ISMAR-CNR (Istituto di Scienze Marine)
(2) Lamont-Doherty Earth Observatory
(3) OGS (Istituto Nazionale di Oceanografia e di Geofisica Sperimentale)
* Correspondence and requests for materials should be addressed to Alina Polonia
(alina.polonia@ismar.cnr.it)
SUPPLEMENTARY MATERIAL
Supplementary – S1: Seismostratigraphic correlation between the HAT found in Cores
CALA 04 and CALA 05 and the HAT previously known in the Ionian Abyssal Plain (Augias
Turbidite or Type B Homogenite).
A: Location map of CHIRP seismic profiles acquired during this study (green lines). Location
of cores CALA 04 and CALA 05 is indicated by the red dots. CHIRP profile shown in Fig. 2 of the
article is indicated by a thick green line crossing coring stations. On sub-bottom profiles, the HAT
correlates with the Augias turbidite described in previous works [Hieke, 2000; Hieke et al., 2003].
B: CHIRP seismic line to_Cala-08_14_02 (thick green line labeled A) acquired in the abyssal plain.
The HAT is a uniform thickness, laterally continuous, about 12-15 m thick and acoustically
transparent near surface layer. C: CHIRP seismic profile M40, PS line 101 [modified from Hieke,
2000]. The Augias turbidite has a uniform thickness of about 15 m in the deep basin while it
pinches out to a few meters towards the basin’s margins.
This figure has the purpose of demonstrating that, the HAT in the Ionian abyssal plain (Type
B Homogenite) correlates well with the Augias turbidite of Hieke, 2000; Hieke et al., 2003. On the
other hand, like in the cases published by [Cita & Rimoldi, 2005], there is no direct
seismostratigraphic correlation between the HAT in the Ionian Abyssal Plain (Type B Homogenite)
and that located on the outer fringes of the Calabrian and Mediterranean Ridges due to the
intervening structural highs and bathymetric constraints. Nevertheless, the similar acoustic
stratigraphic character and the lithostratigraphy allow the correlation among the deposits.
Supplementary S2 - Biogenic content, mineralogy and sediment provenance
Unit
Components
Geochemistry Provenance
Detritic
Biogenic
V
Very small clay
aggregates and pyrite.
Barren
High elemental
concentration in
Ca, Sr and Cl (at
the base) and Fe,
Mn at the top.
IV
The base shows a small
increase in sand content
and it is characterized
by abundance of
pyritized fecal pellets.
This unit contains clay
aggregates, micas,
euhedral quarts,
plagioclase.
Small sized planktonic
foraminifera, benthic
foraminifera, small closed
bivalves, ostracods,
ossicles of holoturoidea,
spiculae of
Demospongiae,
radiolarian, broken
pteropods.
High elemental
concentration in
Sr and Cl at the
base.
III
This unit contains micas,
clay aggregates, Fereddish crusts, quartz,
and very abundant
basaltic glass. Altered
glass is present only at
the unit top.
Small sized planktonic
(Pleistocene and
Cretaceous) and benthic
epiphyte foraminifera
abundant in the upper
part (mainly Spirillina
vivipara), broken
pteropods as Limacina
and Clio, shell hash,
gastropods, bryozoans,
spongae spiculae,
bivalves, unornamented
ostracod, ossicles of
holoturoidea, plant
remnants.
High elemental
concentration in
Sr, Ca.
The overall
composition of this
unit suggests that
the material was
displaced from the
Malta escarpment
and Sicily channel.
Lower part is
characterized by
middle/lower bathyal
biogenic
components
whereas the upper
part by inner shelf
elements
II
Alternation of black and
white levels mainly
composed by large size
biogenic remains
(100m) less abundant
to the top.
Main components are
plagioclase, micas,
glass, crusts of pyrite,
clay aggregates. The
sand peaks are
characterized by
different proportions of
these components and
slightly different
foraminiferal content
(see Supplementary 3)
Very abundant, with
dominant Pleistocene and
rare displaced Cretaceous
planktonic foraminifera,
benthic foraminifera (from
shallow to deep water;
outer shelf to upper slope
species and middle to
lower bathyal show a
marked increase in
abundance), broken
pteropods as Limacina
and Clio, closed and/or
disarticulated bivalves,
bryozoans, shell hash,
ossicles of holoturoidea,
spiculae of
Demospongiae, echinoid
spiculae, gastropods, rare
plant remnants, fish
remains.
High elemental
concentrations of
Fe, Ba, Mn, Ti,
Nb; peaks in Zr,
Rb, Y;
Low elemental
concentrations in
Sr, Ca, K.
Sediment displaced
from the southern
Calabria and
Northeastern Sicily.
Material from the
Malta escarpment
(plagioclase and
basaltic glass is a
source indicator form
Etna volcano) is still
present. Fauna with
bathymetric range
from the inner shelf
to middle/lower
bathyal domains.
I
The base is marked by
an abrupt change in
Broken pteropods
(Limacina and Clio),
High elemental
concentrations of
Sediments displaced
from the Malta
sediment composition
and biogenic content
relative to the underlying
units. It is constituted by
a mixture of plagioclase,
clynopiroxene,
amphibole, basaltic
glass, feldspar,
carbonate grains, pyrite
incrustations, and clay
minerals
planktonic foraminifera
(abundant Pleistocene
“warm species” and
dispalced Cretaceous
taxa), benthic foraminifera
from shallow water to
bathyal, closed and/or
disarticulated bivalves;
bryozoans; fragments of
Lamellibranchiae; shell
hash; ossicles of
holoturoidea, spiculae of
Demospongiae, echinoid
spiculae, shallow water
gastropods, rare plant
remnants, carbonate
reticulate structures, fish
remains.
Sr and Ca
escarpment
(carbonates from the
Hyblean plateau
while clynopiroxene,
amphibole, basaltic
glass, feldspar, are
indicators of the
Etna volcano)
involving bathymetric
ranges from the
inner shelf to
middle/lower bathyal
domains.
Supplementary – S3: HAT sand peaks, composition and foraminifera
Photograph, units and grain size of the basal part of the HAT megaturbidite in core CALA 05.
Detritic and biogenic components, and foraminiferal associations, are described for each sand
peak (numbers from 1 to 15) identified in the coarse basal part of the HAT megaturbidite. The
relative abundance of foraminiferal groups is distinguished by their bathymetric distribution
following the concepts of Jorissen [1987], de Stigter et al. [1998], and Murray [2006], and habitat
preferences. Inner shelf species comprise both shallow water and ephiphyte species. The curve of
abundance of Spirillina vivipara among epiphyte is also indicated (dark green line).
Supplementary – S4: Age modelling results for core CALA 04
Age modelling results obtained for cores CALA 04 using the P_Sequence (a Bayesian model of
deposition) implemented in the computer program OxCal 4.1; this software assimilates
sedimentation as a random process following a Poisson law [Bronk Ramsey, 2008]; marine data
from [Reimer et al., 2009]. The modelling output is represented by the 95.4% probability age
ranges (2σ) of each corrected depth corresponding to a turbidite. a) Stratigraphic log, photograph
(14C and Cs/Pb dated samples are indicated by white and orange rectangles respectively) and
pelagic units with uncalibrated radiometric ages of core CALA-04 (see Fig. 3 and its caption for
symbols used in this stratigraphic log); b) Deposition model built subtracting the thickness of the
turbidites from the total core. Turbidite beds represent the “instantaneous sedimentary events”
whose age is derived through interpolation within the OxCal modelling; c) Calibrated radiometric
dates (2 σ) of the pelagic units using a ΔR147±33. Input parameters to generate the age model are
the uncalibrated 14C ages and respective ΔR with their corresponding corrected depths; d) age
model built using the P_Sequence (a Bayesian model of deposition) implemented in the computer
program OxCal 4.1 [Bronk Ramsey, 2008]. See methods section for more details. The regularity of
sedimentation is determined by the k parameter (here k=3 reflects small variations in
sedimentation rate as deduced from radiometric dating analysis).
Supplementary – S5: Age modelling results for core CALA 05
Age modelling results obtained for cores CALA 05 using the P_Sequence (a Bayesian model of
deposition) implemented in the computer program OxCal 4.1; this software assimilates
sedimentation as a random process following a Poisson law [Bronk Ramsey, 2008]; marine data
from [Reimer et al., 2009]. The modelling output is represented by the 95.4% probability age
ranges (2σ) of each corrected depth corresponding to a turbidite. a) Stratigraphic log, photograph
(dated samples are indicated by white rectangles) and pelagic units with with uncalibrated
radiometric ages of core CALA-05 (see Fig. 3 and its caption for symbols used in this stratigraphic
log); b) Deposition model built subtracting the thickness of the turbidites from the total core.
Turbidite beds represent the “instantaneous sedimentary events” whose age is derived through
interpolation within the OxCal modelling; c) Calibrated radiometric dates (2 σ) of the pelagic units
using a ΔR147±33. Input parameters to generate the age model are the uncalibrated 14C ages and
respective ΔR with their corresponding corrected depths; d) age model built using the P_Sequence
(a Bayesian model of deposition) implemented in the computer program OxCal 4.1 [Bronk
Ramsey, 2008]. See methods section for more details. The regularity of sedimentation is
determined by the k parameter (here k=3 reflects small variations in sedimentation rate as
deduced from radiometric dating analysis.
Supplementary – S6: Table of OxCal age modelling results of core CALA 04
Input (columns 1, 2 and 3) and output (column 4) data of the OxCal modeling [Bronk Ramsey,
2008] for core CALA 04; the age model is shown in Supplementary 4. Column 2: uncalibrated ΔR
value used in this work; C14 dates within the pelagic units P2, P3_1 and P3_2; Cs/Pb date of
pelagic unit P0. Column 3: calibrated but still unmodelled age ranges. Column 4: age distribution of
the turbidite beds at 2σ as result of modelling. The software output is a representative set of
possible ages for each depth point in the sedimentary sequence. These results are also shown in
Supplementary 4, that includes the stratigraphic depth of emplacement of each turbidite within the
background sequence.
1
CALA-04
2
Uncalibrated
From
Name
Curve Marine09
ΔR LocalMarine
3
Unmodelled (BC/AD)
147 ± 33
80
4
Modelled (BC/AD)
To
%
From
To
%
214
95.4
104.5
214.5
95.4
-6761
-5184
95.4
-5215
-4948
95.4
-3400
-3114
95.4
-3314
-3010
95.4
-3308
-1503
95.4
-1286
-996
95.4
-179
621
95.4
P_Sequence CALA-04
Boundary Bottom
R_Date S1
6690 ± 40
-5247
-4969
95.4
T7
R_Date P5
4990 ± 40
-3337
-3024
95.4
T6 (Santorini)
R_Date P4
3420 ± 35
-1306
-1001
95.4
AUGIAS (T4) + T5
R_Date P3_1
1860 ± 30
589
785
95.4
607
786
95.4
R_Date P3_2
1405 ± 30
1046
1251
95.4
1060
1260
95.4
1166
1561
95.4
1476
1651
95.4
1549
1897
95.4
T3
R_Date P2
905 ± 30
T2
Base of P0 :
T1 (Cs-Pb):
≈1900
1470
1651
95.4
Supplementary – S7: Table of OxCal age modelling results of core CALA 05
Input (columns 1, 2 and 3) and output (column 4) data of the OxCal modeling [Bronk Ramsey,
2008] for core CALA 05; the age model is shown in Supplementary 5. Column 2: uncalibrated ΔR
value used in this work; C14 dates within the pelagic units P3_1 and P3_2. Column 3: calibrated
but still unmodelled age ranges. Column 4: age distribution of the turbidite beds at 2σ as result of
modelling. The software output is a representative set of possible ages for each depth point in the
sedimentary sequence. These results are also shown in Supplementary 5, that includes the
stratigraphic depth of emplacement of each turbidite within the background sequence.
1
CALA-05
2
Uncalibrated
Name
Curve Marine09
ΔR LocalMarine
3
Unmodelled (BC/AD)
From
147 ± 33
80
To
214
4
Modelled (BC/AD)
%
95.4
From
To
%
85.5
207
95.4
-6622
-4780
95.4
-4923
-4661
95.4
-3404
-3189
95.4
-3340
-3057
95.4
-3326
-1589
95.4
-976
-777
95.4
-591
667
95.4
P_Sequence CALA-05
Boundary Bottom
R_Date S1
6430 ± 40
-4933
-4667
95.4
T7
R_Date P6
5000 ± 35
-3342
-3047
95.4
T6 (Santorini)
R_Date P4
3195 ± 30
-983
-779
95.4
AUGIAS (T4) + T5
R_Date P3_1
1890 ± 35
560
762
95.4
564
753
95.4
R_Date P3_2
1585 ± 30
848
1055
95.4
851
1052
95.4
T3
950
1699
95.4
T2
1226
1903
95.4
Base of P0 :
(correlation with core
CALA 04)
≈1900
Supplementary S8 – Organic matter characterization in the HAT
Organic matter characterization in the HAT expressed as plots of δ13C vs δ 15N (above) and C/N vs
δ 13C (below). Typical δ13C and C/N ranges for organic inputs to coastal environments taken from
[Lamb et al., 2006]. POC: particulate organic carbon; DOC: dissolved
organic carbon. Both plots outline a dominant component of marine algae in the organic matter of
pelagic sediments and turbidites below the HAT. Conversely, the organic matter found in the HAT
contains a relevant component of terrestrial plants interpreted as sourced from relict, low sea level
shallow-water and emerged areas of the Sicily Channel.
References for the Supplementary Material:
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42-60 (2008).
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seidmentary response. Rend. Fis. Acc. Lincei, 9, 16, p. 137-157 (2005).
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partitioning of live (Rose Bengal stained) benthic foraminifera along a shelf to deep sea
transect in the southern Adriatic Sea. Marine Micropaleontology, 28, 40–65 (1998)
Hieke, W. Transparent layers in seismic reflection records from the central Ionian Sea
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Sea): Morphology, subbottom structures and geodynamic history – an inventory. Marine
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Hajdas, I., Heaton, T. J., Hogg, A. G., Hughen, K. A., Kaiser, K. F., Kromer, B., McCormac, F.
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