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Training of Economic Geology PhD's - a perspective from NERC Facilities -. Adrian Boyce NERC Isotope Community Support Facility at Scottish Universities Environmental Research Centre. What’s a NERC Facility? “A range of specialist analytical facilities to support NERC research.”
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Training of Economic Geology PhD's - a perspective from NERC Facilities - Adrian Boyce NERC Isotope Community Support Facility at Scottish Universities Environmental Research Centre
What’s a NERC Facility? • “A range of specialist analytical facilities • to support NERC research.” • Isotope Community Support Facility (ICSF) • Argon Isotope Facility (AIF) • NERC Isotope Geoscience Lab (NIGL) • Open Uni U Series Facility (OUUSF) Supporting UK Earth Science Research Community NERC Themes Sustainable Use of Natural Resources Earth System Science Environment and Pollution SUPPORTING GOOD SCIENCE
How do we know it’s “Good Science”? NERC Isotope Geoscience Facilities Steering Committee ≥4 for PI research ≥3H for student-based research Partnership with Supervisors and Industry 2000-2010 33 student-based projects involving in-depth training at ICSF/SUERC ICSF involved often from day one of student project development, or NERC grant development Training often starts with the students being principal author of their Facility Proposal
Relevance to Minerals Industry? 90% of students are part funded by Minerals Industry 100% are employed, with 75% now in Industry and related posts Projects from Kazakhstan to Guinea, from Ireland to Peru Spectrum of Commodities Au, Zn, Pb, Ag, Ba, Sn, Cu, Ni, PGE, Mo, Fe, V….. Also working in remediation Understanding of AMD issues from deposit perspective e.g. Iberian Pyrite Belt, Great Northern Coalfield
What do we offer? Isotope Geochemistry Access to truly world-class Isotope Facilities ICSF - Stable Isotope Laboratory (S, C, O and H in minerals and fluids) • World’s first in situ laser S system for sulfides and sulfates • One of only two sulfate O isotope systems in the UK • A total laser fluorination system (≥0.4mg SiO2 equiv) • UK’s only fluid inclusion H system • Autocarb systems - either for µg calcite or mg mixed carbonates • Semi-auto fluid H injection system • Fully auto fluid O & H systems
State-of-the-art ARGUS multi-collector noble gas mass spectrometer AIF - Geochronology What age range does Ar/Ar span? Rocks and minerals 4.6 Ga ( ~ 0.1% precision) to 2 ka (~ 10% precision) Level of precision obtainable is related to the quality of the samples
What Ar/Ar can date Any potassic mineral but we have to consider probable age of the sample (older the rock or mineral the more 40Ar*)
Thermo Electron Triton thermal ionisation mass spectrometer (TIMS) NIGL U-Pb in zircon, monazite, titanite, rutile Very high precision (1Ma - 4.6Ma) U-series dating of carbonates (e.g. travertines) (<450kyrs) Sr, Nd, Pb, Hf - Tracer Nu plasma HR multicollector plasma ionisation mass spectrometer
Gold in K-feldspar crystal Date the K-fspr dating gold emplacement
Ar/Ar age spectra and inverse isochron plots Gave precise age of 405Ma versus Intrusion age of 410Ma
Summary of conventional sulfide 34S from the Navan deposit Fine textures Coarse texture Bacteriogenic Sulfide Hydrothermal Sulfide n 10 9 8 7 6 5 4 3 2 1 -30 -20 -10 0 10 20 34SCDT (‰)
NNW SSE B FAULT COMPLEX MINOR (NNE, NE & ENE) FAULTING MINOR ENE FAULTING BOULDER CONGLOMERATE (OVERLYING EROSION SURFACE) SUB-LOWER SANDSTONE MARKER LOWER DARK MARKER NODULAR MARKER BOTTOM DARK MARKER 5-LENS DOLOMITE FOOTWALL GREEN SHALE c. 50 METRES Stratigraphic interval investigated GEOLOGICAL CROSS-SECTION ALONG TRAVERSE LENGTH.
15 Hydrothermal Hydrogeology 5 Sphalerite -5 -15 Texture-based laser S isotope analyses defines feeder faults >3m into hanging wall, bacteriogenic S dominates. Even minor faults, with early limited movement allow flow 34S 0 -15 -10 -5 5 10 15 15 Galena 5 -5 -15 0 -15 -10 -5 5 10 15 Distance from fault in metres
Bulk S Studies - Each sample represents up to ONE MILLION TONNES of ORE 10 All Concentrates Frequency 5 0 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 Zn Concentrate 15 Sphalerite 10 Frequency 5 0 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 Pb Concentrate 15 Galena 10 Frequency 5 0 -30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30 34S Bulk S Studies 5 LENS - representing ~70% of ore at Navan (so far!) >90% of sulphide is from BACTERIOGENIC source! Frequency distribution of minor hydrothermal S source skewed by ease of sampling, and vice versa.
Message from that S isotope study? No BugsNo Economic Ore Deposit