Paleoseismicity of Western Tethyan Eocene foreland basin margin, Rab Island, Croatia
Authors: Marjanac, Tihomir; Marjanac, Ljerka; Čalogović, Marina
Authors and affiliation
Abstract
Eocene paralic and incised-valley sediments of eastern Adriatic Rab Island, as a part of western Tethys, comprise 23 horizons of soft- and brittle-sediment deformations interbedded with undeformed shoreface heterolithic sediments and estuarine tidal sandstone bodies. The deformed sediments span in thickness 0.5-8 m, and can be traced for 0.5 km. The soft-sediment deformations include: pseudonodules, flame structures and abiotically homogenized sediments, whereas brittle-sediment deformations consist of sand-injection dykes, small-scale faults and sand wedges The studied succession of Rab Island sandstones documents Eocene paleoseismicity characterized by major seismic events possibly reaching M7 magnitude. Their epicenters were probably located over 100 km from the study area, but some may have been also on Rab Island itself as inferred from synsedimentary kink folds and associated blind thrust faults.
Keywords
Paleogene; Dinarides; sedimentary rocks; seismites; liquefaction