Simon M. Jowitt

Global Resource Assessments of Primary Metals: An Optimistic Reality Check

The mining of primary metals is critical for a range of modern infrastructure and goods and the continuing growth in global population and consumption means that these primary metals are expected to remain in high demand. However, metallic deposits are, in essence, finite and non-renewable—leading to some concern that we may run out of a given metal in the future. Here, we address this concern by presenting a brief review of the reporting of mineral resource estimates, compiling detailed datasets for national and global trends in mineral resources for numerous metals, and present detailed case studies of major mining projects or fields. The evidence clearly shows strong growth in known mineral resources and cumulative production over time rather than any evidence of gradual resource depletion. In addition, the key factors that already govern existing mining projects and mineral resources are certainly social, environmental and economic in nature rather than geological or related to physical resource depletion. Overall, there is great room for optimism in terms of humankind’s ability to supply future generations with the metals they will require.

Global platinum group element resources, reserves and mining – A critical assessment

The platinum group elements (PGEs) are used in many technologies and products in modern society, especially auto-catalysts, chemical process catalysts and specialty alloys, yet supply is dominated by South Africa. This leads PGEs to be assessed as critical metals, signalling concern about the likelihood and consequences of social, environmental and economic impacts from disruptions to supply. In order to better understand the global PGE situation, this paper presents a comprehensive global assessment of PGE reserves and resources and the key mining trends which can affect supply. The data shows that global PGE resources have increased from 90,733t PGEs in 2010 to 105,682t PGEs in 2015, a 16.4% increase - despite global production of 2243t PGEs over this period. This suggests that the key issues facing the PGE sector are not geological or resource depletion, but clearly social, economic and environmental in nature - as highlighted by recent social issues in South Africa and volatile global economic conditions. Concerns over PGE supply reliability and the implications of any supply disruption will therefore continue to see the PGEs labelled as critical metals - but certainly not due to resource depletion.

Petrogenesis and timing of emplacement of porphyritic monzonite, dolerite, and basalt associated with the Kuoerzhenkuola Au deposit, Western Junggar, NW China: implications for early Carboniferous tectonic setting and Cu–Au mineralization prospectivity

ABSTRACT The Kuoerzhenkuola epithermal Au deposit is located in the northern part of the West Junggar region of NW China and is underlain by a recently discovered porphyritic monzonite intrusion that contains Cu–Au mineralization. Zircon LA-ICP-MS U–Pb dating of this intrusion yielded an age of 350 ± 4.7 Ma. The porphyritic monzonite is calc-alkaline and is characterized by high concentrations of Sr (583–892 ppm), significant depletions in the heavy rare earth elements (HREE; e.g. Yb = 0.96–2.57 ppm) and Y (10.4–23.3 ppm), and primitive mantle-normalized multi-element variation diagram patterns with positive Sr and Ba and negative Nb and Ti anomalies, all of which indicate that this intrusion is compositionally similar to adakites elsewhere. The composition of the porphyritic monzonite is indicative of the derivation from magmas generated by the melting of young subducted slab material. The area also contains Nb-enriched basalts that are enriched in sodium (Na2O/K2O = 1.20–3.90) and have higher Nb, Zr, TiO2, and P2O5 concentrations and Nb/La and Nb/U ratios than typical arc basalts. The juxtaposition of adakitic rocks, Nb-enriched basalts, and dolerites in this region suggests that the oceanic crust of the expansive oceans within the West Junggar underwent early Carboniferous subduction. Magnetite is widespread throughout the Kuoerzhenkuola Au deposit, as evidenced by the volcanic breccias cemented by late hydrothermal magnetite and pyrite. In addition, the zoned potassic, quartz-sericite alteration, and propylitic and kaolin alteration in the deeper parts of the porphyritic monzonite are similar to those found in porphyry Cu–Au deposits. These findings, coupled with the mineralogy and geochemistry of the alteration associated with the Kuoerzhenkuola Au deposit, suggest that the mineralization in this area is not purely epithermal, with the geology and geochemistry of the porphyritic monzonite in this area suggesting that a porphyry Cu–Au deposit is probably located beneath the Kuoerzhenkuola Au deposit.

Singularity mapping of fracture fills and its relationship to deep concealed orebodies-A case study of the Shaxi porphyry Cu-Au deposit, China

Porphyry Cu-Au type mineralization forms as a result of magmato-hydrothermal activity and involves the migration of hydrothermal fluids through rock fractures, a process that causes the precipitation of fracture-filling minerals with a volume that is much larger than the orebodies themselves. This means that the mineralization-related geochemical anomalies within the minerals that fill these fractures (i.e. fracture fills) can be used to identify areas prospective for deep-seated or otherwise concealed porphyry-type mineralization. This study focuses on the Shaxi deposit, a concealed porphyry Cu-Au deposit located in the Anhui Province, China, and uses singularity techniques to identify and extract geochemical anomalies associated with porphyry Cu-Au-related fracture fills. These data were used to examine the relationships between geochemical anomalies and known deep and concealed mineralization distinguished from unaltered and unmineralized wall-rock material using a concentration–volume (C–V) model in the study area. This analysis indicates that the geochemical anomalies identified in this study are associated with known areas of mineralization in the Shaxi deposit. Areas defined by fracture fills containing anomalous concentrations of Cu only effectively delineate known areas of shallower Cu mineralization, whereas areas with fracture fills containing anomalous concentrations of Au effectively delineate areas containing either Au mineralization and/or deep-seated Cu mineralization. Our study also identified several other targets that have not been explored in the peripheral areas of the Shaxi deposit, some of which should be considered high priority targets for future exploration for concealed orebodies. This indicates that combining singularity mapping with fracture fill geochemical analysis can effectively delineate geochemical anomalies associated with deep-seated or concealed porphyry-type mineralization, an approach that also may well be applicable to exploration for other types of magmato-hydrothermal or hydrothermal mineral deposits.

Large Igneous Provinces and Their Mafic-Ultramafic Intrusions

Here we provide an overview of the range of settings for mafic-ultramafic layered intrusions as part of the plumbing system of Large Igneous Provinces, and address the metallogenic implications.

Acceptance of the SEG Waldemar Lindgren Award for 2014

President Robert, SEG members, and guests: I cannot express what an honor it is to be the 48th recipient of the Waldemar Lindgren award. The list of previous winners reads very much like a who’s who of economic geology and to have my name added to this list is a privilege. However, the achievements that led to this award were certainly not a solo effort and I’d like to devote the rest of my speech to thanking those who helped turn me into the economic geologist I am today.nnMy first real taste of research was part of my master’s degree at Camborne School of Mines, in Cornwall in the UK, an area steeped in mining history. The research component of the degree focused on developing new techniques for exploration for VMS mineralization in Cyprus as part of a joint British Geological Survey, Cyprus Geological Survey, and Natural History Museum project. This opportunity was given to me by Jon Naden of the BGS, who, with numerous colleagues and through …