GREENPEG – exploration for pegmatite minerals to feed the energy transition: first steps towards the Green Stone Age

This is the final version. Available on open access from the Geological Society via the DOI in this recordData availability: All data generated or analysed during this study are included in this published article.The GREENPEG project, which is funded by the European Commission Horizon 2020 ‘Climate action, environment, resource efficiency and raw materials’ programme, aims to develop multimethod exploration toolsets for the identification of European, buried, small-scale (0.01–5 million m3) pegmatite ore deposits of the Nb–Y–F (NYF) and Li–Cs–Ta (LCT) chemical types. The project is being coordinated by the Natural History Museum of the University of Oslo and involves four exploration services/mining operators, one geological survey, one non-profit helix association of administration, industry and academia, two consulting companies and five academic institutions from eight European countries. The target raw materials are Li, high-purity quartz for silica and metallic Si, ceramic feldspar, rare earth elements, Ta, Be and Cs, which are naturally concentrated in granitic pegmatites. Silicon and Li are two of the most sought-after green technology metals as they are essential for photovoltaics and Li-ion batteries for electric cars, respectively. GREENPEG will change the focus of exploration strategies from large-volume towards small-volume, high-quality ores and overcome the lack of exploration technologies for pegmatite ore deposits by developing toolsets tailored to these ore types. This contribution focuses on the methods applied in the GREENPEG project and as such provides a potential pathway towards the ‘Green Stone Age’ from the perspective of pegmatite-sourced minerals.European Union Horizon 2020FCT – Fundação para a Ciência e a TecnologiaScience Foundation IrelandEuropean Regional Development Fund (ERDF)Society of the Friendly Sons of St. Patrick for the Relief of Emigrants from Irelan

Finishing the euchromatic sequence of the human genome

The sequence of the human genome encodes the genetic instructions for human physiology, as well as rich information about human evolution. In 2001, the International Human Genome Sequencing Consortium reported a draft sequence of the euchromatic portion of the human genome. Since then, the international collaboration has worked to convert this draft into a genome sequence with high accuracy and nearly complete coverage. Here, we report the result of this finishing process. The current genome sequence (Build 35) contains 2.85 billion nucleotides interrupted by only 341 gaps. It covers ∼99% of the euchromatic genome and is accurate to an error rate of ∼1 event per 100,000 bases. Many of the remaining euchromatic gaps are associated with segmental duplications and will require focused work with new methods. The near-complete sequence, the first for a vertebrate, greatly improves the precision of biological analyses of the human genome including studies of gene number, birth and death. Notably, the human enome seems to encode only 20,000-25,000 protein-coding genes. The genome sequence reported here should serve as a firm foundation for biomedical research in the decades ahead

Minor elements in layered sphalerite as a record of fluid origin, mixing, and crystallization in the Navan Zn-Pb ore deposit, Ireland

This study tests the utility of the minor to trace element composition of sphalerite to discriminate between possible sources of ore-forming fluids, and to constrain processes involved in ore genesis of the world-class Irish-type Navan Zn-Pb orebody, Ireland. Detailed petrography and electron microprobe microanalyses were performed on layered sphalerite previously analyzed for Zn, Fe, and S isotope compositions. Layered sphalerite displays a wide range of chemical composition at both sample and crystal scales. The color, style, and scale of layering show variations with chemical composition, but none of these correlations are consistent between samples. However, there are strong intersample correlations between chemical and S-Fe-Zn isotope compositions at the millimeter scale. Sphalerite precipitated from deep, hydrothermal fluids with 34S-enriched sulfide is enriched in Cd, Sb, Cu, and Ag, whereas Fe and As are enriched in sphalerite precipitated from shallow, bacteriogenic brines with isotopically light S. Significant chemical variations also occur at the micrometer scale in sphalerite regardless of its genetic affinity. These variations are interpreted as being due to variations in temperature, pH, and sulfur activity following the arrival at the site of deposition of pulses of hydrothermal fluids at specific stages of sphalerite growth. Therefore the chemistry of sphalerite, coupled with its texture, appears to be a powerful tool to elucidate fluid typing and ore genesis. The results support the hypothesis that layered sphalerite forms by rapid crystallization due to mixing of two fluids of contrasting physicochemical properties, a process required for the formation of Irish-type and some other hydrothermal deposits including, most notably, Mississippi Valley-type (MVT) deposits. The existence of layered sphalerite, coupled with its texture and chemical composition, may therefore provide useful insight for the mineral exploration industry in Ireland and elsewhere

Genetic Links between Irish-type Zn-Pb Deposits and Related Geochemical Halos

A broad geochemical dispersion halo has been identified with a direct link to the underlying Tara Deep deposit at Navan, Ireland. In situ laser S isotope analyses have been performed on petrographically well characterized samples from the halo. Four mineral assemblages have been identified. 1) In black shales, laminated pyrite comprising thin layers of framboidal low-delta S-34 pyrite with minor interstitial sphalerite. 2) Pyritized calcarenites are widely distributed and occur chiefly as biodebris replaced by low-delta S-34 pyrite. 3) A replacive assemblage occurs as late remobilizations exhibiting both crosscutting and bedding-parallel styles, overprinting the early laminated pyrite. It comprises mostly marcasite, with minor pyrite, sphalerite, chalcopyrite, galena, stibnite, arsenopyrite and pentlandite, with high delta S-34 values. 4) Hydrothermal cherts comprise thick microcrystalline quartz bands rimmed by dolomite, associated with marcasite, pyrite, sphalerite, chalcopyrite, galena, Ni-sulfosalts and stibnite with high delta S-34 values. These results indicate overlapping diagenetic and multi-phase hydrothermal sulfide mineralization. First, laminated pyrite and pyritized calcarenites suggests a bacterial origin within sediments during early diagenesis. Later, hydrothermal chert and replacive sulfides suggest hydrothermal exhalation during early-mid diagenesis. Similarities in mineralogy and S isotope compositions suggest genetic links between the halo and the underlying Tara Deep deposit

Genetic Links between Irish-type Zn-Pb Deposits and Related Geochemical Halos

A broad geochemical dispersion halo has been identified with a direct link to the underlying Tara Deep deposit at Navan, Ireland. In situ laser S isotope analyses have been performed on petrographically well characterized samples from the halo. Four mineral assemblages have been identified. 1) In black shales, laminated pyrite comprising thin layers of framboidal low-delta S-34 pyrite with minor interstitial sphalerite. 2) Pyritized calcarenites are widely distributed and occur chiefly as biodebris replaced by low-delta S-34 pyrite. 3) A replacive assemblage occurs as late remobilizations exhibiting both crosscutting and bedding-parallel styles, overprinting the early laminated pyrite. It comprises mostly marcasite, with minor pyrite, sphalerite, chalcopyrite, galena, stibnite, arsenopyrite and pentlandite, with high delta S-34 values. 4) Hydrothermal cherts comprise thick microcrystalline quartz bands rimmed by dolomite, associated with marcasite, pyrite, sphalerite, chalcopyrite, galena, Ni-sulfosalts and stibnite with high delta S-34 values. These results indicate overlapping diagenetic and multi-phase hydrothermal sulfide mineralization. First, laminated pyrite and pyritized calcarenites suggests a bacterial origin within sediments during early diagenesis. Later, hydrothermal chert and replacive sulfides suggest hydrothermal exhalation during early-mid diagenesis. Similarities in mineralogy and S isotope compositions suggest genetic links between the halo and the underlying Tara Deep deposit