The Analytical Approach Ralph O. Allen Hany Hamroush Department of Chemistry University of Virginia Charlottesville, Va. 22901
Michael A. Hoffman Earth Sciences and Resources Institute University of South Carolina Columbia, S.C. 29208
Nekhen, later referred to by the Greeks as Hierakonpolis, was the legendary home of the first pharaohs of Egypt (ca. 3100 B.C.). Substantial evidence indicates that the site was also occupied during the Predynastic period (5000-3200 B.C.). Many extensive cemetery and habitation sites of the Predynastic cultural periods are located far from the recent Nile flood plain in one of the two wadis. Now desertlike, these wadis were formed during less arid times by erosion of the older Pleistocene Nile sediment deposits (40,000-20,000 B.C.) and the even older Cretaceous sedimentary deposits of the Nubian formation. Later the inhabited area shifted to a more urban settlement area nearer to the Nile. In the middle of what had once been the water course from the larger or Great Wadi, English archeologists discovered the buried remains of an ancient temple. Near the ancient temple at Nekhen they recovered a ceremonial palette commemorating the unification of Upper and Lower Egypt under Narmer, the first pharaoh. Knowing why this particular site was occupied during the late Predynastic period (ca. 3500-3100 B.C.) through the earliest Dynastic period (3100-2700 B.C) and why the population center shifted may help archeologists understand why Nekhen became the capital city of the first nation state. The area surrounding the temple at Nekhen, today called Kom El-Ahmar, is difficult to study because it is within the modern flood plain and covered by thick sedimentary deposits that have accumulated over the past several thousand years. These deposits are difficult to distinguish from one another; they can be affected by natural processes (erosion and deposition) and by the activities of the local inhabitBlack-topped Plum Red Ware (opposite) manufactured at Hierakonpolis. Most often it held artifacts placed in the tombs of important people during the Predynastic period
Unit A
CHK14 300 B.C.
Protodynastic Predynastic
Figure 1. Relationship among the sediment layers found in the vicinity of the ancient temple of Nekhen with the approximate dates of deposition of the sediments CHK5 and CHK14 are two of the cores, and THK1 is one of the trenches dug during the excavation
ants because they are within the present cultivation zone. Reliance on purely stratigraphie methods can lead to misinterpretations because of human use over the thousands of years that the area was occupied. Investigation of deposits at Kom ElAhmar is further complicated by the high water table, which prevents extensive excavation to the earliest occupation levels. However, during field work in 1984, special techniques were introduced that allowed excavations to be made below the water table along a series of trenches and cores. The results of these efforts revealed a complex pattern of sediments deposited during the extensive period the site was occupied. The sequence of pottery artifacts deposited in the sediments gives a reliable method of dating the sediments. Such pottery provides evidence for the continuous occupation of the site at the very time the nation state was developing, beginning in the Predynastic period and extending through the early Dynastic period. Figure 1 illustrates several discontinuities in the sedimentary layers that were recognized in the field. However, it was difficult to distinguish the sediments on the basis of their physical appearance and correlate them with
different cores and with other sediments in the area. When these materials were brought back to the laboratory for analysis, it was clear that determining the relationships among these sediments and other sedimentary units would require an analytical approach combining geochemical and sedimentological knowledge with detailed analysis of the sediments. River sediments
River sediments are a complex mixture of mineral fragments weathered by the rocks in the drainage basin of the river. The chemical altering of minerals to form clays and the tumbling of mineral grains, which grinds them into smaller particles, are both processes that tend to homogenize the sediments. Therefore, the chemical composition of the sediments is usually taken to represent an average of the composition of rocks in the drainage region. Because the homogenization process also affects the trace elements, trace analysis is not normally an effective way of distinguishing the various deposits of sediments from the same river. However, over the course of time the sediments deposited at Hierakonpolis have had contributions from the two geologically distinct drainage ba-
ANALYTICAL CHEMISTRY, VOL. 58, NO. 4, APRIL 1986 · 573 A
