The Dead Sea Transform (DST) fault system, also sometimes referred to as the Dead Sea Rift, is a series of faults that run from the

Maras Triple Junction Maras or Maraş (pronounced Marash) may refer to: Places *Maraş, Turkey, previous name until 1973 of Kahramanmaraş, a city in the Mediterranean Region, Turkey and the administrative center of Kahramanmaraş Province * Maras, Iran (disambiguation ...

(a junction with the East Anatolian Fault in southeastern

Turkey Turkey ( tr, Türkiye ), officially the Republic of Türkiye ( tr, Türkiye Cumhuriyeti, links=no ), is a transcontinental country located mainly on the Anatolian Peninsula in Western Asia, with a small portion on the Balkan Peninsula ...

) to the northern end of the

Red Sea Rift The Red Sea Rift is a spreading center between two tectonic plates, the African Plate and the Arabian Plate. It extends from the Dead Sea Transform fault system, and ends at an intersection with the Aden Ridge and the East African Rift, forming ...

(just offshore of the southern tip of the

Sinai Peninsula The Sinai Peninsula, or simply Sinai (now usually ) (, , cop, Ⲥⲓⲛⲁ), is a peninsula in Egypt, and the only part of the country located in Asia. It is between the Mediterranean Sea to the north and the Red Sea to the south, and is a ...

). The fault system forms the transform boundary between the

African Plate The African Plate is a major tectonic plate that includes much of the continent of Africa (except for its easternmost part) and the adjacent oceanic crust to the west and south. It is bounded by the North American Plate and South American Plate ...

to the west and the

Arabian Plate The Arabian Plate is a minor tectonic plate in the Northern and Eastern Hemispheres. It is one of the three continental plates (along with the African and the Indian Plates) that have been moving northward in geological history and colliding ...

to the east. It is a zone of left lateral displacement, signifying the relative motions of the two plates. Both plates are moving in a general north-northeast direction, but the Arabian Plate is moving faster, resulting in the observed left lateral motions along the fault of approximately 107 km at its southern end. A component of extension is also present in the southern part of the transform, which has contributed to a series of depressions, or

pull-apart basin In geology, a basin is a region where subsidence generates accommodation space for the deposition of sediments. A pull-apart basin is a structural basin where two overlapping (en echelon) strike-slip faults or a fault bend creates an area of crus ...

s, forming the

Gulf of Aqaba The Gulf of Aqaba ( ar, خَلِيجُ ٱلْعَقَبَةِ, Khalīj al-ʿAqabah) or Gulf of Eilat ( he, מפרץ אילת, Mifrátz Eilát) is a large gulf at the northern tip of the Red Sea, east of the Sinai Peninsula and west of the Arabian ...

Dead Sea The Dead Sea ( he, יַם הַמֶּלַח, ''Yam hamMelaḥ''; ar, اَلْبَحْرُ الْمَيْتُ, ''Āl-Baḥrū l-Maytū''), also known by other names, is a salt lake bordered by Jordan to the east and Israel and the West Ban ...

Sea of Galilee The Sea of Galilee ( he, יָם כִּנֶּרֶת, Judeo-Aramaic: יַמּא דטבריא, גִּנֵּיסַר, ar, بحيرة طبريا), also called Lake Tiberias, Kinneret or Kinnereth, is a freshwater lake in Israel. It is the lowest ...

, and Hula basins. A component of shortening affects the Lebanon restraining bend, leading to uplift on both sides of the

Beqaa valley The Beqaa Valley ( ar, links=no, وادي البقاع, ', Lebanese ), also transliterated as Bekaa, Biqâ, and Becaa and known in classical antiquity as Coele-Syria, is a fertile valley in eastern Lebanon. It is Lebanon's most important ...

. There is local transtension in the northernmost part of the fault system, forming the Ghab pull-apart basin.

Tectonic interpretation

The DST fault system is generally considered to be a transform fault that has accommodated a 105 km northwards displacement of the Arabian Plate. This interpretation is based on observation of offset markers, such as river terraces, gullies and archaeological features, giving horizontal slip rates of several mm per year over the last few million years. GPS data give similar rates of present-day movement of the Arabian Plate relative to the Africa Plate. It has also been proposed that the fault zone is a rift system that is an incipient oceanic spreading center, the northern extension of the

Development of the fault zone

The Dead Sea Transform began to form during the

Late Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', ...

with epeirogenic movement in the region, with the start of the faulting phase beginning in the

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but t ...

and continuing into the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

. During the

Early Early may refer to: History * The beginning or oldest part of a defined historical period, as opposed to middle or late periods, e.g.: ** Early Christianity ** Early modern Europe Places in the United States * Early, Iowa * Early, Texas * Early ...

Middle Miocene The Middle Miocene is a sub-epoch of the Miocene Epoch made up of two stages: the Langhian and Serravallian stages. The Middle Miocene is preceded by the Early Miocene. The sub-epoch lasted from 15.97 ± 0.05 Ma to 11.608 ± 0.005 Ma (million ...

(23–11.6 Ma), there was a change in plate motions and rifting stopped in the

Gulf of Suez Rift The Gulf of Suez Rift is a continental rift zone that was active between the Late Oligocene ( 28 Ma) and the end of the Miocene (c. 5 Ma). It represented a continuation of the Red Sea Rift until break-up occurred in the middle Miocene, with most ...

. The initial phase of northward propagation reached as far as southernmost Lebanon and was followed by a period in the Late Miocene where continuing displacement across the plate boundary was taken up mainly by shortening in the

Palmyride fold belt The Palmyra fold belt forms fold mountains found mostly in Syria. The mountains are formed due to thrusting together of Aleppo plateau in the north and Rubtah uplift in the south. This is according to the modern theory of plate tectonics. Simila ...

. A total displacement of 64 km has been estimated for this early phase of motion. In the Pliocene the DST propagated northwards once more through Lebanon into northwestern Syria before reaching the East Anatolian Fault.

Sections

Southern section

The southern section of the DST is about 400 km long, extending from the spreading center in the Red Sea at southern end of the Gulf of Aqaba to just north of the Hula basin in southernmost Lebanon.

Gulf of Aqaba

The

was created by movement on four left-stepping

strike-slip fault In geology, a fault is a planar fracture or discontinuity in a volume of rock across which there has been significant displacement as a result of rock-mass movements. Large faults within Earth's crust result from the action of plate tectoni ...

segments in a diagonal stepwise sequence known as

echelon formation An echelon formation () is a (usually military) formation in which its units are arranged diagonally. Each unit is stationed behind and to the right (a "right echelon"), or behind and to the left ("left echelon"), of the unit ahead. The name of ...

. In the areas where these segments overlap, pull-apart basins have developed, forming three bathymetric lows known as the Daka Deep, the Aragonese Deep and the Elat Deep. Parts of three of these faults ruptured during the 1995 Gulf of Aqaba earthquake.

Wadi Arabah

The Wadi Arabah (Arava Valley) segment of the DST extends for about 160 km from the Gulf of Aqaba to the southern end of the Dead Sea. Some researchers have further broken down this segment, recognising two separate segments, Avrona and Arava. The Avrona fault extends from the northern part of the Gulf of Aqaba for about 50 km along the Arava Valley. The Arava fault runs from just north of the Avrona fault segment for about 100 km. A slip rate of 4 ±2 mm per year has been estimated from the offset of gullies across the fault. Four major earthquakes are well documented to have occurred due to movement on this fault in the last 1,000 years, in 1068, 1212, 1293 and 1458.

Dead Sea basin

The Dead Sea is formed in a

due to the left-stepping offset between the Wadi Arabah and Jordan Valley segments. The part of the basin with a sedimentary fill of more than 2 km is 150 km long and 15–17 km wide in its central part. In the north, the fill reaches its maximum thickness of about 10 km. The sequence includes

fluvial

sandstone Sandstone is a clastic sedimentary rock composed mainly of sand-sized (0.0625 to 2 mm) silicate grains. Sandstones comprise about 20–25% of all sedimentary rocks. Most sandstone is composed of quartz or feldspar (both silicat ...

s of the Hazeva Formation overlain by a sequence of Late Miocene to early

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58evaporite An evaporite () is a water- soluble sedimentary mineral deposit that results from concentration and crystallization by evaporation from an aqueous solution. There are two types of evaporite deposits: marine, which can also be described as ocean ...

s, mainly

halite Halite (), commonly known as rock salt, is a type of salt, the mineral (natural) form of sodium chloride ( Na Cl). Halite forms isometric crystals. The mineral is typically colorless or white, but may also be light blue, dark blue, purple, p ...

, the Sedom Formation, and a lacustrine to fluvial sequence of Pliocene to recent age.

Jordan Valley fault

The Jordan valley segment of the DST, the Jordan Rift Valley, runs for about 100 km from the northwestern part of the Dead Sea to the southeastern part of the Sea of Galilee along the Jordan Valley. A slip rate of between 4.7 and 5.1 mm per year has been estimated over the last 47,500 years. The entire segment is thought to have ruptured during the earthquake in 749 and again in 1033, the most recent major earthquake along this structure. The deficit in slip that has built up since the 1033 event is sufficient to cause an earthquake of ~7.4.

Sea of Galilee basin

The Sea of Galilee Basin or Kinneret Basin is a pull apart formed between Jordan valley fault along its eastern edge and a set of smaller faults to the north. The central site of the basin's deepest sedimentary fill (its "depocentre" in geologists' jargon) lies on the eastern side, against the continuation of the Jordan valley fault. The thickness of the fill is estimated as 3 km down to the deepest mapped seismic reflection, correlated with the top of a

basalt Basalt (; ) is an aphanitic (fine-grained) extrusive igneous rock formed from the rapid cooling of low-viscosity lava rich in magnesium and iron (mafic lava) exposed at or very near the surface of a rocky planet or moon. More than 90 ...

layer that was extruded about four million years ago.

Korazim Plateau

Hula basin

The Hula pull-apart basin lies to the north of the Sea of Galilee basin and is formed between several short fault segments. The currently active part of the basin is relatively narrow. The Hula Western Border Fault defines the western side of the basin and splays to the north into several faults, including the Roum fault and the

Yammoune Yammoune is a lake, nature reserve, village and municipality situated northwest of Baalbek in Baalbek District, Baalbek-Hermel Governorate, Lebanon. The village has a few hundred inhabitants. During the 1970s Ali Akbar Mohtashamipur lived in Yamm ...

h fault. The Hula Eastern Border Fault continues northwards from the northeastern part of the Sea of Galilee, forming the eastern edge of the basin and linking eventually to the Rachaya fault.

Lebanon restraining bend

The DST splays within the area of the restraining bend, with several distinct active fault segments recognised.

Yammouneh fault

The Yammouneh fault is the main fault strand within the Lebanon restraining bend, carrying most of the plate boundary displacement. It is SSW-NNE trending and runs for about 170 km from the northwestern end of the Hula Basin to its junction with the Missyaf Fault. It has been the location of several major historical earthquakes, such as the 1202 Syria event. The estimated average slip rate along the Yammouneh fault is 4.0 to 5.5 mm per year, with a major earthquake recurrence interval of 1020 to 1175 years. There have been no major earthquakes since that in 1202.

Roum fault

The Roum fault branches away from the Yammouneh fault at the northwestern part of the Hula Basin. It can be traced from there northwards for about 35 km before becoming indistinct. Movement on this fault has been linked to the 1837 Galilee earthquake. A slip-rate of 0.86–1.05 mm per year has been estimated.

Rachaya-Serghaya faults

This fault zone comprises two main fault strands, the Rachaya and Serghaya faults. The Serghaya fault branches off the Hula Eastern Border Fault, continuing northeastwards to the south of Mount Hermon into the Anti-Lebanon range where it becomes SSW-NNE trending. The fault has a slip rate of about 1.4 mm per year. Movement on this fault is thought to be responsible for the November 1759 earthquake. The Rachaya fault also branches off the Hula Eastern Border Fault, trending SSW-NNE, passing to the north of Mount Hermon. No slip rate has yet been estimated for this fault. The Rachaya fault is the interpreted location of the October 1759 earthquake.

Northern section

The northern section of the DST extends from the northern end of the Yammouneh fault up to the triple junction with the East Anatolian Fault. The over all deformation style is

transpression In geology, transpression is a type of strike-slip deformation that deviates from simple shear because of a simultaneous component of shortening perpendicular to the fault plane. This movement ends up resulting in oblique shear. It is generally ve ...

al, in keeping with the relative plate motions as determined from GPS measurements.

Missyaf fault

This fault segment, also known as the Ghab fault, runs for about 70 km from the northern end of the Yammouneh fault into the Ghab basin. The estimated slip rate for this segment is 6.9 mm per year. Major historical earthquakes interpreted to have occurred along this structure include the >7 events in

AD 115 Year 115 ( CXV) was a common year starting on Monday (link will display the full calendar) of the Julian calendar. In the Roman Empire, it was known as the Year of the Consulship of Messalla and Vergilianus (or, less frequently, year 868 ''Ab u ...

and 1170. No major earthquakes have been recorded since 1170, suggesting that such an event is overdue.

Ghab basin

The Ghab basin was formed in the Pliocene and is interpreted to be a pull-apart basin formed due to the overlap at the left-stepping offset between the Missyaf fault and the Hacıpaşa fault. The basin is about 60 km long and 15 km wide. Based on the interpretation of seismic reflection data and a single well penetration (Ghab-1) the fill of the basin is thought to be entirely Pliocene to recent in age. There are two main depocentres in the basin at the northern and southern end, separated by an intrabasinal high.

Hacıpaşa fault

The Hacıpaşa fault extends from the Ghab basin into the Amik basin. It is thought to carry the bulk of the plate boundary displacement linking through on to the Karasu fault. Major earthquakes in 1408 and 1872 have been linked to movement on this fault.

Karasu fault

The Karasu fault or Amanos fault has SW-NE trend and represents part of the transition from the DST to the East Anatolian Fault. It has an estimated slip rate of 1.0 to 1.6 mm per year for the whole

Quaternary The Quaternary ( ) is the current and most recent of the three periods of the Cenozoic Era in the geologic time scale of the International Commission on Stratigraphy (ICS). It follows the Neogene Period and spans from 2.58 million year ...

. No historical earthquakes have been linked with movement on this fault.

References

Dead Sea transform (DST) study
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