Internal structure of the Dead Sea leaky transform (rift) in relation to plate kinematics

Neotectonics of Turkey – a synthesis

https://www.utdallas.edu/~rjstern/egypt/PDFs/Cenozoic%20Red%20Sea/BosworthRedSeaJAES05.pdf

The Red Sea and Gulf of Aden Basins

On causal links between flood basalts and continental breakup

where pis the p-particle, v is an antineutrino, and Q represents the decay energy (0.275 MeV). The recommended decay constant for 87Rb is 1.42 x 10-11 yr-I (Steiger & Jager 1977), and its half-life T is therefore 48.8 Gyr. On geological time scales, the isotopes 84, 86, and 88 are stable, in contrast to 87Sr, and their abundance ratios are therefore invariant. The present-day quantity of isotope 87 (87Srp) depends on its initial stock (87Sr 0) and the amount of radiogenic Sr generated from decay of 87Rb over time t: 87Srp = 87Sro+87Rb (eAt_I).

Strontium Isotopes in Seawater through Time

The Red Sea forks northwards into the Suez Graben and the Dead Sea-Arava Rift (Fig. 1). The southern part of the latter, about 165 km long, is occupied by the Gulf of Aqaba (Elat). A sinistral strike-slip movement of about 107 km which was suggested to have occurred along the Dead Sea–Arava Rift1–3 is related to the opening of the Red Sea proper1,4–6. The opening of the Red Sea was considered to have taken place in two stages. The various dates proposed for the first movement are: from 41 to 34 Myr (ref. 5), from 29 to 24 Myr (ref. 7) and from 20 Myr onwards6. The second movement is generally dated from 4–5 Myr to Recent. Garfunkel and Bartov8 claimed that the rifting in the Gulf of Suez was well under way in the span of the late Oligocene to early Miocene (30–20 Myr) and that a drastic change in the tectonic regime occurred in the middle Miocene (15–16 Myr). We suggest here, however, that the opening of the Red Sea is younger than 19–22 Myr.

Sinistral movement along the Gulf of Aqaba — its age and relation to the opening of the Red Sea

The tectonic development of the western margin of the Gulf of Elat (Aqaba) rift

The volcanism in the western Arabian plate extends from the Red Sea through the Harrat Ash Shaam system to western Syria, as far north as the Bitlis suture in the Taurides. The Harrat Ash Shaam volcanic system in Jordan consists of northwest-trending dikes and a volcanic field that together encompass a width of 220 km. In terms of width, direction, and age of the main volcanic phases, the system is similar to the Red Sea dike belt. About 130 new K-Ar age determinations show that the ages of the Harrat Ash Shaam system (dikes and flows) range from Oligocene to Quaternary. However, there is a distinct gap in the ages between ∼22 and 13 Ma. This gap coincides with an apparent decrease in volcanism in the Red Sea region from around 20 to 12 Ma. We interpret this 9 m.y. gap as a quiescent period interrupting the volcanic activity in the region and suggest that from ∼22 to 13 Ma, tectonic activity in the Arabian plate was mainly restricted to the Red Sea region. A renewal of volcanism along the western margins of the Arabian plate at 13 Ma was very likely associated with the sinistral movement along the north-trending Dead Sea transform. This renewal of volcanism and tectonic activity may reflect the emergence of upper-mantle upwelling beneath the western Arabian plate at that time.

New K-Ar ages of basalts from the Harrat Ash Shaam volcanic field in Jordan: Implications for the span and duration of the upper-mantle upwelling beneath the western Arabian plate

Thirty samples of Upper Tertiary basalts intruding marine and continental sequences were by the K-Ar method. Four volcanic phases are recorded: (a) 24.8±1.5 Ma of the Raqabat e Na'ame dike in Central Sinai; (b) 20.4±0.7 Ma of basalt intrusions in Central Sinai and the Arava. Some of these are offset by E-W to NE-SW dextral faults of the Central Sinai – Negev Shear Zone; (c) 14.5±0.3 to 4.9±1.3 Ma of basalt flows in the Eastern Galilee and the Coastal Plain; (d) 2.7±0.6 Ma of ‘En Yahav dike. These results contribute to the correlation between Tertiary continental formations from different areas, and put limits on the age of tectonic events, such as folding in the Syrian arc, faulting in the Central Sinai - Negev Shear Zone and shearing along the Jordan Rift.

/pdf/k-ar-age-determinations-of-some-miocene-pliocene-basalts-in-2dss4wcnrh.pdf

K-Ar age determinations of some Miocene-Pliocene basalts in Israel; their significance to the tectonics of the Rift Valley

Detailed monitoring of radon (Rn) flux in gravel was carried out for a period of eight years near the active Dead Sea rift fault. The temporal relationship between hundreds of weak earthquakes (4.6 ≥ ML ≥ 0) and Rn flux signals was tested for time intervals related to the start time of 110 Rn flux signals. Earthquakes located within three pull-apart grabens of the Dead Sea rift valley were found to occur preferentially within the time interval of the first 3 days after the start time of 110 Rn anomalies, and the excess of earthquakes (82% relative to the expected value) is highly significant ( p = .003%). However, a similar relationship is not found in the two weeks preceding or following the start time of the Rn anomalies for earthquakes occurring within the Dead Sea rift in structurally higher segments, or out of the Dead Sea rift.

Gideon Steinitz

Papers

Sinistral movement along the Gulf of Aqaba — its age and relation to the opening of the Red Sea

The tectonic development of the western margin of the Gulf of Elat (Aqaba) rift

New K-Ar ages of basalts from the Harrat Ash Shaam volcanic field in Jordan: Implications for the span and duration of the upper-mantle upwelling beneath the western Arabian plate

K-Ar age determinations of some Miocene-Pliocene basalts in Israel; their significance to the tectonics of the Rift Valley

Statistically significant relation between radon flux and weak earthquakes in the Dead Sea rift valley