17 research outputs found
Deformation of intrasalt beds recorded by magnetic fabrics
Funding Information Israel Science Foundation (ISF). Grant Number: 868/17 Israeli Government. Grant Number: 40706 Israel Science Foundation. Grant Number: 868/17Peer reviewedPublisher PD
Localisation and temporal variability of groundwater discharge into the Dead Sea using thermal satellite data
Detrital zircon and rutile UâPb, Hf isotopes and heavy mineral assemblages of Israeli Miocene sands: Fingerprinting the Arabian provenance of the Levant
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Quaternary rise of the Sedom diapir, Dead Sea basin
Mount Sedom is the surface expression of a salt diapir that has emerged since the Pleistocene in the southwestern part of
the Dead Sea basin. Milestones in the uplift history of the Sedom salt diapir since its inception were deduced from angular
and erosional unconformities, thickness variations, caprock formation, chemistry and isotope composition of lacustrine aragonite,
cave morphology, precise leveling, and satellite geodesy. Thickness variations of the overburden observed in transverse seismic
lines suggest that significant growth of the Sedom diapir may have initiated only after this thickness exceeded âŒ2400 m in
the Late Pliocene. The formation of the caprock signifies the arrival of the Sedom diapir from depth to the dissolution level
between 300,000â100,000 yr B.P. During this period and later, angular and erosional unconformities in the upper part of the
overburden near Mount Sedom are attributed to the piercing diapir. Rapid solution of rock salt from parts of Mount Sedom inundated
by Lake Lisan after ca. 40,000 yr B.P. is inferred from Na/Ca ratios in aragonite and their relation to ÎŽ 13 C. On the mountain itself, the older parts (70,000â43,000 yr B.P.) of the lacustrine Lisan Formation are missing. The top
of the preserved sediments is covered by alluvial sediments that must have been deposited when the elevation of Mount Sedom
was not higher than 265 m below sea level (mbsl) at ca. 14,000 yr B.P. The present elevation of these sediments at 190 mbsl
indicates an average uplift rate of âŒ5 mm/yr over the past 14,000 yr. Similar uplift rates of 6â9 mm/yr are inferred for the
Holocene from displacement of the âsalt mirrorâ and hanging passages of caves. The present uplift rate, calculated from precise
leveling and interferometric synthetic aperture radar (InSAR), is similar to the average Holocene rate. Based on the gathered
data, we reconstruct the topographic rise of Sedom diapir and its relation to lake level variations during the late Pleistocene
and Holocene
Stress tensor and focal mechanisms in the Dead Sea basin
We use the recorded seismicity, confined to the Dead Sea basin and its boundaries, by the Dead Sea Integrated Research (DESIRE) portable seismic network and the Israel and Jordan permanent seismic networks for studying the mechanisms of earthquakes in the Dead Sea basin. The observed seismicity in the Dead Sea basin is divided into nine regions according to the spatial distribution of the earthquakes and the known tectonic features. The large number of recording stations and the adequate station distribution allowed the reliable determinations of 494 earthquake focal mechanisms. For each region, based on the inversion of the observed polarities of the earthquakes, we determine the focal mechanisms and the associated stress tensor. For 159 earthquakes, out of the 494 focal mechanisms, we could determine compatible fault planes. On the eastern side, the focal mechanisms are mainly strike-slip mechanism with nodal planes in the N-S and E-W directions. The azimuths of the stress axes are well constrained presenting minimal variability in the inversion of the data, which is in agreement with the Eastern Boundary fault on the east side of the Dead Sea basin and what we had expected from the regional geodynamics. However, larger variabilities of the azimuthal and dip angles are observed on the western side of the basin. Due to the wider range of azimuths of the fault planes, we observe the switching of sigma(1) and sigma(2) or the switching of sigma(2) and sigma(3) as major horizontal stress directions. This observed switching of stress axes allows having dip-slip and normal mechanisms in a region that is dominated by strike-slip motion