Before revision: In this interpretation, dark earth would consist of urban deposits of smoke-impregnated thatch, decayed weeds, timber, and earth floors, reworked and homogenized by worm action, or by agricultural activities, such as ploughing, which mixed building materials from the abandoned Roman cities with material deposited later.
After revision: In this interpretation, dark earth would consist of urban deposits of smoke-impregnated thatch, decayed weeds, timber, and earth floors, reworked and homogenized by worm action, or by agricultural activities, such as ploughing, that mixed building materials from the abandoned Roman cities with material deposited later.