Upload
vienna
View
41
Download
0
Tags:
Embed Size (px)
DESCRIPTION
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.” - PowerPoint PPT Presentation
Citation preview
Training of Economic Geology PhD's - a perspective from NERC Facilities -
Adrian BoyceNERC 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 GOOD SCIENCE
Supporting UK Earth Science Research Community NERC Themes
Sustainable Use of Natural ResourcesEarth System Science
Environment and Pollution
2000-2010
33 student-based projects involving in-depth training at
ICSF/SUERC
How do we know it’s “Good Science”?
NERC Isotope Geoscience Facilities Steering Committee
≥4 for PI research≥3H for student-based research
ICSF involved often from day one of student projectdevelopment, or NERC grant development
Training often starts with the students being principalauthor of their Facility Proposal
Partnership with Supervisors and Industry
Relevance to Minerals Industry?
90% of students are part funded by Minerals Industry100% 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 remediationUnderstanding of AMD issues from deposit perspective
e.g. Iberian Pyrite Belt, Great Northern Coalfield
What do we offer?
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
Isotope GeochemistryAccess to truly world-class Isotope Facilities
Rocks and minerals4.6 Ga ( ~ 0.1% precision) to 2 ka (~ 10% precision)
Level of precision obtainable is related to the quality of the samples
AIF - GeochronologyWhat age range does Ar/Ar span?
State-of-the-art ARGUS multi-collector noble gas mass spectrometer
What Ar/Ar can dateAny potassic mineral
but we have to consider probable age of the sample (older the rock or mineral the more 40Ar*)
Nu plasma HR multicollector plasma ionisation mass spectrometer
Thermo Electron Triton thermal ionisation mass spectrometer (TIMS)
NIGL
U-Pb in zircon, monazite, titanite, rutileVery high precision
(1Ma - 4.6Ma)
U-series dating of carbonates (e.g. travertines)(<450kyrs)
Sr, Nd, Pb, Hf - Tracer
Gold in K-feldspar crystal
Date the K-fspr dating gold emplacement
Stable isotopes place the K-fspr in a hydrothermal event
Ar/Ar age spectra and inverse isochron plots
Gave precise age of 405Ma versus
Intrusion age of 410Ma
Hydrothermal Sulfide
Summary of conventional sulfide 34S from the Navan deposit
Bacteriogenic Sulfide
n 10
9
8
7
6
5
4
3
2
1
-20 -10-30 0 10 20
34SCDT (‰)
Coarse textureFine textures
GEOLOGICAL CROSS-SECTION ALONG TRAVERSE LENGTH.
FOOTWALL GREEN SHALE
5-LENS DOLOMITE
BOTTOM DARK MARKER
LOWER DARK MARKER
SUB-LOWER SANDSTONE MARKER
B FAULT COMPLEX
BOULDER CONGLOMERATE(OVERLYING
EROSION SURFACE)
NNWMINOR (NNE, NE & ENE) FAULTING MINOR ENE FAULTING
c. 50 METRES
NODULARMARKER
Stratigraphic interval investigated
SSE
0-5-10-15 5 10 15
15
5
-5
-15
Galena
Sphalerite
Distance from fault in metres
0-5-10-15 5 10 15
15
5
-5
-15
34S
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
HydrothermalHydrogeology
0
5
10
15
Frequency
-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30
Galena
0
5
10
15
Frequency
-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30
Sphalerite
34S
Bulk S Studies - Each sample represents up to ONE MILLION TONNES of ORE
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.
0
5
10
Frequency
-30 -25 -20 -15 -10 -5 0 5 10 15 20 25 30
All Concentrates
Zn Concentrate
Pb Concentrate
No Bugs
No Economic Ore Deposit
Message from that S isotope study?