Clay Distributions, Grain Sizes, Sediment Thicknesses, and Compaction Rates to Interpret Subsidence in Egypt's Northern Nile Delta

Abstract

ABSTRACT Stanley, J.-D. and Clemente, P.L., 2014. Clay distributions, grain sizes, sediment thicknesses, and compaction rates to interpret subsidence in Egypt's northern Nile Delta. This study focuses on the role of clay on subsidence of Holocene sedimentary sequences in the northern Nile Delta. Proportions of clay in 1262 samples from 87 cores are much higher here than elsewhere in the delta and along the Nile in Egypt. The northern third of the delta lies at a low, near-horizontal elevation (∼1 m above mean sea level), but clay content and total thickness of Holocene deposits in subsurface vary considerably in time and space. Greatest clay content (to >60%) and mud-rich thickness (to 47 m) are concentrated near Manzala lagoon. The volume of Nile water and sediment discharged annually on the delta diminished during the past two millennia as a result of climate change and intensified human activity. During the past two centuries, barrages and dams placed across the Nile and increased water diversion activ...