Towards Thermomechanical Model of the Entire Dead Sea Transform

Dead Sea Transform (DST) fault system is a part of the Syrian-African rift system and it extends from the divergent plate boundary of Red Sea rift at the south to the convergent plate boundary in the Taurus Mountains at the north. DST is a left-lateral transform fault, accommodating differential motion between African and Arabian plates. The Eulerian pole of the relative plate motion is defined at 32.8° N 22.6° E. The morphology of the DST fault system is expressed by several linear stretches separated by a number of pull-apart basins, where the Dead Sea is a largest. Our previous models (Sobolev et al. 2005, Petrunin and Sobolev, 2006,2008) have been focused at two main topics: (1) major controls of the fault localization in strike slip settings and (2) major controls of the structure and evolution of pull-apart basins located at strike- slip faults. To do so, we use realistic elasto-visco-plastic temperature and stress dependent rheology to model lithospheric deformations. The largest limitation of our models appears to be their relatively small size, which does not allow including the source of the strike-slip motion in the region, which is likely opening of the Red Sea Rift, and major obstacle for the propagating fault resulting in its bending in Lebanon. In present work we extend the model to the larger region. The new model domain includes north-western part of the Red Sea and extends to the Lebanon Mountains in the north where deformation becomes more complicated and large part of the strike-slip motion becomes distributed. Because of the significant size of the domain, we made an improvement in the modelling technique taking into account sphericity of the Earth surface. Here we will show first results of our modelling aimed at revealing controls of localisation of the DST and origination of the chain of pull-apart basins in its southern part and transpression in the Lebanon.