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LATE ARCHEAN SHELF-TO-BASIN IRON SHUTTLE CONTRIBUTES TO THE FORMATION OF THE WORLD-CLASS DATAIGOU BANDED IRON FORMATION Econ. Geol. (IF 5.5) Pub Date : 2024-05-01 Changle Wang, Mingguo Zhai, Leslie J. Robbins, Zidong Peng, Xin Zhang, Lianchang Zhang
Banded iron formations (BIFs) are among the few chemical sedimentary archives that capture the biogeo-chemical evolution of Fe cycling and the redox evolution of the early Earth. Although biologically recycled continental Fe has been previously proposed to be a significant source of Fe in BIFs deposited from a stratified ocean at the onset of the Great Oxidation Event (GOE; ~2.5–2.2 Ga), constraining
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Timing and Mechanism of Ore Precipitation in Porphyry Cu Systems: Insight from LA-ICP-MS Analysis of Fluid Inclusions and In Situ Oxygen Isotope Analysis of Hydrothermal Quartz at Zhunuo Porphyry Cu Deposit, China Econ. Geol. (IF 5.5) Pub Date : 2024-05-01 Xiang Sun, Ruyue Li, Xiaobo Si, Ke Xiao, Jun Deng
The timing and mechanism of ore precipitation in porphyry copper systems are hot topics and remain controversial. The large Miocene collision-related Zhunuo porphyry Cu deposit in the Gangdese belt of southern Tibet, China, was produced by multistage quartz veining and hydrothermal alteration, accompanied by Cu sulfide precipitation. In this study, we have combined cathodoluminescence (CL) petrography
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Epithermal Gold Discoveries in the Emerging Khundii Metallogenic Province, Southwest Mongolia Econ. Geol. (IF 5.5) Pub Date : 2024-05-01 M. A. MacDonald, G. Bat-Erdene, M. X. Gillis, P. J. Dalton, I. Kavalieris, B.-E. Khashgerel, A. Kloppenburg, A. Coote, J. W. Hedenquist
Mineral exploration since 2005 in a previously underexplored region of southwestern Mongolia resulted in the definition of the Zuun Mod porphyry Mo-Cu deposit, followed by discovery of the Altan Nar and Bayan Khundii epithermal gold deposits along with several prospects and advanced exploration projects. These discoveries form the core of the emerging Khundii (“Valley”) metallogenic province, ~50 ×
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Discriminating Superimposed Alteration Associated with Epigenetic Base and Precious Metal Vein Systems in the Rouyn-Noranda Mining District, Quebec; Implications for Exploration in Ancient Volcanic Districts Econ. Geol. (IF 5.5) Pub Date : 2024-05-01 Marina D. Schofield, Bruno Lafrance, Harold L. Gibson, K. Howard Poulsen, Christophe Scheffer, Benoît Quesnel, Georges Beaudoin, Michael A. Hamilton
The Rouyn-Noranda mining district of Quebec contains 20 Cu-Zn (±Au ±Ag) volcanogenic massive sulfide (VMS) deposits, including the giant and gold-rich Quemont and Horne deposits. Mineralized epigenetic veins are also present, but their origin and relative timing remain enigmatic. The nature and extent of their alteration signatures and the effect of their superposition on district-scale alteration
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Cu-Au-Platinum Group Element Mineralization in the Mbesa Prospect, Southern Tanzania: Unconventional Magmatic Sulfides Econ. Geol. (IF 5.5) Pub Date : 2024-05-01 Hidaya Hassan, Jacob Kaavera, Akira Imai, Kotaro Yonezu, Thomas Tindell, Kenzo Sanematsu, Koichiro Watanabe
High-grade Cu mineralization was recently discovered in the Mbesa prospect in southern Tanzania, but its origin is poorly constrained. Herein, we present new major element, trace element, rare earth element (REE), and platinum group element (PGE) geochemistry and petrographic data to constrain the origin of the mineralization. The sulfide mineralization is dominated by chalcopyrite and bornite and
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Zircon and Whole-Rock Trace Element Indicators of Magmatic Hydration State and Oxidation State Discriminate Copper Ore-Forming from Barren Arc Magmas Econ. Geol. (IF 5.5) Pub Date : 2024-05-01 Robert R. Loucks, Gonzalo J. Henríquez, Marco L. Fiorentini
To meet surging requirements of copper for the green energy revolution, minable resources subequal to all copper production in history must be found in the next two decades. We show that trace elements in zircon and whole-rock samples that are diagnostic of unusually high-pressure magmatic differentiation and high hydration state and oxidation state of their parent silicate melt are effective for discriminating
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Geology and Structure of the Río Blanco Cu-Mo Porphyry Deposit, Central Chile Econ. Geol. (IF 5.5) Pub Date : 2024-03-01 Jorge Skarmeta, Fernando Ortiz, Marco Solé
The Río Blanco-Los Bronces deposit is the largest Cu-Mo porphyry deposit in the world in terms of contained Cu metal. It is the product of protracted superposed magmatic and hydrothermal activity associated with multiple intrusive and brecciation events, with simultaneous regional uplift, erosion and unroofing, and decompression. Magmatism resulted in three major mineralization-alteration stages. The
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Advances for the Exploration of Tectonic-Magmatic-Related Emerald Deposits Using a High-Resolution Spectral Approach: Unraveling the Spectral Footprint of the Paraná Deposit (NE Brazil) Econ. Geol. (IF 5.5) Pub Date : 2024-03-01 José Ferreira de Araújo Neto, Thais Andressa Carrino, Lauro Cézar Montefalco de Lira Santos, Rosa Elvira Correa Pabón
This study unravels the spectral footprint of the Paraná deposit, northeastern Brazil, and provides strategies for emerald exploration in mafic- and/or ultramafic-hosted deposits using point spectral data and hyperspectral imaging. Potential host rocks (phlogopite and actinolite-phlogopite schists) were discriminated from other associated lithotypes after petrography and whole-rock geochemistry, using
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San Albino, Nicaragua: A Low-Angle, Thrust-Controlled Orogenic Gold Deposit Econ. Geol. (IF 5.5) Pub Date : 2024-03-01 Rael D. Lipson, Richard J. Goldfarb, Ben M. Frieman, John Payne
The San Albino deposit is an orogenic gold occurrence hosted by a low-angle thrust that is the site of a new open-pit mine in northern Nicaragua. The deposit is hosted in greenschist facies rocks of the Jurassic metasedimentary Neuvo Segovia Formation. The schist was uplifted and exposed during arc accretion and Cretaceous thin-skin deformation, forming the NE-striking Colon fold-and-thrust belt. Deformation
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Tin Mineralization in the Triassic Chacaltaya District (Cordillera Real, Bolivia) Traced by In Situ Chemical and δ 18 O-δ 11 B Compositions of Tourmaline Econ. Geol. (IF 5.5) Pub Date : 2024-03-01 Lisard Torró, Matthieu Harlaux, Angela Castro-Morante, Jean Vallance, Lorenzo Tavazzani, Anne-Sophie Bouvier, Thomas Bovay, Cyril Chelle-Michou, Thierry Sempere, Joan Carles Melgarejo
We present a petrographic and geochemical study of tourmaline from the Triassic Chacaltaya Sn-polymetallic district in the Cordillera Real of Bolivia. Tourmaline is associated with greisens, breccias, and veins, which occur around the Triassic Chacaltaya peraluminous granitic stock hosted by Silurian metasedimentary rocks. Three main petrographic types of hydrothermal tourmaline have been identified:
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Tracing Detrital Epidote Derived from Alteration Halos to Porphyry Cu Deposits in Glaciated Terrains: The Search for Covered Mineralization Econ. Geol. (IF 5.5) Pub Date : 2024-03-01 A. Plouffe, R. G. Lee, K. Byrne, I. M. Kjarsgaard, D. C. Petts, D.H.C. Wilton, T. Ferbey, M. Oelze
Distal alteration related to porphyry Cu mineralization is typically characterized by an abundance of green minerals, such as epidote, tremolite, and chlorite, within the propylitic and sodic-calcic alteration zones and extends far outside (>1 km) the mineralized zone(s). Glacial erosion and dispersal derived from rocks affected by propylitic and sodic-calcic alteration have resulted in the development
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Alteration Mapping for Porphyry Cu Targeting in the Western Chagai Belt, Pakistan, Using ZY1-02D Spaceborne Hyperspectral Data Econ. Geol. (IF 5.5) Pub Date : 2024-03-01 Lei Liu, Chuntao Yin, Yasir Shaheen Khalil, Jun Hong, Jilu Feng, Huishan Zhang
The Chagai porphyry Cu belt in Pakistan is an important metallogenic terrain extending approximately 400 km in an east-west direction. Most of the known porphyry Cu deposits, such as the world-class Reko Diq deposit and Saindak deposit, are located in the western Chagai belt. In this study, the ZY1-02D hyperspectral data acquired by a recently launched spaceborne imaging spectrometer with 166 bands
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PLUME-GENERATED 90° STRESS CHANGE LINKED TO TRANSITION FROM RADIATING TO CIRCUMFERENTIAL DOLERITE DIKE SWARMS OF THE SIBERIAN TRAPS LARGE IGNEOUS PROVINCE AND TO EMPLACEMENT OF THE NORILSK-TALNAKH ORE DEPOSITS Econ. Geol. (IF 5.5) Pub Date : 2024-03-01 R.E. Ernst, H. El Bilali, K. L. Buchan, S.M. Jowitt
A 90° change in stress orientation has been previously proposed as the trigger for the final emplacement of the world-class Norilsk-Talnakh magmatic sulfide mineralization via the migration of accumulated sulfide melts from elsewhere within the plumbing system of the Siberian Traps large igneous province (LIP). We propose that this stress change does not require and was not triggered by a distal change
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Giant Rare Earth Element Accumulation Related to Voluminous, Highly Evolved Carbonatite: A Microanalytical Study of Carbonate Minerals From the Bayan Obo Deposit, China Econ. Geol. (IF 5.5) Pub Date : 2024-03-01 Xiao-Chun Li, Hong-Rui Fan, Jian-Hui Su, David I. Groves, Kui-Feng Yang, Xin-Fu Zhao
The giant Bayan Obo deposit in China represents the largest rare earth element (REE) resource in the world, but the mechanisms for its highly anomalous REE enrichment have long been controversial. The central debate concerns the nature and origin of the ore-hosting dolomite. In this study, a texturally constrained microanalytical study of carbonate minerals from the Bayan Obo ore-hosting dolomite is
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Linking Porphyry Cu Formation to Tectonic Change in Postsubduction Settings: A Case Study from the Giant Yulong Belt, Eastern Tibet Econ. Geol. (IF 5.5) Pub Date : 2024-03-01 Ming-Liang Huang, Xian-Wu Bi, Rui-Zhong Hu, Massimo Chiaradia, Jing-Jing Zhu, Lei-Luo Xu, Zong-Yong Yang
Porphyry deposits in magmatic arcs form coincident with changes to steady-state oceanic subduction conditions, such as changes in plate convergence rate and vector or angle of subduction. However, it remains unclear whether such processes also operated during formation of postsubduction porphyry deposits. The Yulong magmatic belt in the eastern Tibetan Plateau consists of middle to late Eocene igneous
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Geochemical Signatures of Mafic Volcanic Rocks in Modern Oceanic Settings and Implications for Archean Mafic Magmatism Econ. Geol. (IF 5.5) Pub Date : 2024-03-01 Marc Lorin Fassbender, Mark Hannington, Alan Thomas Baxter, David Diekrup, Margaret Stewart, Philipp Alexander Brandl
Greenstone belts are dominated by mafic volcanic rocks with geochemical characteristics that indicate a range of possible geodynamic influences. Many analogies with modern tectonic settings have been suggested. Increasing exploration of the modern oceans and comprehensive sampling of volcanic rocks from the sea floor are now providing unique opportunities to characterize different melt sources and
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The Snow Lake Deposits in Manitoba, Canada: Formation of Metamorphosed Amphibolite Facies Orogenic Gold Deposits During a Progressive and Prograde Orogenic Event Econ. Geol. (IF 5.5) Pub Date : 2024-03-01 Kate E.L. Rubingh, Bruno Lafrance, Harold L. Gibson
The Snow Lake camp is located in the ca. 1.89 Ga Flin Flon-Glennie Complex in the Paleoproterozoic Trans-Hudson orogen, Manitoba, Canada. The Flin Flon-Glennie Complex is bordered by the ca. 1.855 to 1.84 Ga metasedimentary Kisseynew domain to the north and by the Archean Superior craton to the east and is underlain by the Archean Sask microcraton. It hosts several orogenic gold deposits, including
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Skarn Zonation of the Giant Jiama Cu-Mo-Au Deposit in Southern Tibet, SW China Econ. Geol. (IF 5.5) Pub Date : 2024-01-01 Qihai Shu, Jun Deng, Zhaoshan Chang, Qingfei Wang, Xudong Niu, Kai Xing, Xiang Sun, Zhongkun Zhang, Qingwen Zeng, Hesen Zhao, Fan Yu
Jiama is a giant skarn-porphyry deposit in southern Tibet, southwestern China. It is the largest Cu (~7.4 Mt), second largest Au (~208 t), and fourth largest Mo (~0.62 Mt) skarn deposit in China. In addition, Jiama also contains considerable amounts of Zn, Pb, and Ag. The mineralization is related to a Miocene (~15 Ma) monzogranite porphyry that intruded the Upper Jurassic Duodigou Formation limestone
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Combined Effect of Organic Carbon and Arsenic on the Formation of Sediment-Hosted Gold Deposits: A Case Study of the Shahuindo Epithermal Deposit, Peru Econ. Geol. (IF 5.5) Pub Date : 2024-01-01 Jean Vallance, Renzo Galdos, Macneill Balboa, Brigitte Berna, Omar Cabrera, Freddy Huisa, Camille Baya, Caroline Van De Vyver, Willem Viveen, Didier Béziat, Stefano Salvi, Stéphane Brusset, Patrice Baby, Gleb S. Pokrovski
Sediment-hosted gold deposits represent a significant portion of the world’s gold resources. They are characterized by the ubiquitous presence of organic carbon (Corg; or its metamorphosed product, graphite) and the systematic occurrence of invisible gold-bearing arsenian pyrite. Yet the role played by these features on ore formation and the distribution of gold remains a long-standing debate. Here
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Alteration Mineral Mapping of the Shadan Porphyry Cu-Au Deposit (Iran) Using Airborne Imaging Spectroscopic Data: Implications for Exploration Drilling Econ. Geol. (IF 5.5) Pub Date : 2024-01-01 Saeid Asadzadeh, Sabine Chabrillat, Thomas Cudahy, Bahman Rashidi, Carlos Roberto de Souza Filho
Porphyry copper deposits are associated with large alteration footprints, and alteration mapping plays a key role in the exploration of these deposits. Imaging spectroscopy is commonly deployed for exploration targeting, yet it has rarely been used to map deposit-scale alteration patterns before initiating drilling. To close this gap, the Shadan porphyry Cu-Au deposit was thoroughly studied using the
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Superimposed Gold Mineralization Events in the Tuanshanbei Orogenic Gold Deposit, Central Jiangnan Orogen, South China Econ. Geol. (IF 5.5) Pub Date : 2024-01-01 Cheng Wang, Yong-Jun Shao, Richard Goldfarb, Shi-Min Tan, Ji Sun, Chao Zhou, Han Zheng, Qing-Quan Liu, Yi-Qu Xiong
The Jiangnan orogen, one of the largest gold-producing areas in China, has experienced multiple orogenic events with complex structural overprinting that is marked by multiple stages of magmatism, deformation, metamorphism, and orogenic gold mineralization. Different orogenic events have been recognized in the Neoproterozoic, mid-Paleozoic, Triassic, and Early Cretaceous, reflecting collisions and
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Nature and Origin of a Massive Sulfide Occurrence in the Karrat Group: Evidence for Paleoproterozoic VMS Mineralization in Central West Greenland Econ. Geol. (IF 5.5) Pub Date : 2024-01-01 Y. M. DeWolfe, J. Kolb, E. V. Sorensen, D. Rosa, P. Guarnieri
Mafic volcanic rocks of the Kangilleq Formation of the Paleoproterozoic Karrat Group host volcanogenic massive sulfide (VMS) mineralization in the area of central Kangiusap Kuua, central West Greenland. The mafic volcanic rocks display evidence of subaqueous, effusive eruption and redeposition by mass debris flows generated along fault scarps on the sea floor. A zone of semiconformable quartz alteration
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Geology and Lithogeochemistry of the Paleoproterozoic Flambeau Cu-Zn-Au Volcanogenic Massive Sulfide Deposit, Wisconsin, USA Econ. Geol. (IF 5.5) Pub Date : 2024-01-01 Robert W.D. Lodge, Zacharie A. Zens, Regan E. Jacobson, Matthew I. Leybourne
The Paleoproterozoic Flambeau Cu-Zn-Au deposit in northwestern Wisconsin is the only volcanogenic massive sulfide (VMS) deposit to reach production in the Pembine-Wausau terrane of the Penokean orogen, despite the discovery of more than 150 million tonnes of mineralization within 14 deposits since the 1970s. Renewed exploration interest in the region and need for critical minerals has highlighted the
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INSTRUCTIONS TO AUTHORS, 2024 Econ. Geol. (IF 5.5) Pub Date : 2024-01-01
Economic Geology is an independent journal published by the Society of Economic Geologists, Inc. Papers submitted to the journal will be evaluated on the basis of appropriateness for the journal, suitability of topic, and quality and significance of the research. Do not send manuscripts that have already been published or accepted for publication elsewhere, that reiterate previously published material
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Escape a los Andes: La historia de Mauricio Hochschild, “el Schindler de Boliva” (Escape to the Andes: The story of Mauricio Hochschild, “the Bolivian Schindler”) Econ. Geol. (IF 5.5) Pub Date : 2024-01-01 Stewart D. Redwood
Escape a los Andes: La historia de Mauricio Hochschild, “el Schindler de Bolivia” (Escape to the Andes: The story of Mauricio Hochschild, “the Bolivian Schindler”). Raúl Peñaranda and Robert Brockmann. 2023. AGUILAR. 511 Pp. Paperback ISBN 978-987-735-311-2. Price US$39.00; eBook https://a.co/d/dGxPPg0. Price US$11.99.Escape a los Andes fills a gap in the literature of Bolivian mining history for a
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MULTIPULSED MAGMATISM AND DURATION OF THE HYDROTHERMAL SYSTEM OF THE GIANT JIAMA PORPHYRY Cu SYSTEM, TIBET, CHINA Econ. Geol. (IF 5.5) Pub Date : 2024-01-01 Bin Lin, Juxing Tang, Pan Tang, Georges Beaudoin, Crystal Laflamme, Faqiao Li, Wenbao Zheng, Yang Song, Jing Qi, Miao Sun, Huawen Cao, Qiufeng Leng, Aorigele Zhou, Bing Zou, Corey J. Wall, Chao Yang
Jiama is the largest porphyry-skarn ore system in the Gangdese metallogenic belt, Tibet. It is composed of porphyry Cu-Mo, Cu-polymetallic skarn, Cu-Pb-Zn manto, and distal vein Au orebodies with associated Ag, W, and Bi. However, the precise timing of the magmatism and hydrothermal events at Jiama remains obscure. Here, using high-precision chemical abrasion-isotope dilution-thermal ionization mass
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ERRATUM Econ. Geol. (IF 5.5) Pub Date : 2024-01-01
In the paper, “Rare Time Series of Hydrothermal Fluids for a Submarine Volcano: 14 Years of Vent Fluid Compositions for Brothers Volcano, Kermadec Arc, New Zealand,” by V. K. Stucker, C.E.J. de Ronde, K.J. Lawrence, and A.M. Phillips (vol. 118, issue 7, p. 1563–1576), Table 1 was published with incorrect units. The error has been corrected in the online version of the paper, and the corrected table
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Silver Behavior During Magmatic and Magmatic-Hydrothermal Evolution of a Highly Evolved Reduced Granitic System Related to the Giant Shuangjianzishan Ag-Pb-Zn-(Sn) Epithermal Deposit, Northeast China Econ. Geol. (IF 5.5) Pub Date : 2024-01-01 Kaixuan Hui, Bertrand Rottier, Kezhang Qin, Zoltan Zajacz, Alexandra Tsay, Junxing Zhao, Shen Gao, Ruizhe Shi
Magmatic-related epithermal silver-rich polymetallic deposits are among the most important sources of Ag in the world, and they are found associated with magmatic systems with striking differences. Most of the time, they are associated either with I-type oxidized (magnetite-series granite) intermediate to evolved intrusions or with S-type/A-type reduced (ilmenite-series granite) highly evolved intrusions
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Enrichment of Rare Earth Elements During the Weathering of Alkaline Igneous Systems: Insights from the Puxiong Regolith-Hosted Rare Earth Element Deposit, SW China Econ. Geol. (IF 5.5) Pub Date : 2024-01-01 Min Wang, Martin Yan Hei Li, Mei-Fu Zhou, Jia-Xi Zhou, Guotao Sun, Ye Zhou, Yin Li
Regolith-hosted rare earth element (REE) deposits have been the focus of recent studies. Most studies concern deposits formed over granites and felsic volcanic rocks, but little is known about those deposits developed over silica-undersaturated alkaline igneous rocks. The recently discovered Puxiong REE deposit in Southwest China formed through the weathering of nepheline syenite that has REE concentrations
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The Roles of Various Types of Crustal Contamination in the Genesis of the Jinchuan Magmatic Ni-Cu-PGE Deposit: New Mineralogical and C-S-Sr-Nd Isotope Constraints Econ. Geol. (IF 5.5) Pub Date : 2023-12-01 Shengchao Xue, Qingfei Wang, Yalei Wang, Wenlei Song, Jun Deng
Addition of crustal sulfur to the Jinchuan magma or oxidation of the magma associated with carbonate assimilation has been considered to be the main cause of sulfide saturation in the magma by two opposing groups of researchers. To address this controversy, we have carried out an integrated mineralogical and C-S-Sr-Nd isotope study of the Jinchuan magmatic Ni-Cu-platinum group element (PGE) sulfide
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Trace Element Composition of Chalcopyrite from Volcanogenic Massive Sulfide Deposits: Variation and Implications for Provenance Recognition Econ. Geol. (IF 5.5) Pub Date : 2023-12-01 Enzo Caraballo, Georges Beaudoin, Sarah Dare, Dominique Genna, Sven Petersen, Jorge M.R.S. Relvas, Stephen J. Piercey
Chalcopyrite from 51 volcanogenic massive sulfide (VMS) and sea-floor massive sulfide (SMS) deposits from six lithostratigraphic settings was analyzed for trace elements by laser ablation-inductively coupled plasma-mass spectrometry (LA-ICP-MS) to evaluate its potential as an indicator mineral for exploration. Partial least squares discriminant analysis (PLS-DA) results reveal that chalcopyrite from
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Hydrothermal Graphite as a Trigger for High-Temperature Orogenic Gold Mineralization at Haoyaoerhudong, Northern China Econ. Geol. (IF 5.5) Pub Date : 2023-12-01 Wenbo Li, Fanghua Zhang, Xueyuan Qiao, Tianyao Fu
Carbonaceous materials are a key factor controlling mineralization processes in many world-class gold deposits. Haoyaoerhudong is the largest carbonaceous metasediment-hosted gold deposit on the north margin of the North China craton. Gold-bearing orebodies are hosted in carbonaceous slates and schists belonging to Mesoproterozoic rift-related successions. Typical hydrothermal minerals are pyrrhotite
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THE ROLE OF SCANDIUM CHLORIDE AND HYDROXIDE COMPLEXES IN THE FORMATION OF SCANDIUM DEPOSITS: INSIGHTS FROM EXPERIMENTS AND MODELING Econ. Geol. (IF 5.5) Pub Date : 2023-12-01 Jiaxin Wang, A. E. Williams-Jones, A. Timofeev, Xueni Zhang, Jiajun Liu, Shunda Yuan
Although scandium is commonly concentrated to economic levels by magmatic processes, hydrothermal fluids also play an important role in its concentration. Indeed, the most important source of scandium is currently the Bayan Obo deposit in China, where scandium is extracted from hydrothermally produced aegirine. To know how and why scandium is concentrated by hydrothermal fluids, it is necessary to
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Origin of Hydrothermal Barite in Polymetallic Veins and Carbonate-Hosted Deposits of the Cyclades Continental Back Arc Econ. Geol. (IF 5.5) Pub Date : 2023-12-01 Sandra C. Wind, Mark D. Hannington, David A. Schneider, Jan Fietzke, Stephanos P. Kilias, J. Bruce Gemmell
Polymetallic veins and breccias and carbonate-replacement ore deposits in the Cyclades continental back arc, Greece, formed from a range of fluid and metal sources strongly influenced by the dynamics of the late Mesozoic-Cenozoic Hellenic subduction system. These complexities are recorded in the isotopic signatures of hydrothermal barite. We investigated 17 mineral occurrences on four Cycladic islands
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Ore-Grade Estimation from Hyperspectral Data Using Convolutional Neural Networks: A Case Study at the Olympic Dam Iron Oxide Copper-Gold Deposit, Australia Econ. Geol. (IF 5.5) Pub Date : 2023-12-01 Elias Martins Guerra Prado, Carlos Roberto de Souza Filho, Emmanuel John Muico Carranza
Acquiring information about the spatial distribution of ore grade in the subsurface is essential for exploring and discovering mineral resources. This information is derived commonly from the geochemical analysis carried out on drill core samples, which allows the quantification of the concentration of ore elements. However, these surveys are generally time-consuming and expensive, usually leading
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Geology of the Nautanen North Cu-Au-Ag-(Mo) Deposit, Norrbotten, Sweden Econ. Geol. (IF 5.5) Pub Date : 2023-12-01 David Drejing-Carroll, Murray W. Hitzman, David Coller
The Nautanen North deposit in the Gällivare-Malmberget area of Norrbotten, Sweden, currently contains a resource of 21 million tonnes (Mt) at 1.46% Cu, 0.78 g/t Au, 6 g/t Ag, and 99 g/t Mo and remains open at depth and along strike. This study, based on extensive examination of drill core, geochemical data, and petrographic analyses, represents the first comprehensive description of the structural
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Elucidating the Role of Hydrocarbons in Cinnabar (HgS) Ore Formation: A Model for Hg Mineralization in the Terlingua Mining District, Big Bend National Park, SW Texas Econ. Geol. (IF 5.5) Pub Date : 2023-12-01 L. Taras Bryndzia
The genetic relationship between organic-rich source rocks and Hg deposits remains the subject of debate. This paper evaluates the role of organic-rich source rocks in cinnabar ore formation in the Terlingua mining district, Texas, which was deposited at relatively shallow depths in Cretaceous sedimentary rocks spatially related to intrusive alkali igneous rocks.The mineralization formed at ~45 bar
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Decoupling of Sulfur Isotope Signatures from Platinum Group Elements in Komatiite-Hosted Ore Systems: Evidence from the Mount Keith MKD5 Ni-(Co-Cu) Deposit, Western Australia Econ. Geol. (IF 5.5) Pub Date : 2023-12-01 Anne B. Virnes, Marco L. Fiorentini, Stephen J. Barnes, Stefano Caruso, Laure A.J. Martin, Matvei Aleshin, Louise E. Schoneveld, Malcolm P. Roberts, Quentin Masurel, Nicolas Thebaud
Komatiites require external sulfur from country rocks to generate immiscible sulfide liquid, which concentrates metals to form economic nickel sulfide deposits. Although signatures related to mass-independent fractionation of S isotopes (MIF-S, denoted as Δ33S) may identify external S sources, their values may not be directly indicative of the S reservoirs that were tapped during the ore-forming process
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Are Placer Platinum Nuggets Formed During Lateritization? The Verdict from the Owendale Alaskan-Uralian Complex in Australia Is an Emphatic No! Econ. Geol. (IF 5.5) Pub Date : 2023-12-01 Bocheng Ma, Reid R. Keays
The thick laterite developed over platinum group element (PGE)-bearing ultramafic rocks of the Owendale Alaskan-Uralian Complex in New South Wales, Australia, provides an ideal environment in which to address the question of whether Pt-Fe nuggets are formed during lateritization. This is an important issue to settle because Pt-Fe nuggets in alluvial placers and eluvial deposits associated with the
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Hydrothermal Alteration Within the Brothers Submarine Arc Volcano, Kermadec Arc, New Zealand Econ. Geol. (IF 5.5) Pub Date : 2023-11-01 Andrew J. Martin, John W. Jamieson, Cornel E.J. de Ronde, Susan E. Humphris, Stephen Roberts, Christopher J. MacLeod, Yuanfeng Cai, Chao Zhang, Lucy E.M. Schlicht, Tatsuo Nozaki
The hydrothermally active Brothers volcano on the Kermadec arc, New Zealand, hosts two geochemically distinct hydrothermal systems within a single caldera. At the NW Caldera, metal-sulfide–rich black smoker spires form on the caldera wall. In contrast, Fe-rich crusts and native sulfur-rich chimneys occur at the resurgent central Upper Cone. Previous studies have revealed that the contrasting styles
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The Origin of Magmas and Metals at the Submarine Brothers Volcano, Kermadec Arc, New Zealand Econ. Geol. (IF 5.5) Pub Date : 2023-11-01 Philipp A. Brandl, Maxim Portnyagin, Heiko Zeppenfeld, Frank J. Tepley, Cornel E.J. de Ronde, Christian Timm, Folkmar Hauff, Dieter Garbe-Schönberg, Romain Bousquet
International Ocean Discovery Program (IODP) Expedition 376 cored the submarine Brothers volcano of the Kermadec arc to provide insights into the third dimension and the evolution of the volcano and its associated ore-forming systems. We present new petrological and geochemical data on dacitic rocks drilled from Brothers as well as mafic rocks collected at two adjacent ridges. These data include major
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Effects of Hydrothermal Alteration and Mineralization on the Paleomagnetic Properties of Rocks from IODP Expedition 376 at Brothers Volcano Econ. Geol. (IF 5.5) Pub Date : 2023-11-01 F. Caratori Tontini, G. M. Turner, A. G. Reyes, F. Speranza, M. A. Tivey, C. Massiot, C.E.J. de Ronde, S. E. Humphris
The 3-D subseafloor architecture of submarine hydrothermal systems is largely unknown, particularly at arc volcanoes. The alteration of volcanic rocks in these systems produces dramatic changes in their magnetic properties. Here, we present the first comprehensive study of paleomagnetic measurements from oriented samples of hydrothermally altered dacites from Brothers volcano (Kermadec arc), drilled
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Fluid Inclusion Evidence for Subseafloor Magmatic-Hydrothermal Processes at Brothers Volcano, Kermadec Arc, New Zealand Econ. Geol. (IF 5.5) Pub Date : 2023-11-01 Hyun Joo Lee, Jung Hun Seo, Cornel E.J. de Ronde, Christoph A. Heinrich
Brothers volcano is a submarine dacitic caldera located on the southern Kermadec arc. It is host to the NW Caldera vent field (Site U1530 and Hole U1530A), which locally discharges more focused, metal-rich fluids, and the Upper Cone hydrothermal vent field (Site U1528 and Hole U1528D), which discharges predominantly diffuse, acidic fluids (pH 1.9). These two active vent sites were drilled in 2018 by
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Rare Time Series of Hydrothermal Fluids for a Submarine Volcano: 14 Years of Vent Fluid Compositions for Brothers Volcano, Kermadec Arc, New Zealand Econ. Geol. (IF 5.5) Pub Date : 2023-11-01 V. K. Stucker, C.E.J. de Ronde, K. J. Laurence, A. M. Phillips
Hydrothermal vent fluids from Brothers submarine arc volcano were previously collected in 2004, 2005, and 2017. We present new data from 2018 along with a unique time series of a submarine volcano hosting two distinct types of hydrothermal venting to better understand subsurface processes and how they evolve over time. Samples were collected from known venting locations along the NW Caldera, the Upper
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Depth Profiles of Re-Os Geochemistry in Drill Cores from Hole U1530A in Brothers Volcano Hydrothermal Field, Kermadec Arc: Mobilization and Extreme Enrichment of Os by Volcanic Gas Econ. Geol. (IF 5.5) Pub Date : 2023-11-01 Tatsuo Nozaki, Mizuki Ishida, Yutaro Takaya, Qing Chang, Jun-Ichi Kimura, Yasuhiro Kato
Better understanding metallogenesis in oceanic crust depends on costly sea-floor drilling projects in areas where metal-bearing deposits, such as sea-floor massive sulfide deposits, are currently forming. In 2018, International Ocean Discovery Program (IODP) Expedition 376 recovered drill cores from an active hydrothermal field at Brothers volcano, in the Kermadec arc. These provide insight into the
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Two Decades of Monitoring Hydrothermal Plumes at the Brothers Submarine Volcano, Kermadec Arc, New Zealand Econ. Geol. (IF 5.5) Pub Date : 2023-11-01 Sharon L. Walker, Cornel E.J. de Ronde
Brothers volcano is arguably the most well-studied submarine arc volcano on Earth. Between 1996, when massive sulfides were first recovered by dredging, and 2018, when International Ocean Discovery Program (IODP) Expedition 376 recovered cores from as deep as 453 m below the sea floor at two chemically distinct hydrothermal upflow zones, over 60 conductivity-temperature-depth (CTD) vertical casts and
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Petrophysical Facies and Inferences on Permeability at Brothers Volcano, Kermadec Arc, Using Downhole Images and Petrophysical Data Econ. Geol. (IF 5.5) Pub Date : 2023-11-01 Cécile Massiot, Iona McIntosh, Jeremy Deans, Sarah D. Milicich, Fabio Caratori Tontini, Cornel E. J. de Ronde, Ludmila Adam, Kannikha Kolandaivelu, Gilles Guerin
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
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Diagenetic History and Timing of Cu and Zn-Pb Sulfide Mineralization in the Permian Kupferschiefer System, Saale Subbasin, Eastern Germany Econ. Geol. (IF 5.5) Pub Date : 2023-09-01 Mohammed S. Mohammedyasin, Joseph M. Magnall, Sarah A. Gleeson, Hans-Martin Schulz, Anja M. Schleicher, Jessica A. Stammeier, Bodo-Carlo Ehling
The Southern Permian basin in central Europe contains a number of important high-grade sediment-hosted Cu deposits. Laterally extensive stratabound Cu and Zn-Pb sulfide mineralized rocks are located at a major stratigraphic redox boundary, where coarse-grained continental sandstones of the uppermost Rotliegend Group are overlain by carbonaceous mudstones (T1) and limestones (Ca1) of the Zechstein Formation
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Genesis of the Questa Mo Porphyry Deposit and Nearby Polymetallic Mineralization, New Mexico, USA Econ. Geol. (IF 5.5) Pub Date : 2023-09-01 Sean P. Gaynor, Joshua M. Rosera, Drew S. Coleman
The Oligocene Latir magmatic center in northern New Mexico is an exceptionally well exposed volcano-plutonic complex that hosts a variety of magmatic-hydrothermal deposits, ranging from relatively deep, F-rich porphyry Mo mineralization to shallower epithermal deposits. We present new whole-rock chemical and isotopic data for plutonic rocks from the Latir magmatic center, including extensive sampling
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Fluid Flow, Alteration, and Timing of Cu-Ag Mineralization at the White Pine Sediment-Hosted Copper Deposit, Michigan, USA Econ. Geol. (IF 5.5) Pub Date : 2023-09-01 Simon M. Jones, Jonathan Cloutier, Anthony R. Prave, Timothy D. Raub, Eva E. Stüeken, Holly J. Stein, Gang Yang, Adrian J. Boyce
White Pine, located in Michigan’s Upper Peninsula, is an archetypal sediment-hosted stratiform copper deposit. The Midcontinent rift system is one of only seven basins globally that host a giant sediment-hosted stratiform copper deposit. Despite many similarities with other deposits of this type, White Pine displays some important differences, including the late Mesoproterozoic age, a thick basalt
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Depositing >1.5 Mt of Tin Within <1 m.y. of Initial Granitic Intrusion in the San Rafael Tin (-Copper) Deposit, Southeastern Peru Econ. Geol. (IF 5.5) Pub Date : 2023-09-01 Matthieu Harlaux, Daniel J. Kontak, Alan H. Clark, Kalin Kouzmanov, Christopher S. Holm-Denoma, Stefano Gialli, Oscar Laurent, Richard Spikings, Alain Chauvet, Andrea Dini, Miroslav Kalinaj, Lluís Fontboté
The San Rafael Sn (-Cu) deposit, located in the Eastern Cordillera of southeast Peru, is one of the world’s largest cassiterite-bearing vein systems (>1 Mt Sn produced since 1969). The deposit consists of a quartz-cassiterite-chlorite-sulfide lode system spatially associated with an upper Oligocene (ca. 24 Ma) S-type granitic pluton. Based on a revised paragenetic sequence for the deposit, we interpret
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Metallogenic Setting and Temporal Evolution of Porphyry Cu-Mo Mineralization and Alteration in the Delamerian Orogen, South Australia: Insights From Zircon U-Pb, Molybdenite Re-Os, and In Situ White Mica Rb-Sr Geochronology Econ. Geol. (IF 5.5) Pub Date : 2023-09-01 Wei Hong, Adrian Fabris, Tom Wise, Alan S. Collins, Sarah Gilbert, David Selby, Stacey Curtis, Anthony J. Reid
Paleozoic porphyry-style hydrothermal alteration and mineralization has previously been recognized within the Delamerian orogen, South Australia, where porphyry prospects include Anabama Hill, Netley Hill, and Bendigo. However, limited exploration due in part to thick postmineralization cover hinders the understanding of the temporal context, metallogenic setting, and mineral potential of the porphyry
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The Characteristics and Origin of Barite in the Giant Mehdiabad Zn-Pb-Ba Deposit, Iran Econ. Geol. (IF 5.5) Pub Date : 2023-09-01 Yingchao Liu, Yucai Song, Mahmoud Fard, Zengqian Hou, Wang Ma, Longlong Yue
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
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U-Pb DATING OF APATITE FROM SILVERMINES DEPOSIT, IRELAND: A MODEL FOR HYDROTHERMAL ORE GENESIS Econ. Geol. (IF 5.5) Pub Date : 2023-09-01 Nicholas Andrew Vafeas, Paul Slezak, David Chew, Maurice Brodbeck, Murray. W. Hitzman, Danny Hnatyshin
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
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Geology of Porphyry Cu-Au and Epithermal Cu-Au-Ag Mineralization at Filo del Sol, Argentina-Chile: Extreme Telescoping During Andean Uplift Econ. Geol. (IF 5.5) Pub Date : 2023-09-01 José Perelló, Richard H. Sillitoe, Joaquín Rossello, Julián Forestier, Guido Merino, Diego Charchaflié
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
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The Age and Origin of the Ruwai Polymetallic Skarn Deposit, Indonesia: Evidence of Cretaceous Mineralization in the Central Borneo Metallogenic Belt Econ. Geol. (IF 5.5) Pub Date : 2023-09-01 Cendi D.P. Dana, Andrea Agangi, Arifudin Idrus, Cyril Chelle-Michou, Chun-Kit Lai, Mizuki Ishida, Marcel Guillong, Ignacio González-Álvarez, Ryohei Takahashi, Moei Yano, Kazuhide Mimura, Junichiro Ohta, Yasuhiro Kato, Doly R. Simbolon, Xiao-Ping Xia
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
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A Model for the Lithospheric Architecture of the Central Andes and the Localization of Giant Porphyry Copper Deposit Clusters Econ. Geol. (IF 5.5) Pub Date : 2023-09-01 Alexander D. Farrar, David R. Cooke, Jon M.A. Hronsky, David G. Wood, Sebastian B. Benavides, Matthew J. Cracknell, James F. Banyard, Santiago Gigola, Tim Ireland, Simon M. Jones, José Piquer
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
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Erratum Econ. Geol. (IF 5.5) Pub Date : 2023-09-01
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.
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Geology of Winu-Ngapakarra, Great Sandy Desert of Western Australia, a Recently Discovered Intrusion-Related Cu-Au Deposit Econ. Geol. (IF 5.5) Pub Date : 2023-08-01 Hilke Dalstra, Adam Black, Inna Mudrovska
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
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Contrasting Features and Volcanostratigraphy of the Mafic-Hosted Mandoos and Shinas Volcanogenic Massive Sulfide Deposits, Samail Ophiolite, Oman Econ. Geol. (IF 5.5) Pub Date : 2023-08-01 André Cravinho, Ana P. Jesus, Bruno Moreira, António Mateus, Bernhard Pracejus, Jorge Figueiras, Mathieu Benoit, Wilfried Bauer, Fernando Rocha
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