Paleo-shoreline changes in the northwestern Persian Gulf during the Holocene

Abstract

The Persian Gulf and the fertile plains of Mesopotamia are the subject of archaeological, sedimentological, and sea-level studies for more than two centuries. However, the complex tectonic setting and coastal morphology around the Persian Gulf have led to conflicting estimation of relative sea-level changes in this region during the Holocene. We analyzed the lithological and geochemical characteristics of several sediment cores from the Lower Khuzestan plains, northwest of the Persian Gulf, to reconstruct the regional facies and environmental changes, and eventually sea-level evolution during the Holocene. Our results show that sedimentary environments changed with transgression and regression phases and the migration of paleo-shorelines, forming internal water bodies, wetlands, flood basins, and playas. We find four distinct relative sea level micro-sequences, during the early Holocene until about 9000 years before present (9 ka BP), early to mid-Holocene between about 9 and 7 ka BP, mid-Holocene between 7 and 4 ka BP, and late Holocene since ∼4 ka BP. Maximum sea-level during these micro-sequences reached −10 m above sea-level (masl), −3 masl, +1 masl, and +3 masl, respectively. Our study underscores the role of local sedimentation processes in modulating the effect of relative sea level changes, and ultimately in shaping the Holocene landscape of southeastern Mesopotamia.