This was one of the not to missed lectures, Dr Hany is a superb communicator who brought the complicated subject to life and made it fascinating. He is very well qualified and has worked with many equally well qualified geologists.

The lecture was sufficiently complicated that I think without his slides my notes make no sense so I will précis.

The Nile has three main tributaries - the White Nile, originating from Lake Victoria, The Blue Nile, originating in the Ethiopian highlands, and the Atbara, which joins the Nile after the merging of the White and Blue Niles at Khartoum. The rest of its course has no tributaries. This makes it suitable for analysing and identifying the deposits - sand, mud and gravel as to their source, whether the main deposits came from Central Africa or East Africa. The rock of central Africa is Precambrian but that of East Africa is Tertiary Igneous. Natural weathering of these rocks means that the broken fragments of these old rocks go down to the delta. Dr Hany has investigated Nile silt of all ages and by normal methods it is impossible to identify differences. They are all the same. The characteristics of the main deposits, by particle size are:-

• Gravel – non existent
• Sand (2mm – 0.063mm) – lots
• Mud (0.063 – 0.004) – majority

The grain composition can be identified by light mineral analysis. Heavy minerals are so sparsely presently as to unfairly weight the sample. This will give a chemical finger print that can be identified. It should be noted that silt is produced by weathering which can alter the chemical composition. So his team analysed grains only of a certain size which made the analysis more effective. This meant they were able to identify silt from different times.

They were then able to draw a graph showing the variation of silt over time indicating whether it had come from central Africa or eastern Africa.

The dug several bore holes in the delta to a depth of 45m. Analysis of the cores showed that when there are high Lithium/Lutetium ratio denotes the source to be Central Africa whereas high Chromium/Scandium ratiosC denote Ethiopian origins. The time period covered was 25,000 -3,000 BP (before present). They were able to identify droughts and high floods and also the level of the Mediterranean Sea and the humidity at the time. The rise in sea level means the sediments had fanned out and that formed the delta area.

Ceramics
The impact of all this on ceramics is a multi-discipline field. Using a variety of techniques such as
• Petroglyph
• SEM-EDX
• X Ray diffraction
• INAA

They were able analysis the pottery and fit in the chemical analysis with periods Gerzean, Amratian, and Badarian. From this, they can identify the mud that was used to form this pottery and whether it was local to the area or not. Once this analysis is done it could be used to trace bartering and exchange of pottery through various places.

It was a fascinating lecture and a whole new area for me. It would be interesting to see analysis of organic materials being fitted into this as well.