238-1 SUITABLE SUBSEA SAND-RICH BORROW AREAS TO REPLENISH ERODED BEACHES OF EGYPT’S NILE DELTA

Session: Recent Advances and New Voices in Marine and Coastal Geoscience

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This coastal and marine text focuses on tracing advances proposed in studies on the seaward transport of land-sourced sediment to and beyond the Nile Delta coast and shelf, and then further northeastward across deeper waters of the Mediterranean. Various sources of recent and ongoing sedimentation are proposed beyond Egypt’s lacustrian-fluvial deposits and how some of these can now be traced in a seaward direction the northeast, well into the Mediterranean beyond coastal Egypt.  Our goal herein is to map advances in sediments originally derived from lacustrian and fluvial terrains, south of the Aswan High Dam near the Mediterranean coast, to areas seaward on the continental shelf until present time, for more than 300 km.

Long-term examination of offshore borehole data collected at sites seaward of the Nile Delta to study coastal and inner-shelf evolution was integral to this exercise. We identified new coarse-grained materials, together with dense heavy minerals displaced onto eroded coastlines.  Until now, this strategy has been helpful as a means of tracing sediment transported seaward and retained offshore. Heavy minerals cannot be neglected, since they are considered critical to sea-floor mapping and interpretations of marine environment displacements mapped in this region.Our studies reveal the extent to which beaches and other land-source materials are being actively eroded and displaced seaward and now require almost complete replacement with denser materials for the protection and maintenance of these former beach and offshore environments. It is of note that the north-trending lacustrian and fluvial lake systems onshore provide useful information needed to interpret displacement of water and sediments that reach the marine continental shelf. Evaluation of coarser and denser materials, such as heavy minerals, provide a productive means for identifying and improving coastal protection systems on land and offshore to limit long-term displacement of sediment sequences in this region identified to date.

Geological Society of America Abstracts with Program. Vol. 57, No. 6, 2025

doi: 10.1130/abs/2025AM-6326

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