Mass transport in Eocene pelagic chalk on the northwestern edge of the Arabian platform, Shefela area, Israel

Abstract

Glides, rotational slumps, debris‐ and mud‐flows occur in the Eocene pelagic chalk of the Shefela region, Israel. The pelagic lithofacies are present from the beginning of the Eocene, but mass transport is initiated only in the latest early Eocene and the early middle Eocene. Slight steepening of the palaeoslope, coupled with increased sedimentation rate and early diagenetic changes lowering inherent strength, led to gravity‐induced mass transport in the poorly consolidated pelagic sediments. Instability of the sediment pile was enhanced by underconsolidation and development of spacious packing associated with a relatively high rate of deposition and low initial strength due to high content of siliceous micro‐biota. The palaeogeographic position indicated by the mass‐transport features is the steepened, distal part of the ramp‐like continental margin of the Arabian Platform. Distal steepening of the ramp as part of regional downwarping is coincident with reactivation of Syrian Arc folding, reflecting northward convergence of the Arabian Plate during the Eocene.

History of faulting and magmatism in the Galilee (Israel) and across the Levant continental margin inferred from potential field data

“…Continuous subsidence of the Arabian plate during this time caused its largest transgression since the Jurassic, with deposition mainly of pelagic chalk, and limestone in shallower environments (Avedat Group). The ramp-shaped Levant margin (Buchbinder et al, 1988) stabilized approximately in late Middle Eocene.…”

Oligocene regional denudation of the northern Afar dome: Pre- and syn-breakup stages of the Afro-Arabian plate

“…65-40 Ma; Segev et al, 2011), when continuous thermal subsidence of the Arabian plate enabled the largest transgression since Jurassic times. The regional subsidence was accompanied by slope failures exhibited by intraformational Eocene conglomerates as well as by widespread submarine mass transport (Buchbinder et al, 1988).…”

The English Chalk and London Clay: two remarkable British bony fish Lagerstätten

“…Mean sedimentation rates are estimated at 25 mm ka 21 and there is abundant evidence (in the form of body and trace fossils) of both benthic organisms that would have scavenged fish carcasses on the seafloor and burrowers that would disrupt shallowly buried remains. Classic views of chalk formation entail a gentle pelagic rain, but it is now clear that deposition of the Chalk and similar deposits elsewhere was dynamic (Bromley & Ekdale 1987;Buchbinder et al 1988;Esmerode et al 2008). Although diagnostic features of mass sediment transport in chalk deposits have been identified, these cannot easily be detected in museum specimens.…”