Tectonic and Geologic Evolution of Syria

Abstract

Using extensive surface and subsurface data, we have synthesized the Phanerozoic tectonic and geologic evolution of Syria that has important implications for eastern Mediterranean tectonic studies and the strategies for hydrocarbon exploration. Syrian tectonic deformation is focused in four major zones that have been repeatedly reactivated throughout the Phanerozoic in response to movement on nearby plate boundaries. They are the Palmyride Mountains, the Euphrates Fault System, the Abd el Aziz-Sinjar uplifts, and the Dead Sea Fault System. The Palmyrides include the SW Palmyride fold and thrust belt and two inverted sub-basins that are now the Bilas and Bishri blocks. The Euphrates Fault System and Abd el Aziz-Sinjar grabens in eastern Syria are large extensional features with a more recent history of Neogene compression and partial inversion. The Dead Sea transform plate boundary cuts through western Syria and has associated pull-apart basins. The geological history of Syria has been reconstructed by combining the interpreted geologic history of these zones with tectonic and lithostratigraphic analyses from the remainder of the country. Specific deformation episodes were penecontemporaneous with regional-scale plate-tectonic events. Following a relatively quiescent early Paleozoic shelf environment, the NE-trending Palmyride/Sinjar Trough formed across central Syria in response to regional compression followed by Permian-Triassic opening of the Neo-Tethys Ocean and the eastern Mediterranean. This continued with carbonate deposition in the Mesozoic. Late Cretaceous tectonism was dominated by extension in the Euphrates Fault System and Abd el Aziz-Sinjar Graben in eastern Syria associated with the closing of the Neo-Tethys. Repeated collisions along the northern Arabian margin from the Late Cretaceous to the Late Miocene caused platform-wide compression. This led to the structural inversion and horizontal shortening of the Palmyride Trough and Abd el Aziz-Sinjar Graben.

Crustal Structure Across the Central Dead Sea Transform and Surrounding Areas: Insights Into Tectonic Processes in Continental Transforms

“…Approximately 7 km deep basement was also interpreted based on published isopach maps constructed from seismic reflection profiles (Meiler et al., 2011), regional gravity models (Rybakov & Segev, 2004; Segev et al. (2014), and gravity studies in southern Syria (Brew et al., 2001). Top basement in our models dips by about 0.5 km toward the DST within ∼15 km of the plate boundary, which is smaller than the amount of basement dip in Meiler et al.…”

“…(2011), and mid‐crustal and Moho depth estimates in Syria (Brew et al. (2001) and the Mediterranean Sea (Netzeband et al., 2006) (white markers and green dots, respectively in Figure 6d). The gravity model of the depth to Moho under the seismic line is anchored by the estimated Moho depths in Syria (Brew et al., 2001) and under the Levant Basin (Netzeband et al., 2006).…”

“…The gravity model of the depth to Moho under the seismic line is anchored by the estimated Moho depths in Syria (Brew et al, 2001) and under the Levant Basin (Netzeband et al, 2006). In addition, the upper/lower crustal interface follows the depth estimate of Brew et al (2001) and it is assumed to be horizontal. A horizontal interface only shifts the calculated gravity anomaly by a constant value but does not affect the shape of the anomaly.…”

“…The following constraints were used: Layer thickness along the seismic profile follows the depth and shape of the forward model layers on land (dashed blue line in Figure 6c), layers extracted from a database of gridded seismic reflection horizons offshore (Gardosh et al, 2008) (dotted blue lines in Figure 6c), the thickness of basalt layer in Dafny et al, 2003, the depth to basement in the Golan Heights from seismic reflection data of Meiler et al (2011), and mid-crustal and Moho depth estimates in Syria (Brew et al (2001) and the Mediterranean Sea (Netzeband et al, 2006) (white markers and green dots, respectively in Figure 6d). The gravity model of the depth to Moho under the seismic line is anchored by the estimated Moho depths in Syria (Brew et al, 2001) and under the Levant Basin (Netzeband et al, 2006). In addition, the upper/lower crustal interface follows the depth estimate of Brew et al (2001) and it is assumed to be horizontal.…”

A validated geomechanical model for the strike-slip restraining bend in Lebanon

“…The SE side of Anti-Lebanon is positioned next to reactivated structures of the Palmyrides. According to 54 , folds created during structural inversion and shortening result in fault-propagation folding. Faults reaching the surface were extrapolated to a 60 degrees dip, and their depth was defined proportionally to the amount of reactivation observed at the surface.…”