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By Lawrence Winter

why are these deposits significant? (i) economically and (ii) in a VMS/geological context. ?Significance of the tectonic setting. ?New understanding of the regional geology: volcanic stratigraphy, first geochronologic data. ?Deposit geology: paleomorphologyof the seafloor setting. ?Lessons and conclusions ?Regional Potential

May 1, 2006

By Franz Posepny

CONTENTS. Introduction. Part I. General Facts And Theories. [ ]

Jan 1, 1902

The Physiographical Features of the Region The Middleback; Range proper, from the Iron Duke in the south to the Iron Prince in the north, extends in a meridional direction for 21 miles, but may well be taken to embrace also the Iron Knob and Iron Monarch prominences so that the total length of the Range is 37 miles.Although no great altitudes are reached, the slopes of the high country are steep and the Range stands out prominently above the peneplaned surface of upper Eyre Peninsula. The Range is built up of sub-parallel ridges at some places, and its continuity is interrupted by transverse breaks or gaps resulting from normal stream erosion and corrosion during earlier periods when precipitation was heavier and streams were more active. Traces of high-level gravels remain on the flanks of Kimba Gap. A former mature stream on the western side of the Range has had its lower reaches blocked by sand and the old stream channel has been converted into an eiongated basin of internal drainage. The sand dunes in this area appear to be practically stationary at present, being fixed by mallee vegetation. Their trend is west-northwest.The relief of the Range is regarded as having been determined primarily by meridional strike faulting and selective silification of some of the beds. Dip faulting on the Iron Duchess leases has produced subsidiary features only.The Rocks of the Region: In order that some of the points made in the discussion of the genesis of the ore bodies may be appreciated it is necessary to consider the stratigraphical succession and the igneous types represented. This classification may be...

Jan 1, 1949

By Max Boehmer

(Pittsburg Meeting, March, 1910.) AFTER 30 years of development and after an output of $350,000,000 in value of gold, silver, lead, zinc, and copper, there has not been published a satisfactory explanation of the origin of the immense deposits of the Leadville district. The original examination find survey of Leadville by members of the U. S. Geological Survey was a most magnificent piece of work, but their attempt to explain the origin of the ores was based upon the then-accepted theory of lateral secretion, originated by Sandberger, which theory was afterwards disproved in many cases by further development in numerous districts. This theory contended that the ore in the veins had been leached by surface-waters from the eruptive rocks in the immediate vicinity, and it had its origin in the fact that the neighboring eruptive rocks all contained, to an appreciable degree, the several metals found in the ore-deposits. But the practical miner, reasoning in a simple manner from the condition of things as he found them underground, soon discovered the fallacy of this proposition. He reasoned that, in the case of the Leadville deposits, this theory could not be true, because, if the ores were leached from the overlying eruptive rocks by surface-waters, they would as a matter of necessity be controlled by the action of gravity, and the main bodies would collect in- natural depressions of the underlying limestone, and at all points where such depressions existed. But this was not in accord with the channels of ore as he found there ; and hence the theory of lateral secretion in this district was never accepted. Another objection to it consisted in the fact that large areas within the ore-bearing district contained no ores whatever, although their formation was the same, and the same limestones were covered by the same thick sheet of

Feb 1, 1910

A genesis based on new developments in the physical chemistry and flow properties of colloidal substances is proposed for the pipe-like Peko orebody. The rheological behaviour of sediments is governed by the contained colloids. Remobilization of thick pasty sediment during diagenesis is regarded as an essential step in the concentration of metal dispersed in sediments. At a high concentration the sediment pore fluid is a dense gelloid such that van der Waals attractive forces between the colloidal particles exceeds the coulombic repulsion. This permits accretion of the colloids into globular clots and their fracture fragments. These have a uniform size distribution dependent upon the rate of shear, and the sediment lithifies to clotted, porphyry-like, "gritty", dolomitic or igneous-looking intrusions and flows. The physical chemical properties of natural sediment colloids appear adequate to account for ore formation.Adsorption accounts for the dispersion and retention of metal in sediments. Accretion accounts for the segregation of the colloidal materials to give the various types of clotted igneous-looking intrusive source rocks. Syneresis enables the colloids to spontaneously draw together and to dehydrate. Formation of an ordered lattice achieves a lower energy state and desorbs metals and insoluble metal compounds "particle by particle" into the escaping water of hydration and pore water. Peptization enables migration of the metal hydrosols as stable dispersions until they merge for outflow through seepage zones or water extrusion channels. Nucleation and concretion precipitate the metal dispersoids from pore waters seeping through hydrous parts of the source rock, porous beds, faults, and zones of weakness by which the connate waters leave the lithifying sediments. Gelatinous precipitated mineral matter in the ore channels is capable of thixotropic reliquefaction when disturbed by shock or movement. Local reintrusion, flowage, interveinings,brecciation, and intermixing of the materials is the result.The principles of the suggested genesis are applicable to both syngenetic and epigenetic mineral accumulations.

Jan 1, 1966

By W. M. Tupper

[The two types of sulfide deposits in the Bathhurst Newcastle area are; (a) epignetic fissure deposits, and (b) massive sulfide deposits. Geological evidence has been variously interpreted to suggest a syngenetic origin, a source bed' origin, or a magmatic hydrothermal origin for the massive sulfide deposits. Sulfides disseminated through the black shales and argillites of the host rocks are enriched in S32 (mean value 22.34, S34. = 5.8 per mil) relative to the meteoritic standard of 22.21, and have a broad spread in range of values. S32/S34 ratios of sulfide minerals from the deposits occur in two distinct groups. The massive sulfide deposits exhibit ratios between 21.88 to 22.05, while the fissure deposits exhibit ratios between 22.18 and 22.21. These results suggest two separate sources for the sulfur, each, however, resulting in magmatic hydrthermal deposition because of the narrow spread of ratios in each group. Granite intrusive into the host rocks of the sulfide deposits have a mean K/A age of 386 ± 10 M.Y. Lead minerals in the sulfide deposits have a mean nodel lead age of 370±20 M. Y. Thus the lead minerals and the granite bodies were emplaced during the same major orogenic event. Sulfide minerals from magmatic hydrothermal deposit have a very narrow range of S32/S34 values, as do those of the Bathurst area. It seems reasonable, therefore, that well homogenized magmatic hydrothermal solutions are the most logical source of the sulfide deposits. Furthermore, the homogeneity of the lead isotopic abundance data gives strong independent evidence that the ores are of a magmatic hydrothermal origin.]

Jan 1, 1960

By Paul M. C. B. M. Cools, Martin Th. van Staveren

In 2010, the 5-years joint industry programme Geo-Impuls started in the Netherlands. The ambitious goal of this programme is to reduce geotechnical failures in our civil engineering projects by half in 2015. In the Geo-Impuls programme over 40 client organizations, engineering firms, contractors, research institutes, and universities are involved. In a risk-driven way, and based on top risks and dilemmas, the participants defined three central development themes. These themes are (1) contracts, for dealing with legal issues, (2) geo-engineering, for dealing with technical issues, and (3) communication, for paying attention to differences in risk perception by the human factor. In total 12 Working Groups contribute to these themes by producing one or more specific tools. These provide practical solutions for how to deal with contractual, geotechnical, and communication issues. The tools include working processes, guidelines, best practices, as well as some instruments. The development of these tools, as well as the available results, will be presented in this paper. From the start, Geo-Impuls embraced geotechnical risk management (GeoRM) as the risk-driven way of working for geotechnical engineering and construction. Over the past years, GeoRM and its supporting tools were already successfully applied in several projects. Therefore, the paper also describes also the GeoRM implementation process, including the quality assurance and control. Finally, the effectiveness of GeoRM will be discussed, by summarizing an analysis of all published geotechnical failures and accidents in construction projects in the Netherlands, which decreased substantially over the past 4 years.

Jan 1, 2017

"The Circular Economy (CE) will play an important role in shaping a resource-efficient society. Enabling this transformation from a linear to a CE requires precise quantification of resource efficiency and thus the economic viability of the system. Based on the development of simulation tools of classical minerals processing and process metallurgy, the Outotec (2018) HSC simulation platform could be further developed (gleaning from many academically published works of the author listed below), permitting the simulation of the CE system and to subsequently calculate its resource efficiency. It enables the estimation of a simulation-based Recycling Index (RI) from a product’s Bill of Material (BoM) and Full Material Declaration (FMD). It is a unique methodology for Design for Recycling (DfR) based on minerals engineering linked to a deep understanding of minerals and metallurgical process engineering. A key to this simulation is a detailed understanding of the mineralogy (both geological and designed) of the CE system and its many products, materials and systems, both in a geological mineral and a product-designer-mineral sense. In addition, a detailed understanding and quantification of the thermodynamic properties of the system (both energy and exergy/entropy) is key to understanding its economics and its limitations. With this approach, the actual losses of the CE system are shown and thus highlights the limits of the CE as defined by minerals and metallurgical process engineering principles. INTRODUCTION From the dawn of the industrial era up to today, many of our products have been created according to the principles of a linear economy: we find resources, make a product, and then dispose of it when we are done using it. But in recent years, there has been a growing awareness of the need to move to a Circular Economy (CE), an approach that aims to maximize the usefulness of products, components and materials across the entire lifecycle. In terms of recycling, this means achieving maximum recovery of materials once products reach the end of their usable life while also maximizing resource efficiency. Of importance is therefore also not only the recovery of critical technology elements that make the CE system run, but also the criticality of the metallurgical infrastructure that must be present to recover these elements economically. Ellen Macarthur (2017) defines the CE as “Looking beyond the current ""take, make and dispose” extractive industrial model, the circular economy is restorative and regenerative by design. Relying on system-wide innovation, it aims to redefine products and services to design waste out, while minimising negative impacts. Underpinned by a transition to renewable energy sources, the circular model builds economic, natural and social capital.” However, when translating this significant message to images, it is striking that the key extractive industry is not depicted in the Ellen Macarthur as well as EU depiction of a CE (EU 2015). Other CE discussions are also wanting in their fundamental detail and description e.g. Accenture (2015) and Beaulieu et al. (2016)."

Jan 1, 2018

Various factors influence the exploration geologist or geochemist in his choice of.an analytical method for gold and other elements which may help him find the elusive gold deposit. One of the first decisions the geologist must make is the nature of sample media to collect for his survey. Needless to say there are many media available depending on the situation. These include rocks, soils, heavy mineral concentrates (from overburden drilling and panned concentrates), humus, vegetation, water, lake bottom sediments, stream sediments, etc. The choice of the sample media will depend to a large degree on the state of development of the particular project from grassroots to mine feasibility. The nature of the geological information required will affect which media and which analytical technique should be chosen for the analysis. Valid sampling from the initial sample collection, preparation and subsampling aspects may also help to determine which analytical procedure is best. Cost and turnaround time are of prime. importance to the explorationist, as it should be, however, these aspects should not be detached from receiving accurate and reliable results.

Jan 1, 1987

The Geograph is a revolutionary seismic system involving special techniques in combining the use of FIT magnetic tape with shock wave echoes created by a weight dropping system.The idea of- weight dropping as a- source of seismic energy is not a new,.,oxie. Records 'indicate òa pos'sihle use of falling weights as early as .1929. 'Dr. Burton McCollum began his experiments in 1938, but it wasn't until 1951 that the method was first proven useful.The first weight dropping crew began commercial operations in Edwards and Sutton .Counties of West Texas in 1953. By 1962, more than '40 weight drop-ping.crews have come into existence with operations in the United States, Canada, Algeria, Iraq, Argent na,òSpanish West Africa, Tunisia, Qatar, Niger Morocco and Libya by most major oil companies and larger independent oil companies. .

Jan 1, 1962

By Vard H. Johnson

"In contrast with the well-publicized Pittsburgh coal, and the Everglades of Florida, most coal-forming swamps of Cretaceous time in western North America occupied relatively limited areas. They formed in areas of irregular subsidence, bounded by the changing levee systems of meandering streams. Coke quality is determined by the physical and chemical behaviour of the vitrain during thermal decomposition. Vitrain is at least in part a colloidal substance, originally containing large proportions of water; its formation and survival depend on maintaining a shallow cover of stagnant water up to the time of burial. Heat from swamp fires or subaerial dyhydration could destroy it or impair its quality. Observed patterns suggest that the metamorphism is almost entirely thermal, and that there is little relation to tectonic stresses, or loading. These coals had probably achieved essentially their present rank prior to deformation. Evidence of frictional heating along the thrust planes is minimal or absent. Normally, coal beds are aquifers. Oxygen carried into the subsurface becomes available and reacts with the vitrain to destroy its natural thermoplastic properties. The tolerance of oxygen without loss of thermoplasticity is inversely related to the volatile content. Significant lateral variations of coal thickness are common and sometimes occur in short distances. In deformed areas these thickness changes are more commonly due to differential tectonic stress rather than to original thicknesses of coal. Locally, coal is known to have flowed into cavities, or fractures. These principals are discussed in relation to coal deposits of western Alberta and eastern British Columbia."

Jan 1, 1972

By Donald A. Brobst

Barite, the sulfate of barium, occurs in many geological environments in sedimentary, igneous, and metamorphic rocks. The commercial deposits of barite may be classified into three major types. 1. Vein and cavity fillings that occur in rock fractures, along bedding planes, and in various solution structures. 2. Bedded deposits in which barite occurs as the principal mineral or cementing agent in stratiform bodies in sedimentary rocks. 3. Residual deposits occurring in unconsolidated material formed by the weathering of preexisting rocks. The geologic characteristics of each type of deposit are of fundamental importance to the successful search, development, and economic use of barite deposits.

Jan 1, 1980

By B. S. Van Gosen

In recent years, U.S. regulatory agencies have placed emphasis on identifying and regulating asbestos dust exposures in the mining environment, with a particular focus upon industrial mineral deposits in which asbestos occurs as an accessory mineral. Because asbestos minerals form in specific geologic environments, only certain predictable types of industrial mineral deposits can potentially host asbestos mineralization. By applying a basic knowledge of asbestos geology, the costly and time consuming efforts of asbestos monitoring and analyses can be directed towards those mineral deposit types most likely to contain asbestos mineralogy, while saving efforts on the mineral deposits that are unlikely to contain asbestos. While the vast majority of industrial mineral deposits in the Western United States are asbestos-free, there are several types that can, in some instances, host asbestos mineralization, or be closely associated with it. These industrial mineral deposits include a few types of aggregate, dimension, and decorative stone, and some deposits of chromite-nickel, magnesite, nepheline syenite, olivine, rare earth elements, talc, vermiculite, and wollastonite.

Jan 1, 2009

By Frederick T. Fischer

INTRODUCTION Post-Lower Ordovician karstification on a continental scale produced a wide-spread paleoaquifer in the upper portion of the Knox Group of the Southeastern United States. The presence of economic zinc deposits in the Knox of Tennessee is considered to be a con- sequence of this paleoaquifer(1). During The New Jersey Zinc Company's initial exploration of the middle Tennessee region the known artesian nature of modern Knox water and its potentially adverse effect upon mining activities was a matter of concern. This concern intensified as a mining situation appeared imminent and a program of hydrologic investigation was begun in early 1969 and continued through August 1972. The preliminary findings of this work were reported at the AIME World Symposium on Mining and Metallurgy of Lead & Zinc in 1970(2). This paper presents additional data acquired during subsequent stages of the program and relates the hydrologic relationships to the overall geologic framework of the area. PHYSICAL GEOGRAPHY The Elmwood mine is 85km east of Nashville and 8km southeast of Carthage in Smith County, Tennessee (Figure 1). Its physiographic location is in the Central Basin of Tennessee, a basin resulting from erosional breaching across the Nashville Dome of the Mississippian strata which now form the bordering Highland Rims. Both the Central Basin and Highland Rims are divisions of the Interior Low- lands Province. Outcropping rock units of the Central Basin are predominantly Middle Ordovician limestones with scattered high hilltops capped by Devonian and Mississippian strata. One outlier

Jan 1, 1977

By William X. Chavez

The Mantos Blancos copper-silver district, a major copper-producing area since 1961, is located on the Tropic of Capricorn about 45 kilometers northeast of the northern Chile port city of Antofagasta, as shown in Figure 1. Copper oxide minerals occurring as atacamite (Cu C1(OH)3) and chrysocolla (copper silicate-hydrate) were discovered in the district in the early 1900's (Knobler and Joseph, 1962). The mine is situated in the northern Atacama Desert, one of the most arid regions on earth, and presently receives less than 1 cm per year of precipitation. The extreme aridity of the Atacama Desert is thought to have prevailed since at least Middle Miocene time (Mortimer et al., 1978) when development of important supervene copper enrichment was slowed in many areas of northern Chile (e.g., Chuquicamata, Exotica). Despite the paucity of precipitation, landform development is mature, with large alluvial fans and alluvial-filled valleys covering much of the region. In addition, the aridity and presence of salts have led to the formation of a sub-surface cementing of alluvium and colluvium by halite-rich caliche ranging from a few centimeters to over 3 meters in thickness. These factors, resulting in poor outcrop exposure, make even reconnaissance mapping difficult.

Jan 1, 1983

By Waldemar Lindgren

CONTENTS. [ ] I. INTRODUCTION. THE precious metals, gold and silver, are the basis of the monetary systems of the world. It is, therefore, natural and inevitable that widespread interest should be manifested in their production and in the various classes of deposits in which they are contained. At times a great scarcity of the precious metals has prevailed; at other times the production has seemed so abnormally large that fears have been entertained regarding their ultimate retention as standards of value. Since most nations have adopted the gold standard, and the remaining ones appear likely to do the same in the near future, the question of available supply of gold for the present and future very naturally arises. This necessarily involves a consideration of the characteristics of the gold-deposits. After the absorption of the gold treasures of the New World by the conquistadores, the gold-placers of Brazil and Russia

Jan 1, 1913

By R P. Langford, T A. Moore

Indonesia over the last 15 years has experienced a surge in coal exploration, which has led to the development of a major export industry. This coal exploration has improved the understanding of the geology of the Indonesian coal deposits. The main economic coal deposits are of Eocene and Miocene to Pliocene age, which mainly occur in Kalimantan and Sumatra and were formed from peat deposits in an equatorial paleoclimate similar to that prevailing today. Some of these peats were domed peats, which grew above the normal water tables, under a climate of year-round rainfall; these peats grew above the level at which waterborne mineral matter can enter the system, resulting in low ash and sulphur, and locally very thick coal. It is believed that such peats have formed the unusually thick, low ash, and low sulphur Miocene coals of Indonesia. Coal deposits of Eocene age are typically characterised by thinner seams, with relatively higher contents of ash and sulphur. The Miocene coals and Eocene coals both appear to have formed in lacustrine, coastal plain or deltaic depositional environments, similar to the modern peat-forming environments of eastern Sumatra and parts of Kalimantan. The Eocene coals formed mainly in extensional tectonic settings. Miocene - Pliocene coal deposits formed in a range of tectonic settings; the most significant, for large economic coal deposits, are the foreland basin setting of the large Neogene coal deposits of South Sumatra.

Jan 1, 1999

Queensland hosts vast deposits of brown and black coal, significant accumulations ranging in age from Permian to early Tertiary. The great diversity of coal resources in the State to some extent reflects the proximity of Queensland to plate-marginal tectonic processes through much of the Phanerozoic eon. Coal is contained within sedimentary basin fills of four fundamental types; 1. extensional, 2. foreland, 3. strike-slip, and 4. intracratonic. Thick (10 m+) though laterally restricted coal bodies are characteristic of extensional and strike-slip basins, whereas coals of more modest thickness but much greater lateral extent are typical of foreland and intracratonic basins.

Jan 1, 1991

By John H. Morris, R. Gwilym Roberts

"The Upper Beaver Mine, Kirkland Lake, Ontario, is a copper-gold deposit in mafic flows and sedimentary rocks. The deposit consists of a number of orebodies of two types: copper- and gold-bearing chalcopyrite-pyrite-magnetite ore; and gold-bearing quartz veins. Chalcopyrite-pyrite-magnetite ore occurs in two structural forms: as cherty interflow material in coarse clastic roks underlying flows; and as veins. Both sedimentary and vein ore occur in each orebody. The goldbearing quartz veins occur in interflow sedimentary units and at the contacts of oligoclase porphyry dykes.The deposit is in a localized, volcanic-sedimentary basin which began to develop during the emplacement of the upper units of the pyroclastic and sedimentary Gauthier Group, and continued to the early mafic flow activity of the overlying Kinojevis Group. The formation of the volcanic-sedimentary basin is ascribed to the D0 deformation. The deformation is significant in terms of the structural configuration in the mine area, and may be significant regionally, but this has not been demonstrated. The early deformation was followed by two tectonic deformations. D 1 is associated with a penetrative mineral foliation, axial planar to upright mesoscopic folds and striking parallel to the trend of regional fold structures. Mesoscopic flexural-slip folds, kink folds and fracture-crenulation cleavage are attributed to the D2 deformation. It is probable that no large-scale fold structures are associated with the D2 deformation. The gold-bearing quartz veins were folded during the D1 deformation.The close spatial relationship of copper-gold, chalcopyritepyrite- magnetite veins with chalcopyrite-pyrite-magnetite in cherty inter flow material is strong evidence for the derivation of the veins from the sedimentary ore by hydrothermal, metamorphogenic processes. By analogy, it is suggested that the gold-bearing quartz veins were formed by similar processes."

Jan 1, 1982

By I. Campbell, P. C. Jones, E. G. Potter, R. P. Taylor

"The Cobalt embayment is a large domain of Paleoproterozoic clastic sedimentary rocks that unconformably overlies the Archean Abitibi greenstone belt. Regionally extensive sills and dikes of Nipissing diabase, emplaced circa 2219 Ma, occur throughout the embayment and are the preferential host to gold-bearing polymetallic vein systems on the Merico-Ethel property, near the northeastern margin of the Cobalt embayment. These gold-bearing, polymetallic veins are predominantly east-west-trending, steeply dipping, discordant calcite- quartz vein systems that formed close to the time of crystallization (within ~15 m.y., based on Pb-Pb ages) of the Nipissing diabase. The ore mineralogy is complex in character, typically comprising sulfides, arsenides, native metals (gold and silver), and specular hematite, preferentially concentrated along the interface between silicate and calcite gangue. A simplified sequence of mineral deposition in the veins is: (1) "Early-stage" pyrite ± chalcopyrite hosted in quartz ± chlorite gangue; (2) "Main-stage" polymetallic (Cu + Co + As + Ag + Au + Bi ± Pb ± Ni ± U) sulfides, arsenides, and native metals hosted in calcite gangue; and (3) "Late-stage" calcite flooding ± galena. Wall-rock alteration in Nipissing diabase is restricted to narrow (<5 cm) haloes of calcite-chloriteepidote- bearing assemblages, whereas a weak alteration halo of specular hematite, calcite, and allanite-epidote has been observed in the surrounding sedimentary rocks. In terms of their age, geology, mineralogy, paragenesis, and morphology, the gold-bearing vein systems at Merico-Ethel closely resemble the silver-sulfarsenide vein deposits of the historic Cobalt and Gowganda mining camps. These observations indicate that the Au-bearing veins are variants of the Ag-vein systems and as such, have a common genesis belt. L’Échancrure de Cobalt est un large domaine de roches sédimentaires clastiques d’âge Paléoprotérozoïque qui reposent en discordance sur la ceinture de roches vertes d’Abitibi d’âge Archéen. La Diabase de Nipissing, mise en place vers 2219 Ma et qui constitue un réseau de sills et de dykes d’importance régionale, est présente dans l’ensemble de l’échancrure et constitue la roche-hôte principale des systèmes de veines aurifères-polymétalliques de la propriété Merico-Ethel, près de la bordure nord-est de l’Échancrure de Cobalt. Ces veines à minéralisation aurifère et polymétallique constituent un système de veines de calcite-quartz sécantes d’orientation principalement est-ouest et à pendage fort qui se sont formées peu de temps après la cristallisation de la Diabase de Nipissing (à ~15 Ma près, d’après les âges Pb-Pb). La minéralogie de la minéralisation est complexe; elle consiste typiquement en sulfures, en arséniures, en métaux natifs (or et argent) et en hématite spéculaire, préférentiellement concentrés à l’interface entre les silicates et la gangue de calcite. La séquence de déposition simplifiée des minéraux dans les veines est : (1) «Stade précoce» pyrite ± chalcopyrite encaissés dans une gangue de quartz ± chlorite; (2) "Stade principal" sulfures polymétalliques (Cu + Co + As + Ag + Au + Bi ± Pb ± Ni ± U), arséniures, et métaux natifs dans une gangue de calcite; et (3) "Stade tardif" calcite massive ± galène. L’altération pénétrative de la Diabase de Nipissing est confinée à des halos étroits (<5 cm) présentant des assemblages marquées par la présence de calcite-chlorite-épidote, tandis qu’un faible halo d’altération en hématite spéculaire, calcite et en allanite-épidote est noté dans les roches sédimentaires environnantes. De par leur âge, leur géologie, leur minéralogie leur paragenèse et leur morphologie, les systèmes de veines aurifères de Merico-Ethel ressemblent beaucoup aux gîtes filoniens d’argent-sulfoarséniures des camps miniers historiques de Cobalt et de Gowganda. Ces observations indiquent que ces veines aurifères constituent une variante des systèmes des veines argentifères et qu’elles partagent"

Jan 1, 2009