Detrital zircon U–Pb–Hf systematics of Israeli coastal sands: new perspectives on the provenance of Nile sediments

Abstract

The Nile drains a large basin covering various source-rock terrains of different age, mineralogical and isotopic characteristics. Its sediments are stored within the Nile delta but significant volumes are swept eastwards in the SE Mediterranean, onto the Sinai–Israeli coasts. Alongside wave transport, aeolian transport plays an important role in recycling the Nile-derived sands. We present new laser ablation inductively coupled plasma mass spectrometry, 882 U–Pb and 586 Lu–Hf analyses of detrital zircons from Quaternary to Recent sands of the Israeli coast and shelf to decipher their provenance. The detrital populations are dominated by 0.56–1.15 Ga zircons with ϵHf(t) of +13 to −27, implying a mixture of juvenile and non-juvenile latest Mesoproterozoic to Neoproterozoic sources. Small populations of Archaean–Palaeoproterozoic and Palaeozoic zircons are also distinguished. The detrital zircon U–Pb–Hf pattern indicates that rather than being sourced from the Arabian–Nubian Shield or older basement terranes in the Nile drainage basin, the sands are dominantly recycling products of older sediments. The detrital zircon U–Pb–Hf spectra resemble those of Cambro-Ordovician sandstones that blanket much of North Africa. These sediments were recycled into younger sand reservoirs that were in turn eroded into the Nile and transported to the coast of Israel. Supplementary material: Details of analytical methods and detrital zircon U–Pb–Hf data are available at www.geolsoc.org.uk/SUP18677 .