Plough soil and backfill from RPP and 2017 and 2018.
Area 17000: trenches
Area 17000: Phase 1 - Roman Occupation
Area 17000: Phase 3 - Collapse
Area 17000: Phase 2 - Roman Occupation
Area 17000: Phase 4 - Post-Collapse Occupation (?)
Matrix for Trench 1 in Area 17000 from 2018