Metallogeny of the Grenville Province revisited

2005 ◽  
Vol 42 (10) ◽  
pp. 1719-1734 ◽  
Author(s):  
Michel Gauthier ◽  
Francis Chartrand
Keyword(s):  
Iron Oxide ◽  
Lower Crust ◽  
Mineral Exploration ◽  
Ore Deposits ◽  
Temporal Association ◽  
Metamorphic Belt ◽  
Grenville Province ◽  
Early Colonial ◽  
Copper Gold ◽  
Zinc Deposits

Four new petrogenetic and metallogenic models are proposed herein to explain the formation of important mineral deposits in the Grenville Province, providing a framework from which to reappraise Grenvillian mineral potential. Recognition of a high-pressure metamorphic belt within the Grenville Province suggests a potential for eclogite-hosted rutile deposits, an important and much-sought commodity. A recently developed Norwegian model proposes that anorthosite genesis occurred through lower crust underplating and coeval partial melting, rather than by plume magmatism. Applied to the Grenville Province, the new petrogenetic model may provide insight into the widespread occurrence of platinum group element (PGE) poor nickel showings and the distribution of chromite, Ti-rich, and low-Ti iron-oxide deposits within the Grenville and adjacent terranes. A new type of sedimentary–exhalative (SEDEX) mineralization formed by oxidized brines has been defined following the discovery of new deposits in Australia. Applied to the Grenville Province, it provides a possible explanation for two long-recognized features of marble-hosted zinc deposits: (i) the presence of meta-siderite beds occurring as distal haloes around SEDEX zinc deposits, and (ii) the mutually exclusive division of these SEDEX deposits into massive sulphide and nonsulphide groups. The discovery of the giant Olympic Dam iron-oxide copper–gold (IOCG) deposit in Australia renewed the interest in magmatic low-Ti iron-oxide deposits in the Grenville Province that have been known and mined since early colonial times. Subsequent exploration in the northeastern part of the Grenville Province revealed the presence of breccia-hosted Cu–Au–U – rare-earth element (REE)-bearing iron-oxide mineralization. This deposit and other low-Ti iron-oxide deposits in the southwestern Grenville Province have a previously undocumented close spatial and temporal association with Ti-rich iron-oxide deposits. These examples demonstrate how new petrogenetic, tectonic, and ore deposit models developed in unmetamorphosed rocks can be successfully adapted to high-grade terranes, where they stimulate mineral exploration in these challenging conditions. Furthermore, by tracking the formation of ore deposits in the lower crust, the existence of unsuspected metallogenic associations in the higher crust, such as the low-Ti and high-Ti iron-oxide association observed in the Grenville Province, may be revealed.

Mineral deposits of Latin America and the Caribbean. Preface

2020 ◽  
Vol 72 (3) ◽  
pp. P250820
Author(s):  
Joaquín A. Proenza ◽  
Lisard Torró ◽  
Carl E. Nelson
Keyword(s):  
Latin America ◽  
Iron Oxide ◽  
Dominican Republic ◽  
Iron Ore ◽  
Mineral Exploration ◽  
Mineral Deposits ◽  
Special Issue ◽  
Gold Silver ◽  
Copper Gold ◽  
The Caribbean

The region that encompasses Latin America and the Caribbean is a preferential destination for mining and mineral exploration, according to the Mineral Commodity Summaries 2020 of the US Geological Survey (https://www.usgs.gov/centers/nmic/). The region contains important resources of copper, gold, silver, nickel, cobalt, iron, niobium, aluminum, zinc, lead, tin, lithium, chromium, and other metals. For example, Chile is the world’s largest copper producer and the second largest lithium producer. Brazil is the world’s leading niobium producer, the second largest producer of iron ore, and the third-ranked producer of tantalum. Cuba contains some of the largest reserves of nickel and cobalt in the world, associated with lateritic Ni-Co deposits. Mexico is traditionally the largest silver producer and contains the two largest mines in this commodity and, along with Peru, Chile, Bolivia and Argentina, accounts for more than half of the total amount of global silver production. The region also hosts several world-class gold mines (e.g., Pueblo Viejo in the Dominican Republic, Paracotu in Brazil, Veladero in Argentina, and Yanacocha in Peru). Also, Bolivia and Brazil are among the world’s leading producers of tin. The region hosts a variety of deposit types, among which the most outstanding are porphyry copper and epithermal precious metal, bauxite and lateritic nickel, lateritic iron ore from banded iron-formation, iron-oxide-copper-gold (IOCG), sulfide skarn, volcanogenic massive sulfide (VMS), Mississippi Valley type (MVT), primary and weathering-related Nb-bearing minerals associated with alkaline–carbonatite complexes, tin–antimony polymetallic veins, and ophiolitic chromite. This special issue on Mineral Deposits of Latin America and the Caribbean in the Boletín de la Sociedad Geológica Mexicana contains nineteen papers. Contributions describe mineral deposits from Mexico, Panama, Cuba, Dominican Republic, Colombia, Venezuela, Ecuador, Chile, and Argentina. This volume of papers covers four mineral systems (mafic-ultramafic orthomagmatic mineral systems, porphyry-skarn-epithermal mineral systems, iron oxide copper-gold mineral systems, and surficial mineral systems). This special issue also includes papers on industrial minerals, techniques for ore discovery (predictive modelling of mineral exploration using GIS), regional metallogeny and mining history.

Iron oxide - copper - gold-type and related deposits in the Manitou Lake area, eastern Grenville Province, Quebec: variations in setting, composition, and style

2005 ◽  
Vol 42 (10) ◽  
pp. 1829-1847 ◽  
Author(s):  
T Clark ◽  
A Gobeil ◽  
J David
Keyword(s):  
Iron Oxide ◽  
Meteoric Water ◽  
Active Faults ◽  
Rare Metal ◽  
Lake Area ◽  
Rare Metals ◽  
Grenville Province ◽  
Copper Gold ◽  
Radioactive Minerals ◽  
Metasomatic Replacement

The Manitou Lake area (Kwyjibo and Lac Marmont sectors), located in Quebec's eastern Grenville Province, contains magnetite-rich deposits with variable morphological, mineralogical, and chemical characteristics. Most Kwyjibo sector deposits are rich in Cu, rare-earth elements (REE), Y, P, F, and Ag and are anomalous in Th, U, Mo, W, Zr, and Au, and Lac Marmont sector deposits are commonly poor in these elements. Deposits occur in or are closely associated with 1175–1168 Ma leucogranite. They contain combinations of magnetite, clinopyroxene, blue–green hornblende, titanite, apatite, fluorite, quartz, biotite, andradite, epidote, albite, hematite, sulfides (chalcopyrite, pyrite, pyrrhotite, molybdenite, sphalerite), ilmenite, allanite, and other REE-bearing minerals. Veins and breccias are common. Most of the magnetite mineralization was preceded by potassic metasomatism (microcline) and was followed by most of the sulfides and radioactive minerals. Nearby sulfide-dominant deposits may be related. The deposits were formed by metasomatic replacement and fracture filling from hydrothermal fluids of variable composition, which were probably channeled in major, active faults. Oxygen-isotope data from magnetite-rich rocks suggest that fluids were predominantly magmatic and (or) metamorphic and that, locally, mixing with cooler meteoric water may have facilitated precipitation of sulfides and rare-metal minerals. Titanites in mineralized rock have been dated at 972 ± 5 Ma, but most magnetite may be older. Mineralization was syn- to post-tectonic and occurred in an orogenic to orogenic-collapse setting. The Cu–REE–Y-rich deposits are similar to iron oxide – copper – gold (IOCG) Olympic Dam type deposits, and copper- and rare-metals-poor occurrences resemble magnetite ± apatite Kiruna-type deposits.

Introduction to the Grenville Province: a geological and mineral resources perspective derived from government and academic research initiatives

2005 ◽  
Vol 42 (10) ◽  
pp. 1637-1642 ◽  
Author(s):  
Louise Corriveau ◽  
Thomas Clark
Keyword(s):  
New Technologies ◽  
Mineral Exploration ◽  
Academic Research ◽  
Mineral Resources ◽  
Ore Deposits ◽  
Mineral Deposits ◽  
Special Role ◽  
Grenville Province ◽  
Mineral Potential ◽  
New Research

Canadian society faces a significant decline in the number of active mines and in the discovery rate of base and precious metal deposits. Exploring in the shadows of active and former mines with improved metallogenic models and new technologies is one way to address this problem. Another way is to diversify mineral exploration outside known mining camps and target prospective but underexplored settings and nonconventional mineral deposits. In Canadian terms, diversifying exploration commonly translates into targeting gneissic and granitic terrains where modern geoscience knowledge may be rare or only at reconnaissance scale and where key regional and local indicators and vectors to ore may be missing in the geological record. Though underexplored settings abound in Canada, only one orogen has an aura that discourages exploration: the Grenville Province. Consequently, even though the Grenville Province provides the best model of a deep continental-collision zone so far studied anywhere on Earth and constitutes a microcosm of continental accretion, it remains underexplored, underprospected, undermapped and underestimated. It is thus essential to revisit the mineral potential of the most accessible orogen of the Canadian Shield, search for its missing volcanic belts, reexamine its ore deposits and mineral occurrences, and explore new research avenues using the best remote-sensing device on Earth: human eyes. This special issue captures advances associated with regional field investigations by government that played a special role in opening up frontier areas for mineral exploration. Papers stemming from academia and government–university–industry consortiums investigate further some of the topics covered by these and earlier surveys and others contribute structural and metamorphic insights that will be valuable in future mapping projects. The advances reported here for the Grenville Province may provide impetus to revisit other Grenville-age terrains worldwide, just as metallogenic models developed in other countries have provided the means to look in a different manner at the Grenville orogen for mineral deposits. Collectively all the various approaches presented in this volume help us to revamp our way of looking at the mineral potential of the Grenville orogen.

A Continuum from Iron Oxide Copper-Gold to Iron Oxide-Apatite Deposits: Evidence from Fe and O Stable Isotopes and Trace Element Chemistry of Magnetite

2020 ◽  
Vol 115 (7) ◽  
pp. 1443-1459 ◽  
Author(s):  
Maria A. Rodriguez-Mustafa ◽  
Adam C. Simon ◽  
Irene del Real ◽  
John F.H. Thompson ◽  
Laura D. Bilenker ◽  
...  
Keyword(s):  
Iron Oxide ◽  
Stable Isotope ◽  
Trace Element ◽  
Minor Element ◽  
Open Pit ◽  
Temporal Association ◽  
Iocg Deposits ◽  
Copper Gold ◽  
Iocg Deposit ◽  
O Isotope

Abstract Iron oxide copper-gold (IOCG) and iron oxide-apatite (IOA) deposits are major sources of Fe, Cu, and Au. Magnetite is the modally dominant and commodity mineral in IOA deposits, whereas magnetite and hematite are predominant in IOCG deposits, with copper sulfides being the primary commodity minerals. It is generally accepted that IOCG deposits formed by hydrothermal processes, but there is a lack of consensus for the source of the ore fluid(s). There are multiple competing hypotheses for the formation of IOA deposits, with models that range from purely magmatic to purely hydrothermal. In the Chilean iron belt, the spatial and temporal association of IOCG and IOA deposits has led to the hypothesis that IOA and IOCG deposits are genetically connected, where S-Cu-Au–poor magnetite-dominated IOA deposits represent the stratigraphically deeper levels of S-Cu-Au–rich magnetite- and hematite-dominated IOCG deposits. Here we report minor element and Fe and O stable isotope abundances for magnetite and H stable isotope abundances for actinolite from the Candelaria IOCG deposit and Quince IOA prospect in the Chilean iron belt. Backscattered electron imaging reveals textures of igneous and magmatic-hydrothermal affinities and the exsolution of Mn-rich ilmenite from magnetite in Quince and deep levels of Candelaria (>500 m below the bottom of the open pit). Trace element concentrations in magnetite systematically increase with depth in both deposits and decrease from core to rim within magnetite grains in shallow samples from Candelaria. These results are consistent with a cooling trend for magnetite growth from deep to shallow levels in both systems. Iron isotope compositions of magnetite range from δ56Fe values of 0.11 ± 0.07 to 0.16 ± 0.05‰ for Quince and between 0.16 ± 0.03 and 0.42 ± 0.04‰ for Candelaria. Oxygen isotope compositions of magnetite range from δ18O values of 2.65 ± 0.07 to 3.33 ± 0.07‰ for Quince and between 1.16 ± 0.07 and 7.80 ± 0.07‰ for Candelaria. For cogenetic actinolite, δD values range from –41.7 ± 2.10 to –39.0 ± 2.10‰ for Quince and from –93.9 ± 2.10 to –54.0 ± 2.10‰ for Candelaria, and δ18O values range between 5.89 ± 0.23 and 6.02 ± 0.23‰ for Quince and between 7.50 ± 0.23 and 7.69 ± 0.23‰ for Candelaria. The paired Fe and O isotope compositions of magnetite and the H isotope signature of actinolite fingerprint a magmatic source reservoir for ore fluids at Candelaria and Quince. Temperature estimates from O isotope thermometry and Fe# of actinolite (Fe# = [molar Fe]/([molar Fe] + [molar Mg])) are consistent with high-temperature mineralization (600°–860°C). The reintegrated composition of primary Ti-rich magnetite is consistent with igneous magnetite and supports magmatic conditions for the formation of magnetite in the Quince prospect and the deep portion of the Candelaria deposit. The trace element variations and zonation in magnetite from shallower levels of Candelaria are consistent with magnetite growth from a cooling magmatic-hydrothermal fluid. The combined chemical and textural data are consistent with a combined igneous and magmatic-hydrothermal origin for Quince and Candelaria, where the deeper portion of Candelaria corresponds to a transitional phase between the shallower IOCG deposit and a deeper IOA system analogous to the Quince IOA prospect, providing evidence for a continuum between both deposit types.

scholarly journals Mineral deposits of Latin America and the Caribbean. Preface

2020 ◽  
Vol 72 (3) ◽  
pp. A250820
Author(s):  
Joaquín A. Proenza ◽  
Lisard Torró ◽  
Carl E. Nelson
Keyword(s):  
Latin America ◽  
Iron Oxide ◽  
Dominican Republic ◽  
Iron Ore ◽  
Mineral Exploration ◽  
Mineral Deposits ◽  
Special Issue ◽  
Gold Silver ◽  
Copper Gold ◽  
The Caribbean

The region that encompasses Latin America and the Caribbean is a preferential destination for mining and mineral exploration, according to the Mineral Commodity Summaries 2020 of the US Geological Survey (https://www.usgs.gov/centers/nmic/). The region contains important resources of copper, gold, silver, nickel, cobalt, iron, niobium, aluminum, zinc, lead, tin, lithium, chromium, and other metals. For example, Chile is the world’s largest copper producer and the second largest lithium producer. Brazil is the world’s leading niobium producer, the second largest producer of iron ore, and the third-ranked producer of tantalum. Cuba contains some of the largest reserves of nickel and cobalt in the world, associated with lateritic Ni-Co deposits. Mexico is traditionally the largest silver producer and contains the two largest mines in this commodity and, along with Peru, Chile, Bolivia and Argentina, accounts for more than half of the total amount of global silver production. The region also hosts several world-class gold mines (e.g., Pueblo Viejo in the Dominican Republic, Paracotu in Brazil, Veladero in Argentina, and Yanacocha in Peru). Also, Bolivia and Brazil are among the world’s leading producers of tin. The region hosts a variety of deposit types, among which the most outstanding are porphyry copper and epithermal precious metal, bauxite and lateritic nickel, lateritic iron ore from banded iron-formation, iron-oxide-copper-gold (IOCG), sulfide skarn, volcanogenic massive sulfide (VMS), Mississippi Valley type (MVT), primary and weathering-related Nb-bearing minerals associated with alkaline–carbonatite complexes, tin–antimony polymetallic veins, and ophiolitic chromite. This special issue on Mineral Deposits of Latin America and the Caribbean in the Boletín de la Sociedad Geológica Mexicana contains nineteen papers. Contributions describe mineral deposits from Mexico, Panama, Cuba, Dominican Republic, Colombia, Venezuela, Ecuador, Chile, and Argentina. This volume of papers covers four mineral systems (mafic-ultramafic orthomagmatic mineral systems, porphyry-skarn-epithermal mineral systems, iron oxide copper-gold mineral systems, and surficial mineral systems). This special issue also includes papers on industrial minerals, techniques for ore discovery (predictive modelling of mineral exploration using GIS), regional metallogeny and mining history.

Geophysical inversions applied to 3D geology characterization of an iron oxide copper-gold deposit in Brazil

Geophysics ◽  
2017 ◽  
Vol 82 (5) ◽  
pp. K1-K13 ◽  
Author(s):  
Aline Tavares Melo ◽  
Jiajia Sun ◽  
Yaoguo Li
Keyword(s):  
Iron Oxide ◽  
Physical Properties ◽  
Gold Deposit ◽  
Mineral Exploration ◽  
Iron Formation ◽  
Copper Ore ◽  
Rock Types ◽  
Objective Interpretation ◽  
Copper Gold ◽  
Host Rocks

Mineral exploration dynamics often requires an efficient and objective means of evaluating a prospect in early exploration stages, when few holes have been drilled. In the case of deep prospects or prospects under cover, this evaluation will mostly be based on geophysical data. To develop an objective interpretation method capable of combining all the information available, we have developed an integrated interpretation scheme of geophysical models and sparse geologic data. Our method is based on the relationship between recovered physical properties obtained from 2D and 3D inversions, aiming to find patterns associated with geologic units, such as iron formation, copper ore, and host rock. The interpretation is guided by theoretical relations of the minerals of interest (chalcopyrite and magnetite) and the sparse geologic information available. It is suitable for prospects in the initial stages of exploration when only limited mineralogical information is available from, say, one drillhole. We have demonstrated the success of the method using magnetic and DC resistivity data from the Cristalino iron oxide copper-gold deposit, located in northern Brazil, which is covered by a thick soil overburden. The theoretical behavior of the physical properties of chalcopyrite and magnetite was first combined with the rock types identified in the drill cores to find groups or classes associated with different amounts of these minerals. Then, these relative relations between units were applied to define four classes in the scatterplot of recovered susceptibility and conductivity values from 2D inversions. These four classes are associated with iron formation, copper ore, and two types of host rocks. After the validation with the known geology, the same interpretation scheme was applied to the scatterplot of recovered susceptibility and conductivity values from 3D inversions. The final interpreted volume allows the explorationist to have an approximate estimate of the copper body extent.

scholarly journals Mineral Physicochemistry Underlying Feature-Based Extraction of Mineral Abundance and Composition from Shortwave, Mid and Thermal Infrared Reflectance Spectra

Minerals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 347
Author(s):  
Carsten Laukamp ◽  
Andrew Rodger ◽  
Monica LeGras ◽  
Heta Lampinen ◽  
Ian C. Lau ◽  
...  
Keyword(s):  
Mineral Exploration ◽  
Relevant Information ◽  
Ore Deposits ◽  
Reflectance Spectra ◽  
Full Potential ◽  
Infrared Reflectance ◽  
Vibrational Modes ◽  
Diagnostic Features ◽  
Wide Range ◽  
Mineral Assemblages

Reflectance spectroscopy allows cost-effective and rapid mineral characterisation, addressing mineral exploration and mining challenges. Shortwave (SWIR), mid (MIR) and thermal (TIR) infrared reflectance spectra are collected in a wide range of environments and scales, with instrumentation ranging from spaceborne, airborne, field and drill core sensors to IR microscopy. However, interpretation of reflectance spectra is, due to the abundance of potential vibrational modes in mineral assemblages, non-trivial and requires a thorough understanding of the potential factors contributing to the reflectance spectra. In order to close the gap between understanding mineral-diagnostic absorption features and efficient interpretation of reflectance spectra, an up-to-date overview of major vibrational modes of rock-forming minerals in the SWIR, MIR and TIR is provided. A series of scripts are proposed that allow the extraction of the relative intensity or wavelength position of single absorption and other mineral-diagnostic features. Binary discrimination diagrams can assist in rapidly evaluating mineral assemblages, and relative abundance and chemical composition of key vector minerals, in hydrothermal ore deposits. The aim of this contribution is to make geologically relevant information more easily extractable from reflectance spectra, enabling the mineral resources and geoscience communities to realise the full potential of hyperspectral sensing technologies.

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