Jamie Woodward, University of Manchester and Mark Macklin, University of Aberystwyth
Our part in the 2013 field season was eventful and highly successful. Building on survey and geomorphological work at Amara West in 2009 and 2011, we had two main objectives:
1. To establish the precise stratigraphic and chronological relationship between the cultural remains at Amara West – when the town was occupied – and the record of Nile sediments in the adjacent palaeochannel. These flood deposits date to when water flowed in that channel.
2. To investigate the evidence for Holocene river activity (since around 10,000 BC) in the wider area to the west, north, and east of Amara West.
A deep trench was dug – pit 4 – with significant mechanical assistance! – through the edge of the ancient island and the palaeochannel north of the site, in front of the now-buried temple. The trench section revealed a thick sequence of pottery-rich sediments, between fine-grained Nile flood units, and below that, thick deposits of fine-grained fluvial silts that were archaeologically sterile. Charcoal samples were collected for radiocarbon dating, and sand samples for Optically Stimulated Luminescence (OSL) dating.
The results of these analyses will allow us to provide independent dating control for the period of human occupation at Amara West – complementing the pottery dating – and to test existing ideas about the nature of the river channel environment before, during and after that occupation (preliminary conclusions were published last year).
Looking at the wider landscape around Amara West, it is clear that the town site and its adjacent palaeochannel sit within a much larger network of Holocene palaeochannels and tributary wadis (dried-up river beds). We have begun to map this area using satellite imagery and ground-based survey, and this fluvial landscape also contains a rich archaeological record. Many of the channel margin sites were recorded by André Vila in the 1970s and a team led by Elena Garcea (University of Cassino) is now re-visiting these prehistoric sites.
A key priority for our fieldwork in January was to record stratigraphy in the older channel system and to collect samples for more OSL dating. Another deep trench (pit 5) was placed through the centre of the lowermost channel, revealing a spectacular stack of steeply-dipping flood units, interspersed with thick beds of windblown sand that had been reworked by the river. This evidence indicated the river channel was migrating south between episodes of not flowing: when the windblown sand was deposited.
In addition to OSL and C14 dates, measuring the strontium isotope ratios in these samples will establish the proportion of Blue Nile and White Nile sediments in their composition – helping us to test ideas about the changing provenance of Nile sediments in flood flows during the course of the Holocene. These samples can also help indicate the age of the flood units and the contribution from desert dust.
Now we await the dates … These will indicate when the Holocene channel 2km north of Amara West was flowing, when it finally dried out, and how it might relate to the operation of the Amara West channel. Was this larger channel flowing when Amara West was occupied? If this was the case, we would need to radically alter how we envision the ancient landscape – potentially very different from that visible today – which shaped the lives of the town’s inhabitants.
Our work upstream in the Northern Dongola Reach, near Kawa, has shown that the Nile river channel network has, in very general terms, contracted over the past 5,000 years with an overall decrease in the number of active channels, although some channels can be briefly reconnected to the main Nile during large floods. Both the Kawa and Amara West evidence will form an important reference for the understanding of the desert Nile.
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