Mehdiabad is the world’s largest Mississippi Valley-type (MVT) Zn-Pb deposit (394 million tonnes [Mt] of metal ore at 4.2% Zn, 1.6% Pb) and contains significant barite resources (>40 Mt). Such large accumulations of barite are not common in carbonate-hosted Zn-Pb deposits. Therefore, the origin of the barite and its association with the Zn-Pb mineralization is of significant interest for further investigation

Uranium-Pb dating of unusual coarse-grained apatite crystals from hydrothermal dolostone breccia in the barite-rich Magcobar zone at the Silvermines deposit, Ireland, indicates an age of 331 ± 5.6 Ma for hydrothermal alteration. This age is in agreement with an Re-Os age on pyrite-sphalerite but differs from previous estimates that were based on palemomagnetism and sphalerite Rb-Sr geochronology at

Filo del Sol is a composite porphyry-epithermal deposit, straddling the frontier between Argentina and Chile at latitude 28°29′ S, that has attracted a great deal of recent attention because of several drill intersections in excess of 1 km long with unusually high Cu, Au, and Ag grades. The deposit is part of the 8.5-km-long, N- to NE-trending Filo del Sol alignment of porphyry and high-sulfidation

The Ruwai skarn deposit is the largest polymetallic skarn deposit in Borneo and is located in the Schwaner Mountains. The skarns and massive orebodies are hosted in marble of the Jurassic Ketapang Complex, which was intruded by Cretaceous Sukadana granitoids. The prograde-stage garnet and retrograde-stage titanite yielded U-Pb ages of 97.0 ± 1.8 to 94.2 ± 10.3 Ma and 96.0 ± 2.9 to 95.0 ± 2.0 Ma, respectively

In the central Andes, giant porphyry copper deposits of similar ages group into discrete geographic clusters that are regularly spaced and aligned within orogen-parallel belts. This clustering highlights how exceptional geologic processes affected localized regions of the lithosphere during mineralization and that the spatial and temporal distribution of giant porphyry deposits is nonrandom. Development

In the paper, “Exploration Targeting in Porphyry Cu Systems Using Propylitic Mineral Chemistry: A Case Study of the El Teniente Deposit, Chile,” by Jamie J. Wilkinson, Michael J. Baker, David R. Cooke, and Clara C. Wilkinson (vol. 115, issue 4, p. 771–791), the online Supplement, Appendix Table A1, contained several rows of incorrect K2O values. The table has been replaced.

The Winu-Ngapakarra Cu-Au deposit (Winu) was discovered in late 2017. Winu is hosted in metamorphosed massive sandstones, siltstones, and lesser mafic rocks that are possible distal and deep-water correlatives of the Malu Formation of the Yeneena basin, also host to the large Telfer Au-Cu deposit. Structure at Winu is dominated by an inclined dome formed through interference between NNW- and WNW-trending

Despite the substantial amount of research on the Cretaceous Samail ophiolite in Oman, the factors controlling the size and metal endowment of the mafic-hosted, Cu-Au(-Zn-Ag) volcanogenic massive sulfide (VMS) deposits remain elusive. This work shows that the volcanostratigraphic position, hydrothermal venting style, and oxidation processes are critical factors controlling the distinct features of

Skarn ores have recently been identified beneath the historically mined placer Sn deposit at Kanbauk of the Dawei region, southern Myanmar. A large-tonnage skarn ore reserve at Kanbauk is estimated to be over 100 million tonnes, with reported ore grades of 0.17% WO3, 0.26% Sn, and 15.4% CaF2, potentially making it one of the largest W-Sn skarn deposits in the Southeast Asian tin belt. The mineralized

The Morelos district, located in the center of the Guerrero gold belt, Guerrero State, southern Mexico, has been the site of several recent gold ± copper skarn discoveries (total of ~8.5 Moz Au) associated with Upper Cretaceous-Paleocene granodiorite intrusions. The Limon, Guajes, and Media Luna skarn deposits developed along the contact of the El Limon granodiorite and the sedimentary host rocks.

Niobium is a critical metal in high demand because of technological advances and the supply risk created by the fact that over 90% of its production is by a single country (Brazil). In this paper, we review the geology of the deposits that are currently being mined and other potentially economic deposits as well as develop models for their genesis. With the exception of the Lovozero deposit (Russia)

The A.M. breccia is part of the Giant Copper porphyry deposit in southern British Columbia. It is the only well-defined zoned tourmaline breccia pipe in the Canadian Cordillera. Tourmaline is a common alteration mineral within the A.M. breccia and is spatially associated with Cu mineralization. Observed changes in tourmaline chemistry range from alkali (schorlitic-dravitic) to calcic (feruvitic-uvitic)

Stratiform to stratabound replacement of a mixed siliciclastic-carbonate host rock is a defining characteristic of many sediment-hosted base metal deposits. Mineralized rocks in clastic-dominated (CD-type) Zn-Pb ore deposits, which represent our highest value base metal resources, are generally thin (101 m), laterally extensive (103 m), and stratiform to stratabound in fine-grained siltstone and mudstone

The Taurus porphyry Cu-Mo district contains four mineralized porphyry centers in the eastern interior of Alaska. All four centers were emplaced during a magmatic episode that spanned from ca. 72 to 67 Ma, with seven distinct igneous suites. Each igneous suite resulted in hydrothermal alteration and mineralization, with younger pulses overprinting older pulses. Each magmatic-hydrothermal system is not

Porphyry, epithermal, and volcanogenic massive sulfide (VMS) deposits can form together in the same mineral district in convergent margin environments. Their spatial association and superposition indicate evolving tectonic settings. The Artvin Au-Cu district is one of the major clusters of VMS bimodal-felsic, porphyry, and epithermal deposits in the Eastern Pontides belt in northeast Turkey. Whereas

Tourmaline-cemented breccia bodies host much of the ore in the Río Blanco-Los Bronces porphyry Cu-Mo deposits. We determined the chemical and B isotope composition of tourmaline as well as S isotope ratios of anhydrite and sulfide minerals to shed light on the composition and origin of mineralizing fluids. Also, the utility of tourmaline as an indicator mineral was tested by comparing mineralized and

Tungsten is a valuable industrial metal with limited effective substitutes for its many industrial uses. Tungsten is classified as a critical mineral by many countries, including Canada and the United States. As such, tungsten mining is expected to increase in the future, generating waste with potential as point sources of metal leaching to the environment. Concerns about the toxicity of tungsten have

Barite is an important industrial mineral used as a weighing agent in fluids during the drilling of oil and natural gas wells, with the majority of United States production originating from Nevada. This paper considers three barite properties at varying stages of development—Rossi, Heavy Spar, and Ann—all located within the northern Nevada barite belt. At all three sites, barite is hosted in the Roberts

Mineral carbonation reactions consume CO2 and thus have the potential for the long-term fixation of atmospheric CO2. This paper explores the possibility of integrating industrial-scale carbon storage into mining operations. Ultramafic rocks are typically considered to be one the most promising rocks for carbon capture and storage owing to their high content of Mg-bearing silicate minerals, such as

Interactions between a cyanide leach used for Au extraction and cinnabar-bearing gossan tailings at the Murray Brook mine have led to the development of an Hg-enriched contaminated groundwater plume that discharges to the nearby Gossan Creek. Naturally occurring cinnabar in the area poses a challenge in distinguishing mining-related contamination from background Hg concentrations. Surface water data

The environmental management of mining operations is an integral part of mine planning that greatly influences the economic viability of a mineral deposit. Much like the resource potential of a deposit, its environmental characteristics can be directly linked to the geologic characteristics of the ore deposit (Plumlee, 1999; Seal and Hammarstrom, 2003; Lottermoser, 2007). Because of the significant

The prediction of water quality from waste-rock stockpiles is an important aspect of mine planning and closure. These predictions are complex, and a well-documented mechanistic approach can provide greater confidence in the results. In this study, humidity-cell experiments (1-kg sample) conducted at 5° and 22°C were used to estimate the effluent water quality and release rates of oxidation products

The Round Mountain mine in Nevada is one of the world’s largest volcanic-hosted precious metal deposits and has been commercially operated since 1976. The deposit is hosted by a thick sequence of Oligocene ash-flow tuffs and volcaniclastic rocks overlying a pre-Tertiary basement. Gold mineralization largely occurs as disseminated electrum in association with quartz, adularia, illite, smectite, pyrite

In 2015, the Red Chris mine in northwestern British Columbia began processing near-surface ores from the Red Chris copper-gold deposit and encountered higher leachable selenium concentrations in process water than had been anticipated from testing of deeper ores. Samples of gossan, near-surface rock, and deeper hypogene rock were submitted for analytical, mineralogical, and kinetic geochemical testing

A critical issue in mine waste management is the management and mitigation of acid rock drainage and metal leaching particularly from waste rock. This requires good understanding and characterization of materials most likely to generate acid pH waters and generate leachable metals and metalloids, as well as the presence of minerals most likely to neutralize acidic pH such as carbonates and certain

Antimony (Sb) is a valuable mined commodity, used mostly in fire retardants, and considered a critical element. It is also a potential environment hazard classed as a carcinogen. Antimony is concentrated in tailings and waste rock from Sb mines as well as other locations, such as precious metal deposits, where Sb is present in the ore but not recovered. This review covers the aqueous geochemistry,

Loma Galena (978,852 t Pb, 206 Moz Ag) is one of eight epithermal deposits in the world-class Navidad Pb + Ag ± (Zn, Cu) district located in the Cañadón Asfalto continental foreland basin, northern Patagonia, Argentina. This basin formed during the Jurassic in an extensional tectonic regime during the breakup of Gondwana. Host rocks comprise major listric faulted and tilted blocks of K-rich andesite

The timescales and duration of ore-forming processes in skarn systems are not well constrained. To better understand this, we present high-precision chemical abrasion-isotope dilution-thermal ionization mass spectrometry (CA-ID-TIMS) U-Pb zircon and isotope dilution-negative-thermal ionization mass spectrometry (ID-N-TIMS) Re-Os molybdenite geochronology of the Xiaojiayingzi Mo skarn deposit (0.13

The Archean Horne 5 deposit, located in the Rouyn-Noranda district in the southern Abitibi greenstone belt, Canada, contains a total resource of 172.4 t Au (5.6 Moz) from 112.7 Mt of ore grading at 1.53 g/t Au. The deposit is part of the Au-rich Horne volcanogenic massive sulfide (VMS) complex that also includes the past-producing Horne mine (i.e., the Upper and Lower H zones plus small subsidiary

Accurately resolving the timing of formation of Au-Sb-W deposits hosted in metasedimentary rocks has been the aim of extensive research but has also led to controversy. In this study, we present high-precision laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) U-Pb dating of hydrothermal apatite and wolframite from the Woxi Au-Sb-W deposit, South China. Veins are dominated by quartz

The Wawa gold corridor, located in the Michipicoten greenstone belt of the Superior province, Canada, comprises Au-bearing shear zones that crosscut the 2745 Ma Jubilee stock and that evolved during protracted deformation (D1-D3). Numerous generations of sulfide minerals crystallized before, during, and after these deformation events, and gold is associated with D1 arsenopyrite, D2 pyrite, and Bi-Te

La Huifa is a breccia-related Cu-Mo porphyry deposit located in the Andes of central Chile, 3 km northeast of the giant El Teniente porphyry Cu-Mo orebody. It was discovered as part of CODELCO’s (Corporación Nacional del Cobre de Chile) brownfield exploration activities in the El Teniente district. It is the first major discovery in the area, and this work presents its first detailed geologic description

Felsic volcanic rocks are abundant in ancient greenstone belts and important host rocks for volcanogenic massive sulfide (VMS) deposits. About half of all VMS deposits are hosted by dacite or rhyolite, an association that reflects anomalous heat flow during rifting, partial melting of basaltic crust, and fractional crystallization in high-level magma chambers. For over 30 years, geochemical signatures

The Alvo Açaí Cu (Au, Mo) skarn deposit forms part of several poorly explored copper deposits in the western sector of the Carajás province in Brazil. Here, a 2.86 Ga metasyenogranitic basement and a 2.71 Ga quartzite of the Liberdade Group are crosscut by diabase and granitic pegmatite dikes in the deposit area. The sequence of hydrothermal alteration at Alvo Açaí is marked by (1) early pervasive

High- and intermediate-temperature alteration assemblages at the East zone in the Red Chris porphyry Cu-Au deposit, northwestern British Columbia, Canada, are varyingly overprinted by a lower-temperature intermediate argillic alteration assemblage composed of illite-kaolinite-hematite-carbonate. The intermediate argillic assemblage extensively overprinted the upper 600 m of the porphyry deposit and

Case studies around porphyry Cu deposits in the glaciated regions of the Canadian Cordillera have identified the indicator mineral signatures of these deposits in till samples and demonstrated that these are useful methods for porphyry Cu exploration. This study applies the same indicator methods to stream sediment samples around the Casino calc-alkaline porphyry Cu-Au-Mo deposit in the unglaciated

Abstract The genesis of the Bayan Obo giant rare earth element (REE) deposit has been debated for several decades. Here, we report the isotopic effects of dynamic recrystallization in the H8 carbonatite, which is the principal ore carrier in the deposit. We studied fresh drill core to a depth of 1.78 km and documented the elemental and C-O-Sr isotope evolution of rock-forming dolomite during its deformation

Abstract Wall-rock assimilation can cause effective sulfide saturation in magmas and lead to the formation of base and precious metal sulfide deposits. Detailed assessments of how assimilation affects the sulfur content at sulfide saturation (SCSS) in magmas have been scarce because of the lack of suitable thermodynamic modeling tools. The Magma Chamber Simulator (MCS) is the first geochemical modeling

Abstract Magmatic Ni-Cu-platinum group element (PGE) deposits are commonly located in tectonically active regions that typically undergo significant deformation and metamorphism and subsequent reworking of sulfide. The Munali Ni deposit is hosted by a dynamic intrusive mafic-ultramafic system situated within the Zambezi belt in southern Zambia. The deposit comprises Fe-Ni–dominant magmatic sulfides

Abstract The Huangshan-Jingerquan belt in Northwest China is one of the most important orogen-hosted magmatic Ni-Cu sulfide metallogenic belts worldwide. The Huangshandong, Huangshan, and Tulaergen deposits are the three largest Ni-Cu deposits along the belt. The orebodies are situated inside mafic-ultramafic complexes. Sulfur isotope data and trace element composition of the sulfide ores and country

Abstract Myanmar, the third largest global tin supplier, is an important component of the Southeast Asian tin province. We have conducted laser ablation-inductively coupled plasma-mass spectrometry U-Pb dating of cassiterite, wolframite, and zircon and Re-Os dating of molybdenite from six primary and two placer Sn deposits in Myanmar. A combination of our geochronological data with previous studies

Abstract The Jinchuan Ni-Cu-platinum group element (PGE) sulfide deposit is one of the world’s major magmatic sulfide deposits. The Jinchuan intrusion originally consists of two independent bodies, named the Western and Eastern intrusions. Recently, an underground exploration program discovered a large economic orebody in the Fine-Grained unit of the Western intrusion, independent of the orebody No

In the paper, “Mount Isa silica dolomite and copper orebodies: The result of a syntectonic hydrothermal alteration system,” by W. G. Perkins (Vol. 79, issue 4, 1984, p. 601–637), the following corrections are needed:

In a companion paper in this issue, the authors reviewed the properties of cobalt, its mineralogy, and the processes that concentrate it to exploitable levels. Using this information and knowledge of the geology of the principal types of cobalt deposits, the present paper assesses the conditions and controls of cobalt transport and deposition and develops/refines plausible models for the genesis of

Iron oxide copper-gold (IOCG) deposits are major sources of Cu, contain abundant Fe oxides, and may contain Au, Ag, Co, rare earth elements (REEs), U, and other metals as economically important byproducts in some deposits. They form by hydrothermal processes, but the source of the metals and ore fluid(s) is still debated. We investigated the geochemistry of magnetite from the hydrothermal unit and

Extrusive and intrusive felsic magmas occur throughout the evolution of silicic-dominated large igneous province magmatism that is temporally related to numerous economically significant iron oxide copper-gold (IOCG) deposits in southern Australia. We investigate zircon trace element signatures of the felsic magmas to assess whether zircon composition can be related to fertility of the volcanic and

Advanced argillic minerals, as defined, include alunite and anhydrite, aluminosilicates (kaolinite, halloysite, dickite, pyrophyllite, andalusite, zunyite, and topaz), and diaspore. One or more of these minerals form in five distinctly different geologic environments of hydrolytic alteration, with pH 4–5 to <1, most at depths <500 m. (1) Where an intrusion-related hydrothermal system, typical of that

The Mesoproterozoic Rondônia Tin Province of the Amazonian craton records a protracted history of about 600 m.y. of successive rare-metal granite intrusions and hosts the youngest known event of tin-granite emplacement of the craton—a rare-metal granite suite known as the Younger Granites of Rondônia intrusive suite. The ~1 Ga suite is currently interpreted as intracratonic magmatism resulting from

The Westwood deposit (4.5 Moz Au) is hosted in the 2699–2695 Ma Bousquet Formation volcanic and intrusive rocks, in the eastern part of the Blake River Group, southern Abitibi greenstone belt. The Bousquet Formation is divided in two geochemically distinct members: a mafic to intermediate, tholeiitic to transitional lower member and an intermediate to felsic, transitional to calc-alkaline upper member

The Westwood deposit, located in the Archean Doyon-Bousquet-LaRonde mining camp in the southern Archean Abitibi greenstone belt, contains 4.5 Moz (140 metric t) of gold. The deposit is hosted in the 2699–2695 Ma submarine, tholeiitic to calc-alkaline volcanic, volcaniclastic, and intrusive rocks of the Bousquet Formation. The deposit is located near the synvolcanic (ca. 2699–2696 Ma) Mooshla Intrusive

The Amba Dongar carbonatite complex in western India comprises an inner ring of carbonatite breccia surrounded by a sövite ring dike. The various carbonatite units in the body include calcite carbonatite, alvikite, dolomite carbonatite, and ankerite carbonatite. The carbonate phases (calcite and ankerite) occur as phenocrysts, groundmass phases, fresh primary grains, and partially altered grains and/or

Tungsten and Sn display similar behavior during magmatic processes and are commonly associated spatially and genetically with highly evolved granites. Nonetheless, they typically form separate deposits, even if their associated granites have the same protolith. This separation may be due to the fractionation of the metals at the magmatic-hydrothermal transition or their differential mobility during

Cobalt is in high demand because of the key role that cobalt-lithium-ion batteries are playing in addressing the issue of global warming, particularly in facilitating the transition from the internal combustion engine to electrically driven vehicles. Here, we review the properties of cobalt and the history of its discovery, briefly describe its mineralogy, and explore the processes that concentrate

Abstract Downhole data and cores collected during International Ocean Discovery Program (IODP) Expedition 376 at Brothers volcano, Kermadec arc, provide unprecedented, in situ views of volcanic facies and fluid pathways in an actively forming volcanogenic massive sulfide (VMS) ore deposit. Brothers volcano is a submarine caldera with extensive sea floor hydrothermal alteration. Downhole data were collected

Abstract The Kalatongke magmatic Ni-Cu deposit features high Ni-Cu grades compared with other Ni-Cu deposits in the Central Asian orogenic belt. The sulfides, mainly hosted by olivine norite and gabbronorite, are characterized by high Cu/Ni ratios. There is wide variety of textural relationships in the mineralized rocks, including globular, sulfide matrix, emulsion, disseminated, net-textured, and

Abstract The Muremera-Rujungu Ni-Cu sulfide mineralized chonolithic bodies are part of the well-endowed East African nickel belt of mafic-ultramafic intrusions in central-east Africa, dating from 1390 ± 10 Ma. Associated with the small, pod-like to tubular mineralized mafic-ultramafic intrusions is a suite of thin but extensive mafic sills that have geochemical patterns very similar to those of the

Abstract Bull Hill is a carbonatite diatreme within the Paleogene Bear Lodge Carbonatite Complex in Wyoming, USA. Rare earth element (REE)-bearing carbonate, fluorocarbonate, phosphate, and oxide minerals occur within near-vertical carbonatite dikes on the western margin of Bull Hill. Changes in mineralogy and REE concentrations with depth are ascribed mainly to late-stage magmatic-hydrothermal and

Abstract At the Gibraltar porphyry Cu-Mo deposit in south-central British Columbia, Canada, geochemical and mineralogical anomalies in till around a cluster of mineral occurrences form amoeboid-shaped dispersal patterns controlled by three phases of ice movement. The glacial dispersal patterns defined by elevated concentrations of ore (Cu, Mo) and pathfinder (Ag, Zn) elements and alteration oxides

Abstract In central Yukon, the Neoproterozoic to Carboniferous complexly deformed Rackla belt is along the northern boundary of the Selwyn basin. Toward the eastern end of the Rackla belt, a series of gold deposits in the Nadaleen trend exhibit similarities with Carlin-type deposits of the southwestern United States and may represent some of the best examples of this type of mineralization outside

Abstract In magmatic nickel-copper-platinum-group element (PGE) deposits, the PGEs are found both in solid solution in base metal sulfides and as platinum group minerals (PGMs). Apart from S, the most common elements that the PGEs combine with to form PGMs are Te, As, Bi, Sb, and Sn (TABS). Whether the TABS play a role in collecting the PGEs or simply partition into the sulfide liquid along with the