The Stratigraphic Units of the Wall (USM)
The cards of USM represent a method of analysis similar to the one used to study archeological layers;
for this reason, they are regarded as indispensable elements for the knowledge of the entire history of the
monument.
The different construction phases are usually evident in the analysis of curtain walls, therefore is necessary
to provide a survey or “mappatura” in order to show the changes of the wall structure during its existence. This survey is very important especially in the study of structural foundations, in which the connections
between horizontal and vertical stratigraphy are combined. In this manner, it is possible to identify the
existent relationship between the wall structure and the archeological area of which it forms part.
