Mining revival

In relation to its size the United Kingdom (UK) is remarkably well-endowed with mineral resources as a result of its complex geological history. Their extraction and use have played an important role in the development of the UK economy over many years and minerals are currently worked at some 2100 mine and quarry sites. Production is now largely confined to construction minerals, primarily aggregates, energy minerals and industrial minerals including salt, potash, kaolin and fluorspar, although renewed interest in metals is an important development in recent years

Critical metals for high-technology applications: mineral exploration potential in the north of Ireland

There is global concern about the availability of ‘critical’ metals: those of growing economic importance but vulnerable to supply shortage. Production from domestic resources could contribute to security of supply. However, we have little information on how critical metals are concentrated in the Earth’s crust and the resources that exist in the British Isles. Ireland’s diverse geology provides many geological environments in which critical metals may be enriched. This review considers mineral exploration potential for selected ‘critical’ metals identified by the European Commission and others considered important for high-technology applications. Known mineral deposits and the Tellus and Tellus Border geochemistry suggest that the north of Ireland is prospective for some of these metals and warrants further investigation. Extraction of these metals as by-products could facilitate the development of otherwise sub-economic ore bodies in Ireland, thus supporting economic growth

Malthus revisited

Although mineral resources are non-renewable and unevenly distributed, global supply has so far kept up with demand. However, mankind is now moving into an era of unprecedented population growth and environmental change. As demand continues to rise and the need to mitigate and adapt to environmental change becomes more pressing can the abundant mineral supply we have enjoyed be sustained

A natural laboratory for critical metals investigations in the Mourne Mountains granites

Certain metals that are vital for many modern technologies occur naturally in the Mourne Mountains Complex of County Down, Northern Ireland. These include niobium, tantalum and the rare earth elements. Using the Tellus geochemistry data and the results of more detailed sampling, we have investigated their geological sources in granite bedrock and their dispersion in stream sediments. From this research, an exploration methodology has emerged that can assist in the search for critical metals globally. Planned follow-on studies include investigations of the environmental fate of these metals and the potentially toxic elements with which they are naturally associated

Developing the lithotectonic framework and model for sulphide mineralization in the Jebilet Massif, Morocco: implications for regional exploration

The central Jebilet massif, part of the North African Variscan Belt, hosts significant polymetallic sulphide mineralization. It is generally considered syngenetic and has many features of volcanogenic massive sulphide (VMS) mineralization. However, some characteristics are not compatible with a classic VMS model and two alternative scenarios for formation have been proposed. Our preliminary research favours a complex, multi-stage development of the sulphide deposits. Uncertainty as to the critical processes controlling the mineralization and lack of agreement on a genetic model inhibit regional exploration. We identify the key knowledge gaps regarding sulphide mineralization in the central Jebilet and outline a research program to address these, with the ultimate aim of improving regional mineral exploration targeting and unlocking the economic potential of this relatively undeveloped district

Deep-ocean mineral deposits: metal resources and windows into earth processes

Deep-ocean mineral deposits could make a significant contribution to future raw material supply. Growing metal demand and geopolitics are focussing increasing attention on their resource potential and economic importance. However, accurate assessment of the total amounts of metal and its recoverability are very difficult. Deep-ocean mineral deposits also provide valuable windows through which to study the Earth, including the evolution of seawater and insights into the exchange of heat and chemicals between the crust and the oceans. Exploration for, and potential extraction of, deep-ocean mineral deposits poses many geological, technical, environmental and economic challenges, as well as regulatory and philosophical questions. Great uncertainty exists, and the development and stewardship of these deposits requires an incremental approach, encouraging transparency and scientific and civil societal input to balance the interests of all

Alkaline magmatism and REE resources: a European overview, and links to Canada

In recent years, the European Union (EU) has prioritised the issue of critical raw materialsa – those materials which are important for the economy, but have risks to their supply. Of the materials identified as critical, the rare earth elements (REE) are considered to have the highest supply risks, since > 90% of global production comes from China. Several programmes are underway in Europe to investigate the supply chain for the REE and other critical materials. These include the EU-funded EURARE projectb, which aims to set the basis for the development of a European REE industry; and the Security of Supply of Mineral Resources (SoS Minerals) research programme in the UK

Geochemical evidence of Milankovitch cycles in Atlantic Ocean ferromanganese crusts

Hydrogenetic ferromanganese crusts are considered a faithful record of the isotopic composition of seawater influenced by weathering processes of continental masses. Given their ubiquitous presence in all oceans of the planet at depths of 400–7000 meters, they form one of the most well-distributed and accessible records of water-mass mixing and climate. However, their slow accumulation rate and poor age constraints have to date limited their use to explore 100 ka paleoclimatic phenomena. Here it is shown how the Pb isotope signature and major element content of a Fe-Mn crust from the north-east Atlantic responded to changes in the intensity and geographic extent of monsoonal rainfall over West Africa, as controlled by climatic precession during the Paleocene. The studied high-spatial resolution (4 μm) laser-ablation multi-collector inductively coupled plasma mass spectrometer (LA-MC-ICP-MS) Pb isotope data is a nearly 2 order of magnitude improvement in spatial and temporal resolution compared to micro-drill subsamples. The record demonstrates cyclicity of the 206Pb/204Pb and 208, 207Pb/206Pb ratios at the scale of single Fe-Mn oxide laminae, in conjunction with variations in the Fe/Mn ratio, Al, Si and Ti content. Time-frequency analysis and astronomical tuning of the Pb isotope data demonstrates the imprint of climatic precession (∼20 ka) modulated by eccentricity (∼100 and 405 ka), yielding growth rates of 1.5–3.5 mm/Ma consistent with previous chemostratigraphic age models. In this context, boreal summer at the perihelion causes stronger insolation over West Africa, resulting in more intense and geographically extended monsoonal rainfalls compared to aphelion boreal summer conditions. This, in turn, influences the balance between the weathering endmembers feeding the north-east Atlantic basin. These results provide a new approach for calibrating Fe-Mn crust records to astronomical solutions, and allow their isotopic and chemical archive to be exploited with an improved temporal resolution of 1000–5000 years

The importance of tectonic setting in assessing European Rare Earth potential

Rare earth element (REE) resources are commonly found associated with alkaline igneous complexes or carbonatites, or as secondary deposits derived from igneous rocks. Globally, many REE deposits occur around the margins of Archaean cratons, most in continental rift zones. Europe contains many such rift zones, which are generally younger in the south. Many of these rifts are intracontinental, whereas others are associated with the opening of oceans such as the Atlantic. All these rift systems have the potential to host REE resources, but whereas the older provinces of northern Europe are deeply exposed, exposures in southern Europe are largely at the supracrustal level. This paper considers how an understanding of the tectonic setting of Europe’s REE resources is vital to guide future exploration

Massive sulphide deposits of the Central Jebilet Massif, Morocco

The Central Jebilet massif, in the Marrakech region of Morocco, comprises a block of Carboniferous sedimentary rocks that were extensively deformed and metamorphosed during the Variscan orogeny. This block, and its extension to the south of Marrakech (the Guemassa massif), are characterised by bimodal intrusive magmatism and abundant massive sulphide deposits that represent a major Cu-Pb-Zn resource. Mining is currently taking place at the Draa Sfar and Hajjar mines. Previously worked deposits at Kettara, Roc Blanc and Koudiat Aicha are not currently being exploited, but have extensive reserves remaining, and prospects such as Laachach and Ben Slimane are being explored