Interpreting Soft-Sediment Deformation Structures: Insights into Earthquake History and Depositional Processes in the Dead Sea, Jordan

Abstract

Soft-sediment deformation structures (SSDSs) typically form in unconsolidated sedimentary deposits before lithification. Understanding these structures involves evaluating their characteristics, genesis timing, and the dynamics of sediment deformation. SSDSs are essential for deciphering ancient environments, reconstructing depositional processes, and discerning past prevailing conditions. In the Dead Sea region, SSDSs are abundant and well preserved due to unique geological and environmental factors, including rapid sedimentation rates and seismic activity. Influenced by the Dead Sea Transform Fault, the area offers insights into tectonic activity and historical earthquakes predating modern instrumentation. This study extensively examines SSDSs along the Dead Sea area in Jordan, focusing on sediments near the Lisan Peninsula, where the prominent Lisan Formation (71–12 ka) exposes numerous deformations. Mineralogical and geochemical analyses using X-ray diffraction (XRD) and X-ray fluorescence (XRF) were applied on deformed and undeformed layers to test the potential trigger of seismite formation in the Dead Sea area. The XRD and XRF results reveal Aragonite and Halite as the predominant compounds. Field observations, coupled with mineralogical and geochemical data, suggest tectonic activity as the primary driver of SSDSs formation in the Dead Sea region. Other contributing factors, such as high salinity, arid climate, and depositional settings, may also have influenced their formation. These structures offer valuable insights into the region’s geological history, environmental conditions, and tectonic evolution.

Keywords

• soft-sediment deformation
• Dead Sea Transform Fault
• Jordan
• earthquakes
• depositional processes