Geochemical Methods for Sourcing Lava Paving Stones from the Roman Roads of Central Italy

Abstract

This paper documents the results of in situ analysis of 306 lava paving stones and 74 possible source rocks using pXRF. Data were collected from sites both in the city of Rome—on major roads beyond the city (including the Viae Flaminia, Cassia, Clodia, Praenestina and Appia)—and in the city of Ostia. Comparison of the pXRF data with lava compositional data from the geological literature allows broad identification of possible sources. The results point to quite distinctive patterns of exploitation for the city of Rome and Ostia, utilizing the Alban Hills lava flows, and the roads of the middle Tiber Valley, drawing on lava flows associated with the Vico and Sabatini volcanoes. The results show the potential of pXRF to produce data to elucidate the exploitation of lava flows for paving the Roman roads.

HHpXRF study of recent zinc and lead pollution on lava stepping stones from Pompeii: Tourist footfall, tyre dust and leaded petrol

“…For example, Worthing et al . (2017, 2018) observed the same surface Pb enrichment in an HHpXRF study of second‐century paving stones from Trajan's Market in Rome. Comparison between the geochemistry of the lava paving stones and the pristine lavas from which they had been quarried revealed surface enrichment in Pb.…”

“…This approach works very well when fine‐grained rocks are analysed (Worthing et al . 2017, 2018). In these studies, the Niton data compared favourably with the geological XRF data obtained from the abundant geological literature of the Roman volcanic province.…”

Trajan's Forum (Hemicycle) and the Via Biberatica (Trajan's Markets): an HHpXRF Study of the Provenance of Lava Paving in Ancient Rome (Italy)

“…To end on a more positive note; it is clear that when large amounts of Niton data obtained from volcanic rocks of known provenance are compared with literature-based geological data of the same rocks, the agreement is good (e.g., Worthing et al 2017). There is an abundance of material available for further study and the production of data-led conclusions.…”

“…The geochemical data for this paper were collected using a handheld Niton XL3t 950 He GOLDD+ X-ray analyser (hereafter referred to as 'the Niton'). We learned from our first project, using the earlier Niton XLt 792 MZ machine, that good calibration is vital to the successful use of the analyser (Worthing et al 2017). The XL3t 950 machine comes with factory calibrations that may have to be customized for specific tasks.…”

“…One of the advantages of this approach is that the geological data provide a reference standard against which the performance of the Niton HHpXRF can be assessed. This approach has also been enhanced by technological improvements, particularly in the development of He-enabled machines, which permit the collection of a wider range of elements (cf., Worthing et al 2017). The paper makes a contribution to developing a scientific basis for the provenancing of the lava paving from a major monumental complex in ancient Rome and the implications for the supply of building materials.…”