Deposition of volcanogenic smectite along the southeastern Neo-Tethys margin during the oceanic convergence stage

The clay mineral assemblage within the marine rocks of the synclinal basins of the Syrian arc deformation belt in the northwest of Israel is dominated by smectitic IS (interstratified illite/smectite rich in smectite layers) accompanied by palygorskite and occasional sepiolite. Based on the observation that the smectitic IS originated by conversion of the smectite transported to the synclinal basins from the open marine environment, the present study focuses on the origin of the precursor smectite converted to smectitic IS. It is shown that the majority of the precursor smectite transported to the basins and converted to smectitic IS was derived from argillized marine volcanic rocks and island arcs volcanism when they erupted during the convergence of the Tethys Ocean. It seems that the peak of that volcanic activity was during the Paleocene, where vast amounts of smectite-rich marine sediments were deposited throughout the Middle East. Activity of strong coastal upwelling currents during the Paleocene probably brought to the transportation of the precursor smectite to the southern Tethys margin.