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Challenges to global mineral resource security
and options for future supply
P. A. J. LUSTY* & A. G. GUNN
British Geological Survey, Environmental Science Centre, Nicker Hill,
Keyworth, Nottingham NG12 5GG, UK
*Corresponding author (e-mail: plusty@bgs.ac.uk)
Abstract: Minerals are vital to support economic growth and the functioning of modern society.
Demand for minerals is increasing as global population expands and minerals are used in a greater
range of applications, particularly associated with the deployment of new technologies. While con-
cerns about future mineral scarcity have been expressed, these are generally unfounded and based
on over-simplistic analysis. This paper considers recent debate around security of mineral supply
and technical, geosciences-based options to improve utilization of the resource base and contribute
to replenishing reserves. History suggests that increasing demand for minerals and higher prices
will generally lead to technological and scientific innovation that results in new or alternative
sources of supply. Recent assessments of global mineral endowment suggest that society should
be optimistic about its ability to meet future demand for minerals, provided that there is continued
innovation and investment in science and technology. Reducing energy consumption and breaking
the current link between metal production and greenhouse gas emissions are among the greatest
challenges to secure a sustainable mineral supply. However, widespread adoption of low-carbon
mineral extraction technologies, underpinned by multidisciplinary research, and increased
global utilization of low-carbon energy sources will allow these challenges to be met.
Gold Open Access: This article is published under the terms of the CC-BY 3.0 license.
Increasing global demand for minerals
Minerals underpin every aspect of our daily life.
They are essential for supporting economic growth,
improving and maintaining quality of life and for
the functioning of modern society. Minerals are
used in larger quantities (Fig. 1) than ever before
and in an increasingly diverse range of applica-
tions, particularly to meet the requirements of new
technologies. Burgeoning demand for minerals
is driven by a range of factors of which the most
fundamental is population growth, predominantly
in the developing world. Global population is pro-
jected to increase to 10.9 billion by 2100, an
increase of more than 50% from 2013 (United
Nations 2013). Unprecedented levels of urbaniz-
ation and the spread of prosperity, especially in
Brazil, Russia, India and China, and other emerging
economies, are using raw materials in quantities
unimaginable only 20 years ago. By 2025 China
will have developed more than 200 cities with
more than 1 million inhabitants, many incorporating
mass-transit systems (Woetzel et al. 2009). Growth
in emerging markets and developing economies is
predicted to reach 5.7% in 2014, compared with
1.1% in the Euro area (International Monetary
Fund 2013).
In addition to using minerals in far greater quan-
tities, modern technology employs a considerably
more diverse suite of metals. For example, a
modern computer chip contains greater than half
of the elements in the Periodic Table (Graedel
et al. 2013). Even though they may be present in
very small amounts, each is essential to the function
and performance of the device. Proliferation of elec-
tronic devices, such as mobile telephones, tablet
computers and flat panel displays, into every aspect
of our daily lives, coupled with increasing demand
from ‘green’ or clean energy technologies (e.g. auto-
catalysts, photovoltaic cells, high-strength magnets
for motors in electric vehicles and wind turbines),
has caused the rate of production of some metals
(e.g. lithium, cobalt, platinum-group metals, anti-
mony, rare earth elements and tungsten) to increase
dramatically since the 1980s (Fig. 1c, d). Greater
demand and higher prices for these commodities is
reflected in increased global exploration activity
for these metals. For example in May 2014 over
50 ‘advanced’ rare earth element (REE) projects,
involving more than 40 companies, operating in
numerous countries were reported (Technology
Metals Research 2014).
This contribution introduces subsequent papers,
originally presented in a session at the 2011 Geo-
logical Society Fermor Meeting, considering min-
eral resource estimation, sustainability of mineral
supply, associated energy demand and the criticality
of metals to society.
From:Jenkin, G. R. T., Lusty, P. A. J., McDonald, I., Smith, M. P., Boyce,A.J.&Wilkinson, J. J. (eds) 2015.
Ore Deposits in an Evolving Earth. Geological Society, London, Special Publications, 393, 265–276.
First published online June 23, 2014, http:// dx.doi.org/10.1144/SP393.13
#The Authors 2015. Publishing disclaimer: www.geolsoc.org.uk/pub_ethics
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How much is left?
Recent history is punctuated by concerns over the
adequacy of natural resources to support popula-
tion and economic growth. The eighteenth-century
economist Thomas Malthus made dismal pre-
dictions that population growth would exceed the
capacity of the Earth to provide resources. During
the 1970s the Club of Rome modelled the rela-
tionship between economic and population growth
and finite resources, considering varying scenarios.
Many of these resulted in pessimistic predictions
about population decline and environmental dete-
rioration. Speculation over the future availability
of adequate, secure and sustainable supplies of the
mineral commodities required to sustain the growth
rates and meet the demand outlined above contin-
ues to this day. A number of authors have recently
forecast impending scarcity, and even exhaustion,
of some raw materials within a few decades (e.g.
Cohen 2007; Bardi & Pagani 2007; Ragnarsdo
´ttir
2008). However, these alarmist views are frequently
based on over-simplistic analysis and misunder-
standing of the meaning of the terms ‘resources’
and ‘reserves’. A mineral ‘resource’ is a natural con-
centration of material in or on the Earth in such
form and quantity that economic extraction of a
commodity is potentially feasible (USGS 2013).
Resources can be subdivided into different cat-
egories, reflecting the level of geological knowledge
and associated confidence in their existence (Fig.
2). Reserves are that part of an ‘identified’ resource
that could be economically extracted at the time of
assessment (USGS 2013). Accordingly reserves
are economic entities that represent only a very
small proportion of the total amount of a mineral
or metal in the Earth, sometimes referred to as the
‘resource base’ (Fig. 2).
Fig. 1. Annual global production of industrial metals and critical minerals and metals 1980 – 2012. All units in
metric tonnes except platinum-group metals (PGM) in kilograms. Data from British Geological Survey World Mineral
Statistics database, 2014 #NERC, except for rare earth elements (REE) courtesy of the US Geological Survey (USGS
2012). (a) Production of iron ore and bauxite. (b) Mine production of copper and zinc (metal content). (c) Mine
production of lithium and tantalum– niobium minerals, cobalt and PGM (metal content). (d) Mine production of
antimony and tungsten (metal content) and REE (rare earth oxide equivalent).
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Reserves are best considered as working inven-
tories at a particular point in time, varying in
response to the rate of extraction of raw materials,
and to new discoveries and numerous economic,
political, social and environmental factors. For
example, innovations in mining and processing
technologies can result in some previously uneco-
nomic deposits becoming reserves. Non-sulphide
zinc deposits (also referred to as ‘zinc oxide’) were
largely ignored in the latter part of the twentieth
century, but new developments in hydrometallurgy
have transformed them into attractive exploration
targets characterized by large size and low pro-
cessing costs (Hitzman et al. 2003). Where a politi-
cal intervention or some other event creates an
actual or perceived shortage, then increased min-
eral exploration activity can also lead to the iden-
tification of new reserves. For example, reserves
of the REE grew by 25% between 2008 and
2010 (USGS 2009; USGS 2011) because of trade
restrictions imposed by China commencing in
2008, which caused prices to rise and stimulated a
major increase in exploration activity for REE.
New exploration and development can also have a
dramatic impact on resource estimations for indi-
vidual mineral deposits. The resource at the Kamoa
copper deposit in the Democratic Republic of
Congo, the world’s largest underdeveloped high-
grade copper deposit, is a good example with indi-
cated mineral resources doubling in less than a
year (Ivanhoe Mines 2013). Similarly, measured
and indicated mineral resources (Fig. 2) of gold at
the Goldrush deposit in Nevada increased by more
than 500% between 2011 and 2012 (Barrick 2012).
It is important to note, however, that even the
best estimates of global mineral reserves, provided
by the United States Geological Survey (USGS),
are not necessarily reliable. For many commodities
uncertainty in these estimates arises from the fact
that they are derived from a wide range of dispa-
rate sources that do not use a common system for
classifying and reporting reserves. In fact, for some
minor metals, such as indium and gallium, no quan-
titative global reserve figures are published by
USGS because of the lack of suitable high-quality
data. Consequently, because of their dynamic nat-
ure and the inherent uncertainties in global totals,
published reserve estimates should not be regarded
as reliable indicators of future availability of min-
eral commodities. Graedel & Nassar (2013) sug-
gest that, in the interests of long-term planning
and policy aimed at ensuring future supply security,
more robust reserve data are required for a wide
range of mineral commodities. However, this is a
major challenge and would require fundamental
improvements in our understanding of the geologi-
cal distribution of many metals and in data collec-
tion and harmonization.
In an attempt to reduce the bias and sometimes
subjective nature of mineral resource assessment,
the USGS has pioneered a probabilistic approach
for quantifying mineral endowment. This method,
based on established mineral deposit models and
delineation of prospective geology, estimates that
there may be approximately 1.3 times as much cop-
per still to be discovered in porphyry copper depos-
its in the upper 1 km of crust of the Andes region as
identified to date (Cunningham et al. 2008). While
providing a valuable indication of the amount of
metal remaining in undiscovered deposits in the
uppermost part of the Earth, in terms of the total
thickness of the continental crust, this is barely
scratching the surface. The deepest current mine
is approaching 4 km and, as technology evolves,
deeper deposits may become economically viable
to develop. One of the key objectives of current
Fig. 2. The relationship between mineral resources and reserves. Mineral reserves generally only represent
a tiny fraction of resources. Resource base refers to the total amount of a mineral or metal in the Earth’s crust.
*‘Modifying factors’ include mining, processing, metallurgical, marketing, social, environmental, legal and
governmental considerations.
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European initiatives on raw materials is to better
define the potential for indigenous resources at
greater depths (European Commission, 2013a).
An alternative approach to mineral resource
assessment is the tectonic-diffusion method, which
estimates the number of mineral deposits of a spe-
cific type at all levels in the crust. This compu-
tational technique, which uses age–frequency data
of known deposits of a particular type, models the
formation of new deposits and tracks their verti-
cal movement in the Earth’s crust through time
(Kesler & Wilkinson 2008). Applying this approach
to porphyry copper deposits, Kesler & Wilkinson
(2008) estimate that the amount of copper in depos-
its above 3.3 km (a suggested limit of mining in
the foreseeable future) in the Earth’s crust could
support global mine production of copper at current
rates for more than 5000 years. The tectonic-
diffusion method is best suited to deposit types,
such as porphyry copper mineralization, with
approximately log normal age – frequency distri-
butions (Kesler & Wilkinson 2008). Kesler & Wilk-
inson (2013) apply this technique to tin deposits
associated with granites in an attempt to evaluate
the use of tectonic-diffusion analysis for a deposit
class with non-ideal age– frequency distributions.
Their modelling estimates that, even if only half of
the tin identified above 1 km in the Earth’s crust
can be discovered and mined, the amount of reco-
verable tin far exceeds global reserve estimates by
the USGS.
Although these studies demonstrate that more
robust, quantitative estimates of global mineral
endowment are being developed, these are generally
restricted to the industrial or precious metals occur-
ring in relatively well-constrained deposit classes,
which have been the focus of decades of research
and for which voluminous data exist. However,
even for these commodities, the resource assess-
ments are restricted by our current understanding
of ore deposit formation.
Security of supply and criticality
In recent years certain metals have been desig-
nated as ‘critical’, chiefly owing to their economic
importance and likelihood of supply shortage, also
termed ‘supply risk’. Many factors affect min-
eral resource availability, ranging from the crustal
abundance of a particular element to social, envi-
ronmental and geopolitical factors. However, the
supply risk for many metals is due mainly to the
geographical concentration of production in a few
countries, such that many consumer nations are
almost entirely dependent on imported supplies.
For example, China produces more than 90% of
global REE, while Brazil accounts for a similar
proportion of the world’s niobium production
(Brown et al. 2014).
A number of recent national and international
studies have attempted to identify materials at risk
of supply shortage and to provide a basis for the
development of appropriate mitigation strategies.
High-profile examples include the European Com-
mission’s assessment of critical raw materials for
the European Union (European Commission 2010)
and the US Department of Energy’s raw materials
strategy focusing on the clean energy sector (US
Department of Energy 2011). These studies use a
wide range of metrics to measure criticality and,
perhaps unsurprisingly, they have delivered widely
divergent, and frequently criticized, results. Apart
from selection of metrics, a common problem fac-
ing all such criticality assessments is the availabil-
ity of complete, high-quality data for many metals.
For some, such as gallium, indium and germa-
nium, reserve and/or production data are either
completely lacking or seriously deficient. Graedel
& Nassar (2013) focus on the geological factors
which influence criticality evaluation. They indi-
cate that significant opportunity exists for the econ-
omic geology community to inform the debate and
enhance the geological information on which these
assessments rely. However, the by-product nature
of many of the critical metals means that acquiring
such data is particularly challenging. Many are cur-
rently produced exclusively as the by-product of
the extraction of major industrial metals such as
copper, lead, zinc and aluminium. The critical met-
als are found in low concentrations in the ores of
the major metals. For example, most tellurium and
selenium are by-products of copper production,
derived from the anode slimes produced during
electrolytic refining of copper. Processing 500 t of
copper ore typically produces less than 0.5 kg tel-
lurium (Selenium–Tellurium Development Asso-
ciation 2010). During electrolytic copper refining
only a very small proportion of the tellurium in
the copper ores is currently recovered. Although
demand for tellurium is growing and its price is
much greater than that of copper, existing levels of
global production are so small, estimated to be
450 t in 2011 (Willis et al. 2012), compared with
19.7 million t of refined copper in 2011 (Brown
et al. 2014), that there is currently little economic
incentive for copper producers to invest in the
recovery of additional tellurium. This reliance on
production of another metal may give rise to so-
called ‘technical’ or ‘structural’ scarcity for some
of the critical metals. The normal supply – demand
market mechanism may not function effectively
to alleviate scarcity of this type. For example,
although global production of copper is continu-
ing to increase (Fig. 1b), a growing proportion of the
total is produced by hydrometallurgical techniques
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(acid leaching followed by solvent extraction–
electrowinning), which do not permit recovery of
tellurium (American Physical Society 2011). Con-
sequently future tellurium availability may be
constrained by this change in copper extraction
technology.
Global responses and supply options
Although current resources and reserves are unreli-
able indicators of long-term mineral availability,
there seems to be a consensus, among geologists
at least, that physical scarcity and exhaustion of
metals in the Earth’s crust are unlikely (e.g. Wil-
liams 2008; European Commission 2010). Although
there are no grounds for complacency, this view
is supported by history: in the past increasing
demand and associated higher prices have generally
led to technological innovation and breakthroughs
that have resulted in the discovery of new or alterna-
tive sources of minerals and metals. As Cathles
(2013) sets out, optimism, preparation and, we
would add, excellent science are key to ensuring
that mankind can meet the resource demands of a
growing, and increasingly wealthy, global popu-
lation. In coming decades a spectrum of non-
geological issues, such as geopolitics, social and
cultural issues, competition for land, resource
nationalism and environmental challenges, are likely
to represent the largest obstacles to secure and ade-
quate mineral supply (Otto 2006; MacDonald &
Gibson 2006). However, the following discussion
focuses on selected technical options that rely on
geology to improve utilization of the resource base
and to contribute to replenishing reserves.
Scientific research and improved mineral
deposit models
Academic research and commercial mineral
exploration are continually adding to our knowledge
of the processes responsible for ore deposit for-
mation and of controls on the distribution of miner-
alization within the Earth’s crust. Ore deposit
models will continue to evolve as they have done
over the last 50 years, enhancing our ability to
predict where mineral exploration should be con-
ducted and how it should be undertaken most effec-
tively. Even for the major industrial metals and their
main deposit classes, such as porphyry copper
deposits, which have been the subject of decades
of study, researchers are continuing to enhance the
knowledge base and to question some of the funda-
mental controls on their formation, particularly for
giant systems (Sillitoe 2010a). There are likely to
be continued developments in our understanding
of the role of biological processes and bacteria
in ore deposit formation and the importance of
‘economic geomicrobiology’ (Southam & Saunders
2005; Shuster et al. 2013). This knowledge will
have applications in mineral exploration, mineral
processing, tailings management and site remedia-
tion (Zammit et al. 2012; Kalmar 2014). Until
recently many of the critical metals have largely
been neglected by the research community owing
to their limited economic importance and, conse-
quently, little is known about the processes mobiliz-
ing and concentrating these elements in natural
systems. New research, coupled with exploitation
of critical metals in a broader range of geological
environments, is likely to result in a step change in
our understanding of the global distribution of
these resources.
History suggests that entirely new ore deposit
classes will potentially contribute to future mineral
supply. Unconformity-related uranium deposits,
which host more than 30% of the Western world’s
uranium resources and represent some of the larg-
est and highest grade deposits known (World
Nuclear Association 2010), were first described
in the 1970s (Jefferson et al. 2007). The processes
responsible for formation of iron oxide – copper –
gold deposits, which are important sources of
several metals, are poorly understood. These depos-
its were not known about until the fortuitous dis-
covery of Olympic Dam in Australia in 1975, one
of the world’s largest mineral deposits. The geolog-
ical setting and characteristics of the Olympic
Dam deposit were unlike any other deposits known
at the time. However, since then, broadly compar-
able deposits have been identified in several other
countries, notably Brazil, but no unifying genetic
model has been developed (Williams et al. 2005).
For some critical metals that are used in small quan-
tities and have very low abundances in the crust,
new deposit types or a small number of additional
operations (probably as by-products of other met-
als) could have a major impact on future supply.
For example, production from the Kankberg gold –
tellurium mine in Sweden is estimated to contrib-
ute an additional 10% to global tellurium output
(Metal Bulletin 2011). Another potential source of
tellurium supply is provided by small, very high-
grade deposits associated with alkaline igneous
rocks in China (Zhenhua et al. 2005). Accordingly,
even for a geologically scarce metal such as tellur-
ium, which is one of the rarest elements in the
Earth’s crust with estimated concentrations in the
range of 0.36–10 ppb (Hein et al. 2003), com-
parable to platinum (0.4 ppb, Wedepohl 1995), a
range of future supply options exist.
Refinement of mineral deposit models and
the identification of new classes of ore deposit
will lead us to re-evaluate the mineral potential of
terranes that have previously been little explored.
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In some instances non-geological factors, such as
changing political climate and improved infrastruc-
ture, may be important drivers in this respect. Dur-
ing the last 30 years a number of world-class
mineral deposits have been discovered or delin-
eated in what may be considered frontier terranes.
Examples include the Aynak sediment-hosted cop-
per deposit in Afghanistan, the Oyu Tolgoi porphyry
copper–gold deposit in Mongolia and the Reko
Diq porphyry copper–gold system in Pakistan.
The increasing demand for minerals and asso-
ciated higher commodity prices, together with the
availability of new datasets and improved mineral
exploration technology, will encourage re-evalu-
ation of mature exploration terranes and known
deposits. For example, although the Lumwana cop-
per deposit in Zambia was discovered in 1961, it
was not seriously explored until the late 1990s.
This led to the delineation of a very large resource
and the development of one of Africa’s largest
copper mines at Lumwana. The Hemerdon tung-
sten–tin deposit in Devon, UK, is another exam-
ple of how reassessment of well-known deposits is
likely to contribute to future supply. This deposit,
worked on a small scale during the Second World
War, was further explored in the 1970s, but was not
developed owing to depressed commodity prices.
However, with higher metal prices and concerns
over future tungsten supplies (tungsten is com-
monly defined as a critical metal, e.g. European
Commission 2010), an updated mineral reserve
has been defined at Hemerdon and funding has
been secured for development of what will be one
of the world’s largest tungsten mines. The recent
greenfield discovery of the Sakatti magmatic
copper–nickel–platinum–group metal deposit in
northern Finland, attributed to the determination
of the exploration team, coupled with the use of
conventional exploration techniques, illustrates the
potential for further significant mineral deposit
discoveries in known European mining regions
(Mining Journal 2012a; Brownscombe et al. 2014).
New baseline datasets and mineral
exploration technologies
Globally the acquisition of new baseline datasets,
comprising geological, geochemical and geophysi-
cal data, will continue to stimulate mineral explo-
ration interest, both in areas previously regarded
as unprospective and in well-explored regions.
Northern Ireland is now considered one of the best
surveyed parts of the planet as a result of recent
geochemical and airborne geophysical surveys of
the province. These high-resolution datasets con-
tributed to a significant revival in mineral explora-
tion in the region, with the land area under licence
increasing fourfold following release of the new
data (Lusty 2010). Scientists are also developing
novel methodologies to improve baseline data
capture with applications to mineral exploration.
For example, airborne Light Detection and Rang-
ing (LiDAR) and airborne multispectral imaging
have been applied to geological and structural
mapping in areas of dense vegetation cover (Grebby
et al. 2010, 2012).
During the last 50 years there have been major
advances in geochemical, geophysical and remote
sensing technologies (Sillitoe & Thompson 2006),
and further improvements in resolution and accu-
racy are likely to continue. For example, high-
resolution geochronology is improving our under-
standing of the duration and timing of hydrothermal
systems, with significant implications for mineral
exploration (e.g. Braxton et al. 2012; Rohrmeier
et al. 2013), and geochemical methods for exploring
under superficial cover are continually evolving
(e.g. Lilly et al. 2014).
Our ability to quickly and efficiently manage,
process, model and visualize large and complex
digital datasets is constantly evolving and will con-
tinue to have a major impact on how we approach
mineral exploration. For the modern geologist Geo-
graphic Information Systems (GIS) capable of
managing and integrating large volumes of spatial
data are becoming as important as the geological
hammer. Field-portable systems place an array of
data at the geologist’s fingertips and allow digital
field mapping and logging (Brimhall et al. 2006).
GIS facilitates effective visualization, analysis and
dissemination of disparate exploration datasets and
is increasingly being used for mineral explora-
tion targeting and assessment of resource potential
(e.g. Carranza & Sadeghi 2010). There are sugges-
tions that amalgamated datasets, currently con-
sidered too large and complex to process using
conventional data management tools and appli-
cations (‘big data’), cloud computing and more
efficient 3D inversion could impact on future dis-
covery rates (Heffernan 2013). Numerical simu-
lations and modelling are also contributing to
improved understanding of ore forming processes
(Weis et al. 2012) and providing new insights into
resource availability (Kesler & Wilkinson 2013).
Improved mineral exploration targeting will be
supported by more advanced mineral exploration
and resource characterization technologies, for
example, real time, on-site geochemical analysis,
measuring while drilling, geophysical tomography
and 3D visualization.
Despite our optimism, there is no disputing that
the last 50 years have seen a decline in major
mineral deposit discoveries (Beaty 2010), which
some commentators have attributed to declining
grassroots mineral exploration activity (Sillitoe
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2010b). It has been suggested that much of the
planet is well surveyed and has been intensively
explored (Beaty 2010), and that it is harder to dis-
cover new ore deposits than it was several decades
ago (Wood 2012). We would agree that mineral
exploration has become more challenging, partic-
ularly in mature terranes in the developed world,
such as parts of Australia, North America and
Europe. In these regions most exposed deposits, or
those with a significant surface expression, are
likely to have been identified and legal, regulatory,
policy and social factors can deter investment
(Otto 2006; Bloodworth et al. 2009; Tiess 2010).
However, the subsurface in these regions has huge
potential for new discoveries and the next phase of
major mineral deposit discoveries is likely to be
made under cover, where deposits have little or no
surface expression. For example, although Australia
is considered to be a mature exploration terrane,
approximately 80% of its land area is covered by
regolith and sedimentary rocks. However, the bur-
ied basement is as prospective as that exposed at
the surface and which has supplied the majority of
Australia’s mineral production to date. The key to
unlocking this potential is improved understand-
ing of the ‘distal footprints’ of mineral deposits
under cover and the associated development of cost-
effective mineral exploration techniques (Austra-
lian Academy of Science 2012). Elsewhere, in
Brazil for example, the geology is known to be
potentially favourable for the development of a
wide variety of mineral deposit types, but mineral
exploration is hampered by the lack of reliable geo-
logical maps at a useful scale. Even in Europe,
although the geology is relatively well studied and
mapped, the reality is that in some countries, such
as the UK, Austria and Italy, there has been lit-
tle mineral exploration activity in recent years
(Mining Journal 2012b, 2013) and modern high-
resolution geoscience datasets are available only
for limited areas. Despite a surge in mineral explo-
ration activity in the Nordic countries (Mining Jour-
nal 2012b), Europe only attracted 4% of global
exploration for non-ferrous metals in 2012, less
than countries such as Peru and Mexico (Metal
Economics Group 2013). Since 2008 the Euro-
pean Commission has developed new policies and
funded associated research programmes aimed
at boosting raw material supply from European
sources and increasing mineral exploration in the
region (European Commission 2008, 2011, 2013b).
With regard to mineral exploration the European
Commission is implementing a number of actions
focused on improved and cost-effective explora-
tion technologies, provision of high-resolution 3D
data to depths of 4 km and the development of
new models for mineral deposit formation and/or
mineral belts (European Commission 2013a).
New frontiers
Increased demand for minerals and higher commod-
ity prices will lead the minerals industry into more
extreme and technically challenging environments.
Cathles (2013) suggests that seafloor mineral
resources, and the oceans in general, offer huge
potential for the recovery of a range of elements
including uranium, copper, zinc, cobalt, nickel,
lithium, REE and phosphate. Enormous resources
of copper and zinc are calculated to exist on the
ocean floor: even half of the estimated copper
resource would be capable of supplying a global
population of 10.5 billion for many centuries
(Cathles 2013). Appreciation of the mineral poten-
tial in the marine environment is not new, with the
first resource estimates being made in the 1960s.
However, in recent years there has been a revival
of interest in seafloor minerals, as illustrated by
the number of exploration licences for polymetallic
sulphides and nodules issued to a host of countries
(International Seabed Authority 2014). Nautilus
Minerals Inc. has been assessing the potential of sea-
floor massive sulphide deposits in the territorial
waters of Papua New Guinea for a number of
years. UK Seabed Resources was recently granted
a licence to explore a 58 000 km
2
area of the Paci-
fic’s Clarion-Clipperton Zone for polymetallic
nodules (Lockheed Martin 2013). Development of
minerals in new environments will not come with-
out its challenges, not least the potential impact on
delicate ecosystems. However, with sufficient regu-
lation, underpinned by improved scientific under-
standing and new research, this is unlikely to be
an insurmountable hurdle. Many would also ques-
tion the economics of seafloor mineral recovery
and the potential for commercialization, given the
technical challenges of operating in very deep
water environments. However, preliminary analysis
(Cathles 2013) and the recent enthusiasm of some
seabed explorers suggest that metal recovery from
some seafloor resources is economically competi-
tive with terrestrial deposits.
Returning to the example of tellurium, should
demand continue to rise and production from exist-
ing sources not increase, it will be necessary to con-
sider alternative sources of supply. A number of
critical metals are highly enriched in hydrogenous
iron–manganese crusts that precipitate from sea-
water onto the surface of seamounts. Tellurium is
enriched more than any other element, by a factor
of 10
4
relative to the Earth’s crust. While the
levels of enrichment of cobalt are less impressive,
mean concentrations are 3 – 10 times greater than
in currently economic land-based cobalt deposits
(Hein et al. 2010). Crusts in the ‘prime iron –manga-
nese crust zone’ in the central Pacific are estimated
to contain 9 times more tellurium and 3.8 times
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more cobalt than the global terrestrial ‘reserve base’
reported by the USGS (Hein et al. 2013). The
majority of work on iron– manganese crusts has
focused on the Pacific. However, the Atlantic also
has significant potential, particularly for platinum-
enriched crusts (Muin
˜osac et al. 2013).
The polar regions represent another potentially
huge, but largely untapped, source of minerals (e.g.
Lindholt 2006; Gautier et al. 2009). Reduced sea ice
in the Arctic over the last decade, improved ship
access and new infrastructure have contributed to
heightened mineral exploration interest in the re-
gion (e.g. Rosenthal 2012; Braden 2014). Although
this largely under-explored region has the potential
for the discovery of new world-class mineral depos-
its, the challenges and risks for explorers and miners
are significant. In addition to the practical issues of
operating in this remote and extreme environment
(e.g. Sengupta et al. 1990), there are ongoing terri-
torial disputes (Isted 2009; Geopolitical Monitor
2012), and major concerns about the vulnerability
of the environment and social impacts (Gibson &
Klinck 2005; Fridtjof Nansen Institute 2012; Euro-
pean Commission 2013c).
Eco-efficiency
Cathles (2013) suggests that ‘energy is the most
essential resource’. The mining industry is a very
energy-intensive sector. For example, the Chilean
mining industry accounts for 16% of the country’s
total industrial sector fuel consumption (US
Energy Information Administration 2013). Commi-
nution of ore alone accounts for more than 50% of
mine-site energy consumption and is estimated to
consume up to 3% of global power production
(Coalition for Eco Efficient Comminution 2013).
The deficiencies of energy infrastructure and the
high cost of energy supplies already pose a signifi-
cant threat to mine production in several parts of
the world, particularly Africa (e.g. Visser 2013).
As the industry is forced into more challeng-
ing environments (e.g. the development of ultra-
deep open pits .1 km, deeper underground mines
.3 km, the marine environment and the Arctic),
coupled with the general trend of reducing ore
grades (Wood 2012), energy demand is likely to
increase. Mining companies are already making
major investments to increase security of energy
supply and reduce costs: for example, 20% of
Brazilian miner Vale SA energy supply is derived
from renewable sources (Green 2014). Water scar-
city is a further major challenge facing the mining
sector (Carbon Disclosure Project 2013). The scale
of this risk is illustrated by the number of water-
related issues impacting on mining operations glob-
ally and the investments that the mining sector
is making in securing sustainable water supplies
(Carbon Disclosure Project 2013; BHP Billiton
2013).
Although major research and innovation will be
required to address these challenges, mining com-
panies are already investing in related research.
Future developments in this area are likely to focus
on automated drilling and mining, more selective or
‘smart blasting’, improved ore sorting, more effec-
tive waste removal and pre-concentration, enhanced
grinding technology, in-situ mining, re-working of
tailings and slags, improved water management
and increased application of bio-technology, par-
ticularly improving the performance and cost-
effectiveness of microbial bio-leaching and its
application to low-grade and complex ores. Geome-
tallurgy, the integration of geological and miner-
alogical understanding with mineral extraction and
processing, will also become increasingly impor-
tant, particularly in the early stages of project plan-
ning and decision-making, as the minerals industry
seeks to become more efficient and reduce costs
and environmental impacts (Hoal 2008). A transi-
tion from fossil fuels to ‘low-carbon energy sources’
(Cathles 2013) will also significantly contribute
to reducing the future environmental impact of the
mining sector.
Conclusions
As the world population increases over the next 100
years and living standards are raised across the
globe, demand for all natural resources, including
minerals, is expected to continue growing. The
trend of using an increasingly diverse range of min-
erals and metals is also likely to persist. The evi-
dence presented above and the papers in this
section suggest that society has every right to be
optimistic about meeting this demand, provided
that there is continued innovation and investment
in science, research and technology. The geological
community has an integral role to play. While
mineral deposit science and our understanding of
ore forming systems have evolved greatly over the
last century, our understanding of the geological dis-
tribution of some metals, which hitherto have been
of marginal economic interest, is very poor. New
focused research will improve our understanding
of the processes mobilizing and concentrating
these elements, enhancing our exploration models
and ability to identify new deposits. Researchers
will increasingly need to adopt a multidisciplinary
approach, working at the interface of the biological,
chemical and physical sciences. Improved under-
standing of ore deposit formation and more sophis-
ticated targeting will lead to both the re-evaluation
of well-characterized geological terranes and
known deposits, and the assessment of regions that
P. A. J. LUSTY & A. G. GUNN272
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have previously been little explored. Increasing
demand for minerals will push mineral exploration
and extraction into new environments. This will
require significant innovation and investment (e.g.
equipment for deep sea resource evaluation and
mining) and new regulatory frameworks to ensure
that these resources are recovered in a sustainable
manner. Our ability to explore under cover and to
identify concealed mineralization will also be key
to replenishing mineral reserves. This will require
improved understanding of the distal signatures
of mineral deposits at depth, coupled with more
cost-effective exploration, potentially employing
remote data-capture techniques and with increased
emphasis on 3D modelling of the sub-surface.
Advances in mineral deposit science will inform,
and be complemented by, developments in mining
and mineral processing technology, which may
significantly augment resources by allowing the
working of previously uneconomic ore types and
grades. Further efficiency savings will be achieved
through economies of scale, delivered via larger
mines and equipment, and by more cost-effective
transportation, including autonomous methods.
However, the greatest challenge facing the mining
sector is breaking the current link between metal
production and greenhouse gas emissions. This
requires significant multidisciplinary research and
innovation, the widespread adoption of low-carbon
extraction technologies and increased global utiliz-
ation of low-carbon energy sources.
Geoscientists and all those involved in the min-
eral resource lifecycle have a major role to play in
providing better and regularly updated resource
and reserve data for a wider range of metals.
Although this is not a trivial task, this information
is essential to activities such as criticality assess-
ment and material flow analyses, which are used
to inform long-term planning and policy-making
in relation to future security of mineral supply.
This information will also serve to counter concerns
about physical scarcity and exhaustion of metals.
P. L. and A. G. G. publish with the permission of the
Executive Director, British Geological Survey (NERC).
Andrew Bloodworth is thanked for his comments on the
text. Two anonymous reviewers are thanked for their
many constructive comments. BGS #NERC 2014. All
rights reserved.
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