La primera explotació de coure a Catalunya. Dades arqueològiques i arqueomètriques de la Mina de la Turquesa (Cornudella de Montsant, Priorat)

Aquest treball exposa l’estat de la recerca a la mina de coure de la Turquesa (Cornudella de Montsant Priorat) l’explotació prehistòrica que vam identificar l’any 2011. Es van realitzar tres campanyes d’excavació que han permès recuperar i estudiar 117 artefactes lítics miners i s’han analitzat mostres de minerals i roques del jaciment amb diverses tècniques (isòtops de plom fluorescència de raigs X i difracció de raigs X). Els resultats obtinguts permeten detectar coincidències amb altres elements metal·lúrgics de la zona i datar la primera explotació de la mina durant el III mil·lenni cal ANE

An Alternative Scenario on the Origin of Ultra-High Pressure (UHP) and Super-Reduced (SuR) Minerals in Ophiolitic Chromitites: A Case Study from the Mercedita Deposit (Eastern Cuba)

The origin of the assemblage of ultra-high pressure (UHP), super-reduced (SuR) and several crustally derived phases in ophiolitic chromitites is still hotly debated. In this paper, we report, for the first time, this assemblage of phases in ophiolitic chromitites of the Caribbean. We studied the Mercedita chromitite deposit in the eastern Cuban ophiolitic complexes. The mineral phases were characterized using microRaman spectroscopy, energy-dispersive spectroscopy with a scanning electron microscope (SEM-EDS), X-ray microdiffraction and electron microprobe analyses. Mineral concentrates were prepared using hydroseparation techniques. We have identified oriented clinopyroxene lamellae in chromite, oriented rutile lamellae in chromite, moissanite hosted in the altered matrix of the chromitite, graphite-like amorphous carbon, corundum and SiO2 hosted in healed fractures in chromite grains, and native Cu and Fe–Mn alloy recovered in heavy-mineral concentrates obtained by hydroseparation. This assemblage may correspond to UHP-SuR conditions, implying recycling of chromitite in the mantle or formation of the chromite grains at deep mantle depths, followed by emplacement at a shallow level in the mantle. However, the chromitite bodies contain gabbro sills oriented parallel to the elongation of the chromitite lenses, and these show no evidence of HP/UHP metamorphism. Therefore, the identified “exotic” phases may not be indicative of UHP. They formed independently as oriented clinopyroxene lamellae in chromite during cooling (clinopyroxene and rutile), in super-reduced microenvironments during the serpentinization processes, and by transference of subducted crustal material to the mantle wedge via cold plumes.This research was financially supported by the Spanish Project CGL2015-65824 granted by the Spanish “Ministerio de Economía y Competitividad” to J.A.P., the Ramón y Cajal Fellowship RYC-2015-17596 to J.M.G.-J. and a FPU Ph.D grant to N.P.-S. by the Ministerio de Educación of the Spanish Government

An Alternative Scenario on the Origin of Ultra-High Pressure (UHP) and Super-Reduced (SuR) Minerals in Ophiolitic Chromitites: A Case Study from the Mercedita Deposit (Eastern Cuba)

The origin of the assemblage of ultra-high pressure (UHP), super-reduced (SuR) and several crustally derived phases in ophiolitic chromitites is still hotly debated. In this paper, we report, for the first time, this assemblage of phases in ophiolitic chromitites of the Caribbean. We studied the Mercedita chromitite deposit in the eastern Cuban ophiolitic complexes. The mineral phases were characterized using microRaman spectroscopy, energy-dispersive spectroscopy with a scanning electron microscope (SEM-EDS), X-ray microdiffraction and electron microprobe analyses. Mineral concentrates were prepared using hydroseparation techniques. We have identified oriented clinopyroxene lamellae in chromite, oriented rutile lamellae in chromite, moissanite hosted in the altered matrix of the chromitite, graphite-like amorphous carbon, corundum and SiO2 hosted in healed fractures in chromite grains, and native Cu and Fe-Mn alloy recovered in heavy-mineral concentrates obtained by hydroseparation. This assemblage may correspond to UHP-SuR conditions, implying recycling of chromitite in the mantle or formation of the chromite grains at deep mantle depths, followed by emplacement at a shallow level in the mantle. However, the chromitite bodies contain gabbro sills oriented parallel to the elongation of the chromitite lenses, and these show no evidence of HP/UHP metamorphism. Therefore, the identified "exotic" phases may not be indicative of UHP. They formed independently as oriented clinopyroxene lamellae in chromite during cooling (clinopyroxene and rutile), in super-reduced microenvironments during the serpentinization processes, and by transference of subducted crustal material to the mantle wedge via cold plume

Critical Elements in Supergene Phosphates: The Example of the Weathering Profile at the Gavà Neolithic Mines, Catalonia, Spain

The essential role of Critical Elements (CE) in 21st century economy has led to an increasing demand of these metals and promotes the exploration of non-conventional deposits such as weathering profiles. The present work is focused on the study of a weathering profile located at the Archaeological Park of the Gavà Neolithic Mines, Barcelona, Catalonia, Spain. In the Gavà deposit, acid and oxidising meteoric fluids generated intense weathering during the early Pleistocene, affecting series of Llandoverian black shales and associated syn-sedimentary phosphates. The circulation of these acid fluids at deeper levels of the profile generated supergene vein-like mineralisations comprised of secondary phosphates (e.g., variscite, perhamite, crandallite, phosphosiderite) and sulphates (e.g., jarosite, alunite). This supergene mineralisation is significantly enriched in certain CE (e.g., Ga, Sc, REE, In, Co and Sb) that were mobilised from host rock components and later hosted in the crystal lattice of supergene minerals. Weathering processes and corresponding supergene enrichment of CE at the Gavà deposit could be used as an example to determine exploration guidelines of CE in weathering profiles and associated supergene phosphates worldwide

La primera explotació de coure a Catalunya. Dades arqueològiques i arqueomètriques de la Mina de la Turquesa (Cornudella de Montsant, Priorat)

Altres ajuts: HUM2004-04861-C03 ; HUM2007-65725-C0

The pilot project of the mineral collections from the University of Barcelona: An opportunity to create updated teaching material to be shared with other universities

The Mineralogy teaching collection from the University of Barcelona has proved to be a successful tool for students. The urge of its renewal to meet the necessities of modernCindustry brought the idea to replicate this collection in order to offer high quality teaching material to other universities worldwide. This project has led to an international collaboration aiming to enhance international solidarity among universities and make evident the importance of Mineralogy in Geology studies

The Barcelona SGA-SEG student chapter: New fronts for international cooperation in teaching Geology and student exchanges

The Barcelona SGA-SEG Student Chapter is a student organization created and organized by students from the Faculty of Earth Science (University of Barcelona; UB). It offers to students interested in Mineralogy, Mineral Deposits and Economic Geology the opportunity to participate in research projects, student exchanges, seminars and courses in an international level. The students develop capacity of self-organization, team-work and public social skills. Recent activities are international exchange of student groups and participation in the project to update and replicate the mineral collection of the UB

Les col·leccions de mineralogia de la UB. Una eina d'aprenentatge i de participació dels estudiants

Les col·leccions de Mineralogia de la Universitat de Barcelona poden ser de litoteca (emprades en l'ensenyament presencial i no presencial) i sistemàtica (usades com a material de referència de recerca). Comprenen mostres de mà, làmines primes i probetes. Les col leccions de referència son controlades per estudiants, els quals comproven la identitat del mineral i en fan la catalogació. Així s'introdueix els estudiants en les tècniques de caracterització i en les tècniques de musealització

An alternative scenario on the origin of ultra-high pressure (Uhp) and super-reduced (sur) minerals in ophiolitic chromitites: A case study from the mercedita deposit (eastern cuba)

The origin of the assemblage of ultra-high pressure (UHP), super-reduced (SuR) and several crustally derived phases in ophiolitic chromitites is still hotly debated. In this paper, we report, for the first time, this assemblage of phases in ophiolitic chromitites of the Caribbean. We studied the Mercedita chromitite deposit in the eastern Cuban ophiolitic complexes. The mineral phases were characterized using microRaman spectroscopy, energy-dispersive spectroscopy with a scanning electron microscope (SEM-EDS), X-ray microdiffraction and electron microprobe analyses. Mineral concentrates were prepared using hydroseparation techniques. We have identified oriented clinopyroxene lamellae in chromite, oriented rutile lamellae in chromite, moissanite hosted in the altered matrix of the chromitite, graphite-like amorphous carbon, corundum and SiO hosted in healed fractures in chromite grains, and native Cu and Fe–Mn alloy recovered in heavy-mineral concentrates obtained by hydroseparation. This assemblage may correspond to UHP-SuR conditions, implying recycling of chromitite in the mantle or formation of the chromite grains at deep mantle depths, followed by emplacement at a shallow level in the mantle. However, the chromitite bodies contain gabbro sills oriented parallel to the elongation of the chromitite lenses, and these show no evidence of HP/UHP metamorphism. Therefore, the identified “exotic” phases may not be indicative of UHP. They formed independently as oriented clinopyroxene lamellae in chromite during cooling (clinopyroxene and rutile), in super-reduced microenvironments during the serpentinization processes, and by transference of subducted crustal material to the mantle wedge via cold plumes.his research was financially supported by the Spanish Project CGL2015-65824 granted by the Spanish “Ministerio de Economía y Competitividad” to J.A.P., the Ramón y Cajal Fellowship RYC-2015-17596 to J.M.G.-J. and a FPU Ph.D grant to N.P.-S. by the Ministerio de Educación of the Spanish Government

Una explotación de cobre prehistórica: la mina "de la Turquesa" (o del Mas de les Morenes), Cornudella de Montsant, el Priorat, Tarragona

Con permiso de la revistaIn this paper we synthetically present the results of the studies carried out at La Turquesa prehistoric copper mine, preceded by an introduction to the oldest European mining, that has the role of contextualizing the mine. The results of the archaeological excavations carried out and the research on the structure and mineralogy of the mine (where there is not turquoise) within the framework of its local geological environment are presented. The analysis of the more than one hundred stone mining tools found in the course of the excavations shows their un-doubtedly prehistoric nature, as well as their main characteristics from the point of view of the raw materials used and their manufacturing processes. The archaeometallurgical study has focused on two types of characterisation of the ores from the mine: elemental analyses (pXRF and X-ray diffraction) and characterisation by lead isotope analysis to define the isotopic field, allowing comparative studies to be made of the archaeological finds and iden-tification of possible prehistoric objects manufactured using this copper ore. This chaeometallurgical research has shown the affinities between some ores and objects and indicates the use of the copper of La Turquesa mine in the elaboration of some of them. The results of a pioneering research implemented with the aim of verifying the existence of mining operations using the fire-setting technique are also presented. All this allows to establish the period of exploitation of the mine between the Chalcolithic and the Middle Bronze Age (2,800 to 1,300 BC), helps to know prehistoric mining in Catalonia, the character of the communities that occupied the territory and its relationship with mining and exchange and shows the importance of protecting and investigating the prehistoric mining heritage.Peer reviewe