GRAVIMETRIC STUDY OF MOUNT TESTACCIO

The archaeological area of Mount Testaccio was studied in detail by means of a gravimetric survey in order to understand the inner composition of the hill.

Gravimetric stations were placed on the top of the hill as well as on the lower slope at a distance of 36 m. The results obtained from the gravity shows an average density of mass of 1340 kg/cm. This is a quite low value, but normal considering the kind of material and its volume. The residual anomalies in gravity were calculated by taking away the anomalies Bouguer for Mount Testaccio to the total value for Rome. This method removes variations in density due to geological reasons.

Gravimetric model of the Mount Testaccio.

A map of residual anomalies from Mount Testaccio was created. The areas recording gravimetric minimum are the central part (A) with a value of 0,360 mGal; the South-eastern slope and the Western side on the hill’s foot (B) with 0,310 m/Gal. The maximum value was recorded in the entrance to the archaeological park (C) with a value of 0,510 mGal.

A graviometric model from these results was defined, displaying two accumulations of pottery. The first deposit with a density of 1350 Kg/cm, while the second one, which is covered by the first one, has a density of 1000 kg/cm.

It can be presumed from the anomalies in gravimetric values and the model that the first core consists of untidily low density material. Later, the material was unloaded in an arranged way, building walls of contention with amphorae and compacting it.


Gravimetric map of residual gravity anomalities.

The mean density obtained from these values and contrasted with the excavations weights is 1350kg/cm From this total

Volume of the Mount 550.000 m3
Whole mass of amphorae 742.500.000 kg.
Numero de ánforas acumuladas 24.750.000
Olive-oil arrived in Rome 173.250.000 kg.