scholarly journals Automated Indicator Mineral Analysis of Fine-Grained Till Associated with the Sisson W-Mo Deposit, New Brunswick, Canada

Minerals ◽  
2021 ◽  
Vol 11 (2) ◽  
pp. 103
Author(s):  
H. Donald Lougheed ◽  
M. Beth McClenaghan ◽  
Daniel Layton-Matthews ◽  
Matthew I. Leybourne ◽  
Agatha Natalie Dobosz
Keyword(s):  
Mineral Exploration ◽  
Test Site ◽  
Coarse Fraction ◽  
Heavy Mineral ◽  
Optical Methods ◽  
Morphological Data ◽  
Fine Grained ◽  
Ore Minerals ◽  
Indicator Mineral ◽  
Liberation Analysis

Exploration under thick glacial sediment cover is an important facet of modern mineral exploration in Canada and northern Europe. Till heavy mineral concentrate (HMC) indicator mineral methods are well established in exploration for diamonds, gold, and base metals in glaciated terrain. Traditional methods rely on visual examination of >250 µm HMC material. This study applies mineral liberation analysis (MLA) to investigate the finer (<250 µm) fraction of till HMC. Automated mineralogy (e.g., MLA) of finer material allows for the rapid collection of precise compositional and morphological data from a large number (10,000–100,000) of heavy mineral grains in a single sample. The Sisson W-Mo deposit has a previously documented dispersal train containing the ore minerals scheelite, wolframite, and molybdenite, along with sulfide and other accessory minerals, and was used as a test site for this study. Wolframite is identified in till samples up to 10 km down ice, whereas in previous work on the coarse fraction of till it was only identified directly overlying mineralization. Chalcopyrite and pyrite are found up to 10 km down ice, an increase over 2.5 and 5 km, respectively, achieved in previous work on the coarse fraction of the same HMC. Galena, sphalerite, arsenopyrite, and pyrrhotite are also found up to 10 km down ice after only being identified immediately overlying mineralization using the >250 µm fraction of HMC. Many of these sulfide grains are present only as inclusions in more chemically and robust minerals and would not be identified using optical methods. The extension of the wolframite dispersal train highlights the ability of MLA to identify minerals that lack distinguishing physical characteristics to aid visual identification.

scholarly journals Exploration Potential of Fine-Fraction Heavy Mineral Concentrates from Till Using Automated Mineralogy: A Case Study from the Izok Lake Cu–Zn–Pb–Ag VMS Deposit, Nunavut, Canada

Minerals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 310 ◽  
Author(s):  
H. Donald Lougheed ◽  
M. Beth McClenaghan ◽  
Dan Layton-Matthews ◽  
Matthew Leybourne
Keyword(s):  
Mineral Exploration ◽  
Fine Fraction ◽  
Test Site ◽  
Massive Sulfide ◽  
Heavy Mineral ◽  
Morphological Data ◽  
Indicator Mineral ◽  
Automated Mineralogy ◽  
Sediment Cover ◽  
Liberation Analysis

Exploration under thick glacial sediment cover is an important facet of modern mineral exploration in Canada and northern Europe. Till heavy mineral concentrate (HMC) indicator mineral methods are well established in exploration for diamonds, gold, and base metals in glaciated terrain. Traditional methods rely on visual examination of >250 µm HMC material, however this study applies modern automated mineralogical methods (mineral liberation analysis (MLA)) to investigate the finer (<250 µm) fraction of till HMC. Automated mineralogy of finer material allows for rapid collection of precise compositional and morphological data from a large number (10,000–100,000) of heavy mineral grains in a single sample. The Izok Lake volcanogenic massive sulfide (VMS) deposit, one of the largest undeveloped Zn–Cu resources in North America, has a well-documented fan-shaped indicator mineral dispersal train and was used as a test site for this study. Axinite, a VMS indicator mineral difficult to identify optically in HMC, is identified in till samples up to 8 km down ice. Epidote and Fe-oxide minerals are identified, with concentrations peaking proximal to mineralization. Corundum and gahnite are intergrown in till samples immediately down ice of mineralization. Till samples also contain chalcopyrite and galena up to 8 km down ice of mineralization, an increase from 1.3 km for sulfide minerals in till previously reported for coarse HMC fractions. Some of these sulfide grains occur as inclusions within chemically and physically robust mineral grains and would not be identified visually in the coarse HMC visual counts. Best practices for epoxy mineral grain mounting and abundance reporting are presented along with the automated mineralogy of till samples down ice of the deposit.

scholarly journals Indicator mineral and till geochemical signatures of the Broken Hammer Cu–Ni–PGE–Au deposit, North Range, Sudbury Structure, Ontario, Canada

2019 ◽  
Vol 20 (3) ◽  
pp. 337-356
Author(s):  
M. B. McClenaghan ◽  
D. E. Ames ◽  
L. J. Cabri
Keyword(s):  
Heavy Mineral ◽  
Laurentide Ice Sheet ◽  
Surface Zone ◽  
The North ◽  
Visual Identification ◽  
Mineral Fraction ◽  
Sudbury Structure ◽  
Platinum Group Minerals ◽  
Indicator Mineral ◽  
Liberation Analysis

The Broken Hammer Cu–Ni–PGE–Au footwall deposit in the North Range of the Sudbury Structure in Canada consists of a shallow surface zone of vein-hosted and vein stockwork-hosted mineralization within Sudbury breccia developed in the quartz monzonite Levack Gneiss Complex. The surface of the deposit consists of a 2–120 cm wide chalcopyrite vein and numerous smaller veins dominated by chalcopyrite–magnetite–millerite with trace gold, platinum group minerals, tellurides, bismuthides and selenides. The Laurentide Ice Sheet flowed southward across the region depositing a sandy till that contains abundant sperrylite (hundreds of grains), chalcopyrite, pyrite and gold in the heavy mineral fraction down-ice of mineralization. Mineral liberation analysis of the <0.25 mm heavy mineral fraction of metal-rich till identified a broader suite of PGM and sulfides than visual identification methods. The <0.063 mm fraction of till displays a strong geochemical signature of the mineralization for Pd, Pt, Au, Cu and Ag and, to a lesser extent, Bi, Te and Sn; however, geochemical signatures are not detectable as far down-ice as indicator minerals. Till sampling has not been used for exploration in the Sudbury region because of the abundant outcrop and the use of geophysical and prospecting techniques. This study demonstrates that indicator mineral and till geochemical methods are useful exploration tools for the region. The presence of sperrylite and chalcopyrite in oxidized till indicates that even thin (<1 m) highly weathered till is an effective sample medium here.

scholarly journals Current Techniques and Applications of Mineral Chemistry to Mineral Exploration; Examples from Glaciated Terrain: A Review

Minerals ◽  
2021 ◽  
Vol 12 (1) ◽  
pp. 59
Author(s):  
Daniel Layton-Matthews ◽  
M. Beth McClenaghan
Keyword(s):  
Mineral Exploration ◽  
Mineral Chemistry ◽  
Heavy Mineral ◽  
Optical Identification ◽  
Glacial Sediments ◽  
Volcanogenic Massive Sulfides ◽  
Kimberlite Indicator Minerals ◽  
Indicator Mineral ◽  
Automated Mineralogy ◽  
Indicator Minerals

This paper provides a summary of traditional, current, and developing exploration techniques using indicator minerals derived from glacial sediments, with a focus on Canadian case studies. The 0.25 to 2.0 mm fraction of heavy mineral concentrates (HMC) from surficial sediments is typically used for indicator mineral surveys, with the finer (0.25–0.50 mm) fraction used as the default grain size for heavy mineral concentrate studies due to the ease of concentration and separation and subsequent mineralogical identification. Similarly, commonly used indicator minerals (e.g., Kimberlite Indicator Minerals—KIMs) are well known because of ease of optical identification and their ability to survive glacial transport. Herein, we review the last 15 years of the rapidly growing application of Automated Mineralogy (e.g., MLA, QEMSCAN, TIMA, etc) to indicator mineral studies of several ore deposit types, including Ni-Cu-PGE, Volcanogenic Massive Sulfides, and a variety of porphyry systems and glacial sediments down ice of these deposits. These studies have expanded the indicator mineral species that can be applied to mineral exploration and decreased the size of the grains examined down to ~10 microns. Chemical and isotopic fertility indexes developed for bedrock can now be applied to indicator mineral grains in glacial sediments and these methods will influence the next generation of indicator mineral studies.

Application of indicator mineral methods to mineral exploration

2014 ◽  
Author(s):  
M B McClenaghan ◽  
A Plouffe ◽  
D Layton-Matthews
Keyword(s):  
Mineral Exploration ◽  
Indicator Mineral

The Witwatersrand pyrites and metamorphism

1983 ◽  
Vol 47 (345) ◽  
pp. 473-479 ◽  
Author(s):  
D. K. Hallbauer ◽  
K. von Gehlen
Keyword(s):  
Trace Element ◽  
Fluid Inclusions ◽  
Depositional Environment ◽  
Volcanic Rocks ◽  
Source Rocks ◽  
Fine Grained ◽  
Mineral Inclusions ◽  
Ore Minerals ◽  
Hand Specimen

AbstractEvidence obtained from morphological and extensive trace element studies, and from the examination of mineral and fluid inclusions in Witwatersrand pyrites, shows three major types of pyrite: (i) detrital pyrite (rounded pyrite crystals transported into the depositional environment); (ii) synsedimentary pyrite (round and rounded aggregates of fine-grained pyrite formed within the depositional environmen); and (iii) authigenic pyrite (newly crystallized and/or recrystallized pyrite formed after deposition). The detrital grains contain mineral inclusions such as biotite, feldspar, apatite, zircon, sphene, and various ore minerals, and fluid inclusions with daughter minerals. Most of the inclusions are incompatible with an origin by sulphidization. Recrystallized authigenic pyrite occurs in large quantities but only in horizons or localities which have been subjected to higher temperatures during the intrusion or extrusion of younger volcanic rocks. Important additional findings are the often substantial amounts of pyrite and small amounts of particles of gold found in Archaean granites (Hallbauer, 1982) as possible source rocks for the Witwatersrand detritus. Large differences in Ag and Hg content between homogeneous single gold grains within a hand specimen indicate a lack of metamorphic homogenization. The influence of metamorphism on the Witwatersrand pyrites can therefore be described as only slight and generally negligible.

scholarly journals Development of Sustainable Test Sites for Mineral Exploration and Knowledge Spillover for Industry

2020 ◽  
Vol 12 (5) ◽  
pp. 2016 ◽  
Author(s):  
Michaela Kesselring ◽  
Frank Wagner ◽  
Moritz Kirsch ◽  
Leila Ajjabou ◽  
Richard Gloaguen
Keyword(s):  
Resource Use ◽  
Physical Environment ◽  
Mineral Exploration ◽  
Test Site ◽  
Business Practices ◽  
The Social ◽  
Social And Physical Environment ◽  
Key Drivers ◽  
Environmental Measures ◽  
Social Environmental

In mineral exploration, pressure is growing to develop innovative technologies and methods with a lower impact on the social and physical environment. To assess the performance and impact of these technologies and methods, test sites are required. Embedded in the literature on sustainable development, this paper explores how social and environmental measures can be implemented in the design of test sites and what industry stake can learn from sustainable test sites. Through qualitative research, two value networks were developed, one for a sustainable test site approach and another for the existing business practice in mineral exploration. Respondents include public sector officials as well as experts in the social, environmental, business, geoscience, and industry fields. The analysis identifies key drivers for the development of socially and environmentally accepted test sites, thus drawing up actionable points for the mineral exploration industry to increase sustainability. The findings of this paper suggest that the integration of experts and partners from social, as well as environmental, sciences drives sustainability at test sites. For industry application, this results in the need to adapt the activities performed, align resource use with sustainability indicators, and also reconfigure the network of partners towards more socially and environmentally oriented business practices.

scholarly journals Application of the Fine-Grained Soil Prospecting Method in Typical Covered Terrains of Northern China

Minerals ◽  
2021 ◽  
Vol 11 (12) ◽  
pp. 1383
Author(s):  
Hanliang Liu ◽  
Bimin Zhang ◽  
Xueqiu Wang ◽  
Zhixuan Han ◽  
Baoyun Zhang ◽  
...  
Keyword(s):  
Mineral Exploration ◽  
Mineral Resources ◽  
Northern China ◽  
Gobi Desert ◽  
Test Results ◽  
Fine Grained ◽  
Ore Body ◽  
Ore Bodies ◽  
Fine Grained Soil ◽  
Body Location

In recent years, mineral resources near the surface are becoming scarce, causing focused mineral exploration on concealed deposits in covered terrains. In northern China, covered terrains are widespread and conceal bedrock sequences and mineralization. These represent geochemical challenges for mineral exploration in China. As a deep-penetrating geochemical technology that can reflect the information of deep anomalies, the fine-grained soil prospecting method has achieved ideal test results in arid Gobi Desert covered terrain, semi-arid grassland covered terrain, and alluvium soil covered terrain of northern China. The anomaly range indicated by the fine-grained soil prospecting method is very good with the known ore body location. The corresponding relationship can effectively indicate deep ore bodies and delineate anomalies in unknown areas. Overall, the fine-grained soil prospecting method can be applied to geochemical prospecting and exploration in covered terrains.

scholarly journals <sup>40</sup>Ar/<sup>39</sup>Ar dating of a hydrothermal pegmatitic buddingtonite–muscovite assemblage from Volyn, Ukraine

2022 ◽  
Vol 34 (1) ◽  
pp. 7-18
Author(s):  
Gerhard Franz ◽  
Masafumi Sudo ◽  
Vladimir Khomenko
Keyword(s):  
Age Determination ◽  
Optical Methods ◽  
Mineralogical Characterization ◽  
Fine Grained ◽  
Laser Ablation Method ◽  
Supplementary Method ◽  
Plutonic Complex ◽  
Backscattered Electron ◽  
Electron Imaging ◽  
Hydrothermal Environments

Abstract. We determined 40Ar/39Ar ages of buddingtonite, occurring together with muscovite, with the laser-ablation method. This is the first attempt to date the NH4-feldspar buddingtonite, which is typical for sedimentary–diagenetic environments of sediments, rich in organic matter, or in hydrothermal environments, associated with volcanic geyser systems. The sample is a hydrothermal breccia, coming from the Paleoproterozoic pegmatite field of the Korosten Plutonic Complex, Volyn, Ukraine. A detailed characterization by optical methods, electron microprobe analyses, backscattered electron imaging, and IR analyses showed that the buddingtonite consists of euhedral-appearing platy crystals of tens of micrometers wide, 100 or more micrometers in length, which consist of fine-grained fibers of ≤ 1 µm thickness. The crystals are sector and growth zoned in terms of K–NH4–H3O content. The content of K allows for an age determination with the 40Ar/39Ar method, as well as in the accompanying muscovite, intimately intergrown with the buddingtonite. The determinations on muscovite yielded an age of 1491 ± 9 Ma, interpreted as the hydrothermal event forming the breccia. However, buddingtonite apparent ages yielded a range of 563 ± 14 Ma down to 383 ± 12 Ma, which are interpreted as reset ages due to Ar loss of the fibrous buddingtonite crystals during later heating. We conclude that buddingtonite is suited for 40Ar/39Ar age determinations as a supplementary method, together with other methods and minerals; however, it requires a detailed mineralogical characterization, and the ages will likely represent minimum ages.

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