Evolution and Propagation of an Active Plate Boundary: U-Pb Ages of Fault-Related Calcite From the Dead Sea Transform

We utilize in situ U-Pb geochronology of fault-related calcite to date faulting activity along the Dead Sea Transform (DST) plate boundary and constrain the evolution of continental breakup. U-Pb ages from 30 well-constrained Tera-Wasserburg data sets of syntectonic calcite precipitates along the northern part of the DST delineate two key periods of faulting activity: (1) Maastricht (latest Cretaceous) to Eocene (70–37 Ma) and (2) middle Miocene (18–10 Ma). The latter period is more extensive and is associated with normal and left-lateral shearing deformation. Ages of ~18 Ma, obtained from the western and eastern most strands (~20 km apart), indicate that branching in the northern DST occurred during the initial stage of the DST development. Comparison of the new ages from the northern part of the DST with U-Pb ages from the southern part highlights prominent faulting activity during the early to middle Miocene (20–10 Ma), with earliest ages of ~18 Ma in the south and younger ages of ~14 Ma in the north. This pattern suggests that the genesis of this plate boundary started adjacent to the Red Sea rift and migrated from south to north during a 3.5–4 Ma period (between 18 and 14 Ma) at an average rate of 11–13 cm/year. Such propagation data can be used to decipher the mechanical evolution of the lithosphere along evolving plate boundaries.