Roman Republican coarse ware from Norba, Southern Lazio (Italy): a multi-analytical study of production technology and trade

Abstract

The first objective of this paper is to reconstruct the production technology of fourth-first centuries BCE coarse ware from surveys near the ancient town of Norba in the Lepini Mountains of Southern Lazio, Italy, adopting a multi-analytical method, combining macroscopic observation with polarised light optical microscopy (OM), X-ray diffraction (XRD) and scanning electron microscopy (SEM). The second objective of this study is to gain insight into Norba's integration in broader production and distribution networks in Southern Lazio between the fourth-first centuries BCE, by comparing the results with previous data for coarse ware prevalent in the region at that time. The results indicate that the coarse ware from Norba was produced with Fe-rich, Ca-poor, and illite-muscovite clays and fired in an oxidising atmosphere between 750 and 900 °C. Differences among the coarse ware exist in the paste recipes, e.g. intentionally added temper. Most coarse ware from Norba bears compositional similarities to that from the Alban Hills and the Tiber Valley, north of Rome, suggesting that Norba was integrated into the marketing of pottery that was common in Southern Lazio during the fourth-first centuries BCE. In comparison, only a few coarse wares seem to have been produced in the surrounding area (e.g. Satricum and Forum Appii), or even locally in Norba. The results further indicate changes in these regional/local distribution networks; some coarse ware seems to have been imported from Satricum, where a workshop was active during the fourth century BCE. When ceramic production at Satricum ceased, potters settled in the towns of Forum Appii and Norba, where they produced ceramic building material and fine ware in the second-first centuries BCE, respectively. The results of this study tentatively suggest that potters in these locations may have also manufactured coarse ware during this period.

Keywords: Archaeometric approach; Italy; Roman Republican Coarse Ware; Southern Lazio; Technology.

Fig. 1

Location of the Pontine region in Southern Lazio, Italy, with the archaeological surveys (red dots) around Norba where the analysed coarse ware was found (Map compiled by T. De Haas)

Fig. 2

Type 2 and type 3a jars from Norba (redrawn from De Haas , plate 30 no. 15 and plate 39 no. 19)

Fig. 3

Images of the four macrogroups identified in the coarse ware assemblage from Norba, based on the type, sorting, and abundance of coarse inclusions: a Macrogroup 1: coarse pyroxene and K-feldspar in sample NO8. b Macrogroup 2: coarse quartz, K-feldspar and pyroxene in sample NO15. c Macrogroup 3: moderately sorted K-feldspar and quartz in sample NO5. d Macrogroup 4: poorly sorted coarse K-feldspar, rounded opaque (Mn or Fe) aggregates, and pyroxene in sample NO1. Scale bar = 2 mm for all images

Fig. 4

Optical micrographs with crossed polarizers of the four petrogroups and clay sample: a, b Petrogroup 1: clinopyroxene (Cpx), K-feldspar (Kfs), amphibole (Amp), leucite (Lct), muscovite (Ms), and biotite (Bt) in NO12 and NO19 respectively. c Petrogroup 2: quartz (Qz), biotite, and chert in NO15. d Pottery waste from Satricum: quartz, K-feldspar, and clinopyroxene. e Petrogroup 3: K-feldspar, quartz, opaque inclusion (OI) with shrinkage rim, and quartzite (Qzt) in NO2. f Petrogroup 4: K-feldspar, clinopyroxene, and pumice in NO4. g, h Clay sample of paleosoil on weathered tuff in PPL and XP, respectively. For images a to f, the polarizers were crossed at ≠ 90 °for a better distinction between matrix (Mx; very dark hue) and voids (V; light grey; elongated and irregular shape)

Fig. 5

Representative diffractogram of each petrogroup with estimated firing temperatures. Illite-muscovite (Ilt-Ms), quartz (Qz), leucite (Lct), feldspar (Fsp, undifferentiated), clinopyroxene (Cpx, undifferentiated), hematite (Ht), and maghemite (Mgh)

Fig. 6

Secondary electron images of the matrix. Petrogroup 1: a Sintered matrix with sheetlike phyllosilicates in NO31. b Vitrification in NO3. c, d Advanced vitrification visible in deformed phyllosilicates in NO13 and NO19; Petrogroup 2: e Vitrification visible through smoothed margins of phyllosilicates in NO9; Petrogroup 4: f Vitrification in NO4. The arrows point to vitrified areas

Fig. 7

Secondary electron images and EDX spectra of clayey matrix (a, b) in NO3 and glass (c, d) in NO1. Scale bar is 100 μm for a, and 5 μm for c. The white rectangles mark the measurement areas

Fig. 8

Textural and mineralogical changes during firing: a, b Glass resulting from the transformation of plagioclase, with corresponding EDX spectrum in NO13; c, d Mn- and Fe-rich aluminosilicate microspheres with EDX spectrum in NO19; both measured areas have the same spectrum; e, f Hemispheric formations with EDX spectrum in NO4; g, h Clusters of isometric Fe-rich aluminosilicate crystals (i.e. ‘ceramic pyroxene’) with EDX spectrum in NO13. The white rectangles mark the measurement areas

Fig. 9

EDX spectra of inclusions in the ceramics: a K-feldspar in NO1. b Clinopyroxene in NO10