Black Slate Research Articles

Tectonic Stress Analysis of Shivnath-Salena Area, Using Stress Response Structure

The geological mapping of the Shivnath-Salena area and structure analysis of the same area were conducted in the LesserHimalayan sequence, Far West Nepal, unveiling the characteristics of kinematics and the associated stress field in the region. Thearea comprises of the Salena Formation and Chachura Formation. The Salena Formation is sandwiched between the PachkoraThrust and Dudulakhan Thrust, and the Chachura Formation occurs between the North Dadeldhura Thrust and Pachkora Thrust.The Salena Formation is composed of light grey and white quartzite and black slates that are intensely deformed, with folds. The Malena Anticline and the Lamalek Syncline are the intraformational folds observed in the study area. Superimposed folding was also observed. The Chachura Formation comprises Paleocene to Late Eocene green sandstone, grey and purple shale, and approximately 1 m thick grey fossiliferous limestone. This study interprets stress-response structures to show the tectonic stress field in the Salena Formation. Twenty-seven fault slip data (slickenside) were collected in the field and used to determine the stress regime by applying the stress inversion technique. The direction of the maximum principal stress axes is interpreted as NE-SW. The average value of the stress index R' is about 0.30, indicating an extensional tectonic stress regime in the study area. As σ1 is vertical, R = R' in the study area suggests normal faulting in an extensional regime.

The Mousty Formation (Brabant Massif, Belgium): state of the art

The Mousty Formation has unique and particularly interesting lithological, mineralogical, sedimentological, metamorphic and tectonic characteristics which have been the subject of much research in connection with the new geological map of Wallonia, but also within the framework of a large amount of academic research, sometimes unpublished. An effort to synthesise and upgrade it in an updated framework seemed necessary. After a history of its definition, mapping and outcrop areas, the following topics are successively addressed in detail and illustrated with diagrams and photos: its lithostratigraphy with the probable discovery of its base near the Court-St-Etienne anticline, its well-constrained biostratigraphy and chronostratigraphy, a new estimate of its minimum thickness, its sedimentology—a subject little addressed until now—, and the resulting depositional sedimentary environment. Its geochemistry, never addressed, is comparable to black shale international standards, except for abnormally high manganese and very low calcium contents; high radon levels in buildings are related to the black slate presence in outcrops. Its mineralogy is rich in manganese-bearing metamorphic minerals, its metamorphism in which we go beyond the strict framework of the formation to deal with the entire southern outcropping rim of the Brabant Massif. Finally, the relationship between the Mousty Formation and the tectonic is discussed, with additional field data, in the context of the innovative and unifying concept of a low-angle extensional detachment called the Asquempont Detachment System. All these observations, some old and some very recent, discussed in the updated framework of the geology of the Caledonian basement of Brabant and in the global stratigraphy and palaeogeography of the lower Palaeozoic, allow us to renew in depth the vision we had of the Mousty Formation and of its place in the Brabant Massif.

Towards Archaeological Printmaking

With the advancement of the ink manufacturing industry and methods in the 19th century, it has been argued that artists lost intimacy with the raw materials used in almost all techniques. The composition of ingredients in even the most common drawing and printing inks, tusches, or crayons became a mystery. If, on one hand, the advancement of chemistry and industry allowed the improvement of paints and led artists to understand how to combine them, on the other hand, putting high-quality ready-to-use materials on the market pinpointed the beginning of the broken connection between artists, raw materials, and the process of their fabrication. The model of work in this research is posited in a more complex and desirable situation, such as working in situ as opposed to a well-provided printmaking workshop. To achieve a better understanding of local culture, this research aims to deepen the knowledge of the processes embodied in the use of print media and the construction of artists’ tools. The local black slate, used as a matrix for lithographic printing, its colourful variation for coating papers, gum printing, inks, and crayons, extend the innovative experimental approaches and offer a variety of strategies to understand and read local collective memories and the history of communities. Reconstructing 19th-century materials used in commercial printing or looking at vernacular buildings makes us consider the use of hereditary methods and knowledge and the need to include traditional skills and craftsmanship. It prompts us to learn from a constructive culture that has been informed by the collective memory of knowledge and skills, both popular and erudite, and to acknowledge these repositories of knowledge as evidence of the dynamic connection between the past and future of humankind’s adaptation to the environment, where printmaking in situ may have a role in negotiating culture and history.

A pre-Sturtian depositional age of the lower Paraguay Belt, Western Brazil, and its relationship to western Gondwana magmatism

The Neoproterozoic Paraguay Belt in mid-eastern Mato Grosso, western Brazil, records the geological evolution of the margins of western Gondwana. The lack of absolute geochronology for the Paraguay Belt has hampered both regional and global stratigraphic correlations. Here we determine the depositional age for the Peresopolis black slate that belongs to the base of the Cuiabá Group in the Paraguay Belt using Re-Os geochronometry. We obtain a narrow Re-Os age interval of 784 ± 8 Ma and a juvenile initial 187Os/188Os composition (Osi) of 0.15 ± 0.03. These data indicate that the Peresopolis black slate is Tonian in age and was deposited in a basin strongly influenced by the weathering of juvenile material, and potentially linked to the early rifting of Rodinia on western Gondwana. These slates record a time interval that is poorly represented in Brazil and with few counterparts in other Neoproterozoic basins globally. As such, our work is a foundation for future geochemical correlations and paleoenvironmental reconstructions of this critical transition of Earth history in Brazil and elsewhere.

Lichens Bite the Dust - A Bioweathering Scenario in the Atacama Desert.

SummaryBioweathering mediated by microorganisms plays a significant role in biogeochemical cycles on global scales over geological timescales. Single processes induced by specific taxa have been described but could rarely be demonstrated for complex communities that dominate whole landscapes. The recently discovered grit crust of the coastal Atacama Desert, which is a transitional community between a cryptogamic ground cover and a rock-bound lithic assemblage, offers the unique chance to elucidate various bioweathering processes that occur simultaneously. Here, we present a bioweathering scenario of this biocenosis including processes such as penetration of the lithomatrix, microbial responses to wet-dry cycles, alkalinolysis, enzyme activity, and mineral re-localization. Frequently occurring fog, for example, led to a volume increase of microorganisms and the lithomatrix. This, together with pH shifts and dust accumulation, consequently results in biophysical breakdown and the formation of a terrestrial protopedon, an initial stage of pedogenesis fueled by the grit crust.

The Black-Slate Edict of Punakha Dzong

This text provides an introduction to and a translation of an inscription engraved on black slates at Punakha rDzong chung. The inscription purports to contain a legal code of Zhabs-drung Ngag-dbang rnam-rgyal, the founder of the Bhutanese State. The main intention of the text is to equate the organization of the newly established ‘Brug-pa state to the organization of the Tibetan imperial state of Srong-btsan sgam-po, thereby legitimizing and sanctifying the Zhabs-drung´s rule in Bhutan. For this purpose, the inscription takes as its point of reference the Section on Law and State, a chapter on Tibetan imperial law and administration found in the mid 16th century text mKhas pa’i dga’ ston by dPa'-bo gTsug-lag phreng-ba (1504-1566).

Depositional environments of redox-sensitive trace elements in the metalliferous black slates of the Okcheon Metamorphic Belt, South Korea

Metalliferous black slates consisting of black slates and interbedded coaly slates in the Okcheon Metamorphic Belt of South Korea were analyzed for redox-sensitive trace elements and rare earth elements (REEs) to examine their depositional conditions. Our data show that the coaly slates have elevated concentrations of redox-sensitive trace metals (U, V, Mo, and Cr), low Mn contents, high V/(V + Ni), V/Cr, and U/Th ratios, and high total organic carbon (TOC) contents. A general tendency of positive correlation between TOC and trace metals was established. The results suggest that the coaly slates were developed under a strongly reducing environment, while the black slates were deposited under a suboxic-oxic condition. The REE patterns of the coaly slates typically show positive Eu and negative Ce anomalies compared to the North American Shale Composite reference and they are essentially inherited from submarine hydrothermal fluids under high temperature reducing condition. The enrichment of the redox-sensitive elements including V (up to 3,564 ppm) and Mo (up to 358 ppm) may have been controlled by direct hydrothermal input of metals into the rift basin from hydrothermal vents, proximal from the vent sites, as supported by textural evidences, and the metals could have been fixed from seawater by means of scavenging process via exhalative oxide particles in a hydrothermal plume. The sorption of metals from seawater under anoxic conditions into organic-rich sediments occurred as well. The metal enrichments in the black slates seem to have been achieved in somewhat similar way to black shales in South China.

Organic acids, siderophores, enzymes and mechanical pressure for black slate bioweathering with the basidiomycete Schizophyllum commune

Although many fungi are known to be able to perform bioweathering of rocks and minerals, little information is available concerning the role of basidiomycetes in this process. The wood-rotting basidiomycete Schizophyllum commune was investigated for its ability to degrade black slate, a rock rich in organic carbon. Mechanical pressure of hyphae and extracellular polymeric substances was investigated for biophysical weathering. A mixed ß1-3/ß1-6 glucan, likely schizophyllan that is well known from S. commune, could be identified on black slate surfaces. Secretion of siderophores and organic acids as biochemical weathering agents was shown. Both may contribute to biochemical weathering in addition to enzymatic functions. Previously, the exoenzyme laccase was believed to attack organic the matter within the black slate, thereby releasing metals from the rock. Here, overexpression of laccase showed enhanced dissolution of quartz phases by etching and pitting. At the same time, the formation of a new secondary mineral phase, whewellite, could be demonstrated. Hence, a more comprehensive understanding of biophysical as well as biochemical weathering by S. commune could be reached and unexpected mechanisms like quartz dissolution linked to shale degradation.

Microbiomes in an acidic rock-water cave system.

Belowground ecosystems are accessible by mining, where a specific microbial community can be discovered. The biodiversity of a former alum mine rich in carbon, but with a low pH of 2.6-3.7, was evaluated by DNA- and cultivation-dependent methods using samples of the black slate rock material, secondary mineralization phases and seepage water. Pyrite oxidation within the low-grade metamorphic Silurian black slate established high concentrations of Fe and $\rm{SO}_4^{2-}$ forming the extreme conditions visible with acidophilic and Fe-oxidizing microorganisms. In addition, an unexpected predominance of fungi in this C-rich and acidic cave ecosystem, including high numbers of Mucoromycota and Mortierellomycota, was detected. Therefore, fungal cultures were obtained, mainly from the secondary mineral phases that are iron phosphates. Hence, the fungi might well have been involved in phosphate mobilization there. The rock material itself is rich in organic carbon that can be used by oxidase activity. The cultivation setup mimicked the cave conditions (low temperature, low pH, oxic conditions), with one oligotrophic and one medium rich in nutrients that allowed for isolation of different fungal (and eutrophic bacterial) groups. The acidic conditions prevented the occurrence of many basidiomycetes, while the isolated fungi could survive these adverse conditions.

A New Small Stone Icon from Chersonesos

For 190 years of research of Chersonesos (Byzantine Сherson), twelve stone, in the vast majority, steatite icons were found. In 2002, during the excavation of quarter L in the southern part of the site, a one-sided fragmented black slate pendant icon was found. Its upper left part is lost. The dimensions of the preserved fragment are 3.2 x 3 cm, the thickness of the icon is 0.6 cm. The icon was found in the destruction layer of a residential building dating back to the last period of the city’s existence. On it is carved a bosom image of Christ Emanuel in a double arched frame. The quality of the icon is low. A separate image of the young Christ on stone icons is a rather rare phenomenon. The icon from Chersonesos has analogues, but differs from them in more details. This icon was found in the destruction layer of a residential building dating back to the last period of the city’s existence. Close analogies and conditions of the find will allow attributing this icon to Byzantine imports of the 13 th century.

Geochemistry and provenance of the Turquoise Bluff Slate, northeastern Tasmania: tectonic significance

The Ordovician Turquoise Bluff Slate in northeastern Tasmania is a 2 km-thick sequence of deep-marine siliceous black slates. It is dominated by meta-siltstones with bimodal grainsize distributions typical of turbidite TE-1 and TE-2 facies. The slates have high SiO2 indicating they are hemipelagites. The high Ba and V indicate they were deposited in an anoxic environment associated with high oceanic productivity. All these features are common in muddy turbidites. U–Th–Pb dating of detrital monazite and authigenic xenotime in the slates supports previous evidence that the dominant cleavage, in this unit, formed during the Benambran Orogeny. The whole-rock composition of the slates is similar to black slates in the Adaminaby Group, NSW. A review of Paleozoic whole-rock compositions from the Lachlan Orogen confirms they all have trace element contents similar to average Australian shale. However, there are subtle differences in composition. The Turquoise Bluff Slate and other Mathinna Supergroup rocks from the Eastern Tasmania Terrane have higher average Cr content than similar age turbidites from Victoria and NSW. This probably reflects a small contribution from Tasmania Cambrian ultramafic rocks in the provenance. If this were correct, northeastern Tasmania was closer to western Tasmania in the Paleozoic than other provinces of the Lachlan Orogen, southeastern Australia. Other subtle features of the whole-rock composition of Paleozoic sedimentary rocks from the Lachlan Orogen indicate it may be possible to recognise provincial variations in composition that will provide new constraints on tectonic models of southeastern Australia.

Enzymatic Bioweathering and Metal Mobilization From Black Slate by the Basidiomycete Schizophyllum commune.

Schizophyllum commune is a filamentous basidiomycete causing white-rot in many wood species with the help of a broad range of enzymes including multicopper oxidases such as laccases and laccase-like oxidases. Since these enzymes exhibit a broad substrate range, their ability to oxidatively degrade black slate was investigated. Both haploid monokaryotic, and mated dikaryotic strains were able to grow on black slate rich in organic carbon as sole carbon source. On defined media, only the monokaryon showed growth promotion by addition of slate. At the same time, metals were released from the slate and, after reaching a threshold concentration, inhibited further growth of the fungus. The proteome during decomposition of the black slate showed induction of proteins potentially involved in rock degradation and stress resistance, and the gene for laccase-like oxidase mco2 was up-regulated. Specifically in the dikaryon, the laccase gene lcc1 was induced, while lcc2 as well as mco1, mco3, and mco4 expression levels remained similar. Spectrophotometric analysis revealed that both life forms were able to degrade the rock and produce smaller particles.

Metal release and sequestration from black slate mediated by a laccase of Schizophyllum commune.

Schizophyllum commune is a filamentous basidiomycete which can degrade complex organic macromolecules like lignin by the secretion of a large repertoire of enzymes. One of these white rot enzymes, laccase, exhibits a broad substrate specificity and is able to oxidize a variety of substances including carbonaceous rocks. To investigate the role of laccase in bioweathering, laccase gene lcc2 was overexpressed, and the influence on weathering of black slate, originating from a former alum mine in Schmiedefeld, Germany, was examined. The metal release from the rock material was enhanced, associated with a partial metal accumulation into the mycelium. A sequestration of metals could be shown with fluorescent staining methods, and an accumulation of Zn, Cd, and Pb was visualized in different cell organelles. Additionally, we could show an increased metal resistance of the laccase overexpressing strain.

Erratum to: Gossans, Slates, and the Red and Black Hamlets of Segovia (Spain): Interrelated Geological and Architectural Features

The Sierra of Ayllon in Central Spain has a rich heritage from both the architectonic and geological perspectives. On one hand, the low lands flanking the northern side of the sierra in the Segovia Province host the so-called red hamlets and black hamlets (pueblos rojos-pueblos negros). The red and black terms derive from the traditional local building materials: Miocene red gossan breccias and Ordovician-Silurian black slates, respectively. Although these hamlets have a series of undeniable esthetic and historical values, it is the geology of this realm which accounts for most of the remarkable features in the studied zone. In this regard, near the hamlet of Madriguera, there are outstanding, unique outcrops of Miocene gossan deposits and deeply hydrothermally altered Silurian slates, forming what we have here defined as the “Madriguera Gossan Corridor” geosite. This, together with the intrinsic historical and esthetic values of the red and black hamlets, confers to the area (both at the regional and local scales) an immense scientific, educational, and touristic potential. The formal assessment of this site following the official methodology of the Geological Survey of Spain (IGME) confirms its highly valuable interest as a geosite.

Stone-Eating Fungi: Mechanisms in Bioweathering and the Potential Role of Laccases in Black Slate Degradation With the Basidiomycete Schizophyllum commune.

Many enzymes, such as laccases, are involved in the saprotrophic lifestyle of fungi and the effects of those may be linked to enhanced bioweathering on stone surfaces. To test this hypothesis, we studied the decomposition of kerogen-enriched lithologies, especially with black slate containing up to 20% of Corg. Indeed, a formation of ditches with attached hyphal material could be observed. To address enzymes involved, proteomics was performed and one group of enzymes, the multicopper oxidase family members of laccases, was specifically investigated. A role in bioweathering of rocks containing high contents of organic carbon in the form of kerogen could be shown using the basidiomycete Schizophyllum commune, a white rot fungus that has been used as a model organism to study the role of filamentous basidiomycete fungi in bioweathering of black slate.

PGE distribution in the metalliferous black slates of the Okcheon Metamorphic Belt, South Korea

Chinese Ni-Mo sulfide ores. Chondrite-normalized PGE pattern for the coaly slates displays a strong positive Ru anomaly and slightly negative Pt anomaly. The Zn-rich shale of Czech and the black shale of South China show similar patterns to the coaly slates except its slightly enriched Au and positive Pt anomaly, respectively. Positive correlations of organic carbon and the redox-sensitive trace elements such as U, V and Mo with PGEs concentrations in the coaly slates suggest that the PGEs were most likely introduced by submarine hydrothermal activity and precipitated with organic matters under anoxic environment. In general, the metalliferous black slates in the OMB seem to be metamorphosed analogue of the Early Cambrian black shales of the South China Block in the former continental back-arc basin setting, which host metalliferous Ni-Mo-PGE sulfide ores.

Mineralogy and sulfur isotope compositions of the uraniferous black slates in the Ogcheon Metamorphic Belt, South Korea

Uraniferous black slates, extending for over 100km in the Ogcheon Metamorphic Belt, South Korea, have been explored for their uranium mineralization. Coaly slates interbedded in the black slates, forming a layer about 20–40m thick showing brecciated and flow texture with random-oriented minerals, are more carbonaceous and uraniferous than the surrounding rocks. Uranium minerals include uraninite, uranothorite, brannerite, ekanite, thorutite, and coffinite. Of these, uraninite is the most abundant phase in the coaly slates, while uranothorite is the most abundant in the black slates. Chlorites in the black slates have Fe/(Fe+Mg) ratios of 0.42–0.66, while those in the coaly slates have lower values, 0.10–0.20. Chlorite geothermometry indicates temperature ranges of 259–309°C, and 200–287°C in the coaly and black slates, respectively. Muscovites in the coaly slates have higher concentrations of 0.85–1.55wt.% BaO and 0.22–0.28wt.% V2O3 than those in the black slates. This can be ascribed to hydrothermal venting of Ba-V-rich fluids into the marine basin. Most uranothorites in the black slates have lower U and higher Th contents than those in the coaly slates due to their solubility differences. In contrast to the comparatively low and wide-ranging δ34S values of pyrite from −5.9 to 6.6‰ in the black slates, the coaly slates have relatively high and uniform values from 11.0 to 12.7‰, implying an influx of isotopically heavy sulfur derived from the inorganic reduction of seawater sulfate under a high temperature hydrothermal system. The differences of rock texture, mineralogy, and sulfur isotope geochemistry in relation to uranium mineralization between the black slates and the coaly slates would reflect the influence of submarine hydrothermal process before they suffered regional metamorphism.

Ore deposit types and tectonic evolution of the Iberian Pyrite Belt: From transtensional basins and magmatism to transpression and inversion tectonics

A new interpretation of the structural evolution of the Iberian Pyrite Belt (IPB) and volcanogenic massive sulfide mineralization (VMS) is presented in this work, based on a review of the ore deposit types, the analysis of the hosting volcanic sequences and the tectonic evolution. The VMS deposits of the IPB are hosted by volcanic and siliciclastic rocks. Four main volcano-sedimentary sequences (VSC), from VSC0 to VSC3, have been assumed, the main deposits being located in the VSC0 and at the top of the VSC2.We have defined three main sectors oriented approximately E-W and hosting the VMS deposits. In the Northern sector, which is mostly located in Spain, graben basins and local pull-aparts are the main structures. In this sector, two belts can be distinguished, the deposits being located at the top of the VSC2 felsic volcanism (Rio Tinto-type IPB deposits). In the Central sector, both in Spain and Portugal, half-graben basins are the most common structures, and the deposits are mostly located in the VSC0 andesitic volcanic-sedimentary sequence (Tharsis-type IPB deposits). In the Southern sector, which is only located in Portugal, a graben basin with a pull-apart is again the main structure, and the deposits are located in black slates and at the top of a felsic volcanism, Strunian in age (VSC0). The deposits located in graben basin with a pull-apart are essentially felsic volcanic-hosted with some siliciclastic material, mostly black shales. By contrast, those located in half-graben basins are mainly hosted by black-shales with minor amounts of andesitic rocks.The tectonic evolution shows that as a result of a counterclockwise rotation of the stress axes, the formation of the IPB and the associated ore deposits took place during several episodes, from transtension (with the development of both graben with pull-aparts and half-graben basins), through left lateral E-W shearing, to transpression. At the beginning of the transtensional process, several extensional, roughly E-W trending faults that developed graben and half-graben basins were generated and the first volcanic andesite-rhyolite rocks (VSC0) formed. The Tharsis-type deposits, mainly hosted by black slates with some volcanic rocks, were formed in the Central sector while the Neves Corvo-type deposit, hosted by black slates and felsic volcanism formed in the Southern one. After a period characterized by barren mafic volcanism (VSC1), a sinistral shear affected the previous fractures due to the stress axis rotation and felsic crustal volcanism started (VSC2). Rhyolites and dacites were particularly abundant in two graben basins, which developed rollovers in pull-apart zones, forming the Rio Tinto-type deposits in the Northern sector. The thermal increase associated with VSC0 and VSC2 gave rise to the development of crustal-scale hydrothermal convective cells, which generated both types of deposits.After a barren VSC3 felsic volcanism, subsequently, during the Variscan transpressional phase, the E-W extensional faults were reactivated as reverse faults, affecting the volcanic sequence (VSC0 to VSC3) as well as the interbedded sedimentary rocks (mostly black shales). As has been recognized at the Rio Tinto deposit, buttressing must have played a significant role in the geometry of inverted structures, and the VMS ores were intensely recrystallized.It should be emphasized that this new regional geological model for the IPB is an approach to provide a better insight into VMS deposits and could be a key-point for further studies, providing a new tool to improve knowledge of the VMS mineralizations and exploration guidelines elsewhere in the IPB.

Palaeoredox geochemistry and bioturbation levels of the exceptionally preserved early Cambrian Indian Springs biota, Nevada, USA

The Sirius Passet Lagerstatte (SP), Peary Land, North Greenland, occurs in black slates deposited at or just below storm wave base. It represents the earliest Cambrian microbial mat community with exceptional preservation, predating the Burgess Shale by 10 million years. Trilobites from the SP are preserved as complete, three-dimensional, concave hyporelief external moulds and convex epirelief casts. External moulds are shown to consist of a thin veneer of authigenic silica. The casts are formed from silicified cyanobacterial mat material. Silicification in both cases occurred shortly after death within benthic cyanobacterial mats. Pore waters were alkali, silica-saturated, high in ferric iron but low in oxygen and sulphate. Excess silica was likely derived from remobilized biogenic silica. The remarkable siliceous death mask preservation opens a new window on the environment and location of the Cambrian Explosion. This window closed with the appearance of abundant mat grazers later as the Cambrian Explosion intensified.

Geology and mineralogy of the Au-As (Ag-Pb-Zn-Cu-Sb) polymetallic deposit of Valiña-Azúmara (Lugo, NW Spain)

Valina-Azumara is a polymetallic Au-As (Ag-Pb-Zn-Cu-Sb) deposit, located in the province of Lugo (NW Spain), that was mined for arsenic at the beginning of the 20th century. The mineralization is hosted in a Variscan thrust fault with a dip direction of N247-261oE, and N-S and NE-SW Late-Variscan faults. These structures are hosted in black slates, Cambrian in age. To a lesser extent, the mineralization also occurs disseminated within narrow, weakly silicified and sericited selvages. Mineralization is divided into two hypogene stages. The first consists of quartz, calcite, rutile, sericite, arsenopyrite and pyrite. Two types of pyrite (Py-I and Py-II) are defined according to their chemical and textural characteristics. Py-II occurs as overgrowth of previous Py-I crystals. Py-II is As-rich (≤1.7 wt.%) and often contains traces of Te, Zn, Cu, Bi, Sb and Au. The mineralized drill core sections show a significant correlation between Au and As. This is due to Au occurring as invisible Au within the Py-II grains, with contents of up to 176 ppm. The Au/As ratios of Py-II indicate that Au was deposited as Au 1+ , as solid solution within the pyrite structure. The second stage of mineralization is enriched in Ag-Pb-Zn-Cu-Sb, replacing the first stage, and consists of quartz, calcite, chlorite, sphalerite, jamesonite, Ag-rich tetrahedrite, freibergite, chalcopyrite, pyrrhotite and galena. Although jamesonite shows traces of Ag, the Cu-Ag sulfosalts are the main carriers of the Ag mineralization in the deposit, with contents that vary from 13.7 to 23.9 wt.% of Ag. In the most superficial levels of the area, secondary Fe oxide and hydroxide, scorodite and anglesite developed due to the oxidation of the ore.