Late Holocene Paleoclimate reconstruction of the northern Gulf of Aqaba using foraminifera as a proxy

Abstract

A multiproxy analyses of sediment from a 4.3 m core extracted from 25 m water depth on the shelf of the northern Gulf of Aqaba suggest shifts in depositional environments over the past 4000 yrs. Foraminifera assemblages, grain-size distribution, sediment characterization, and radiocarbon age dating indicate several eco-stratigraphic zones including two periods of aridity from ~3900 to 2900 yr BP and ~1130 yr BP to present, a transitional period from ~2900 to 2500 yr BP, and an abrupt shift to wetter conditions between ~2500 to 1130 yr BP. Furthermore, this study records two foraminifera-barren horizons at 170 and 190 cm that correlate to grain size anomalies at that depth. A tsunami wave generated sometime during 2200-1800 yr BP is one possible explanation for this occurrence. Seismic stratigraphy indicates a reflector at approximately 3 m below the seafloor that delineates the boundary between a relict, coral fringing reef horizon, U8, and the overlying U9 strata. Sedimentation rates that adjust for sediment compaction suggest the sequence lies near the foraminifera-barren horizons at ~200 cm in the core. These data signify a dramatic environmental event possibly corresponding to reef termination on the Northern Gulf of Aqaba shelf.