19th October 2012, 01:06 PM
Couple of thousand years of farmers tend to have a flattening effect? And its a wacky site where theres much change within the confines of a trial trench. Hopefully of course you're not machining below the highest points in the natural anyway (although as discussed on here previously some outfits seem to have a habit of doing that anyway presumably to cut down on pesky archaeology). Since, as noted by PP above, the art of identifying R&F seems to be disappearing, following the top of 'natural' and machining out furrow bases is probably over-ambitious....