Three-dimensional P-wave model of the shallow crustal structure, a complementary method for detecting a trapped hydrocarbon: A case study in the DehDasht region, SW Iran

Abstract Local P-wave tomography is an efficient method to study geologically complex areas where the seismic exploration methods are not ideal for unraveling shallow crustal heterogeneity due great thickness of evaporitic deposits. Despite geological features in salt-rich DehDasht region, SW Iran, we used more than 11 000 micro-earthquake events, which have been recorded by a temporary network (deployed between October 18th, 2016, and July 1st, 2017), derive three-dimensional velocity structure based on first arrival time. We selected subset events (1571 micro-earthquakes) various strict criteria our processing, then 1D model was calculated computer program VELEST. Afterward, 3D initial inversion procedure with 1.5 km horizontal 1 depth intervals parametrized using model. Finally, observed data (first traveltimes locations) inverted optimum regularization parameter iteration SIMULPS14. Our tomographic results indicate basin as relatively low-velocity zone filled out dominantly Gachsaran Formation surrounded high-velocity Asmari-Pabdeh-Sarvak Formations. The has bowl shape that elongated NW-SE direction or oval view. varies 3–5 contains many folding-faulting systems, lead locally patches. Moreover, some evaporate deposits, overlying Formation, emerge thin layer (e.g. Aghajari, etc.).