Why does volcanism associated with the Dead Sea fault occur only along its crossing with the Irbid rift and Harrat Ash-Shaam volcanic field?

Abstract

The N-trending Dead Sea Fault (DSF) transform plate boundary developed since the Early Miocene (∼20 Ma) by progressively separating Sinai from the Arabian plate. Volcanic activity accompanying the DSF displacement occurred mainly along its intersection with the older NW-trending Irbid rift and Harrat-Ash-Shaam (HAS) volcanic field. Most studies associate the volcanism pre ∼13 Ma with HAS rooting (i.e., off-transform) and post ∼13 Ma with DSF faults (i.e., on-transform). We challenge this consensus by reviewing and re-examining the DSF structural architecture, the location of eruptive centers, and volcanic rock accumulation through integrating stratigraphic, geophysical, and tectonic evidence. Our results indicate that since ∼13 Ma, trans-pressure increased across the DSF of northern Israel, while Irbid rifting and HAS volcanism continued. In contrast to the prevailing paradigm, we show that the DSF architecture prevented magma ascent from forming on-transform volcanism. Meanwhile, ongoing HAS rooting and Irbid rifting promoted off-transform volcanism, some of which have descended over the steep topography into the DSF valley. These conclusions are a game-changer in understanding the DSF evolution and its equivalent transform plate boundaries worldwide since the DSF is an extensively cited analog.