(LR), Eratosthenes Seamount (ES), Levant basin, and Nile Delta. Offshore Israel and ..... Figure 17.11 (left). Schematic cross-sectional (left) and stratigraphic.
E30°
TURKEY
Egypt
Israel
SSW 0
Lebanon 1.0
Miocene Messinian
Yafo Sand Member
Unnamed mudstone
2.0 2.5
Afiq Formation
Nahr Menashe
3.0
Rosetta Formation
Mavqiim Formation
Unnamed evaporite
3.5
Qawasim Formation
Ziqim Formation
Unnamed mudstone?
Figure 17.4. Chronostratigraphic diagram showing relationships among Messinian-Zanclean accumulations in offshore Egypt, Israel, and Lebanon. [Frey-Martinez et al., 2007; Ishmail et al., 2010].
MSC surfaces
**
supra-MSC units MSC units sub-MSC units
4.0
N
2
Cyprus
4
LR
MEDITERRANEAN SEA N34°
Levant basin
ES
Leba
DST Nile Delta
N33°
NE
supra-Messinian
Fig. 17.12
LEVANT BASIN
N32° Nile Delta Egypt
sub-Messinian Not to scale
Figure 17.2. Diagram showing geometric relationships among sub-Messinian, Messinian, and supra-Messinian deposits and their respective bounding surfaces.
150
200
Jord
UU (Lago Mare) clastics MU
Israel an
Figure 17.1. Map of the eastern Mediterranean Sea. Convergence of the Eurasian and African plates created the Latakia Ridge (LR), whereas sinistral displacement across the African and Arabian plates formed the Dead Sea Transform (DST).
SW
E36°
non
Mediterranean Sea
Israel
Figure 17.3. Bathymetric map of the Levant basin study area (Fig. 17.1), showing Latakia Ridge (LR), Eratosthenes Seamount (ES), Levant basin, and Nile Delta. Offshore Israel and Lebanon are characterized by a narrow shelf (20-35 km wide), whereas the Nile Delta in Egypt forms a broad and rugose physiography. Arrows denote known (green) and previuosly unknown (red – this study) source directions. Red and white polygon delineate 3D seismic data (Fig. 17.10 – red).
250
300
350
400
NNE 450km
Lebanon UU MU
Yafo Sand Member **
Abu Madi Formation
MES: margin erosion surface TES: top erosion surface IES: intermediate erosion surface BS: bottom surface WS: welded surface
LR
E35°
E34°
MSC source directions (previous studies) MSC source directions (this study)
1.5
Time (sec TWTT)
Pliocene Zanclean
Yafo Mudstone Member Kafr El Sheikh Formation
100
50
N35°
E33°
17.5
MARGIN ARCHITECTURE The Messinian–Zanclean stratigraphy of the Levant basin is divided into sub-Messinian, Messinian, and supra-Messinian reflections bounded by seismically defined surfaces (i.e., MES, TES, IES, and BS). Sub-Messinian deposits (PMU) contain Oligo-Miocene marine accumulations that are overlain by evaporitic rocks of the Messinian Salinity Crisis (MSC). Intra-Messinian strata are differentiated into evaporitic (MU) and clastic units (UU). Evaporitic rocks are locally more than 4-km thick and are internally deformed; the southern edge of the Levant basin is interpreted as welded. Messinian evaporites are locally overlain by a carapace of nonmarine clastic sediments associated with the Lago Mare phase (UU) called the Nahr Menashe unit, which extends north of Latakia Ridge and likely originated from western Syria or the southern Anatolian Plateau. Supra-Messinian strata (PQS) form a deep-marine clastic wedge that includes the Yafo Sand Member, a remobilized submarine fan (sand injectite) sourced through the el-Arish and Afiq canyons in Egypt and Israel [Frey-Martinez et al., 2007].
STUDY AREA
E32°
Fig.
TECTONIC AND SEDIMENTARY SETTING The Levant basin in the eastern Mediterranean is a remnant of Neotethys oceanic lithosphere situated between the Cyprus and Syrian arcs, and the African plate. The northern and eastern basin flanks are defined by the Cyprus–Lamaca and Tartus thrust zones, which form the Latakia Ridge (LR) to the north, and the Dead Sea transform (DST) to the east [e.g., Hall et al., 2005]. The southern and western basin margins are physiographically delineated by the northern limit of the Nile Delta cone and the Eratosthenes Seamount. The Levant basin contains over 10 km of Upper Jurassic through Cenozoic rocks that overlie a rifted Triassic to Lower Jurassic succession [Gardosh and Druckman, 2006; Netzeband et al., 2006a]. The southern and eastern flanks of the basin are cut by deep canyons of Oligocene and Miocene age [Druckman et al., 1995].
0
E31°
17.A- NORTHERN LEVANT BASIN
REGIONAL SETTING
Authors: Madof A. S. & Connell S. D.
Time (sec TWTT)
17. NORTHERN LEVANT BASIN
**
**
PQS
Nahr Menashe unit
TES IES BS MES
**
PMU
Figure 17.5. Drawing of 2D seismic line from the eastern Levant basin, showing interpreted sub-Messinian, Messinian, and supra-Messinian seismic stratigraphy. Geophysical character, geometric relationships, and biostratigraphic control demonstrate an upper Messinian stratigraphic position for the Nahr Menashe unit, which underlies the lower Pliocene Yafo Sand Member.
PQS: Plio-Quaternary succession YSM: Yafo Sand Member UU: upper unit (interpreted as Lago Mare) MU: mobile unit PMU: pre-Messinian units
Acknowledgements: the authors thank Chevron for permitting publication and PGS for release of 3D seismic data.
IMPLICATIONS FOR PERIPHERAL SEDIMENT SOURCES INTO THE NORTHERN LEVANT BASIN Drainage into the southern Levant basin was directed through onshore canyons in Egypt and Israel, which were subsequently filled by the Abu Madi and Afiq Formations. Previous workers suggested that west-oriented drainages existed in the Arabian Plateau [Gvirtzman and Buchbinder, 1978]; however, feeder canyons in Lebanon and Syria have not been previously observed. This study confirms peripheral sediment sources that fed a large and previously unknown fluviodeltaic system in the northern Levant basin (Lago Mare Nahr Menashe unit - UU), which was comparable in size to the Miocene Eonile River.
17. NORTHERN LEVANT BASIN Authors: Madof A. S. & Connell S. D.
0
SW
NE
TES: high-amplitude laterally continuous peak separating PQS and UU. IES: high-amplitude laterally continuous peak separating UU and MU (i.e., Messinian gap). BS: high- to low-amplitude laterally continuous trough separating MU and PMU.
Sea level >5.96 Ma
pre-Messinian 2.5
Not to scale
A
W
0
1 km
E
0
W tion
nca
~5.96 Ma MES: truncation B
~5.55 Ma Lake level
Time (sec TWTT)
Tru
Lake level
0
5 km
N
1 km
IES
5 km
E PQS
UU
3.0 MU
Channel belt Tributary
3.5
BS: onlap
-
C
Amplitude
Floodplain
PMU
+
Tributary
Figure 17.7. Uninterpreted (left) and interpreted (right) seismic profile from the northern Levant basin, showing character of the BS, IES, and TES. Intra-Messinian deformation (shortening) is locally marked by high-angle truncation of intra-MU reflections with repsect to the overlying UU (Nahr Menashe unit). 5.33 Ma TES: truncation
MU
-
Channel belt
Nahr Menashe unit
Amplitude
Valley
Fluvial terrace Older T0 T1 T2 T3 T4 T5 Younger
+
Figure 17.8. Uninterpreted (left) and interpreted (right) seismic profile from the northern Levant basin, showing the character of the IES and TES. Profile was flattened on the IES to illustrate rugosity of the TES, which is interpreted to represent topographic inversion caused by episodic fluvial incision and associated fluvial terraces.
0
F
Figure 17.6. Schematic diagram showing interpretation of MSC in the Levant basin. Onset of the MSC (A) was marked by sea-level fall at or just prior to 5.96 Ma. By that time (B), evaporites accumulated in both shallow-marine and deep-water settings, with fluvial readjustments creating erosional surfaces in marginal locations (MES). In basinal settings, sediment starvation was responsible for forming the BS. By 5.55 Ma (C), widespread evaporitic deposition ceased in deep-basinal settings, creating a Messinian gap (IES). Fluvial input into the northern Levant basin was responsible for over 350 km of progradation of post-evaporitic (p-ev1 and p-ev2) Lago Mare clastics (Nahr Menashe unit) after 5.55 Ma (D). From 5.45-5.33 Ma (E), the Nahr Menashe unit backstepped more than 125 km towards its northeast source due to lake expansion. At that time, the top of the Nahr Menashe incised by 50 msec, forming the youngest and most deeply incised parts of the TES. At 5.33 Ma, abrupt sea-level rise inundated the entire Mediterranean and preserved the MSC succession (F).
T4
MU
supra-Messinian sub-Messinian
Fig. 17.7
T3 T5
UU
Flattened
T0
T1
T2
Eroded
E
UU (Lago Mare) clastics
SE
PQS
0
D
Lake level
2 km
5 km
Fig
PQS
. 17
.8
E Frequency 50 Hz
T
30 Hz
C
Time sec (TWTT) 2.7 3.2
Figure 17.9. View looking east towards Lebanon, illustrating the morphology of the IES surface. The rugose pattern (foreground – C) reflects small-scale folding associated with gravity-driven contraction. Larger depressions and ridges (background – E) are associated with extension; smoother intermediate areas reflect translation of underlying evaporites (T).
60 Hz
Figure 17.10. Spectral decomposition of interval surrounding TES, showing lateral distribution of frequencies. Thicker successions of tributary and meandering channel belts (lower frequency – red) eroded into thinner flood plain deposits (higher frequency – blue). Detail at right illustrates youngest inset valley fill that was created by an incised meandering channel belt.
17.B- NORTHERN LEVANT BASIN
MSC SURFACES
MSC UNITS
Authors: Madof A. S. & Connell S. D.
Figure 17.11 (left). Schematic cross-sectional (left) and stratigraphic (right) diagrams, illustrating MSC evolution in the northern Levant basin. Evaporative drawdown began (A) as sea-level dropped (B) before widespread evaporite accumulation by 5.96 Ma (C). Precessional cyclicity produced halite-gypsum/clastic packages that reflected dry-wet episodes (D), which continued until the Messinian gap, when Lago Mare (UU) deposition began with more than 350 km of progradation of the Nahr Menashe unit (E). Continued lake-level rise resulted in backstepping of fluviodeltaic deposits (F), leading to deep incision of updip fluvial valleys (G). Marine inundation at 5.33 Ma (H) preserved the MSC, leading to the resulting stratal geometries and stratigraphic trends (I).
Lake level
~5.96 Ma
B
e dg Ri 5 km
Transverse system
20 m Wet Dry
C
32° E
965
966
SM
SM
NM
= Core and well
Nahr Menashe unit
SM
34° N Unconfined
Channel belt
Axial system
NP
~5.55 Ma
B D
500
E
5.33 Ma
Israe
l
Lake level
= Lacustrine shoreline
34° E
δ18O N35˚
32° N
supra-Messinian UU (Lago Mare) clastics MU
sub-Messinian
3.2
West
150
A
100
0 CI = 50 ms
B
Afiq
50 km
Egypt
SM 34° E
Figure 17.12. (above). Isochrons of Messinian evaporites (MU), Yafo Sand Member (PQS) [Frey-Martinez et al., 2007], and lateral extent of Nahr Menashe unit (UU), which includes transverse (flanking) fluvial fans and an axial-fluvial system that fed six fluviodeltaic (lacustrine) lobes and associated shorelines (A-F). Interpretation of core and well data (ODP 965-967 and Afiq-2) [Druckman et al., 1995; Robertson, 1998]: SM = shallow marine; NM = nonmarine; S = salina; NP = not present. CI = isochron contour interval.
S Valley
5.4
p-ev2
50
East Unnamed mudstone
C
Nahr M enash e
H
50 CI = 10 ms
Insolation (W/m )
D E F G?
5.5
H?
p-ev1
0 CI = 100 ms
80
Margin 2
5.3
A (Myr) (M ) Age
500
Deep-marine (PQS)
1000
Nahr Menashe (UU)
~5.33 Ma
Evaporite (MU)
Older F E D C B A Younger Time (msec TWTT) 200 150 1500
Sea level
Basin
(‰)
Messinian gap
Unnamed evaporite
34° E 5.6 0.1 0.3
>5.33 Ma
G
I
Yafo Sand Member
A = Lacustrine delta
400 500
500
2.8
F
Lake level
50 0
Eratosthenes Seamount
S
100
non
Wet Dry
967
Leba
Lake level
Time (msec TWTT) 150
Fig.
0 5.96 Ma
La
NE
Sea level
17.13
SW
= Sediment input = Paleovalley axis
EURASIAN PLATE
Eccentricity
Lacuna
Figure 17.14. Chronostratigraphic interpretation of Nahr Menashe unit (UU) as precessionally modulated fluviodelatic lobes (Fig. 17.12); illustrated by oxygen-isotope and local eccentricity and insolation curves [Zachos et al., 2001; Laskar et al., 2004].
3.C- NORTHERN LEVANT BASIN
17. NORTHERN LEVANT BASIN
