scholarly journals Suitability of surficial media for Ni-Cu-PGE exploration in an established mining camp: a case study from the South Range of the Sudbury Igneous Complex, Canada

2021 ◽  
pp. geochem2021-051
Author(s):  
Sarah Hashmi ◽  
Matthew I. Leybourne ◽  
Stewart Hamilton ◽  
Daniel Layton-Matthews ◽  
M. Beth McClenaghan

A geochemical study over the southwestern part of the South Range of the Sudbury Igneous Complex (SIC) was completed to assess the suitability of surficial media (humus, B-horizon soil and C-horizon soil) for delineating geochemical anomalies associated with Ni-Cu-PGE mineralization. Another objective was to test whether Na pyrophosphate can eliminate the effects of anthropogenic contamination in humus. Results of this study suggest that the natural geochemical signature of humus is strongly overprinted by anthropogenic contamination. Despite no indication of underlying or nearby mineralization, metal concentrations in humus samples by aqua regia collected downwind from smelting operations are higher compared to background, including up to 13 times higher for Pt, 12 times higher for Cu and 9 times higher for Ni. The high anthropogenic background masks the geogenic signal such that it is only apparent in humus samples collected in the vicinity of known Ni-Cu-PGE deposits. Results of this study also demonstrate that anthropogenically-derived atmospheric fallout also influences the upper B-horizon soil; however, lower B-horizon soil (at > 20 cm depth) and C-horizon soil (both developed in till) are not affected. Glacial dispersal from Ni-Cu-PGE mineralization is apparent in C-horizon till samples analyzed in this study. Compared to the background concentrations, the unaffected C-horizon till samples collected immediately down-ice of the low-sulfide, high precious metal (LSHPM) Vermilion Cu-Ni-PGE deposit are enriched over 20 times in Pt (203 ppb), Au (81 ppm) and Cu (963 ppm), and over 30 times in Ni (1283 ppm).Supplementary material:https://doi.org/10.6084/m9.figshare.c.5691080

2021 ◽  
pp. 104301
Author(s):  
Sarah Hashmi ◽  
Matthew I. Leybourne ◽  
Daniel Layton-Matthews ◽  
Stewart Hamilton ◽  
M. Beth McClenaghan ◽  
...  

2021 ◽  
pp. SP520-2021-89
Author(s):  
Mariano Tenuta ◽  
Paola Donato ◽  
Rocco Dominici ◽  
Rosanna De Rosa

AbstractThe Ofanto river drains volcanic rocks from the Monte Vulture, lacustrine-fluviolacustrine deposits associated with the same volcano and sedimentary deposits of the Southern Apennines and the Bradanic foredeep sequences. Comparing the modal composition of river sands and the outcrop area of different lithologies in the different sub-basins, an over-concentration of the volcaniclastic fraction, mainly represented by loose crystals of clinopyroxene, garnet and amphibole, is shown. This has been related to the preferential erosion of pyroclastic deposits, characterized by high production of sand-sized loose minerals, together with the carbonate lability and the low sand-sized detritus production from claystones and marls. The occurrence of volcaniclastic components upstream of Monte Vulture can be explained with a contribution from the lacustrine-fluviolacustrine deposits outcropping in the upstream sector or from pyroclastic fall deposits of Monte Vulture and/or Campanian volcanoes. This research shows that the volcanic record in the fluvial sands of the Ofanto river comes from weathering and sorting processes of volcaniclastic deposits rather than of the lavas building the main edifice. Therefore, caution must be taken during paleoenvironmental and paleoclimatic reconstructions when relating the type and abundance of the volcanic component in sediments to the weathering stage and evolutionary history of the volcano.Supplementary material at https://doi.org/10.6084/m9.figshare.c.5643959


2020 ◽  
Vol 177 (5) ◽  
pp. 965-980
Author(s):  
Robert J. Stern ◽  
Kamal Ali ◽  
Paul D. Asimow ◽  
Mokhles K. Azer ◽  
Matthew I. Leybourne ◽  
...  

We analysed gabbroic and dioritic rocks from the Atud igneous complex in the Eastern Desert of Egypt to understand better the formation of juvenile continental crust of the Arabian–Nubian Shield. Our results show that the rocks are the same age (U–Pb zircon ages of 694.5 ± 2.1 Ma for two diorites and 695.3 ± 3.4 Ma for one gabbronorite). These are partial melts of the mantle and related fractionates (εNd690 = +4.2 to +7.3, 87Sr/86Sri = 0.70246–0.70268, zircon δ18O ∼ +5‰). Trace element patterns indicate that Atud magmas formed above a subduction zone as part of a large and long-lived (c. 60 myr) convergent margin. Atud complex igneous rocks belong to a larger metagabbro–epidiorite–diorite complex that formed as a deep crustal mush into which new pulses of mafic magma were periodically emplaced, incorporated and evolved. The petrological evolution can be explained by fractional crystallization of mafic magma plus variable plagioclase accumulation in a mid- to lower crustal MASH zone. The Atud igneous complex shows that mantle partial melting and fractional crystallization and plagioclase accumulation were important for Cryogenian crust formation in this part of the Arabian–Nubian Shield.Supplementary material: Analytical methods and data, calculated equilibrium mineral temperatures, results of petrogenetic modeling, and cathodluminesence images of zircons can be found at https://doi.org/10.6084/m9.figshare.c.4958822


2015 ◽  
Vol 26 (1) ◽  
pp. 57-79 ◽  
Author(s):  
Giuliano Almeida Marodin ◽  
Tarcísio Abreu Saurin

Purpose – The purpose of this paper is twofold: to classify the risks that affect the lean production implementation (LPI) process, and to demonstrate how that classification can help to identify the relationships between the risks. Design/methodology/approach – Initially, a survey was conducted to identify the probability and impact of 14 risks in LPI, which had been identified based on a literature review. The sample comprised 57 respondents, from companies in the south of Brazil. An exploratory factor analysis was carried out to analyze the results of the survey, allowing the identification of three groups of risks in LPI. Then, a case study was conducted in one of the companies represented in the survey, in order to identify examples of relationships between the risks. Multiple sources of evidence were used in the case study, such as interviews, observations and documents analysis. Findings – The risks that affect LPI were grouped into three categories: management of the process of LPI, top and middle management support and shop floor involvement. A number of examples of relationships between the risks were identified. Research limitations/implications – The survey was limited to companies from the south of Brazil and therefore its results cannot be completelly generalized to other companies. Moreover, the results of the survey were not subjected to a confirmatory factor analysis. Originality/value – This study helps to improve the understanding of LPI, as: it re-interprets the factors, barriers and difficulties for LPI from the perspective of risk management, which had not been used for that purpose so far; it presents a classification of the risks that affect LPI, which can support the understanding of the relationships between the risks and, as a result, it can support the development of more effective methods for LPI.


2021 ◽  
pp. jgs2020-167
Author(s):  
Ben Yang ◽  
Michael Steiner

Classical sections, such as the Maidiping and Daqiao Mine sections of South Sichuan (China), expose early Cambrian deposits that are crucial for understanding the biological and environmental evolution of Yangtze Craton. These sequences are rich in Terreneuvian small shelly fossils, which can be assigned to assemblages I and III from South China. The Anabarites trisulcatus– Protohertzina anabarica Assemblage Zone (Assemblage I) is recognized at the lower Maidiping Formation. The second assemblage (Paragloborilus subglobosus – Purella squamulosa Assemblage Zone) cannot be verified in South Sichuan, although previous reports claimed its existence based on the occurrence of Paragloborilus subglobosus. The third assemblage (Watsonella crosbyi Assemblage Zone) is confirmed in the upper Maidiping Formation. The abundant bioclasts in this interval indicate abrasions and bioerosions by winnowing or starved sedimentation. Carbon isotope values from the Maidiping section present no negative excursion at the presumed Ediacaran–Cambrian transition. A positive carbon isotope excursion is observed in the upper Maidiping Formation (Assemblage III) which is correlated to the ZHUCE excursion in the Dahai Member of eastern Yunnan. The shallow water deposits of South Sichuan can be correlated with the South China, western Mongolia and Siberia successions based on biozonations and carbon isotope trends.Thematic collection: This article is part of the Advances in the Cambrian Explosion collection available at: https://www.lyellcollection.org/cc/advances-cambrian-explosionSupplementary material:https://doi.org/10.6084/m9.figshare.c.5326834


2021 ◽  
Vol ahead-of-print (ahead-of-print) ◽  
Author(s):  
Nancy Harding

PurposeThis paper aims to disrupt assumptions about leadership by arguing those who are ostensibly “followers” may be utterly insouciant towards the existence of people categorised as “leaders”. It contributes to anti-leadership theories.Design/methodology/approachThis article uses an immersive, highly reflexive methodology to explore subjective meanings of leadership at community levels ostensibly governed by local government leaders. It uses a case study of the South Wales Valleys, one of the hubs of the Industrial Revolution in the 19th century but now economically deprived.FindingsThrough drawing on their rich and complex history, the author shows how in these communities there is a culture of neo-communitarianism that is anti-leadership and suspicious of attempts to establish hierarchies of superior over inferior. The author explores the complex webs of meaning through which ancient experiences reverberate like dead metaphors, informing contemporary understandings without conscious awareness of such a heritage. This is a history in which “leaders” betrayed or oppressed and exploited the population, which in response turned against hierarchies and evolved practices of self-government that continue today, invisible and unrepresentable within the wider culture.Research limitations/implicationsThe study draws on contemporary feminist research methods that emphasise subjectivity, flux and change. These are often not understood by readers not accustomed to stepping out of a positivist onto-epistemological frame.Practical implicationsThe paper challenges the universalising tendencies of leadership theories that assume a shapeless mass; “followers” await the advent of a leader before they can become agentive.Social implicationsThe paper offers insights into a day-to-day world that is rarely explored.Originality/valueThe article demonstrates how emerging forms of qualitative research give insights into communities that undermine dominant, universalising theories of leadership, followership and government more generally.


2020 ◽  
Vol 31 (3) ◽  
pp. 602-623
Author(s):  
Thendo Masia ◽  
Kahilu Kajimo-Shakantu ◽  
Akintayo Opawole

PurposeGreen building is a relatively new concept with limited applications in property development in South Africa. The objectives of this study are therefore threefold: identify key green building principles considered by property developers, establish the benefits of implementing the principles and determine the barriers to its applications.Design/methodology/approachThe study adopted a case study of two Green Star South Africa (SA)-certified buildings in Sandton, Johannesburg. These are Alexander Forbes building, and Ernst & Young Eris Towers. The two certified buildings were purposefully selected because of the insightful information they provide regarding application of green building principles. The main themes investigated in the cases are environmental awareness, green building principles applications, as well as benefits and barriers of green building. A total of six interviewees from the contractors', property developers', environmental/green building consultants' and sustainability consultants' organizations who were involved in the implementation of green building principles in the two cases provided the qualitative data for the study. The qualitative data were supplemented with data relating to the two case studies obtained from the ‘Earth Works for a Sustainable Built Environment’. The interviews were arranged over a period of two months, and each interview took between 20 and 30 minutes. Analysis of the data was done through a phenomenological interpretation of the qualitative opinions expressed by the interviewees.FindingsKey green building principles comprising energy efficiency, water efficiency, resource efficiency, occupants' health and well-being and sustainable site development were implemented in the two cases. The fact that the buildings were rated 4-star enabled inference to be drawn that the implementation of the principles was less than 60 per cent. Energy efficiency of 35 per cent indicated in Case I suggests that the level is consistent with the South African green building standard of 25 per cent to 50 per cent. However, the energy and water efficiency assessment of the building were based on projections rather than on ongoing monitoring and evaluation of the buildings' performance. Moreover, perceived saving in operational cost was identified as dominant driver to green building principles implementation. Conversely, lack of government incentives and absence of reliable benchmarking data regarding performance of green buildings were major barriers to its full implementation.Practical implicationsThe findings of this study provide important implications to the developers and government on the application of green building principles. In the first place, the evidence that initial high cost premium could be off settled by long- term saving on operational costs as a result of use of local materials, energy and water savings as well as use of recycled material, as implemented in the two case projects, would improve investment decision in green building by developers. The understanding of the drivers and barriers to implementation of green building principles also has implications for guiding government policies and programmes towards green building.Originality/valueThe significance of this study stems from the fact that limited studies, especially in the South African context, have indicated the drivers and barriers to the implementation of green building principles. The case study approach adopted gave a novelty to the study by providing hands-on information from the stakeholders who were known to have played specific roles in the application of green building. The findings indicated that initial high cost premium was not a consideration in developers' choice of green building which justifies the possibility of a costlier product when factors such as environmental sustainability benefit is considered to be ultimate. The study thus suggests further research involving larger cases on energy efficiency, water efficiency and costs of green buildings compared to the conventional type to bring the findings to a broader perspective and assist to benchmark data for green building assessment.


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