Wednesday, February 17, 2010
The Dead Sea Fault is a Left lateral transform plate boundary, separating the Arabian plate and the Sinai sub-plate and has been active since the Miocene, with movement still occurring in present day. (Fig. 1). (Garfunkel, 1981). This fault zone lies within the Dead Sea graben of which this post will focus upon. More specifically, depositional attributes of the laminated layers that comprise the sedimentary record of the Dead Sea and how those layers can serve as a portal into the past regarding paleo-seismic events.
Syndepositional faulting in the Dead Sea sediments has been interpreted as when (Marco et al, 2004) a fault offsets a surface creating subaqueous scarp. The top of the sediment is deformed due to liquefaction and suspension during a seismic event, and a mixed layer forms on both sides of fault scarp. After the suspended sediments resettle, the mixed layer in down-thrown block is slightly thicker. As further sedimentation ensues, a thicker sequence accumulates on down-thrown block. The lower mixed layer in the downthrown block is also bent and overlain by folded layers.
Bookman (Ken-Tor), R., Enzel, Y., Agnon, A. and Stein, M. 2004: Late Holocene lake levels of the Dead Sea. GSA Bulletin 116, 555 71.
Garfunkel Z (1981) Internal structure of the Dead Sea leaky transform (rift) in relation to plate kinematics. Tectonophysics 80:81-108
Marco, S., and Agnon, A., 1995. Prehistoric earthquake deformations near Masada, Dead Sea graben. Geology, 23: 695-698.