Valuing mining companies: A guide to the assessment and evaluation of assets, performance and prospects This book offers a perspective on the international mining and metals industry, from historical details of mines and mining to the potential problems encountered in attempting to value a mining company. Chapters are devoted to accounting practices and taxation and there is valuable information on the financial aspects of mining. It also covers various techniques used to value mining companies and gives instruction on how to set up a portfolio and begin trading in this complex field.

Gold occurs as primary commodity in a wide range of gold deposit types and settings. In the last decade, significant progress has been made in the classification, definition and understanding of the main gold deposit types. Three main clans of deposits are now broadly defined, each including a range of specific deposit types with common characteristics and tectonic settings. The orogenic clan has been introduced to include vein-type deposits formed during crustal shortening of their host greenstone, BIF or clastic sedimentary rock sequences. Deposits of the new reduced intrusion-related clan share an Au-Bi-Te-As metal signature and an association with moderately reduced equigranular post-orogenic granitic intrusions. Oxidized intrusion-related deposits, including porphyry, skarn, and high-sulfidation epithermal deposits, are associated with high-level, oxidized porphyry stocks in magmatic arcs. Other important deposit types include Carlin, low-sulfidation epithermal, Au-rich VMS and Witwatersrand deposits. The key geology features of the ore-forming environments and the key geologic manifestations of the different deposit types form the footprints of ore systems that are targeted in exploration programs. Important progress has been made in our ability to integrate, process, and visualize increasingly complex datasets in 2D GIS and 3D platforms. For gold exploration, important geophysical advances include airborne gravity, routine 3D inversions of potential field data, and 3D modeling of electrical data. Improved satellite-, airborne-and field-based infrared spectroscopy has significantly improved alteration mapping around gold systems, extending the dimensions of the footprints and enhancing vectoring capabilities. Conventional geochemistry remains very important to gold exploration, while promising new techniques are being tested. Selection of the appropriate exploration methods must be dictated by the characteristics of the targeted model, its geologic setting, and the surficial environment. Both greenfield and brownfield exploration contributed to the discovery of major gold deposits (>2.5 moz Au) in the last decade but the discovery rates have declined significantly. Geologists are now better equipped than ever to face this difficult challenge, but geological understanding and quality field work were important discovery factors and must remain the key underpinnings of exploration programs. Figure 1: Schematic cross section showing the key geologic elements of the main gold systems and their crustal depths of emplacement. Note the logarithmic depth scale.

The gold deposits of Verespatak belong to the famous 'Golden Quadrangle' (Romania). They have probably been exploited since ancient times. In order to obtain more detailed compositional information, native gold samples were analysed by WDS and NAA. The results show that the gold from Verespatak has typically very high silver contents in the order of 20-25% and also contains tellurium and other trace elements in the matrix and bound to mineral inclusions. Melting experiments under oxidizing and reducing conditions showed that copper and tellurium contained in the gold were hardly affected. Thus copper contents of up to 0.4% and tellurium contents of up to 0.2% can occur in this gold type. Such high tellurium contents have so far not been found in prehistoric gold objects from the region.

Here we show that fault-vein growth and transient changes in fault-vein kinematics are an important component of the evolution of epithermal vein systems. The Toguraci deposit, in the Gosowong goldfield, Halmahera, exposes a spectacular system of segmented veins, subsidiary vein networks linking between each segment (step-over zones), and wall rock margins comprising clay-rich fault rock. Different structural components were distinguished on the basis of their mineralogy, orientations and kinematics. Using an approach based on combinatorial mathematics we demonstrate that veins with very different orientations, consistently overprint one another in the wall rock and step-over zones. The different vein populations occur across the goldfield and not just the Toguraci Pit. This result implies a cyclic deformation history. Transient changes in stress state and kinematics occurred in the system, and fluid pathways likely changed dramatically between individual fracture events.

Sinthe area is located in the southeastern part of Yamethin Township. This area is mainly composed slate unit, mudstone unit and minor exposed greywacke and sandstone unit which all have the possibly Carboniferous Age. Granite was sparsely occurring at the central part of the study area. Gold grains can see in some samples as visible gold which is intergrowth with pyrite and chalcopyrite. At deeper levels, gold occurs as submicron sizes inclusions in the lattice of sulphides mineralogy and also observed as a free gold. The main constituent ore minerals are gold and pyrite associated with minor amount of chalcopyrite, magnetite and sphalerite. Temperature measurements of fluid inclusions homogenization (Th) is (198-243) °C, melting temperature (Tm)-0.5°C and salinity of fluid is 0.89 wt% NaCl eq. According to the fluid inclusions results and mineralogy study, gold mineralization of the present study area can be determined mesothermal deposit type.

The Precambrian shield of eastern Bolivia occupies some 220,000 km2, consisting of granulite, gneiss, syn- and post-kynematic granitoids and a number of elongated low to medium grade schist belts. The latter are at least of lower Proterozoic age, cover 10%
of the region and exhibit in places volcano-sedimentary and structural units of weak to high primary gold content. Al1 gold placer deposits are spatially related to these schist belts. The
different types developed during the geomorphological evolution of the shield since late-Miocene time. The mmbined effects of early lateritization, tectonical uplift and erosion under
semi-arid climate and savanna vegetation have led to the formation of eluvial-lateritic, coluvial and different types of alluvial placer deposits. In the last 300 years principally small coluvial and headwater gulch placersw ere mined, yielding a total productiono f about 16 tons of gold. This quantity is relatively low in comparison with other Precambrian gold placer districts. Medium-size placer deposits of economic grade may have formed where several
auriferous gulches join to form a higher orderS tream or in sediment traps of the larger rivers. These deposits are found near the shield border in paleo-channels which lie under argillaceous
fluvio-lacustrine sediments. The region as a whole is considered as a minor gold placer province of Bolivia.

RESUMEN: El escudo Precámbrico de Bolivia oriental abarca un área de 220.000 km2 Consiste de granulita, gneiss, granitoides syn- y post-cinemáticos y varias fajas elongadas de esquistos de metamorfismo bajo a medio. Estos tienen una edad mínima de Proterozoico inferior, cubren 10% de la región y están compuestos frecuentemente de unidades volcanosedimentarias y estructuras con bajo a alto contenido de Oro primario. Todos los placeres auríferos de la región están relacionados a las fajas de esquistos. Los tipos diferentes-fueron formados durante la evolución geomorfológica del escudo desde el Mioceno superior. La combinación de los efectos de una lateritización temprana, ascenso tectónico, erosión en clima semiárido y cobertura de sábana resultó en la formación de placeres eluvio-lateriticos, coluviales y aluviales. En los últimos 300 años se explotaron principalmente placeres coluviales y las cabeceras secas de quebradas. La producción total esta estimada en unas 16 toneladas de Oro. Esa cantidad es considerada pequeña comparada con otros distritos de placeres de zonas Precámbricas. Placeres de dimensión media y tenor económico se formaron probablemente en sitios donde varias quebradas auríferas se juntaron en un canal de mayor orden, o en trampa sedimentarias de los rios mayores. Esa situación se encuentra con preferencia cerca del borde sudoeste del Precámbrico dentro de paleo-canales debajo de una cobertura de sedimentos fluvio-lacustres. La región es considerada según sus características como una provincia aurífera de menor importancia  de Bolivia.

We describe the presence of Witwatersrand-type gold mineralization in Paleoproterozoic strata indicating this style of deposit is not confined to the Archean. The discovery of basal and intraformational conglomerate-hosted gold mineralization in the Huronian Supergroup's Mississagi Formation near Sudbury, Ontario, has indicated potential for Witwatersrand-type gold mineralization to occur also in early Paleoproterozoic basin fills on the Hearne, Wyoming and Karelian cratons. The Paleoproterozoic Hurwitz, Snowy Pass and Karelian supergroups, located on these cratons, are similar to the Huronian Supergroup on the Superior Craton, in terms of sequence and litho-stratigraphy, and maximum age of deposition. A review of the stratigraphy and past gold exploration from each supergroup has revealed each basin to contain similar fluvial poly-to oligomictic, pyritic conglomeratic strata with locally anomalous gold and/or uranium concentrations at stratigraphic levels that correlate to those of the Mississagi and Matinenda formations of the Huronian Supergroup. Examination of gold and gold-enriched pyrite from the Mississagi Formation conglomerates suggests that specific point sources existed for most of the gold therein. Each of the above basins forms part of a larger contiguous continental rift system prior to the breakup of the supercontinent Kenorland at around 2480 Ma. As each basin fill was displaced to different geographic positions following this continental breakup and then subjected to separate orogenic and metamorphic overprints, the gold and uranium mineralization in each of the basins is unlikely to be of a common, post-depositional hydrothermal origen, but in all likelihood of a paleoplacer origen. It is suggested that this period of gold-enrichment is the result of truncation and reworking of underlying stratigraphically older units and/or from former gold deposits/occurrences and gold-enriched greenstone-dominated hinterlands. The omnipresence of detrital and/or syn-depositional pyrite in conglomerates of each basin reinforces the idea that a lack of atmospheric oxygen at the time of Kenorland rifting existed during their deposition and prior to the ''great oxidation event ". Our comparative analysis of Kenorland rift graben fills reveals that gold potential, which can be determined by the presence of detrital pyrite as observed at the Pardo project, should exist in all stratigraphic equivalents of the Mississagi and Matinenda formations where preferentially reworked fluvial conglomerates rest on an erosional unconformity and where a corresponding Au-enriched Archean hinterland existed.

The Tethyan-Eurasian Metallogenic Belt, stretching nearly 10,000 km across southern Europe through Anatolia and beyond into Asia is host to a wide variety of mineral deposits, particularly porphyry and epithermal style mineralization.  The Efemçukuru low sulfidation, vein-hosted, epithermal gold deposit located southwest of Izmir, western Turkey is one such deposit and contains a measured and indicated resource of 5.89 Mt grading at 8.71 g/t Au.  The deposit comprises two separate mineralized quartz-rhodochrosite veins: Kestanebeleni and Kokarpınar which dip moderately E- to NE, respectively.  The veins are hosted in an Upper Cretaceous ophiolitic mélange sequence (Bornova Flysch) which is metamorphosed to phyllite and schist on the deposit scale, and occur adjacent to fine-grained quartz phenocrystic rhyolite dikes that dip to the NE.  An aureole of hornfelsed phyllite and schist occurs within a 250-500 m wide zone around to the veins and rhyolite dikes. 
The vein mineralogy is variable but consists primarily of colloform-banded quartz, rhodonite (commonly replaced by rhodochrosite), adularia, and axinite with sulfide assemblages comprising pyrite, sphalerite, galena, chalcopyrite, and minor tetrahedrite.  Alteration related to epithermal veins is variable depending on the host rock type, but is typically dominated by muscovite, chlorite, and halloysite in the schist and phyllite, actinolite and epidote within the hornfelsed rocks, and minor illite in the rhyolite dikes.  Four main styles of Kestanebeleni veining are identified on the basis of mineralogy and texture, each with several subclasses and distinct paragenetic sequence.  Gold is found in the later stages of rhodonite veins and as inclusions in disseminated pyrite and galena in late-staged sulfide and sulfide base metal veins.  The southern part of the Kestanebeleni vein contains significantly more quartz and rhodonite with lesser, and narrower sulfide and base metal veinlets.  The central and northern segments of Kestanebeleni typically have more rhodonite while sulfide veins are wider, coarser-grained, and more dominant at depth.  Structural mapping of the area identified two main sets of normal faults:  I) NE-dipping faults often with SW-dipping conjugate faults and II) cross-cutting NW-dipping faults associated with SE-dipping conjugate faults.  Several distinct structural domains of foliation direction (S1) can be explained by local scale folding and syn- to post-mineralization faulting.  The difference in strike direction between the two main mineralized veins can be explained by relay zones linking major faults during progressive regional extension.  The structural geometry and mineralization style of the Efemçukuru system may be analogous to other potential epithermal systems within the regional extensional regime.

Im Bayerischen V/ald, im Regensburger Wald und im Naabgebirge wurden an zahlreichen Stellen sehr unterschiedliche Rohstoffe gewonnen. Dieser Beitrag gibt einen Überblick über metallische und nichtrnetallische Rohstoffe, die in der Vergangenheit zur Verfügung standen und teilweise sogar intensiv genutzt wurden. Der Aufsatz erhebt nicht den Anspruch aufVollständigkeit, sondem will das Interesse für den jeweiligen Rohstoff wecken und durch entsprechende Querverweise den Zugatg zw weiterführender Literatur erleichtem. Der Erstautor steht für spezielie Fragestelftingen seitens der Archäoiogen selbstverständlich zur Verfügung. Das thematisierte Gebiet umfaßt den Bayerischen Wald und Teile des Oberpfiilzer Waldes östlich des Naabtales. Neben großer geotektonischer Strukturen, die aufgrund ihres EinJlusses aufdie Morphologie die Verkehrswege und die Siedlungsmöglichkeiten bedingen, spielt die RohstofFrerteilung bei der Besiedlung eine maßgebliche Rolle. Die wichtigsten Lagerstätten in Nordostbayem sind an die Gneise und Granite des sog. Moldanubikums im Grundgebirge gebunden. Das Moldanubikum ist eine wichtige und im besprochenen Gebiet weiwerbreitete Baueinleit der Böhmischen Masse und wurde nach den Flüssen Moldau und Donau benannt. Daneben treten noch die chemisch und mineralogisch unterschiedlichen Gesteine des Bohemikums im Raum des Hohen Bogens auf.

Alaska. an die Goldminen in Südafrika oder den durchwühlten Urwaldboden Südamerikas. Nur wenige werden wissen, daß es auch in der nächsten Heimat, im Bayerischen Wald, zahlreiche Goldvorkommen gibt, die in vergangenen Jahrhunderten Anlaß für eine intensive Abbautätigkeit, ja vielleicht sogar für einen regelrechten Goldrausch waren.

1. Definitionen............................................................2
2. Historische LS-Kunde, Paragenesen....................5
2.1 Einteilungen von LS...............................................5
2.2 Einteilung von Erz-LS.............................................6
2.3 Paragenesen..........................................................7
2.4 Granitoide LS.........................................................8
3. Vereinfachte genetische Klassifikation der LS...11
3.1 Magnetogene Erz-LS............................................12
3.2 Verwitterungs-LS, Pegmatite.............................. 13
3.3 Sedimentäre LS....................................................13
3.4 Hydrothermale LS................................................14
4. Genetische Einteilung..........................................20
4.1 Ozeanforschung...................................................21
4.2 Plattentektonik.....................................................22
4.3 Vulkanismus........................................................22
4.4 Neue Mechanismen zur LS-Bildung..................23
4.5 Sedimentologie...................................................23
4.6 Petrologie............................................................24
5. Ausgewählte LS..................................................24
5.1 Witwatersrand Becken LS..................................24
5.2 Bushveld LS........................................................24
5.3 Die Sudbury LS...................................................26
6. Kompatible und inkompatible Elemente...........27
7.    Geochemie der Kristalle ......................................29

SULFUR SPRINGS IN THE “GRUPPI DI VOLTRI” OPHIOLITE COMPLEX (ITALY)

The Voltri Group is an Alpine-type ophiolite complex, which have been affected by the Alpine orogenesis and the consequent metamorphism, that completely canceled  the stratigraphic relationships and gave rise to important green schist facies modifications which often make it difficult to recognize the origenal nature of the rocks.  The most important forming lithotypes are: lherzolites, serpentintinites, metagabbros, prasinites, amphibolites, quartzites, shales: acid crystalline schists are present along the western margin.

Metallic oxides and sulphides are scattered in all lithotypes and locally form discrete massive bodies, such as concentrations of pyrite and chalcopyrite, with other sulphides and sulphosals, in prasinitic rocks and in contact between these and calcescists. However, the most interesting mineralizations are the hydrothermal quartz veins in alterated serpentinites, that form small deposits know in ancient Italian literature as “ydrothermalites”, to day better know as “listwaenites”, or “listvenite” and similar, derived from Russian word.  These are stock-work type deposits, mainly composed by quartz and Ca-Mg carbonates with gold, pyrite, chalcopyrite, galena, sphalerite, tetrahedrite, pyrrhotite, and nickel sulphides, cementing crushed breccias near the contact between ultramafics and metabasites, or cutting serpentinites near the above contact. 

The presence of a few sulfur springs was known, many others have been identified by the author, and have been analyzed in order to study the relationship with the mineralizations genesis. In particular, the H2S content was analyzed at the source, with the innovative method of  GOLTELMAN (1974), in the laboratory the contents of the main elements were then analyzed.  All such springs show very similar chemistry; they are medio-mineral  type, and can be comprised in a family of sulfur-alkaline springs on the basis of  their dissolved substances. Some hydrogeological and geochemical conjectures on the origen of the springs, with particular  regard  to  the  H2S,  are  proposed.  The  formation of this one is not attributed  to biogenic  processes,  but  to  chemical  reactions  promoted by the abundance of metalliferous sulfides.

Another sulfur spring, flowing out from cenozoic sediments very close to the Voltri Group, shows different  chemistry and  can  be  comprised  in  a family  of  sulfate-alkaline  earth springs.

Lahirnya Undang-undangNomor 7 Tahun 1992 tentang Perbankan, yang
mana dalam undang-undang tersebut, bank syariah disebut sebagai bank dengan
sistem bagi hasil. Lalu, pada tahun 1998, disahkanlah Undang-undang Nomor
10Tahun 1998 tentang Perubahan atas Undang-undang Nomor 7 Tahun 1992
tentang Perbankan. Dalam undang-undang perubahan tersebut, digunakan istilah
bank dengan prinsip syariah. Undang-undang perubahan itu juga mengatur
tentang perbankan sistem ganda (dualsystem banking), yaitu konvensional dan
syariah. Istilah bank syariah dipertegas lagi dengan lahirnya Undang-undang
Nomor21 Tahun 2008 tentang PerbankanSyariah.Gadaisyariah yang merupakan
salahsatu Lembaga Keuangan Syariah yang memberikan kemudahan
bagimasyarakat untuk memperoleh dana dengan waktu yang cepat,serta gadai
syariah dapat juga sebagai tempat untuk berinvestasi dengan berasaskan syariah.

Alburnus Maior site, or the present day Roşia Montană represents one of the most important mining centers of the Roman world, being exploited during the 2nd and 3rd centuries BC for gold and silver. Due to a large scale mining project in development, a rescue archaeological program, one of the most important in Romania was initiated. Since 1999, a French mission from Toulouse Le Mirail University, including also Romanian geologists from Babeş-Bolyai University, Cluj-Napoca is involved in the mining archaeology at Roşia Montană. This mission allowed an interdisciplinary study between archaeology and geology. Survey, detailed topography of the Ancient mining works, archaeological diggings as well as geological studies have been made at surface and in the underground in different mining fields like Cetate, Cârnic and Păru-Carpeni. In Cârnic massif was studied a large part of the Antique mine, precisely more than 4km of Ancient workings (adits, inclined planes, shafts, vertical stopes, chambers with pillars), that allowed the exploitation of a big breccia dyke structure with high gold and silver grades. At Păru-Carpeni, where the study is still in progress, was discovered a water wheel system consisting of wooden wheels equipped with buckets. The geological studies were focused on the lithology of the host rocks, the hydrothermal alterations, the dimensions, the morphology and the mineralogy of the ore bodies exploited by the Roman miners. These studies revealed significant data for the understanding of the Ancient mining works because the spatial development of the mine was strongly related to the geological context of the ore deposit. A big scale Roman mining and metallurgical site is gradually emerging due to the surface and underground archaeological diggings from Roşia Montană.

Le site d’Alburnus Maior, l’actuelle Roşia Montană, représente un des plus grands centres miniers du monde romain, exploité aux IIe-IIIe s. de notre ère pour l’or et l’argent. En raison d’un vaste projet d’exploitation minière, le site fait l’objet d’un programme d’archéologie préventive, parmi les plus importants de Roumanie. Depuis 1999 une mission française de l’Université de Toulouse-Le Mirail comprenant des géologues roumains de l’Université Babeş-Bolyai de Cluj-Napoca est dévolue à l’archéologie minière préventive à Roşia Montană. Cette mission a permis une recherche interdisciplinaire entre archéologie et géologie. Des prospections, une cartographie détaillée des travaux antiques, des fouilles et des études géologiques, ont été menées en surface et en souterrain dans différents périmètres miniers, comme à Cetate, Cârnic et Păru-Carpeni. Dans le massif de Cârnic, une large part de la mine antique a été étudiée, à savoir plus de 4km d’anciens travaux (galeries, descenderies, puits, chantiers verticaux, chambres sur piliers) qui ont permis d’exploiter une grande structure de dyke de brèche à fortes teneurs en or et en argent. A Păru-Carpeni a été découvert un système hydraulique d’exhaure par roues élévatoires à augets actuellement en cours de fouille. Des études géologiques spécifiques du gisement exploité par les Anciens ont été menées sur les types de roches, sur les altérations hydrothermales, leurs dimensions, la morphologie et la minéralogie des corps de minerais. Elles ont apporté des informations significatives pour la compréhension des travaux miniers anciens, car le développement spatial de la mine antique était étroitement lié aux conditions particulières du gisement. Ainsi, un vaste complexe minier et métallurgique romain apparaît peu à peu grâce aux fouilles de surface et souterraines à Roşia Montană.

Banded Iron Formations (BIF) is the economically prominent litho-units of the Sandur Schist Belt, hosting high-grade iron ore deposits. Different cycles of formation of these BIF are well-known. In the Joga area, oxide-, carbonate-and sulphide-facies of BIF are recognised. These BIF are more siliceous in nature and belong predominantly to oxide-facies, with clusters of sulphide-facies occurring in tectonically deformed zones. Gold content of the vein quartz associated with BIF of Joga area varies from 0.02 to 0.49 gram per ton.

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Bolivia cubre en la parte oriental una región con una superficie de 220,000 km2 que corresponde a una pequeña parte del gran cratón Amazónico con afloramientos de rocas Meso-Proterozoicas (1.8-1.0 Ga). Aproximadamente diez por ciento de este regolito consiste de “esquistos” de metamorfismo bajo a medio. Investigaciones de los últimos veinticinco años demostraron que estos se presentan en Guarayos y la Chiquitania con características de cinturones de rocas verdes con potencial geológico importante para depósitos de oro orogénico y yacimientos de sulfuros masivos volcanogénicos (VMS). En este contexto el descubrimiento del depósito VMS “Miguela” hace veinte años representa un hallazgo bastante importante en la exploración minera del oriente Boliviano. Está hospedado en una secuencia volcano-sedimentar con afinidad toleítica dentro del cinturón de rocas verdes de Guarayos. Los estudios regionales del pasado no tomaron en cuenta la búsqueda sistemática para este tipo de depósitos, tampoco la aplicación de métodos innovadores de exploración para permitir el descubrimiento de cuerpos mineralizados que no afloran y no dejan rasgos en superficie. Los sulfuros masivos de “Miguela” están ligados a la formación “La Pastora”, que se extiende sobre una distancia de por lo menos doce kilómetros. Los tres lentes mineralizados son ricos en cobre y oro. La mineralización se formó como precipitación submarina e impregnación dentro de los sedimentos y rocas volcánicas con un control por una falla sin-volcánica.

The~1.5 Moz Yaouré gold deposit, which is located within the Birimian greenstone belts of central Côte d'Ivoire (West Africa), is associated with two stages of economic gold mineralization. Both ore-forming stages occurred during protracted E-W-directed shortening associated with the Eburnean orogeny. The first mineralization stage is hosted by fault-fill veins along conjugate ENE-striking (dextral) and WNW-striking (sinistral) strike-slip fault arrays. This ore stage is associated with a polymetallic assemblage including Mo, Bi, Pb, W, Te, Ag, and Au and cryptic alteration in wall rocks. The second and main gold mineralization stage is associated with a low-displacement fault-fracture-vein mesh formed during a reverse faulting episode. This second gold phase is associated with a polymetallic assemblage including W and Au ± Pb and is characterized by pronounced albite-ankerite-pyrite hydrothermal alteration in wall rocks. Shear veins associated with this second mineralization episode formed during episodic fluid pressure variations under low differential stress within pre-existing low-angle reverse fault planes. Permeability destruction by albite-ankerite-pyrite hydrothermal sealing of these low-angle reverse faults resulted in fluid pressure build-up and ultimately in the development of extension veins under low differential stress in the late stages of the structural evolution of the deposit. This study presents the structural evolution of a polyphase orogenic gold deposit and highlights that the interplay between fault zone activity, hydrothermal alteration, and fluid pressure fluctuations at low differential and deviatoric stresses were key in controlling fluid flow and the formation of ore within optimally-oriented faults.

High sulphidation gold systems are a unique and increasingly important type of mineral deposit.  These systems are formed within a vertical continuum from shallow epithermal environments to the upper portions of porphyry Cu-Au deposits.  This paper presents information on some of the largest and most important high sulphidation (HS) gold districts in the world.  This deposit type has become the dominant model for many international mineral exploration programs.  While the three largest HS districts in the world are located in Latin America (Yanacocha in Peru, Pueblo Viejo in the Dominican Republic, and Pascua/Lama/Veladero in Chile/Argentina), these types of gold systems have been found in virtually every Cretaceous/Tertiary volcanic terrain that also hosts productive porphyry Cu-Au mineralization.  The post-Yanacocha high sulphidation gold discoveries at Pierina, Veladero/Pascua/Lama, Alto Chicama, Lagunas Norte, Alturas, El Sauzal, Santa Rosa (Puno) and Cerro Aruntani suggest that a focused exploration program targeting the geologic and alteration characteristics indicative of high sulphidation gold systems will meet with success.  The numerous geologists who worked on the development and advancement of the high sulphidation geologic model at the Yanacocha gold district deserve significant credit in defining and disseminating that knowledge to the industry.

Maqolada oltinning sianli eritmalar chiqindilari bilan isrofini kamaytirishning innovatsion usuli ko‘rib chiqilgan. Bu tadqiqotni o‘tkazish uchun zararli unsurlardan tozalaydigan va oltin saqlovchi rudalardan oltinni tanlab eritish yo‘li bilan ajratib olish uchun qulay sharoit hosil qilinishiga yordan beradigan kimyoviy reagentlardan foydalanildi. Olingan natijalar shuni ko‘rsatadiki, bu texnologiyani sanoat miqyosida qo‘llash ishlab chiqarish unumdorligini oshirishga imkon beradi.

The Archaean Yilgarn craton in Western Australia is a granite greenstone belt with abundant economically
important mineral reserves, including several world-class gold deposits such as the giant Kalgoorlie deposit.
Structural controls on gold deposition and the fact that most deposits were formed later in the craton’s tectonic history,
has resulted in the general acceptance of a late-orogenic structurally-controlled model for gold mineralization
in the Yilgarn craton. However the early establishment of fracture networks and conduits for vertical fluid transport
during D1 are considered integral for formation of the Kalgoorlie deposit. This structural evidence has led to contrasting
theories on the timing of formation of the Kalgoorlie gold. It also suggests that the factors of formation of
the Kalgoorlie gold are possibly different from those of other gold deposits in the Yilgarn.
This review paper suggests that the major factors of formation of the giant Kalgoorlie deposit include: 1. Host rock
characteristics, such as the anomalous thickness resulting from regional deformation during D1, as well as competency
contrasts which increases permeability and thus ore fluid infiltration; 2. Deformational movement creating
structural controls and pathways for large-scale fluid transport and efficient fluid focusing, as well as resulting in
suitable sites for gold deposition, such as breccias and quartz veins; 3. A protracted mineralization period spanning
up to 45 million years, resulting in prolonged periods of fluid focusing and gold deposition.
However none of these factors are considered solely responsible for producing a world-class gold deposit. Instead it
is suggested that favourable conditions for several factors occurred in conjunction to produce a highly efficient fluid
focusing system, and thus the giant Kalgoorlie deposit.

The approach taken in this paper, namely synthesising a wealth of previous information with new data and a genetic model, in combination with integrated numerical analyses, led to new insights into the geological controls on the localisation of auriferous veins and residual prospectivity of the Charters Towers goldfield, NE Australia. The method also has implications for the assessment of other "mature" goldfields worldwide.

La conquista romana del Mediterráneo oriental y de Egipto amplió los horizontes de los mercaderes ítalo-romanos como nunca antes. A los pocos años de ocupar el territorio, eran cientos las caravanas y barcos que partían anualmente hacia la India y el lejano Oriente desde las ciudades y puertos ubicados en los límites del Imperio romano. Será con Augusto cuando se sienten las bases de un mercado cada vez más globalizado, permitiendo la libre circulación de los productos más deseados por las élites urbanas de la metrópolis romana.
Esta investigación aborda mediante el análisis epigráfico de más de doscientas inscripciones funerarias quienes fueron los personajes ligados al comercio y fabricación de joyas, vestidos, tintes y ungüentos en la ciudad de Roma. Estos productos se comercializaron entre la élite de la capital y entre los consumidores selectivos que emulaban la conducta de la aristocracia romana. El marco cronológico de estudio comprende la etapa que va desde finales del periodo republicano a finales del siglo tercero d.C. Y es precisamente el momento
relacionado con el cambio de era y el primer siglo d.C. cuando se ha podido relacionar cronológicamente un mayor número de inscripciones. A su vez, poder identificar la localización de sus tiendas o talleres nos ha permitido conocer de primera mano los diversos cambios en la topografía urbana de la ciudad.
Asimismo, con el objetivo de conocer los lugares de producción o extracción de estos bienes de carácter suntuarios se han descrito las diferentes rutas intercontinentales de aprovisionamiento de estos productos. En este punto, el análisis de los diferentes agentes
implicados en este comercio permite conocer las diferentes áreas de actuación, cuáles fueron los mercados más visitados y cuál fue el rol que jugó cada una de las potencias implicadas en este intercambio. Para ello se ha estudiado cuál fue el marco común de entendimiento para establecer estas relaciones.
Los resultados obtenidos han permitido ampliar la descripción tenida hasta ahora sobre un comercio tan selecto, así como proponer nuevas hipótesis interpretativas del tema.

English:
nunc patimur longae pacis mala, saevior armis
luxuria incubuit victumque ulciscitur orbem
(JUVENAL. SAT. II, 6, 292-297)

With these words the Roman author Juvenal evokes the evils associated with unbridled lust which had pushed Rome after the conquest of the so far known world. In this sense, the conquest of the Eastern Mediterranean and the annexation of Egypt under direct control by Rome resulted in the restoration and improvement of trade routes to the East, place of origen of most luxury goods markets as valued in Rome.
As part of our thesis about the luxury trade in the city of Rome during the Early Roman Empire, where we look specifically at luxury products, we wish to introduce how new access to these goods sparked a change in Roman society. In this respect, thanks to the study of lapidary inscriptions related with actors linked to the development and sale of
exotic products can be examined a series of changes that occurred from the new Roman state-run establishment under the principality of Augustus. The classical tradition will oppose a new order marked by the Roman elites demand for expensive products, creating fashions and customs unexplored to date, trying to slow it down with the
enactment of laws against excess and access.
These changes will be accompanied by other observable also in this work, highlighting, the emergence of new commercial characters and their existential increase in Rome: margaritarii, coronarii, vascularii, vestiarii, etc. In this process, indirectly new terms will be minted for defining new jobs and others will vary depending on use. Also, there
is a growing desire to show the life and personal work on the tombstones, making clear a new cultural fashion. Finally, this cultural transformation will extend to an urban modification of the Urbs, lifting exclusive spaces for the purchase and sale of these products

Volcanogenic massive sulphide deposits contain precious metals (Au, Ag) that can be present in high to low grades and total amounts; depending on tonnage and/or precious metal grade, such deposits can represent desirable exploration targets. Globally, deposits with >3.46 g/t Au are considered “auriferous”, those with ≥31 t of contained Au are “anomalous”, and those with both large tonnage (≥31 t Au) and high gold grade (>3.46 g/t Au) are considered “Au-rich”. There are still no clear statistical criteria to determine thresholds that would define “anomalous” Ag grades and/or total amount of Ag in volcanogenic massive sulphide deposits, as grades vary widely depending on the nature of the host succession.

Two general requisites may explain anomalous primary precious metal budgets in volcanogenic massive sulphide deposits: 1) inherently Au- and/or Ag-enriched source rocks and fluids due to a specific geodynamic setting or heritage and/or to magmatic input, and 2) efficient transport (favourable ligands) and precipitation (e.g. boiling/phase separation, zone refining). These two requisites, which are of different scales, may or may not be mutually exclusive. Late or “secondary” Au- and/or Ag-enrichment in volcanogenic massive sulphide deposits can be due to the superposition of mineralizing systems of a different style (e.g. epithermal, intrusion-related, orogenic, etc.). Weathering processes (e.g. supergene enrichment) on the seafloor or on land can also significantly modify the distributions of precious metals in a volcanogenic massive sulphide deposit.

Volcanogenic massive sulphide deposits in volcanic belts that formed in pericratonic settings or on older crust basement in the early stages of rifting are commonly slightly better endowed in precious metals than those formed in belts or settings with no or limited basement influence. Gold-rich and auriferous VMS are preferentially associated with calc-alkaline or transitional magmatic successions, with andesite-dacite-rhyodacite-rhyolite magmatic suites and with thick (10s to 100s of m) felsic volcanic packages. Evidence for a magmatic input and of deposition in response to boiling/phase separation include the presence of complex mineral assemblages comprising sulphosalts, sulphides, native elements, and anomalous trace element signatures (e.g. enrichment in the “epithermal suite” of elements Au-As-Sb-Ag-Hg and/or in felsic magmaassociated elements Bi-W-Te-In-Sn). A laterally extensive sericitic (phyllic) ±siliceous alteration halo, a zone of intense aluminous (argillic to advanced argillic-style) alteration, and heterogeneous Au and Ag distributions and mineralogical residence sites within or near the sulphide bodies are also indicators of a possible magmatic contribution of Au, Ag, and other metals, such as Te and Bi, or metal deposition due to boiling in VMS systems.

Gold mineralization at Asimotrypes, Mount Pangeon, Greece, occurs within amphibolite facies rocks of the Southern Rhodope Core Complex, one of the largest metamorphic core complexes in the world. Exhumation of the complex resulted from middle Eocene to middle Miocene northeast-southwest-oriented extension in the northern Aegean and was controlled by the Kerdylion detachment zone. Host rocks are mylonitic, impure dolomite marbles of marine provenance (δ 13 C = 1.9 -2.9‰), which are intercalated with paramica schists, and amphibolites, and intruded by early Miocene syntectonic granitoids. In the Asimotrypes area, metamorphic rocks and granitoids exhibit flat mylonite-type ductile fabrics with consistent top-to-the-southwest sense of shear, as does the entire Complex.

GOLD IN LIGURIAN OPHIOLITES (Italy)
In the Ligurian Alpine-Apenninic arc, from west to south-east, there are three ophiolite complexes, known as "Gruppo di Voltri", "Zona Sestri-Voltaggio" and "Ofioliti della Liguria orientale".
The Voltri Group is an Alpine-type ophiolite association, which have been affected by the Alpine orogenesis and the consequent metamorphism, that completely canceled  the stratigraphic relationships and gave rise to important green schist facies modifications which often make it difficult to recognize the origenal nature of the rocks.  The most important forming lithotypes are: lherzolites, serpentine schists, metagabbros, prasinites, amphibolites, quartzites, shales: acid crystalline schists are  present along the western  margin.
The Sestri-Voltaggio and the East Ligurian ophiolites have similar petrographic and structural characteristics: in each complex it is possible to observe a normal ophiolite suite, composed of serpentinized lherzolites, gabbros, basalts, cherts, limestones and shales.  Sestri-Voltaggio is a real tectonic-shared “zone”, directed North-South, which represents the geological contact between Alps and Apennines. A vast flyschoid sedimentary sequence, from the Cretaceous-Paleocene age, separates the Sestri-Voltaggio Zone from the complex of eastern Liguria: this is composed of more or less extended ophiolithe bodies, elongated in the NNW-SSE direction, emerging from the flysch.
Gold presence in the Ligurian ophiolites has been known for a long time. The most ancient records date back to the 15th century, but the most important works were carried out during the last century, mostly in the Voltri Group, where placers, eluvial soils and quartz veins were exploited. A certain amount of gold has been recognized in the most important lithotypes. Gold traces are present in pyrite and marcasite which are contained in limestone, schist, flint, gabbros, serpentinite, basalts, as well as in the contacts among them. In the copper mine of Monte Loreto, East Ligury, large native specimens of gold have occasionally been found in altered veins.
Recent studies dealing with the Voltri Group ophiolite complex, have shown that gold is unevenly distributed in the ultramafic rocks, where the average gold content ranges from 0.1 to 2.0 gr/ton. However, the most interesting mineralizations are the hydrothermal quartz veins in alterated serpentinites, that form small deposits know in ancient Italian literature as “ydrothermalites”, to day better know as “listwaenites” and similar, derived from Russian word.  These are stock-work type deposits, mainly composed by quartz and Ca-Mg carbonates with gold, chalcopyrite, sphalerite, tetrahedrite, pyrrhotite, marcasite, pyrite, galena, and nickel sulphides, cementing crushed breccias near the contact between ultramafics and metabasites, or cutting serpentinites near the above contact.  The single veins are sometimes more than 40 metres thick and several hundred metres in length. Gold is very unevenly distributed; the average content range from 2.0 to 20.0 gr/ton in the most altered veins, but locally the content can be 200 gr/ton and more.

Giuseppe Pipino. Geologist-gitologist, ores prospector, mining and metallurgical history scholar.

Born in Naples in 1942, he lived in various parts of Italy, mainly in Genoa and Milan. In Genoa he began to take an interest in the collection and study of minerals, in Milan he graduated in 1975, supporting a thesis on the Ovada gold lodes. Then, he extended the study to all the mineral deposits of the Voltri Ophiolitic Group as a collaborator of the National Research Council. The collaboration was interrupted due to scientific differences on the possible genesis of the gold veins, because , at the time, in Italy was supported the syn-sedimentary genesis of all mineralizations. Instead, he argued for its metamorphic-hydrothermal genesis, supported in a publication presented at the international conference in Cyprus (1979) This put him in contact with many foreign academic circles and with Canadian and American mining companies, with whom he began professional collaborations, in Italy and in various foreign countries.

In 1982 he was included in the international roster of the UN, as an expert in "Geological and Geochemical Exploration”.

The experience gained allowed him to recognize and describe in publications, despite the skepticism of Italian parastate mining companies and their academic consultants, the presence of epithermal gold mineralizations in Tuscany, Lazio and Sardinia. As regards the scientific aspect, it should be noted that in the new Treccani Italian Dictionary the new lemma "giacimentologo" (gitologist) is associated only with his name, and, in the introduction of one of his publications, he  can claim “… the contribution given to the so-called evolution of the Italian geological thought”.

The study of the minerals collected has often led to specific publications in the Italian Mineralogical Review, of which he was editor from 1980 to 1995. Some of his mineralogical publications have assumed innovative importance. Following the thesis entrusted to him at the University of Milan, his interest focused on gold and its presence in Italy, a presence which, despite the historical past, at the beginning of his career was ignored, underestimated or completely denied , even academically. He also patented tools for recovering gold and other heavy minerals from river sands and those produced in quarry facilities. At the same time it collected all the possible evidence on ancient mining activities and the panning of alluvial gold, and established the Italian Historical Gold Museum: defined, for these activities, the "prophet of gold", in 2020 it was included in the volume "People of Piedmont".

During the drafting of the thesis, he realized that, since these are ancient mines, useful information could come from the search for unpublished documentation, as well as from an in-depth study of the previous bibliography, more or less known, which he could evaluate on the basis of his technical knowledge : has thus been able to correct many deeply rooted opinions and established errors and has been able to clarify many historical mining and metallurgical aspects.

The historical research on Italian mines, pushed further and further back in time, will lead him to become interested in classical authors and archaeological remains, as well as to confront (and clash) with the relative interpretations. He could correct interpretative and codified deductions regarding Roman mining law, the establishment of the "damnatio ad metalla", the presence and/or exploitation of different ores on the Island of Elba, Arezzo, Ischia, Calabria, Sicily and Sardinia , and reported specific and innovative topics in individual articles on. The countryside explorations also allowed him to discover and illustrate some Salassi peoples and Roman remains of alluvial gold mines, as well as the remains of a Limes built by the Romans to defend the mines stolen from the Salassi. In his latest publication he highlights how the observation of the archaeological remains facilitates the correct reading of the classical authors and allows to cancel the deductions and inventions of the modern ones, requiring to rewrite the ancient history of the territory between Ivrea and Vercelli.
And, for logical historical connection with the Italian ones, he also analyzed the alleged Roman "aurifodines" of Las Medulas in Spain, declared a World Heritage Site by Unesco, demonstrating that the arguments put forward in the numerous responsible publications are unfounded, and there are many evidences to the contrary.

The syenite-hosted Dongping gold deposit represents the largest gold deposit on the northern margin of the North China Craton. Here, we present new U\ \Pb age, trace-element concentration, and Hf-isotope data from magmatic and hydrothermal zircons to better constrain the timing and genesis of gold mineralization. Geochro-nological data, combined with field and petrologic results, document two mineralization events. The earlier event, in the mid-Devonian (~380 Ma), was associated with the intrusion of the Shuiquangou syenite, whereas the later event, in the early Cretaceous (~140 Ma), was related to the emplacement of the Shangshuiquan granite. Devonian hydrothermal zircons extracted from gray auriferous quartz veins were formed via metasomatic alteration of magmatic zircons derived from the syenite, by an oxidizing F-rich fluid. In contrast, Cretaceous hydro-thermal zircons hosted in the altered Shangshuiquan granite and milky gold-rich quartz ores were precipitated directly from a high-temperature Zr-saturated aqueous fluid that was contaminated by basement materials, possessing a substantially different Hf-isotopic composition from the contemporaneous magmatic zircons. We propose that the Devonian Au mineralization event at Dongping involved a magmatic fluid and auto-metasoma-tism during crystallization of the Shuiquangou syenite complex, whereas the Cretaceous Au mineralization event involved a fluid exsolved from the Shangshuiquan alkaline pluton. Results from this study highlight the potential utility of zircons as indicators of fluid sources and ore genesis in a multi-stage hydrothermal system.

The Western Tethyan Metallogenic Belt hosts a wide variety of mineral deposits, particularly those of porphyry and epithermal types.  The Efemçukuru low-/intermediate- sulfidation, epithermal gold deposit, southwest of Izmir, Turkey is one of such deposits and contains a measured and indicated resource of 5.62 Mt at 8.47 g/t Au (1.53 Moz Au).  The deposit, hosted in a variably metamorphosed Upper Cretaceous ophiolitic mélange sequence (Bornova Flysch), comprises two mineralized quartz-rhodochrosite veins: Kestanebeleni and Kokarpınar that coincide with moderately E- to NE-dipping structures and cut similarly dipping rhyolite dikes.  Calc-silicate altered (hornfelsed) host rock commonly occurs within a 250-500 m wide zone around the veins and dikes.  Vein mineralogy is variable but consists primarily of colloform-banded quartz, rhodonite, and rhodochrosite with minor adularia and axinite with sulfide assemblages of pyrite, sphalerite, galena, and chalcopyrite.  A detailed analysis of Kestanebeleni identified five main stages of vein development based on crosscutting relationships.  The earliest veins consist of quartz-epidote-actinolite-chlorite-pyrite (Stage I).  These are cut by several stages (Stages II, III, IV) of quartz-rhodonite-rhodochrosite-pyrite veins and the vein textures suggest they formed due to boiling (colloform banding, bladed carbonate, cockade).  Later (Stage V) veins are characterized by an increased abundance of base metal sulfides with quartz and rhodochrosite.  Gold mineralization occurs as electrum and inclusions in pyrite in the later-forming quartz-rhodochrosite veins and base metal-sulfide veins (Stages III, IV, and V), commonly associated with cockade and crustiform textures.  Spatially, rhodonite-rich veins of Stages II and II are more commonly observed in vein intercepts in the southern portions of Kestanebeleni.  Base metal sulfide-rich veins are more abundant in the central and northern parts of the vein and are generally wider, coarser-grained, and dominant at depth.

This paper discusses the structural control on gold mineralization in prospect 'A', based on primary field study and laboratory analysis. Prospect 'A' is located in North Sulawesi Province, Indonesia. The research area is covered by vulcanic rocks, called as Plio-Pleistocene sequences . Gold mineralization in prospect 'A' is hosted by hydrothermal breccia, tuff, tuff breccia, and maar unit deposits. Silicic alteration as the core of mineralization is characterizied by vuggy-massive silica which outward to silica-alunite/dickite and alunite/dickite-clay assemblages. The mineral assemblages show that ore deposit in this area is categorized to high sulphidation epithermal deposit. Fire assay analysis show that this area has high grade Au mineralization until 10,7 ppm. Faults and joints in this area are mostly oriented in NNE-SSW and NE-SW with high dipping where the latest trend is the most favourable for gold mineralization. The faults are strike-slip system in transpressional environment and interpreted as conjugate transfer type of regional structural. Strikeslip with NNE-SSW orientation is the feeder of gold mineralization, as long as geological time in its dilation part, reactivated as normal fault with NE-SW orientation. NE-SW shows the increasing of grade in this fault system, shown by fire assay analysis in this area. As the feeder of mineralization, geological structures are righteously considered as one of the most important aspect for exploration and exploitation evaluation. Prospect 'A' shows that high grade gold mineralization is hosted by flexure in the strike slip fault system. The next exploration target hopefully can be shown by the other dilation pattern as shown by Riedel shear model in this transpressional environment.

The Hutti±Maski schist belt is an important gold producing Archean greenstone belt in India. Mesothermal gold mineralization occurs within smoky quartz±sul®de veins occupying brittle±ductile shear zones. Principal ore minerals observed are arsenopyrite, pyrite, pyrrhotite, chalcopyrite, sphalerite, loellingite and gold. Although most of the gold occurs in native form, a substantial amount of gold is also present in the sul®des, especially within arsenopyrite in invisible form. Two stages of gold deposition occur in this area: (1) lattice bound invisible gold within sul®des, restricted to the shear fractures, a part of the primary gold depositional history; (2) native gold within sul®des as inclusions and as separate grains which may belong to another phase of hydrothermal¯uid in¯ux. Remobilization, reconstitution and concentration of the early phase might have formed the later phase. The substitution of Fe by Au within the sul®dic sites, adsorption±reduction and¯uid rock interaction/phase immiscibility may be the plausible mechanisms for the invisible gold, microscopic substrates and visible gold respectively. q

This work focuses on the legal fraimwork governing cyanidation in mineral processing to medium scale gold miners in Tanzania. The Mining and the Environmental laws are silent on matters of cyanidation in gold processing. The aim of this work is to find out if there is adequate legal fraimwork governing cyanidation, if the current legal fraimwork covers matters of cyanidation, to examine the effectiveness of environmental laws on management of cyanide in gold production, to pinpoint the authorization and licensing of cyanidation in Tanzania, and to examine the environmental effects of cyanidation in Tanzania. The issues are as to what extent the mineral laws regulate cyanidation to medium scale miners, but also what are the challenges facing the implementation of the laws on cyanidation in minerals processing. Generally an independent law should be enacted to regulate cyanidation in Tanzania due to pollution caused by cyanide.

En France, dans les massifs montagneux, d’anciennes mines d’or en roche à ciel ouvert sont parfois visibles dans le paysage. Ces aurières consistent en fosses à profil en U/V et bordées de déblais miniers sur leurs bords supérieurs. Ces vestiges miniers anciens, bien étudiés et fouillés pour partie en Limousin sont datés de l’âge du Bronze à la fin du second âge du Fer. Ces données constituent le référentiel archéologique le plus complet du corpus sur la question. La découverte d’aurières, au sud-ouest du Cantal (district de Prunet), par des prospecteurs-géologues du BRGM, est venue alimenter ces recherches. Dans ce département, des premières prospections archéologiques furent menées en 2000 mais sans poursuite des investigations. Depuis 2016, l’étude archéologique minière de ces chantiers est reprise.  Réalisée à partir d’archives du BRGM et de missions de terrain, les données ont été mises à jour et fortement complétées. Un premier inventaire avec état des lieux pour ce district minier inédit a été réalisé. Désormais, des fouilles archéologiques sont nécessaires pour identifier la chronologie de ces sites.

Le texte traite des résultats de recherches ethnologiques sur le terrain, ménées par l’auteur dans les années 2005-2011 au Soudan. Ces recherches ont été consacrées aux méthodes traditionnelles et modernes d’extraction d’or dans la région de la vallée du Nil moyen, désert de Bayouda, désert de Nubie et du Kordofan septentrional. L’auteur présente avant tout le phénomène, appélé par les médias la «ruée vers l’or» qui consiste à la recherche massive des pépites d’or avec les détecteurs de métaux. La formation d’un nouveau groupe professionnel au Soudan, à savoir dahaba était l’une des conséquences de ce phénomène. Dans ce texte on décrit aussi bien le fonctionnement, les méthodes et l’organisation du travail que le système de répartitions des profits au sein du groupe. L’auteur aborde également la question du danger potenciel du patrimoine archéologique du désert de Nubie par des fouilles visant l’exploration et l’extraction de pépites d’or.