The Quaternary succession of the Bulè and Alpetto valleys (Monviso Massif, Piedmont) as a possible supply for prehistoric jade axes raw material

Abstract

This contribution presents a geological mapping of the Quaternary succession of the Bulè and low Alpetto tributary valleys (Po Valley, Piedmont), together with preliminary data on its petrography. The investigated area, covering an altitude range between 3015 and 1485 meters a.s.l., is located in the Monviso Massif Ophiolite Complex, at the contact with marble and calcschist of the DoraMaira Massif cover. The Quaternary sequence mainly consists of glacial, outwash, debris and landslide deposits, with local torrential/avalanche and colluvial bodies. The investigation on the petrographic composition of these sediments has allowed to recognize the occasional occurrence of jadeitite boulders, likely exploited during the Neolithic period for axe head production. Four possible jadeitite blocks have been found, one of them is described here for the first time, sizing up to 1 m 3 . In detail, one of the finds is a Neolithic site of jade polishing in the high Bulè Valley, that was referred to the middle of V millennium B.C. (Allisio, 2012). The jadeitite blocks have been found in the debris (site a), landslide (site b), glacial (site c) and outwash (site d) sediments. The petrographic characterization of the new jadeitite samples, might potentially shed light on the still controversial genesis of these peculiar rocks.

The Neolithic greenstone industry of Brignano Frascata (Italy): Archaeological and archaeometric study, implications and comparison with coeval sites in the Grue, Ossona and Curone valleys

“…Similar jadeitite boulders (up to one m 3 ) were reported from the Po valley Quaternary succession, thus reinforcing the hypothesis for a supply of raw materials from secondary deposits (Forno et al, 2015). Presence of different pyroxenes, exsolutions and overgrowths were also described in jadeitites from Cuba (García-Casco et al, 2009), Antigua, Guatemala (Harlow et al, 2006; and Dominican Republic (Schertl et al, 2012).…”

The Neolithic greenstone industry of Chiomonte (northwestern Italy): mineralogy, petrography and archaeometric implications

“…The Piedmont region represents an important area for analysing the trade and exchange circuits of greenstone artefacts that spread over Europe during the Neolithic, bordered to the west and south by the Monviso and Voltri massifs, respectively (the two main sources of supply in the Western Alps; Pétrequin et al, 2005aPétrequin et al, , 2006Lunardi, 2008a;P. Pétrequin et al, 2012a, b;Forno et al, 2015). The relatively small set of polished tools from Chiomonte is considered to have utilitarian purposes in a sort of "habitat" environment .…”