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

• Published in: Tectonophysics Vol. 848; p. 229718
• Main Authors: Segev, A., Schattner, U.
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 05-02-2023
• Subjects: Continental transform; Dead Sea Fault; Harrat-Ash-Shaam Volcanic field; Irbid Rifting; Levant; Magmatism; Dead Sea Fault; Magmatism; Continental transform; Harrat-Ash-Shaam Volcanic field; Levant; Irbid Rifting
• ISSN: 0040-1951; 1879-3266
• DOI: 10.1016/j.tecto.2023.229718

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.
(a) Main tectonic and volcanic elements in the northwestern Arabian plate (after Segev et al., 2014 and Downs et al., 2019). DSF - Dead Sea Fault, HAS - Harrat-Ash-Shaam. Volcanic fields (Harrats) in gray. Black lines mark main faults and the location of Irbid rift, double-headed arrows – extension. Red frame marks the location of the study area presented in (b). CYA – Cyprus Arc(b) Simplified distribution of volcanism since the Miocene in the Galilee showing general northward younging (after Wetzler et al., 2022). Yellow-black line marks the DSF location as interpreted in the current study. Circle size represents volcanism intensity and extent. Kin – Kinneret (Sea of Galilee), CF – Carmel fault, GF – Gilboa fault. (c) Elevation map of the study area overlaid by the distinct structural blocks interpreted here (thick white lines), location of volcanic centers, main faults (black lines), and the new trace of the DSF according to the present study (yellow-black line). Gray arrows indicate the volcanic drainage directions suggested here, from the DSF shoulders into its axial valley. KD – Kinneret Diagonal fault, HD – Hula diagonal fault, DP – Dalton Plateau. [Display omitted]
•Sinistral trans-pressure motion along N-trending DSF prevents on-transform volcanism.•Ongoing extension across NE-trending Irbid rifting promotes off-transform volcanism.•DSF Pliocene reorganization formed paired releasing-restraining bends.•We redefine the DSF trace and tectono-magmatic development in the study area.