Nile silt

In most areas of the wadi floor and the low desert area, the Nubian formation is covered by an average of 5-7 m of Pleistocene Nile silts (9). These older Nile sediments represent different episodes in the evolution of the Nile River (10-13), The oldest Nile sediments (called Protonile) in the area, exposed at high (about 125 m above sea level) Pleistocene terraces, were deposited during the Lower to Middle Paleolithic period (10). 

Below the sediments disrupted by cultivation, a unit (Unit A) was found that was about 120 cm thick and that contained a disorderly mixture (almost an inverse time sequence) of Roman, Pharaonic, and Predynastic sherds. The next 15 cm or so was a clay-rich Nile silt (Unit B) in which there was a normal ceramic sequence with sherds dating from about 300 B.C. to about 2500 B.C. Table I describes the typical core sample. The layers of sediments were compacted and, in some cases, partially hardened by a calcareous cement, but in all cases, the samples could be easily crumbled. 

Averages for the 27 bulk samples are given in Table II for some of the elements measured. These averages, called Nile River Sediment Composite (NRSC), are very similar to the averages for modern Nile sediments compiled by Tobia and Sayer (2). This similarity clearly confirms that, other than the variations due to grain size (sand content), the modern Nile silts are quite uniform in composition. 

Yet another example of natural chemical bonding is solidification of desert soils to build bird houses in Egypt. Nile silt was mixed with desert grass and river water to make tower shapes on concrete roofs (Fig. 1.2). Holes made in these towers provide shelter to the birds, which eventually are sold for food. The minerals from such rich soils consolidate when they are mixed with water and are dried in the intense sun of the desert. 

The importance of stratigraphic studies and the identification of sedimentary units at extensively disrupted sites like Hierakonpolis can be illustrated by the excavations at locality II, where there is evidence for habitation (trash mounds and pottery) as well as industry (pottery kilns). This locality ofiered a unique opportunity to study Predynastic ecology because of the excellent state of organic preservation in an area where there was a clustering of multi-functional components (6,14). Four test pits were dug in one area through the site, in the direction NIO °E-SIO °W. The correlation profile is shown in Figure I. The oldest unit identified was Nile silt (Masmas formation). In some areas, this silt was covered by eolian and/or wadi sands, which probably represents a local feature of sand accumulation under arid to semiarid conditions. 

Hassan 16) suggested that grain size parameters of sediments could be used to differentiate among the Nile silts deposited over the last 90,000... 

Table I. Average Concentrations in Nile Silts and Pottery from...

Although the number of samples analyzed is limited, the inescapable conclusion to be drawn from our data is that some of the Nile silt formations can be differentiated on the basis of trace element contents and REE distribution patterns. In addition, we conclude that the Early Predynastic (Amratian) pottery was made from clays found in the immediate vicinity of the kiln. Older shales that are found layered with the much earlier sandstone deposits that were cut by the Great Wadi were also analyzed. The REE patterns as well as the scandium, chromium, and iron concentrations are different enough to suggest that these materials were not used to produce pottery (21), In a previous paper, we discussed the possibility that some of this shale, or the white salt found associated with it (anhydrite-CaSOj, was mixed with the local clay to produce the finer, harder plum red ware (21). This addition could account for the slight difference in the average composition of the sherds from localities 11, 39, and 59 and the Masmas silt. 

---