We’re making good progress in Trench 2 (the trench we first opened in 2013). So, refreshed from their day off, yesterday the team set to work on Trench 1.
This lies just to the north of Trench 2, and we suspect from the results of Mike’s (Dr Mike Allen) auger survey last year, may contain a substantial depth of hill wash. Hill wash (or colluvium as its called) is produced when intense rainfall cause soil from upslope to wash down hill. There seem to have been several episodes of in the Avebury landscape, particularly in the Bronze Age and the Medieval period, both of which suffered sustained wet weather at times.
Hill wash can be a fairly localised phenomena, if its deep it can mask archaeology that lies beneath from the view of most geophysical techniques and aerial photography. It can also show as blanks in fieldwalking, as the finds and features lie untouched below the hill wash. On the upside though the reason for this is that the deep layer of soil protects the archaeology lying beneath from damage by the plough (or other random human intervention). So it may cost our team a few thousand calories to get to it but if there’s archaeology in Trench 1 we’re hoping it could be well preserved.