Subsidence Evolution of the Musandam Peninsula & Subsurface Architecture of the Pabdeh Foreland Basin

Abstract

AbstractSurface and subsurface geology of the Musandam Peninsula recorded a tectonostratigraphic evolution of the northeastern Arabian Plate since the late Permian. In order to quantitatively determine this evolution, backstripping method has been applied to two exploration wells located within and around the Musandam Peninsula. The backstripping technique uses stratigraphic data extracted from the wells and quantitatively determines the depth that basement would be in the absence of water and sediment loading. As a result, the tectonically-driven subsidence data allows us to determine basins developed within the study area and their driving-mechanisms to form.The tectonically-driven subsidence data from the wells recorded development of a rifting and two flexural foreland basins. The rifting episode formed in response to a continental breakup and opening of Neo-Tethys Ocean, approximately from ~ 185 to ~ 93 Ma. Heating and stretching of the continental lithosphere at the time of the rifting caused the lithosphere to subside. After this rifting event, the tectonic subsidence curves indicate that the studied area was subjected to evolution of two foreland basins after two uplift events happened around ~ 93 and ~ 25 Ma. We refer these uplifts to the Late Cretaceous Semail Ophiolite obduction and the late Tertiary Musandam culmination, whereby both of them produced lithospheric loads on the top of the northeastern Arabian plate and led to a development of two foreland basins, Aruma (~ 80 to 25 Ma) and Pabdeh (~ 20 to present day), respectively.With the rise of interest for unconventional resources, we have to better evaluate the essential petroleum system elements. Normally, the total subsidence (tectonically-driven plus sediment and water loading) is used to construct the burial history of a basin. Since the backstripping method is able to separate the tectonically-driven subsidence from the total subsidence, we can exactly pinpoint the deposition time of deep-water sediments which can act as a source rock or an impermeable seal. In addition, the tectonic subsidence curve was able to identify precise ages of two uplifts which mark the critical timing of potential structural traps and migration pathways for hydrocarbons.