Stone types, wear, and other clues to chronology

So how are we approaching the question of phasing? This was a major part of our work in 2022 and again this year: to try to problematise and link together distinct areas of late building that seem very different in style or somehow connected in the logic of their construction. The simplest way is simply to describe wall sections which seem to share common attributes, especially building materials, or which have hard boundaries. But it is often a case of studying tiny ‘trace elements’ within masonry, such as broken roof tiles or shattered marble revetment, that link walls, as much as the big blocks they contain. How did such material become available only at a certain point on time, when even small pieces might have been repurposed for opus sectile floors? We sometimes think earthquakes could be a possibility, especially, if shattered and damaged blocks are found in quantity in the same layers. Thus, the condition of the material becomes as important as its origin: a wall made with mortar pieces of shattered opus sectile floor is of course going to be later than the floor itself, even if no direct stratigraphic connection exists between the two.

Yet, one can suggest that two walls belong together more often via the style of building adopted to work with reused material, as in the sorting, disguise or decorative use of older blocks. Apart from that, there are of course a range of more conventional methods: the study of ‘off-sets’ in walls or the coincidence of common door heights, or the study of how different parts of a building functionally come together to make up a whole. The scrutiny of wear patterns is also of considerable importance: we see adjacent structures with very little wear, from feet or from the elements, compared to others. This means that those street surfaces with the least wear might well be some of the latest to have been laid. This doesn’t sound very exciting stuff perhaps, to those of us who have come into archaeology for gold and drama. Nonetheless, it helps unpick late antique repairs to roads, walls, and stairs from those of earlier centuries, and often to find far more than one late antique phase within a rebuilt portico or the perimeter walls of a cellular shop.

27.1 Shattered revetment

27.2 Offsets in T2. See how this back wall has a projecting shelf two blocks up fro mthe bottom, marked by white marks on the top of the stones. This is an 'offset', a projecting line in the wall, to support the join with a floor. However, in the southern third it has been eliminated where the wall has been rebuilt with broken brick and reused material, at a time when the shop floor was lowered below the offset, to its present level.