Tectono-Sedimentary Evolution of the Iranian Zagros in a Global Context and Its Impact on Petroleum Habitats

Abstract

Abstract Spatially widespread and extended periods of sedimentation coupled with distinct phases of tectonism resulted in complex stratigraphic relationships on the northeast margin of the Arabian Plate. The Mesozoic and Cenozoic strata were incorporated into the Late Jurassic to present-day tectonic events. This tectono-stratigraphic evolution led to the formation of promising petroleum systems. Most of the explored Zagros areas are structural traps; after more than a century of hydrocarbon exploration, stratigraphic traps have become the focus of exploration. Consolidation of knowledge of regional tectono-stratigraphic evolution of the region is crucial to unlock the remaining potential. The regional architecture of sedimentary basins in central Zagros shows major changes that occurred from the Late Jurassic to the present. Coupled sedimentary and tectonic processes exerted significant controls on the facies and distributions of the strata and associated hydrocarbon systems. Sedimentary architecture and the timing of structural events on the northeast margin of the Arabian Plate were analyzed in this study using seismic profiles, well data, and gross depositional environmental maps. A tectono-sedimentary evolution of the Zagros shows a correlation with changes in the rates and vectors of displacement for the hosting and surrounding plates. Increases in rates and changes in the displacement vectors of the African and Indian Plates since opening of the Atlantic Ocean produced distinct tectonic events together with reactivation of inherited structures on the northeast margin of the Arabian Plate that induced facies changes and stratal variations. Sedimentary processes controlled the strata architectures, sequences, and facies during tectonically quiescent periods that favored the development of intrashelf basins along the margin.