Following the 2007 investigations four geognostic soundings were undertaken at the edge of the excavations which aimed to evaluate the area’s archaeological potential. Depths of ten metres (S1, S2, S3) and fifteen metres (S4) below ground level were reached. Starting at the lowest levels a series of alluvial deposits was recorded, datable, on the basis of the pottery fragments present, to the beginning of the 1st millennium B.C. From the Etruscan-orientalizing period onwards the area was settled and was characterised by a marshy environment, at the edge of an ancient riverbed identified in thermographic images of the Pisan substrate. In S1, S2 and S3 numerous fragments of wattle and daub, kernels, baked and partially vitrified clay and a small copper sheet were present, perhaps to be linked to the presence of production activities. This material was associated with pottery – bucchero Kylikes and a small container for transporting wine (perhaps of oriental production) – which would seem to indicate a privileged economic context. S4 contained the most plant and wood remains which supports the hypothesis of the presence of an ancient riverbed, to whose banks S4 was the closest. Overlying this situation the core samples documented a layer of sand between 20 and 40 cm thick interpreted as flooding which occurred between the archaic and Hellenistic periods. Up until the Augustan period little residual material was noted. The transformation fits in well with the foundation of the Colonia Opsequens Iulia Pisana between 41 and 27 B.C.

The Roman occupation seemed to have lasted from the Augustan period until the 2nd century A.D. It was documented by a large quantity of material, mostly small abraded fragments, associated with fragments of panchina stone and opus signinum. The sediment typology, large quantity of faunal remains and charcoal, the size and fragmentation of the materials suggest the presence of an open area used for cultivations or as a rubbish dump.

The excavation at Santa Apollonia revealed the presence of a building that remained in use during the 1st century and, probably, until the end of the 2nd century A.D., confirming the dating from the core samples. Between the Roman and early medieval phases the cores S1, S2, S4 showed a series of layers characterised by an abundance of shale slabs perhaps resulting from the roof collapse.

What little material was present was mainly Roman, but the presence of such a large amount of shale suggests a late medieval date, as the use of this material became common in this period. Above these layers were strata characterised by a large amount of waste from iron working, datable to the early medieval by 9th century Forum Ware and attributable to the presence of an ironworks. During the middle centuries of the Middle Ages the more or less continuous presence of waste from iron working was interrupted in the levels dating to between the 11th and 12th century by the creation of new floors.