3-D density modelling of underground structures and spatial distribution of salt diapirism in the Dead Sea Basin

Abstract

S U M M A R YA new compilation of Bouguer gravity data stemming from airborne, shipborne and terrestrial data set in the entire Dead Sea Basin (DSB) was reinterpreted by applying 3-D density modelling that incorporated independent information on other geophysical researches allowing for regional and residual filtering in the gravity field, carrying out curvature analysis and Euler deconvolution of the combined gravity field. 3-D density modelling enables us to detailed resolution of upper crustal structures from the southern to the northern subbasin below the saline Dead Sea. 3-D gravity modelling led to the identification of three salt structures, which are found beneath the Sedom area, the Lisan Peninsula and the Dead Sea. In the vicinity of the western margin of the Dead Sea, a salt diapir segment with a thickness of about 4 km has been identified at a top depth of about 2 km, which has not been recognised by any other geophysical interpretations. The thickness of the sedimentary infill overlying the basement in the DSB decreases from 14 km in the vicinity of the Lisan Peninsula to 8 km in the northern and the southern subbasins. Large negative gravity anomalies (lower than -100 × 10 −5 m s −2 ) observed in the DSB correspond with the spatial distribution of salt diapirism with an average density of 2 100 kg m −3 . The shallower microearthquakes registered in the DSB are related to the movement of salt diapir in the DSB.

Crustal metamorphic fluid flux beneath the Dead Sea Basin: constraints from 2-D and 3-D magnetotelluric modelling

“…Geophysical studies (gravity and seismics) conducted in and in the vicinity of the DSB suggest a sedimentary thickness of approximately 6-8 km for the northern sub-basin (Ten Brink et al 1993;Choi et al 2011). A southward drop-down along the Boqeq normal fault could result in deposition of an additional 4 km of sediments into the southern sub-basin (Ben-Avraham & Schubert 2006).…”

“…Other density modelling studies carried out in the framework of DESIRE project suggest a smaller volume of sedimentary basin infill. Choi et al (2011) estimated a thickness of 14 km in the vicinity of the Al-Lisan Peninsula, and thicknesses of approximately 8 km towards the northern and southern sub-basins. The Al-Lisan and Sedom salt diapirs appear as pronounced features in both mentioned density studies.…”

The association of micro‐earthquake clusters with mapped faults in the Dead Sea basin

“…The DSB has been active since the Miocene and has accommodated the majority of the total > 100 km left‐lateral motion in this area [ Garfunkel , ; ]. Several geophysical studies in the DSB reveal a partial picture of the crustal structure [e.g., ten Brink et al ., ; Ginzburg and Ben‐Avraham , ; ten Brink et al ., ; Choi et al ., ; ten Brink and Flores , ]. Seismic reflection surveys in particular provide a tool for identifying faults within the top few kilometers of the upper crust [ Neev and Hall , ; Kashai and Croker , ; Gardosh et al ., ; Ginzburg et al ., ].…”

Teleseismic traveltimes residuals across the Dead Sea basin

“…Choi et al . [] applied 3‐D density modeling to new compilations of airborne, shipborne, and terrestrial data sets of Bouguer gravity of the entire DSB. They identified three main salt diapirs: one in the northern Dead Sea subbasin, the Lisan diapir and Mount Sodom diapir.…”

“…Our estimate is larger than the estimate of Al‐Zoubi and ten Brink [], but with better agreement with the results of Choi et al . [] and Meqbel et al . [] (see Table ).…”