Paleoclimatic studies withDead Sea Sediments

The Levant is located between two major climate belts and its late Quaternary climate history reflect global shifts of the major ocean-atmospheric systems.

The lakes in the Dead Sea basin received their water from a very large drainage area and they loss water mainly by evap-oration, thus, they behave like a big hydrological gauge of the entire drainage area and the east Mediterranean-Levant region.The lakes changed frequently their levels reflecting rapid shifts from arid to wet climate. In the picture-extent (maxi-mum stand) of lake Lisan the late Pleistocene (70-14 ka BP) precursor of the Dead Sea.

Large changes in lake levels between the high stand of Lake Lisan at ~ 25 ka BP to the that of the Dead Sea (e.g. at the 19 th century). The picture shows the retreat terraces on the walls of the Judea Mt.

The Dead Sea basin located along a major tectonic feature in the earth crust accommodated several water-bodies that deposited sequences of evaporitic and detrital sediments. These sediments contain information on the geochemical-hydrological-climatic history of the region throughout the past 3 Ma.

The Levant was the cradle of human prehistory and a major region of migration and settling of our ancient ancestors. Their cultural development was intimately associated with climate-environmental changes in the region.

Monitoring these shifts is important for understanding the mechanism of past climatic changes and for inferring future climate patterns that are so critical in our evaluation of the global warming effects.

De

ad

Se

a

Saharo-Arabian desert belt

ITCZJuly

Dead Seabasin

Maximum extension

of Lake Lisan

Sea of Galilee

De

ad

Se

a

Massada

Hula Basin

Gulf of Elat (Aqaba)

Negev

Desert

Mt. Hermon

Jebel Druze

30°

31°

32°

33°

36°35°

30°

31°

32°

33°

W. A

rava

N. ZinW. Hasa

W. Mujib (Arnon R

Low

er J

orda

n R

iver

W. Zarqa (N. Yaboq)

Yarmouk R.

Up

per

Jord

an R

iver

0 50 km

N. P

aran

Me

di t

er r

an

ea

n S

ea

The exposures of the lake Lisan sed-iments beneath the archeological of Massada. The section is dominated by whitish deppsits of primary-evap-oritic aragonite, which alternate with brown-dark detrital laminae to form pairs of annual deposits. These ex-posures contains high-resolution en-vironmental history of the last glacial period at the region.

Magnified section of laminated aragonite (white) and detritus (brown) laminae of Lisan sediments. The aragonite was deposited from the lake water and requires supply of freshwater - thus, it is proxy for the behavior of the hydrological system. The aragonite is also an excellent material for radioactive dating and is used to establish the lake chronology.

The brown detritus is desert dust washed to the lake by the winter floods. It provides information on the dust sources and mode of transport to the region.

The reconstruction of a lake level curve is a prime target in the scientific investigation of the Dead Sea lakes since it serves as a regional-hydrological proxy telling about the climatic conditions in the Levant. Lake level curves were established for the late Pleistocene lake Lisan and the Holocene Dead Sea. The level curve can be compared with global climate archives such as the ice core records.

Interval ofNeanderthal

extinction

LE

14C anomaly

Lake

leve

l ele

vatio

n (m

a.s

.l.)

-420

-380

-340

-300

-260

-220

-180

Age (calibrated ka)15 20 25 30 35 40 45 50 55 60

MIS 2 MIS 3

H1 H2 H3 H4 H5

a b

c

Intraclastic breccias identified in the lake sed-iments and are used to monitor paleoearthquakes and reconstruct the seismic history of the region throughout the upper Pleistocene and Holocene times.

a - cross-section of sediment recordb - seismite within the recordc - surface of a seismite

Strartigraphic column of the sedimentary deposits in the Late Quaternary Dead Sea basin, the older parts of the section as well as part of the Holocene section are buried in the subsurface (excpet for the exposure of the mid to late Pleistocene Amora Formation that was uplifted by Mt. Sedom salt diapir (next picture).The ICDP drilling campaign intends to recover sedimentary cores that will recover in high-resolution details (e.g. annu-ally deposited carbonates and detritus) the entire sedimentary history of the Dead Sea basin during the past 1Ma.

Perazim Creek outcropMIS

Age(ka)

Lake level(m a.s.l.)

0

40

80

120

160

200

2

1

3

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5

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7

DeadSea

LakeLisan

LakeSamra

LakeAmora

LisanFm

SamraFm

AmoraFm

- 400 - 200

5 m

Two drilling campaigns (carried by teams of GFZ-Potsdam, Tel Aviv University, The Hebrew University of Jerusalem and the Geological Survey of Israel (at 1993 and 1997) recovered sediment cores from the bottom and the recently exposed margins of the Dead Sea. The cores were used to construct the Holocene environmental (climagte and seismicity) history of the Dead Sea.Proposed site of the ICDP drilling campaign in the northern deep basin of the Dead Sea at depth of 600 m below mean sea level and 200 m below the current water level. The drill aims to reach ~ 400 m.

The exposed section of the mid to late Pleistocene Amora Formation uplifted and tilted by the rising Sedom salt diapir.The formation consists of sequences of laminated primary evaporitic aragonite and detritus similar to those deposited in lake Lisan and thus can provide information on the environmental history during the time interval of ~ 700-140 ka BP.

20 m

15

10

5

0

sed

imen

t d

epth

[m]

HeverZe'elimEin Gedi

Ein Feshkha

halitedark coloured layerswithin laminationdark coloured marl

alternating marland aragonitelaminated marl

marl

silt / sand

sand, coarse grained

-728

Massada

Mt.

Sed

om

-500

-700

-725

-410

31°30´

35°30´

Lync

h C

hann

el

Lisa

n St

rait

DS7-1SC

DS6-1SC

DS2-3KB

DS3-1KB

DS11-1KBDS12-1KBDS14-1KBDS13-1KB

David

Arugot

Hever

Zeelim

Arnon

5 km

DSEnDSF DSH DSZ

EinBokek

LISAN PENINSULA

Ein Gedi

31°00´

South Basin

WI

LD

ER

NE

SS

O

F

JU

DA

E

MO

AB

Jord

an-f

ault

No

r th

Ba

si n

Zeelim Valley DSZ-A,B,C

HeverDSH-A

Ein Feshkha DSF-A,B

35°30´

DS8-1SCDS9-1SC

DS1-1KBDS4-1KBDS10-1SC

Ein GediDSEn-A,B,C

DS5-1SC

Jord

an

transformfaultfaultdiapir

proposedby ICDPin 1997in 1993

Coring projects

Mount SedomOlder sediments

~150 metersYounger sediments

Arubotaim Cave (CA) section