Search

Muon absorption radiography is an imaging technique based on the measurement of the absorption of cosmic ray muons. This technique has recently been used successfully to investigate the presence of unknown cavities in the Bourbon Gallery in Naples and in the Chephren Pyramid at Cairo. The MIMA detector (Muon Imaging for Mining and Archaeology) is a prototype muon tracker for muon radiography for application in the fields of archaelogy and mining. It is made of three pairs of X-Y planes each consisting of 21 scintillator bars with a silicon photomultiplier readout. The detector is compact, robust, easily transportable, and has a low power consumption: all of which makes the detector ideal for measurements in confined and isolated environments. With this detector, a measurement from inside the Temperino mine in the San Silvestro archaeo-mining park in Tuscany was performed. The park includes about 25 km of mining tunnels arranged on several levels that have been exploited from the Etruscan time. The measured muon absorption was compared to the simulated one, obtained from the information provided by 3D laser scanner measurements and cartographic maps of the mountain above the mine, in order to obtain information about the average density of the rock. This allowed one to confirm the presence of a partially accessible exploitation opening and provided some hints regarding the presence of a high-density body within the rock.

The MIMA muon tracker, developed by the INFN Unit of Florence and the Department of Physics and Astronomy of the University of Florence, has been designed to test the application of muon radiography (or muography) to multidisciplinary case studies, to demonstrate its validity as an imaging tool in different fields and to develop dedicated data analysis strategies. The MIMA detector is a scaled-down version of the muon trackers developed for the "Mu-Ray" INFN R&D project and the MURAVES (MUon RAdiography of VESuvius) "Progetto Premiale", financed by the Italian government. Thanks to its compactness, MIMA allowed the use of slightly different technical solutions with respect to the other detectors. Its construction was completed in the first half of 2017 and since then it has been used for several different measurements. In the second half of 2017 the detector was installed in the Bourbon Gallery inside Mount Echia, a hill in the center of Naples containing a complicated system of tunnels and cavities that have been dug over many centuries. The installation of the MIMA tracker was required to validate with an independent detector the results obtained in two previous measurements by the Mu-Ray tracker. After this measurement, the detector has been used in the Tuscany region, mainly for investigating two possible fields of application: geo-hydrological risk assessment and mining activity. The preliminary results of these tests and the future perspectives are shortly presented in this paper.

A novel algorithm developed within muon radiography to localize objects or cavities hidden inside large material volumes was recently proposed by some of the authors (Bonechi et al. 2015 J. Instrum. 10, P02003 (doi:10.1088/1748-0221/10/02/P02003)). The algorithm, based on muon back projection, helps to estimate the three-dimensional position and the transverse extension of detected objects without the need for measurements from different points of view, which would be required to make a triangulation. This algorithm can now be tested owing to the availability of real data collected both in laboratory tests and from real-world measurements. The methodology and some test results are presented in this paper. This article is part of the Theo Murphy meeting issue 'Cosmic-ray muography'.

A novel algorithm developed within muon radiography to localize objects or cavities hidden inside large material volumes was recently proposed by some of the authors (Bonechi et al. 2015 J. Instrum. 10 , P02003 ( doi:10.1088/1748-0221/10/02/P02003 )). The algorithm, based on muon back projection, helps to estimate the three-dimensional position and the transverse extension of detected objects without the need for measurements from different points of view, which would be required to make a triangulation. This algorithm can now be tested owing to the availability of real data collected both in laboratory tests and from real-world measurements. The methodology and some test results are presented in this paper. This article is part of the Theo Murphy meeting issue ‘Cosmic-ray muography’.

The Etruscan site of Populonia-Baratti (Southern Tuscany, Italy) became in the first millennium BCE one of the most important iron metalworking sites in the Mediterranean region thanks to the exploitation of nearby Elba Island iron ores. Recent studies, however, have demonstrated that, before iron, copper was smelted therein (9th–8th century BCE). The ancient Hellenistic text De mirabilibus auscultationibus by Pseudo-Aristotle states that the ancient inhabitants of Elba Island firstly exploited copper and that, later in, iron was won from the same mines by the inhabitants of Populonia. However, copper occurrences are extremely scanty on the island, while mainland southern Tuscany hosts a number of copper-rich deposits which could have been profitably exploited since Eneolithic. In order to investigate if, and to what extent, copper mining and smelting/working was practiced in this area in Final Bronze Age (FBA) to Early Iron Age (EIA), we have thus compared the lead isotope composition of copper slags found in the Populonia-Baratti area and dated to the 9th–8th century BCE with those of copper-rich ore deposits of southern Tuscany and Elba Island. In addition, few copper-based items from to FBA-EIA hoards of Elba Island have been investigated as well. All copper slag from Baratti-Populonia have lead isotope composition fully comprised within the nearby Campiglia Marittima district, but the ophiolitic copper (either form Tuscan mainland or the neighboring island of Elba) was never worked in this site. Differently, all items from the island of Elba do not show clear genetic relationship neither with Elban nor with the Tuscan mainland copper ores but display a “foreign” Pb signature, suggesting that, even before iron exploitation started, the island of Elba - one of the main crossroads of the Mediterranean Sea - was probably involved in metal trading (rather than metal working) with other regions.

Questo volume è dedicato alle miniere e ai minerali del Campigliese (Toscana). Tre millenni di storia mineraria di un territorio geologicamente e mineralogicamente affascinante che, insieme alla vicina Isola d'Elba, può essere definito come un grandioso museo mineralogico a cielo aperto. Da quasi due secoli le rocce e i minerali di quest'area sono studiati da geologi e mineralogisti di tutto il mondo stimolando importanti discussioni scientifiche. Oramai tutte le miniere metallifere sono chiuse (l'ultima, la miniera del Temperino, è stata chiusa definitivamente nel 1976) e restano attive solo le cave di rocce carbonatiche e le miniere di materiali per l'industria della ceramica. Oggi non è più possibile trovare gli splendidi esemplari di ilvaite, quarzo e gesso che si possono ammirare in molte collezioni pubbliche e private ma è comunque possibile collezionare ancora campioni di interesse sistematico e scientifico. Molti affioramenti esterni, le cave di "granito" di Botro ai Marmi, e anche le gallerie della ex-miniera del Temperino (grazie alla convenzione fra gruppi mineralogici e Parchi Val di Cornia S.p.a.) continuano a fornire esemplari mineralogici di notevole interesse scientifico come è dimostrato dalle molte nuove segnalazioni riportate in queste pagine. Purtroppo va anche segnalata l'attività di alcuni collezionisti che si sono introdotti abusivamente nelle gallerie del Parco Archeominerario o che hanno abbandonato rifiuti nella grotta-miniera delle Buche al Ferro. Atteggiamenti di questo tipo sono da condannare in quanto illegali o comunque poco rispettosi dell'immenso patrimonio naturalistico, geo-mineralogico e archeologico del Campigliese. L'ilvaite del Campigliese I magnifici cristalli di ilvaite delle miniere del Temperino e dei Lanzi, insieme a quelli della località tipo di Rio Marina (Isola d'Elba), hanno costituito fin dal XIX secolo esemplari ambiti da Musei e collezioni private di tutto il mondo. Fino alla recente scoperta di splendide ilvaiti in Russia, Grecia e Mongolia, il Campigliese e l'Isola d'Elba erano le uniche località al mondo a fornire esemplari estetici. Soprattutto negli anni '1970, le coltivazioni nella miniera del Temperino (zona Ortaccio-Le Marchand) produssero esemplari eccezionali con cristalli prismatici neri lucenti grandi fino a 8 centimetri impiantati in druse di quarzo latteo-ialino. Il Parco Archeominerario di San Silvestro Ma il Campigliese non è solo ilvaite; per tre millenni i minatori etruschi, romani, pisani, fiorentini, tirolesi, francesi, inglesi e infine italiani hanno estratto nel sottosuolo del Campigliese una grande varietà di metalli (rame, ferro, argento, piombo, zinco, stagno) e minerali industriali (feldspati, allume, vetrioli). Il legame fra insediamenti umani (es. il villaggio medievale di San Silvestro) e risorse minerarie costituisce nel Campigliese un filo rosso mai interrotto. Qui per millenni si sono stratificate le fasi di estrazione e di lavorazione dei metalli, dagli etruschi fino ai primi anni '80 del secolo scorso. Il Parco Archeominerario di San Silvestro ha salvato la memoria di questa lunga storia rendendo fruibili percorsi minerari, geologici e archeologici straordinari. Un museo mineralogico a cielo aperto La storia geologica in questo territorio è complessa e appassionante e la ricchezza mineralogica del sottosuolo campigliese fa brillare gli occhi di ricercatori e collezionisti. Le specie mineralogiche identificate sono oltre un centinaio e due di esse, campigliaite e johannsenite, sono state caratterizzate per la prima volta su campioni della miniera del Temperino. Molte sono le specie, più o meno rare, identificate negli ultimi anni (brochantite, calcofanite, glaucocerinite, ktenasite, schulenbergite, etc.) ma numerosi sono pure le specie in campioni estetici: l'auricalcite del Monte Spinosa e delle Buche al Ferro, il quarzo e il gesso della miniera Temperino-Lanzi, le scapoliti gigantesche della Cava Maffei, etc. Non meno interessante è la storia della piccola miniera di stagno di Monte Valerio dove era possibile trovare piccoli cristalli di cassiterite talvolta associati a tormalina e pirite. Eccezionali sono anche le relazioni tra rocce magmatiche (granito e porfidi) e rocce idrotermali (skarn), che hanno portato un gruppo di scienziati del Consiglio Nazionale delle Ricerche e dell'Università di Pisa a svolgere un dettagliato studio geo-mineralogico nelle gallerie del complesso Temperino-Lanzi. I risultati di questi nuovi studi stravolgono le interpretazioni geologiche fornite dai geologi precedenti e aprono interessanti scenari sui rapporti fra intrusioni magmatiche e origine dei giacimenti a skarn.

Sardinien, Korsika, Samos und auch Korinth - aufgrund weit reichender Handels - kontakte galt Populonia bereits unter den Etruskern als wichtiger Verkehrsknotenpunkt im Mittelmeerraum. Doch nicht nur das: Ab dem 6. Jh. entwickelte sich die Stadt zu einem der bedeutendsten Zentren für Eisenverarbeitung. Nun wurden Reste der einst riesigen Schlackenhalden untersucht, die Interessantes zur antiken Metallindustrie Populonias preisgaben.

Transmission-based muography (TM) is an innovative imaging technique based on the measurement and analysis of the cosmic ray muons flux attenuation within the target under investigation. This technique allows imaging inner-body density differences and has successfully been applied in a wide range of research fields: geology, archaeology, engineering geology and civil engineering. The aim of this study is to show the reliability of TM as an innovative, noninvasive geophysical method for ore body prospecting and other mining related studies. The measurements were carried out at the Temperino mine in the San Silvestro Archaeological and Mining Park (Campiglia Marittima, Italy), where several magmatic and metasomatic geological units are embodied. Among them, a Cu–Fe–Zn–Pb(–Ag) sulfide skarn complex primarily composed by hedenbergite and ilvaite minerals. Using the acquired muon imaging data obtained with the MIMA (Muon Imaging for Mining and Archaeology) detector prototype (cubic detector of 0.5 × 0.5 × 0.5 m3), the presence of a high-density vein inside the skarn body within the rock volume above the muon detector was identified, localized and interpreted. Applying a back-projection algorithm to the obtained 2D transmission map made it possible to estimate and visualize as point cloud data, in a 2D or 3D environment, the identified high-density body and its relative distance from the detector. The results of this study highlight the potential of muography as a support tool to other geophysical methods in the field of mining exploration.

The Etruscan site of Populonia-Baratti (Southern Tuscany, Italy) became in the first millennium BCE one of the most important iron metalworking sites in the Mediterranean region thanks to the exploitation of nearby Elba Island iron ores. Recent studies, however, have demonstrated that, before iron, copper was smelted therein (9th–8th century BCE). The ancient Hellenistic text De mirabilibus auscultationibus by Pseudo-Aristotle states that the ancient inhabitants of Elba Island firstly exploited copper and that, later in, iron was won from the same mines by the inhabitants of Populonia. However, copper occurrences are extremely scanty on the island, while mainland southern Tuscany hosts a number of copper-rich deposits which could have been profitably exploited since Eneolithic. In order to investigate if, and to what extent, copper mining and smelting/working was practiced in this area in Final Bronze Age (FBA) to Early Iron Age (EIA), we have thus compared the lead isotope composition of copper slags found in the Populonia-Baratti area and dated to the 9th–8th century BCE with those of copper-rich ore deposits of southern Tuscany and Elba Island. In addition, few copper-based items from to FBA-EIA hoards of Elba Island have been investigated as well. All copper slag from Baratti-Populonia have lead isotope composition fully comprised within the nearby Campiglia Marittima district, but the ophiolitic copper (either form Tuscan mainland or the neighboring island of Elba) was never worked in this site. Differently, all items from the island of Elba do not show clear genetic relationship neither with Elban nor with the Tuscan mainland copper ores but display a “foreign” Pb signature, suggesting that, even before iron exploitation started, the island of Elba - one of the main crossroads of the Mediterranean Sea - was probably involved in metal trading (rather than metal working) with other regions.