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.
Table of Contents
Introduction -- Study area -- Foraminifera -- Methods -- Results -- Discussion -- Conclusion -- Appendix A. Foraminifera spreadsheet -- Appendix B. Foraminifera graphs -- Appendix C. Grain size -- Appendix D. Matrix composition -- Appendix E. Core lithology and field description
Degree
M.S.