I was being ironic, but can now say what's turned up.
They've unearthed a stone drain - in reality 2 rows of stones with a lid of stones on top. Origin unknown, but probably late 19th Century. Doesn't look at all much to me, but the someone from the County Archaeologist team wants it all recording - drawings, photos, measurements, depths etc.
This has taken a further day and there will be 2 of them tomorrow. It is also holding us up a bit as we're having to work round them.