Publication Date:
2018-03-12
Description:
We study the sedimentary record of past tsunamis along the coastal area west of Alexandria (NW Egypt) taking into account the occurrence of major historical earthquakes in the eastern Mediterranean. The two selected sites at Kefr Saber (~ 32-km west of Marsa-Matrouh city) and ~ 10 km northwest of El Alamein village are coastal lagoons protected by 2 to 20-m-high dunes parallel to the shoreline. Field data were collected by: (1) Coastal geomorphology along estuaries, wedge-protected and dune-protected lagoons, and (2) identification of paleotsunamis deposits and their spatial distribution using five trenches (1.5-m-depth) at Kefr Saber and twelve cores (1 to 2.5-m-depth) at El Alamein. Detailed logging of sedimentary sections were analysed using X rays, grain size and sorting, total organic and inorganic matter, bulk mineralogy, magnetic susceptibility and radiocarbon dating necessary for the identification of past tsunamis records. Generally of low energy, the stratigraphic succession made of marine and alluvial deposits includes intercalated high-energy deposits made of mixed fine and coarse sand with broken shells, interpreted as catastrophic layers correlated with tsunami deposits. Although the radiocarbon dating of 46 samples consist in mixed old (〉 13 000 year BP) and young (
Electronic ISSN:
2195-9269
Topics:
Geography
,
Geosciences
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