World Mineral Production 2012-16

The latest edition of this annual publication from the British Geological Survey (BGS) is now available to download. This volume contains mineral production statistics for the five year period from 2012 to 2016, for more than 70 mineral commodities, by country worldwide. Additional tables containing European production of aggregates and cement are included as an Appendix. It is the latest publication from the World Mineral Statistics dataset which began in 1913. The information contained in the dataset, and associated publications, is compiled from a wide range of sources: home and overseas government departments, national statistical offices, specialist commodity authorities, company reports, and a network of contacts throughout the world

Deep to shallow-marine sedimentology and impact of volcanism within the Middle Triassic Palaeo-Tethyan Semantan Basin, Singapore

The Middle Triassic Pulau Ayer Chawan Formation is a predominantly deep-marine, occasionally shallow-marine sedimentary succession, deposited in the Singapore sector of the Palaeo-Tethyan Semantan Basin. The formation provides an important record of the dynamic interplay between a siliciclastic sedimentary system and the products of an adjacent active volcanic arc. It is characterised by six sub-environments, including: deep-marine turbidite fan, deep-marine background sedimentation, subaqueous debris cone, shallow-marine, volcanically-sourced turbidite fan, and hyaloclastite mound or ridge. Turbidite fan deposits preserve the input of both siliciclastic and volcaniclastic sediments from the shelf, transported into the deep-marine environment by a suite of subaqueous sediment gravity flow processes, including: turbidity currents; mixed flow types (hybrid event beds); concentrated and hyper concentrated sediment gravity flows, and debris flows. Thick heterolithic successions of debrites were likely sourced through regular collapse of an unstable shelf. The presence of hybrid event beds, encountered within the deep-marine turbidite fans, supports a slope that was out-of-grade, and may have been actively retreating towards the hinterland. Together, these factors suggest regional-scale uplift of the eastern margins of the Semantan Basin during Triassic times, most likely facilitated through volcanic activity in the adjacent Palaeo-Tethys Sukhothai Arc. Evidence for contemporaneous, arc-related magmatism includes ubiquitous volcaniclastic sedimentary rocks within formation, including pyroclastic density current deposits and perhaps more-strikingly through the hyaloclastites of the Nanyang Member. The hyaloclastites formed through quenching of magmas delivered into the deep-marine setting from a series of sub-sea vents or mounds

Paleozoic to Cenozoic sedimentary bedrock geology and lithostratigraphy of Singapore

A new lithostratigraphical framework for Singapore is proposed, based on the analysis of c. 20,000 m of core recovered from 121 c. 205 m deep boreholes and augmented with 218 field localities from across Singapore. The new framework describes a succession dating from the Carboniferous to the Quaternary. New U-Pb detrital zircon dates and fossil analysis were used to constrain the ages of key sedimentary units. The oldest known sedimentary rocks in Singapore are found to be the deformed Carboniferous (Mississippian) Sajahat Formation. These are succeeded by the newly erected, Middle and Upper Triassic, marine to continental Jurong Group and Sentosa Group successions that accumulated in the southern part of the Semantan Basin. The Jurong Group comprises four formations: the Tuas Formation, the Pulau Ayer Chawan Formation, the Pandan Formation and the Boon Lay Formation. The Sentosa Group contains two formations: the Tanjong Rimau Formation and the Fort Siloso Formation. In Singapore, the depositional record during this time is related to late Permian to Triassic arc magmatism in the southern part of the forearc basin to the Sukhothai Arc. The Jurong and Sentosa groups were deformed and weakly metamorphosed during the final stages of the Late Triassic to Early Jurassic orogenic event, deformation that led to the formation of the syn-orogenic conglomerates of the Buona Vista Formation. Following this, two distinct Lower Cretaceous sedimentary successions overstepped the Jurong and Sentosa group strata, including the Kusu Formation and the Bukit Batok Formation, both deposited in the southern part of the Tembeling Basin. A series of Neogene to Quaternary formations overly the Mesozoic and Palaeozoic stratigraphy, including the Fort Canning Formation, Bedok Formation and the Kallang Group

Potential for critical raw material prospectivity in the UK

The UK Critical Minerals Strategy (BEIS, 2022) includes a commitment to “begin a nationalscale assessment of the critical minerals within the UK. By March 2023, we will collate geoscientific data and identify target areas of potential”. This report provides that national-scale assessment of the geological potential for critical raw materials in the UK. It represents the published output of a study, jointly funded by the British Geological Survey and the Department for Business and Trade, which reviewed available geoscientific data in order to identify areas of potential geological prospectivity for critical raw materials in the UK. Critical raw materials (CRMs) are those mineral commodities that are both economically important and at risk of supply disruption. The commodities addressed in this report are those identified as critical to the UK by the Critical Minerals Intelligence Centre (CMIC) (Lusty et al., 2021). These CRMs are currently obtained from mining across the world, but at the time of writing none are produced in the UK, although tungsten has been mined in recent years. Some CRMs such as lithium, tin and graphite are typically the primary products of mines, whereas others are produced as co- or by-products of major commodities such as gold, copper or zinc. Current understanding of the UK’s mineral resource endowment rests largely on evidence from historic mining and exploration, together with targeted academic research. The UK has an extensive history of mining that dates to prehistoric times. Gold, barite, fluorite, gypsum, potash and polyhalite are among the commodities that are currently mined, and exploration for many raw materials is occurring across the whole of the UK. The work presented in this report follows a methodology known as a mineral systems approach, which relies on the concept that all mineral deposits of a certain type were formed by a combination of particular geological processes (McCuaig et al., 2010). The processes that must operate for a mineral deposit to form are identified and translated into mappable target criteria derived from available datasets. Key datasets to be used would typically include geological maps, geochemical soil and stream sediment maps, geophysical maps, and mineral occurrence databases. The UK has full geological map coverage, but other datasets are incomplete, with high-resolution geophysical data only being available for limited areas. New stream sediment geochemistry maps were created as part of this work and are available on the CMIC interactive map portal1 , but the whole country is not covered for all elements. These data limitations mean that this report only provides a knowledge-driven assessment of geological potential for CRM prospectivity across the UK. It provides maps for CRMs (grouped or singly as geologically appropriate) indicating the areas where the geological criteria have been met and thus there is potential for deposits of these CRMs to occur. It is important to note that the maps represent areas of potential prospectivity, not where deposits of critical minerals are guaranteed to be found, and also that mineral deposits could be found beyond the identified prospective areas, where localised geological conditions are suitable. The areas identified in the maps can be considered as targets for more detailed research and exploration. This report focuses solely on the geological potential and does not consider other aspects such as environmental designations and planning considerations that may affect the development of a mineral deposit. Combining all the individual maps highlights areas that are prospective for several CRMs and are thus priority for further geological investigations. From north to south, these areas include: areas of prospective geology around Loch Maree near Gairloch; parts of the central Highlands and Aberdeenshire; areas of prospective geology in mid-County Tyrone in Northern Ireland; parts of Cumbria; parts of the North Pennine Orefield; areas in north-west Wales and Pembrokeshire; and south-west England. These areas should now be the focus for collection of new geological, geochemical and geophysical data, in order to identify new CRM prospects for detailed investigation

National geological screening : Northern Ireland

This report is the published product of one of a series of studies covering England, Wales and Northern Ireland commissioned by Radioactive Waste Management (RWM) Ltd. The report provides geological information about Northern Ireland to underpin its process of national geological screening set out in the UK’s government White Paper Implementing geological disposal: a framework for the long-term management of higher activity radioactive waste (DECC, 2014). The report describes geological features relevant to the safety requirements of a geological disposal facility (GDF) for radioactive waste emplaced onshore and up to 20 km offshore at depths between 200 and 1000 m from surface. It is written for a technical audience but is intended to inform RWM in its discussions with communities interested in finding out about the potential for their area to host a GDF

Critical materials for infrastructure: local vs global properties

Introducing new technologies into infrastructure (wind turbines, electric vehicles, low-carbon materials and so on) often demands materials that are ‘critical’; their supply is likely to be disrupted owing to limited reserves, geopolitical instability, environmental issues and/or increasing demand. Non-critical materials may become critical if introduced into infrastructure, owing to its gigatonne scale. This potentially poses significant risk to the development of low-carbon infrastructure. Analysis of this risk has previously overlooked the relationship between the ‘local properties’ that determine the selection of a technology and the overall vulnerability of the system, a global property. Treating materials or components as elements having fixed properties overlooks optima within the local–global variable space that could be exploited to minimise vulnerability while maximising performance. In this study, a framework for such analysis is presented along with a preliminary measure of relative materials criticality by way of a case study (a wind turbine generator). Although introduction of critical materials (in this case, rare earth metals) enhances technical performance by up to an order of magnitude, the associated increase in criticality may be two or three orders of magnitude. Analysis at the materials and component levels produces different results; design decisions should be based on analysis at several levels

Exploration for porphyry-style copper mineralisation near Llandeloy, southwest Dyfed

Geological, geochemical and geophysical surveys followed by drilling in the area around Llandeloy, southwest Dyfed, have located disseminated copper mineralisa tion of porphyry type associated with intermediate intrusive rocks masked by thick overburden. Intermediate intrusive rocks in the area were selected for investigation as potential hosts for disseminated copper mineralisation on the basis of the known geology and tectonic setting. An initial assessment of the area involved revising the geological maps, analysing rocks from surface exposures, studying available geophysical data and carrying out a stream sediment survey in the catchment of the River Solfach. This work revealed the presence of weak poly metallic sulphide m ineralisation associated with the margin of a tonalitic intrusion at Middle Mill. In view of the very poor exposure, more detailed geochemical and geophysical surveys were carried out across the two areas underlain by intrusive rocks of dioritic or tonalitic composition. At Middle Mill six traverse lines, spaced 300 m apart and totalling 10.5 km in length, were surveyed by IP, VLF-EM and magnetic methods. Soil samples, subsequently analysed for Cu, Pb and Zn were collected at 25 m intervals. Few anomalies were located. Most of those found could be ascribed to artificial sources and it was concluded that no substantial body of disseminated copper mineralisation was present at or near the surface in the area. The mineralisation found in Middle Mill quarry is thought to be minor, epigenetic mineralisation, associated with the intrusion. At Llandeloy 13 traverse lines spaced 600 m apart and covering an area of 12 km2 were surveyed by IP, VLFEM, magnetic and radiometric methods. Soil samples were collected along these lines at 50 m intervals and analysed for Cu, Pb and Zn. In about 4 km2 around Treffynnon additional lines were sampled and measured to close the spacing to 200 m. Gravity data were also collected from some traverses and sites to supplement the Hational Gravity Survey. Several strong copper-insoil and geophysical anomalies were identified. Nine boreholes were drilled to investigate the causes, Disseminated copper mineralisation was intersected in the boreholes. It occurs principally within a concordant or semiconcordant sheeted complex of dioritic and tonalitic rocks, believed to be uppermost Cambrian or low Arenig in age, whose composition is consistent with e mplacement within a volcanic arc setting. The intrusions and their host rocks have suffered a two phase, pervasive, hydrothermal alteration which is inseparable from the sulphide mineralisation and recorded in boreholes over an area of 1 km2. The alteration shows features common to porphyry copper systems, consisting of an early patchy and irregularly developed propylitic and potassic alteration, overprinted by a widespread and locally intense late propylitic alteration. The potassic alteration is only well preserved locally and is divisible into K-feldspar and biotite types. When intense, the potassic alteration is characterised by substantial changes to the bulk chemistry of the rocks involving increases in K, K/Na, K/Rb, Rb/Sr, Cu/S and, erratically Ba and losses of Na, Sr and Ca. In the most altered rocks so called 'immobile1 elements such as Y a ~ d Nb are redistributed. The late propylitic alteration affected rocks in all boreholes except one and gave rise to the dominant alteration assemblage of sericite, chlorite, epidote, albite, pyrite and magnetite. Introduction of Fe and S appears to have accompanied this event but any other bulk chemical changes are confused by host rock variation. Retrograde effects on potassic alteration, such as the lowering of Rb/Sr, K/Na and Cu/S are probable but not clearly defined. Mineralisation, involving the introduction of Cu, Fe and S, accompanied the first phase and ?Cu, Fe and S the second phase of alteration. Cu levels are generally modest, the best intersection being 0.1% over 3.4 m in borehole 2. Cu and particularly the Cu/S ratio are generally highest in the most altered (potassic) rocks but locally high levels of Cu may be found in weakly altered rocks, There is only weak and erratic enrichment in Mo, and high levels of Cu and Mo show only a weak correlation. There are localised very weak enrichments of AS, Pb and Zn. Au was not determined. It is suggested that the present erosion level cuts a deep section through a copper porphyry deposit, this explaining the imperfectly developed zonation, low Cu content and abundant magnetite. The part of the system most likely to have contained ore grade material has, therefore, been eroded away and some of the material is found in the overlying lacustrine sediments which contain abundant magnetite, clay, feldspar and up to 640 ppm Cu. The style of mineralisation, chemistry of the rocks and geological setting all suggest that mineralisation took place in conditions consistent with an island arc setting. The detailed geology of the area is, however, imperfectly understood because of the extremely poor exposure, and the possibility exists that, because of downfaulting and tilting, parts of the deposits may be preserved and concealed to the north and east of the area drilled. The case history shows that in such areas of low relief and thick overburden drainage sampling can be an ineffective mineral exploration technique. Surface rock sampling also failed to indicate the presence of the deposit, partly because of poor exposure and partly because of the patchy, multi-phase alteration pattern. The locally thick sequence of interbedded sands and clays containing copper and magnetite overlying the deposit confused to varying degrees all the geochemical and geophysical survey results except lithogeochemistry. If the sands and clays had not contained anomalous copper the deposit would probably not have been located. Borehole results suggest that Cu, S and the Cu/S ratio provide the best li thogeoche m ical targets