Volcanic Grinding Tools in Ustica Island (Tyrrhenian Sea, Italy): Local Production vs. Import of Morgantina-Type Millstones in the Hellenistic-Roman Period

Abstract

This archaeometric study was focused on 28 grey to dark-grey lava artifacts found in Ustica Island (Southern Tyrrhenian Sea, Italy) and referable to different grinding tools: saddle querns, rotary Morgantina-type millstones, rotary hand-mills and one small mortar. Mineralogy, petrography and bulk rock geochemical analyses emphasized that most of the grinding artifacts belonged to the Na-Alkaline series of Ustica, mainly basalts, hawaiites and mugearites. Nevertheless, some millstone samples did not match major and trace elements of Ustica lavas, in particular, one high-TiO2 Na-Alkaline basalt from Pantelleria Island, some tholeiitic/transitional basalts from the Iblei Mountains and one Calcalkaline basaltic andesite, most likely from the Aeolian Archipelago. The Hellenistic–Roman re-colonisation of Ustica Island, after ca. one millennium of nearly complete abandonment, was testified by the import of the non-local Morgantina-type rotary millstones, very widespread in the Mediterranean area from 4th–3rd century BC. This import of millstones represented, for the Ustica inhabitants, a real breakthrough for developing a local production of grinding artifacts on the basis of the new rotary technique which was much more efficient than that of the archaic saddle querns, largely used in the Middle Bronze Age. The results are also discussed in the framework of the overall volcanic millstone trade in the Mediterranean area and the different milling technology in antiquity.

The millstone trade from the most exploited Italian volcanic areas: an overview from the phoenicians to the roman period

“…Buonviaggio) in the Vulsini Volcanic District close to the Northern Latium-Umbria border (Roman Magmatic Province) [Peacock, 1980[Peacock, , 1986[Peacock, , 1989Ferla et al, 1984;Lorenzoni et al, 1996Lorenzoni et al, , 2000Daniele, 1997;Buffone et al, 1999Buffone et al, , 2003Oliva et al, 1999;Antonelli et al, 2001Antonelli et al, , 2005Renzulli et al, 2002;Renzulli and Santi, 2005;Santi and Renzulli, 2006;Santi et al 2004;Antonelli and Lazzarini 2010]; 2) hawaiites and mugearites from Etna volcano [Williams-Thorpe 1988;Renzulli et al, 2002;Santi and Renzulli, 2006;Antonelli and Lazzarini, 2010;Santi et al, 2013Santi et al, , 2015Santi et al, , 2020; 3) Tholeiitic/Transitional basalts from Hyblaean Mountains [Renzulli et al, 2002;Santi et al, 2013Santi et al, , 2015Santi et al, , 2020 and 4) High-TiO 2 Na-alkaline basalts from Pantelleria Island [Williams-Thorpe, 1988;Williams-Thorpe and Thorpe, 1990;Renzulli et al, 2019;Santi et al, 2020].…”

“…dated from the Archaic to the Roman period [Williams-Thorpe, 1988;Williams-Thorpe andThorpe, 1990, 1991;Santi et al, 2013Santi et al, , 2015Santi et al, , 2020Di Bella et al, 2016;Renzulli et al, 2019]. In particular, the presence of basaltic millstones coming from Etna, Hyblaean Mountains and Pantelleria was discovered, together or separately, in the sites of Motya and Entella [Daniele, 1997], Altamura [Lorenzoni et al, 1996[Lorenzoni et al, , 2000, Fossombrone [Renzulli et al, 2002], Pompei [Buffone et al, 1999[Buffone et al, , 2003, Cyrenaica (Libya) [Antonelli et al, 2005], Aeolian Islands, Morgantina, and Ustica Island [Santi and Renzulli, 2006;Santi et al, 2013Santi et al, , 2015Santi et al, , 2020.…”

“…Several archaeometric studies of numerous millstones from a long chronological period and from a variety of archaeological sites in the Central-Western Mediterranean, including shipwrecks, have been published in the last four decades [Peacock, 1980[Peacock, , 1986[Peacock, , 1989Ferla et al, 1984;Williams-Thorpe, 1988;Williams-Thorpe and Thorpe, 1988, 1990, 1991, 1993Renzulli et al, 2002Renzulli et al, , 2019Santi et al, 2004Santi et al, , 2013Santi et al, , 2015Santi et al, , 2020Antonelli et al, 2004Antonelli et al, , 2010Antonelli et al, , 2014Santi and Renzulli, 2006;Gluhak and Schwall, 2015;Di Bella et al, 2018 ]. These studies allowed to unravel the millstone typologies preferentially used through time and to establish the exploited lava lithotypes, also leading to a better understanding of the trade routes throughout the Mediterranean.…”

“…Although reserves of lavas are widespread throughout the entire Mediterranean region, decades of researches on provenance of lava millstones point to quarries (or provenance areas if quarries were not found) located in two main Italian districts: the Latium-Umbria border and Sicily (Eastern Sicily and Sicilian Channel) in Central and Southern Italy, respectively [Peacock, 1986[Peacock, , 1989Williams-Thorpe, 1988;Williams-Thorpe and Thorpe, 1993;Renzulli et al, 2002Renzulli et al, , 2019Santi et al, 2004Santi et al, , 2013Santi et al, , 2015Santi et al, , 2020Antonelli et al, 2010]. In particular, the literature well established that the most exploited lavas to manufacture millstones in antiquity were: (i) a leucite phonolite from the Vulsini Volcanic District in Central Italy, (ii) hawaiites and mugearites from Etna, and basalts from (iii) Hyblaean Mountains and (iv) Pantelleria (Sicily and Sicilian Channel).…”

“…Plotting lava millstone geochemical parameters in the proposed diagrams, has to be however complemented by verifying compatibility through thin section modal mineralogy, Total Alkali-Silica (TAS) classification and petrogenetic signature (i.e., magmatic series). Besides the most exploited areas of Latium-Umbria border, Eastern Sicily and Sicilian Channel, additional minor source areas for volcanic millstone production in antiquity were however recognized in some trachyte lavas from the Euganean Hills (Venetian Magmatic Province [Renzulli et al, 2002;Santi and Renzulli, 2006;Antonelli et al, 2004], a dacite to rhyolite welded ignimbrite from the Mulargia area (Sardinia) [Antonelli et al, 2014], and lavas from Vesuvius, Aeolian Archipelago and Ustica Island [Williams-Thorpe, 1988;Williams-Thorpe and Thorpe, 1993;Renzulli et al, 2002Renzulli et al, , 2019Antonelli et al, 2010;Santi et al, 2013Santi et al, , 2020Di Bella et al, 2018]. Although lava millstone provenance from volcanic areas in the Eastern Mediterranean (Greece, Lebanon, Syria, Israel and Jordan) is beyond the scope of the present work, a brief discussion on these potential volcanic rock sources will be also given.…”