Argentiera di Sant'Anna (Stazzema, Toscana) : uno straordinario esempio di attività mineraria rinascimentale

This study concerns the Argentiera di Sant’Anna mining complex, located in the southern Apuan Alps near the village of Sant’Anna di Stazzema. The area contains many mineral deposits, including Pb-Zn(-Ag) and pyrite±baryte±Fe-oxide ores, and minor deposits like Cu(-Au) and Hg ores. The mining activity in the Argentiera di Sant’Anna mines can be traced back to the Etruscan/Roman period, although there is no evidence to support this. The first documents describing mining activity from the site date back to the 13th century under the nobles of Corvaia and Vallecchia. In 1513, with the “Lodo of Pope Leone X”, the mines passed to the Republic of Florence, which exploited them for almost a century under the leadership of the De Medici family. Many of the excavations were resumed during the 19th and 20th centuries, and the mining area passed into the hands of many different companies who performed only modest research activities without ever going into production. This allowed many ancient excavations made during the Renaissance period with hammers and chisel to be preserved. More modern activities have only partially obliterated the ancient excavations, which are still clearly visible with small galleries and a characteristic “coffin” shape. The mineralization exploited in this mining complex consists of lenses of galena (PbS) and sphalerite (ZnS) mixed with Ag-rich-tetrahedrite with thicknesses generally in centimetres and only occasionally in decimetres, developed along the main schistosity of the rock. The host rock is the Filladi inferiori formation of Cambrian- Lower Ordovician age (ca. 540-470 Ma), consisting of whitish quartzitic phyllites and phyllites rich in tourmaline. The exploration and topographic survey of the gallery system that makes up the mining complex of Argentiera di Sant’Anna, along with the comparison with existing cartography, have allowed us to outline the underground heritage present in the area. The mining complex consists of 12 main galleries and 12 minor excavations, totalling a spatial development of 3,5 km, of which approximately 34% are ancient galleries entirely hand-dug dating back to at least the 16th century. Almost all these excavations are easily accessible, except for two galleries known in the literature as “Pungitopi Gallery” and “Buca Piena Gallery”, which have their entrance completely blocked by landslide debris. The purpose of this study is to explore and document the mining complex of the Argentiera di Sant’Anna to draw attention to this important site for its preservation and cultural enhancement.

Il complesso minerario dell’Argentiera di Sant’Anna di Stazzema è ubicato nelle Alpi Apuane meridionali e rappresenta una eccezionale te- stimonianza dell’attività estrattiva per la produzione di argento in epoca Rinascimentale, anche se, alcuni autori, hanno ipotizzato saltuarie attività già a partire dal periodo etrusco/romano. Alcune gallerie sono state successivamente riprese ed allargate nel corso del XIX e XX secolo con parziale obliterazione delle tracce delle lavorazioni più antiche. Le gallerie minerarie risultano tutt’ora ben visibili e caratterizzate, per lunghi tratti, da gallerie di piccole dimensioni di forma a “ogiva”. Il rilievo topografico dell’intero complesso minerario ha permesso di delinearne il patrimonio sotterraneo che consiste di 12 ingressi principali e 12 scavi minori per uno sviluppo spaziale complessivo di 3,5 km di gallerie. Il rilevamento ha, inoltre, permesso di stimare che circa il 34% delle gallerie non è stato modificato durante le ultime fasi di lavorazione, preservandone le originali caratteristiche morfologiche e le tecniche di scavo manuale.