Geological Structure of the Dead Sea
The entire Dead Sea region is part of the Great Rift Valley that stretches, north to south, from Northern Syria down to Central Africa. It is also located in the desert belt that
runs, from west to east, between North Africa and the Sind Desert in western India.
geological periods it was rich in water and in animal and plant life, signs of
which are found both in the quantity of minerals and in the type and structure
of the soil.
Animals whose bones and hard structures were compressed and
refined between the limestone strata on the sea floor constitute the source of
the layers of phosphoric chalk, important today for industry and agriculture.
This organic life, which separated out into various carbonic materials, also
constitutes a source for clay and bituminous chalk. Some of these layers are
found only after drilling, while others are clearly visible on the surface,
indicated by the brown-black color of the crevices and the combustibility of the rock.
Layer of Organic Remains Compressed
Lumps of Conglomerate Swept Down in Winter Floods to the Dead Sea
Esterbon, the first century geographer, mentions Massada
clay in his writings. This clay is found along the wadies and cliff walls and adheres to the
soil and gravel, making lumps of conglomerate which are swept down in the winter
floods. In Esterbon's view, the ancients regarded this marl as the remains of the
destroyed biblical cities of Sodom and Gomorrah,
which are traditionally believed to have sunk under the southern basin of the
Bedouin fellahs in the Judean Desert used to burn the bituminous
chalk for lime and related the secret of the combustion to the influence
of 'Nebi Musa', the holy tomb of Moses located in the area.
In addition to the bituminous chalk and the clay found within
the layers on both sides of the Dead Sea, there is floating clay which the
Egyptians used to smear on their vessels and to embalm their dead and which
rises spontaneously from the sea floor.
Drawing of Egyptian Boat
Egyptians Used Floating Clay to Embalm their Dead
These and other geological signs create hopes that oil or
petroleum may be found deep in the geological strata, and indeed trial drillings
are undertaken here from time to time.
The pure sulfur, whose formation is associated with separation
of oil into the strata of the Jordan Valley and into hydrogen gas which erupts
from the hot springs and various fissures in the ground, was used most
effectively by the local inhabitants, among other things, as a means of
repelling snakes and at a later stage in the preparation of gunpowder for their
Sulfur is also found in the Dead Sea region between the layers
of lissan marl and the gypsum formed as a result of the climate. Gypsum (used as
a basis for plaster) sometimes attains a height of six meters and more; and has
a property of rapid hardening that makes it useful in the construction and
casting industries, as well as in sculpture and medicine.
The Dead Sea area is the richest region of mineral resources in
Israel. Enormous deposits of phosphates, shale oil and natural gas, raw
materials for the building and cement industries, and materials for ceramics and
glass-making are located nearby in the mountains of the north-eastern Negev and
in the Judean Hills.
Some of these resources are being mined at present, but for
ecological reasons others are not, as the striking landscape of the area has to
||Mount Sodom, a uniquely scenic structure, rises 230 meters above
the level of the Dead Sea. The mount is 2-3 kilometers wide and eleven
This mountain, which is nothing other than a block of salt that
sank into the bottom of the ancient lake and was lifted out as a slab by
tectonic tremors, consists of about a billion tons of pure salt which is almost
ready for the table.
Inside, it is pierced by caverns and tunnels which originated as
funnels and chimneys on the mountaintop. Rainwater dissolved first the upper
layers of the gypsum marl, and then the layers of salt below as it penetrated
the mountain in its movement towards the sea.
The chill that pervades the caverns on summer days as well as in
winter is the result of the draughts of air that take up the damp that oozes
through their hygroscopic walls and lower the temperature.
The number and sizes of the tunnels and caves, sometimes
hundreds of feet long, are a striking proof that only great deluges of water in
prehistoric times could have been capable of dissolving such thick layers of
salt and forcing the solution out to the sea.
A process of cave
and labyrinth formation is continuing even today. The cap rock and the pillars
of salt that have fallen from the mountain top or formed within it have
themselves become carved and shaped by changes in climate, erosion, and
rainfall, and resemble sculptures of tropical hats, huge mushrooms altars,
dolmens and of course Lot's wife.
The fault scarp consists mainly of hard limestone and dolomites
from the Kinoman and Toron periods.
Canyons cut through it from the Judean Desert in the west and
from the Moab Plateau, whose eminences change their hue from hour to hour with
the changing color of the glass-smooth sea.
The wild landscape, together with the pastoral calm that imparts
to the place the aura of Creation have, from time immemorial, formed the
compelling scenic background to the Dead Sea.
Salt Crystallization in the Dead Sea
The area is principally an 'orographic desert'. Its aridity
results from the high barrier of the Judean and Hebron Hills, which obstruct the
moisture-bearing low fronts coming in from the west and from the zone of the
global desert belt.
The high air temperature, over 40 degrees Celsius in the summer
and 20 degrees Celsius in the winter, the slight cloudiness and the rare occurrences
of rainfall, together with the relatively low humidity and the wind regime in
the region, give rise to massive evaporation, in spite of the low level of solar
radiation. This evaporation has an annual daily average of 12.1 cubes, while in
July it can reach 18 cubes a day, resulting in the crystallization of salt on the lake.
The amount of water supplied by the River Jordan, the streams'
springs, and the floodwaters on both sides of the Dead Sea, does not equal the
very high evaporation rate on the lake, which amounts to approximately 2 billion
cubes a year; for comparison, the figure for water consumption of Israel in 1980
was about 1.6 billion cubes. This has urged many people to start thinking about
the necessary steps for preserving this unique
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