2007 GSA Denver Annual Meeting (28–31 October 2007)

Paper No. 47
Presentation Time: 1:30 PM-5:30 PM

TEXTURAL CHARACTERIZATION OF SANDS COLLECTED FROM ARCHEOLOGICAL SITES NEAR ASWAN, SOUTH EGYPT


ACEVES, Danae, División de Ciencias de la Tierra, Facultad de Ingeniería, Universidad Nacional Autónoma de México, Ciudad Universitaria, Mexico D.F, 04510, Mexico, CARVAJAL-MORENO, Magda, Instituto de Biología, Universidad Nacional Autónoma de México, Ciudad Universitaria, México D.F, 04510, Mexico and CENTENO-GARCIA, Elena, Instituto de Geologia, Universidad Nacional Autonoma de Mexico, Ciudad Universitaria, Mexico D. F, 04510, Mexico, tilaphair@hotmail.com

Sand samples were collected from the main archeological sites near Aswan, and at Lake Nasser and islands, as well as from Luxor. They studied under the binocular microscope in order to characterize their texture and composition. Point counting was carried out from nine samples, and a total of 100 points were recorded for roundness, mineral composition and size. Overall the samples show similar abundances of rounded vs angular fragments, except for samples from Nubia and Luxor that show between 42 to 49% of angular grains. Lake Nasser sample contains the highest percentage of well rounded grains. The rest of the samples, that come from Horenheb Temple in Aswan, the Sahara desert, Philos Island, Pilae and the Obelisk in Aswan, show equivalent percentages of angular (20-35%), subangular (10-35%), subrounded (22-35%) and well rounded (21-37%) sand grains. Samples are very well sorted to well sorted (standard deviation between 0.25 to 0.40 , and average size is medium to very fine sand (4 to 2and few grains >1.5). Clasts are mostly made up of quartz, but feldspar, iron minerals, zircon and mica are also present. There are few rocks fragments, mostly made up of limestone and very fine-grained sandstone. The rounded grains have textural characteristic of sediments transported by the wind. In contrast, sub angular to angular grains do not show evidence of mayor abrasion, therefore they may have been transported by water, as suspended load. Thus we suggest that sands in the studied area are the result of a mixture eolian sands and suspended sand grains transported by the Nile River. Other possible explanation for the occurrence of angular sand grains around Aswan is that they may have been derived from local granite sources (Aswan quarries).