SERVICES & FACILITIES ANNUAL REPORT - FY April 2009 to March 2010
SERVICE: Open University
Uranium Series facility (OUUSF)
FUNDING
block
AGREEMENT
F14/G6/47
ESTABLISHED as S&F
1998
TERM
3 year
TYPE OF SERVICE PROVIDED:
The purpose of the Open University Uranium-Series Facility (OUUSF) is the application of U-series methodologies to
research in Earth and environmental sciences and science-based archaeology. Research projects are carried out, subject to
approval by the NERC Isotope Geosciences Steering Committee, NIGFSC, in collaboration with NERC stakeholders in
the pursuit of knowledge and understanding of the Earth system.
U-series chronology is an essential component of many projects in Earth and environmental science, oceanography,
hydrology and science-based archaeology. Current OUUSF research includes projects on global climatic change through
dating of authigenic deposits, human (Neanderthal) evolution, mid-ocean ridge magma evolution and volcano
development, and abyssal sedimentation rates. Uranium-series determinations, e.g. 234U/238U, 230Th/232Th, 231Pa/235U
230
Th/234U ratios, and U, Th Pa and Ra concentrations by isotope dilution, are performed on a dedicated TIMS MAT262RPQ-II instrument or a Nu Instruments MC-ICPMS. Both mass spectrometers have a deceleration lens to achieve the
required abundance sensitivity, and have ion counting for superior detection statistics. Th isotope ratios in samples
containing less then 0.5 pg 230Th can be measured with a precision better than 1% (2m) and Ra abundances, as low as 4
fg, can be determined to 1% (2m). OUUSF uses Picotrace state-of-the-art ultra-clean chemical laboratories for sample
separation and purification. The low total procedure blanks and excellent instrument sensitivity are required to analyse
very low abundances in samples, such as Ra in mid-ocean ridge basalts and Th dissolved in ground-water.
OUUSF provides the equivalent of one user-year of training and analyses per annum, which represents 25% of the
Open University Isotope Geochemistry Laboratory, OUIGL, capacity and corresponds to circa 150 samples. PGRS and
PDRA teaching and training is the most important aspect of OUUSF activity and usually a PGRS or PDRA works under
close supervision in the laboratory for a number of short periods using Standard Operating Procedures and learn to work
with radioactive materials in low-blank chemistry and mass spectrometry laboratories and to carry out data reduction and
evaluation protocols.
Quality Assurance is maintained through the repeated analysis of Certified Reference Materials (e.g. Appendix 3.2),
Total Procedure Standards, Total Procedure Blanks, internal laboratory standards, reagents and calibrations performed by
staff and users and reviewed on a weekly basis. QA efforts are equivalent to >30 samples per year. OUUSF staff has some
capacity to perform analyses for collaborators.
Scientific results of collaborative research may be included in PhD thesis, published in peer-reviewed journals,
presented at international conferences, or disseminated in electronic media. Results of pilot projects may be essential for
NERC Research Grant proposals.
OUUSF has an extensive web-site URL: http://www2.open.ac.uk/ou-usf/
ANNUAL TARGETS AND PROGRESS TOWARDS THEM
The OUUSF Agreement provides for the equivalent of 150 analyses, equating to 25% of capacity and this has been
achieved. Most data were communicated to the PI within the timeframe of the project.
SCORES AT LAST REVIEW (each out of 5)
Need
Uniqueness
CAPACITY of HOST ENTITY
FUNDED by S&F
25%
Quality of Service
Date of Last Review:
Quality of Science & Training
Staff & Status
Dr P van Calsteren, Senior Research Fellow: 48%
Dr L E Thomas, Project Officer: 100%
Ms A Kwateng, Grade 6 technician: 50%
FINANCIAL DETAILS: CURRENT FY
Total Resource
Unit Cost £k
Allocation
Unit 1
Unit 2
Unit 3
£k
157.94
1.053
FINANCIAL COMMITMENT (by year until end of current agreement) £k
2009-10 147.98
2010-11 157.00
2011-12 TBD
2012-2013
STEERING COMMITTEE
NIGFSC
Independent Members
7, (chair Prof J Andrews)
Meetings per annum
2
Average
Next
Review
(March)
2010
Capital
Expend £k
Income
£k
~£35K
none
TBD
2013-2014
Other S&F Overseen
NIGL, AIF, ICSF
Contract
Ends
(31 March)
2011
Full
Cash
Cost £k
157.94
TBD
APPLICATIONS: DISTRIBUTION OF GRADES (current FY — 2009/10)
R*/Pilot
Reject
5
4
3
2
1

NERC Grant projects*
Other academic
3
1
Students
1
Pilot
5
3
1
1
5
0
TOTAL
APPLICATIONS: DISTRIBUTION OF GRADES (per annum average previous 3 financial years —2007/2008, 2008/2009 & 2009/2010)
R*/Pilot
Reject
5
4
3
2
1

NERC Grant projects*
.67
.33
Other Academic
2.33
.67
.67
Students
Pilot
2.67
2.33
1.3
2.67
1
TOTAL
PROJECTS COMPLETED (current FY – 2009/10)
5
NERC Grant projects*
Other Academic
Students
Pilot
4
3
2
1

R*/Pilot
2
5
USER PROFILE - funding type (current FY – 2009/10)
Infrastructure
Grand
Student
Total
Supplement to NERC Grant *
NERC Other
PAYG
Student
NERC Other
NERC
C/S
Other
2
6
8
USER PROFILE - funding type (per annum average previous 3 financial years - 2007/2008, 2008/2009 & 2009/2010)
Infrastructure
PAYG
Grand
Student
Student
NERC
NERC
Total
Supplement to NERC Grant *
Other
C/S
Grant* NERC Other
NERC Other
NERC
C/S
Other
1
5.67
1
1
NERC
C/S
Other
NERC
Grant*
2.67
USER PROFILE – user type (current FY – 2009/10)
Academic
Centre/Survey
NERC Fellows
PhD
7
2
USER PROFILE - user type (per annum average previous 3 financial years - 2006/2007, 2007/2008 & 2008/2009)
Academic
Centre/Survey
NERC Fellows
PhD
3.67
2
Commercial
Commercial
OUTPUT & PERFORMANCE MEASURES (current year)
Publications (by science area & type) (calendar year 2009)
SBA
ES
MS
AS
TFS
EO
Polar
Grand Total
Refereed
Non-Ref/ Conf Proc
6
6
2
Distribution of Projects (by science areas) (FY 2009/10)
SBA
ES
MS
AS
TFS
EO
.14
5.4
.8
.08
OUTPUT & PERFORMANCE MEASURES (per annum average previous 3 years)
Publications (by science area & type) (Calendar years 2007, 2008 &2009)
SBA
ES
MS
AS
TFS
EO
Polar
Grand Total
Refereed
Non-Ref/ Conf Proc
2.33
2.33
2.33
Distribution of Projects (by science areas) (FY 2006/2007, 2007/2008 & 2008/2009)
SBA
ES
MS
AS
TFS
EO
.77
3.67
.43
.13
.33
PhD Theses
4
Polar
PhD Theses
1.33
Polar
Distribution of Projects by NERC strategic priority (current FY 2009/10)
Climate System
3.8
Biodiversity
Earth System Science
Sustainable Use of
Natural Resources
3.9
Natural Hazards
.3
*Combined Responsive Mode and Directed Programme grants
NOTE: All metrics should be presented as whole or part of whole number NOT as a %
Environment, Pollution
& Human Health
Technologies
OVERVIEW & ACTIVITIES IN FINANCIAL YEAR (2009/10):
This year was the second year of the fourth Agreement and 7 new projects were submitted: 3 projects attracted good 4
grades, one was allowed with an 3high as a student project; a pilot study was approved to show that the samples were
suitable for dating and one projects received 2 grades and was not funded, a further 3 pilot projects were carried out within
OUUSF remit. There are 12 ‘live’ projects and for 7 projects the analytical work was completed. During this year 4 PhD
theses were completed which contain significant U-series data obtained in large part by PGRS who were trained and active
in the OUUSF laboratory. Two papers were published in 2009 but the number of papers in preparation or review is at a
record high.
The MAT262 mass spectrometer has been performing well, but the focus potential supply unit which was installed by
Spectromat in 2009, was replaced with an upgraded system and the mains power distribution unit was replaced with a new
design. The Nu Instruments MC-ICPMS also performed well but this instrument, and associated parts, have suffered from
an uncharacteristic number of breakdowns: 2 SEMs were replaced; 3 HV1000 were repaired, 1 under warrantee; the
digital control box was replaced; the 15-24V utility PSU was repaired and most recently, the IC-RPQ PSU was repaired.
Moreover, 3 chillers failed, a newly purchased one was repaired under warrantee, twice.
The Nu Instruments MC-ICPMS is used for most U and Th measurements because increasingly, higher sensitivity and
therefore smaller sample size is important as well as good precision. All Pa analyses where sensitivity is essential are
performed on the Nu Instruments, equally, all Ra analysis are performed on the TIMS with >20% ionisation efficiency.
The Ametek gamma spectrometry system for the tracking of 237Np and 233Pa through our chemical separation procedure
231
for Pa quantification, is now fully calibrated using a dedicated multi-nuclide source and is in routine operation.
The second batch of 231Pa samples has been much delayed by the tribulations with the Nu Instruments MC-ICPMS and
is now in progress
The OUUSF website has been kept up-to-date and now has a ‘wiki’ to facilitate some types of communication. The
‘public’ website has an Introduction into Uranium-series methodology, examples of Projects and lists of Publications. For
laboratory users at OUUSF there are intranet links to all Standard Operating Procedures and Training Manuals, the
laboratory Risk Assessments and spreadsheets and compilations of our laboratory standards and blanks. The intention of this
e-documentation is to comply with the spirit of ISO:9001-2000: Quality Assurance by Quality Control at a day-to-day level
and by frequent evaluation of QC data.
The Nu Instruments MC-ICPMS, is now in almost continuous use for U-series isotope ratio determinations. The normal
mode of operation is that on Sunday evening the plasma is switched on and run on a wash cycle. Monday morning is used to
tune all instrument variables and this culminates in a four ‘magnet cycle’ analysis of CRM U112a (see Appendix 3.2). This
allows monitoring of many performance indicators including SEM yields, hydride formation, Abundance Sensitivity and
RPQ performance. Then follows analysis of the ‘bracketing’ standard, -with isotope ratios and signal intensities similar to
samples- and when the bracketing standard reproducibility is within expectation, samples are introduced. The instrument is
then kept running (with overnight extended wash & standard cycles) for the rest of the week, or until the reproducibility of
the bracketing standard gives cause for concern.
19 Total Procedure Samples of our Young Spele rock-powder standards were analysed as unknowns, as well as >60
total procedure blanks, and numerous reagent blanks and shelf standards traceable to Certified Reference Materials to
maintain high levels of Quality Control. The CRM U112a database accumulates ~40 data-sets each year.
The MAT262 TIMS has been used to determine isotope ratios in both ‘bracketing’ standards and other solution
standards, ensuring that our MC-ICPMS data remain compatible with TIMS.
SCIENCE HIGHLIGHTS:
The main highlight for OUUSF is that U-series data are an integral part of 4 PhD thesis, all within the paleo-environment/
global change area and contributing to better understanding the forces and feedbacks that drive the Earth System
Cath Jex, School of Geography, Earth and Environmental Sciences, University of Birmingham, Thesis title:
Palaeoclimate records from Speleothems in the eastern Mediterranean Speleothem palaeoclimate reconstructions from
North East Turkey. (IP/877/1105) GC
Abi Stone, Arid Environments Research Group and OLD laboratory, School of Geography and the Environment, Oxford
University, Thesis title: Multi-proxy reconstructions of late Quaternary environments in western southern Africa.
(IP/937/1106) GC
Jenni Turner, School of Environmental Sciences, University of East Anglia, Thesis title: The Tectonic Significance,
Sedimentology and Palaeoenvironments Of Uplifted Marine Terraces In A Forearc Setting, Southern Greece.
(IP/1115/0509) GC
Jenny Mason, School of Environmental Sciences, University of East Anglia, Thesis title: Palaeoclimate records from
Speleothems in the eastern Mediterranean. (IP/998/1107; IP/977/0507) GC
A potential new U-series dating application:Analysis of Lithophaga shells. Dr J Turner, UEA. IP-1143-1109
Mediterranean limestone coastlines often contain L. lithophaga shells and reliable U-series ages from these
can be used to establish the chronology of raised palaeo-shorelines. Lithophaga secretes acid mucous into
limestone substrates and the bivalve shell remains recessed in the hole, while extruding the soft body part
beyond the aperture when feeding (Figure). Populations are concentrated in the zone between mean and low
water mark, the upper bore holes thus delineating mean sea level to ±0.5 m. Bored holes may contain
preserved shells where relative sea-level fall is abrupt, placing the shells above the littoral zone where they
would be otherwise prone to degradation by encrusters and bio-eroders. The unique bore hole habitat of L.
lithophaga in impervious limestone ensures ‘closed system’ and makes these shells suitable for U-series
dating. First results of U-series analyses from Holocene shells from impermeable limestone have marine
(234U/238U)init ratios, and ages close to control 14C ages, suggesting U uptake is from seawater. (see 10., below)
U-series dating of L. lithophaga
shows promise of a major advance
in
establishing
pre-Holocene
chronologies for Mediterranean
sealevel and tectonic studies. The
method may be extendable to other
Lithophaga species, offering a new
mid- and low-latitude dating tool.
Figure Lithophaga shells ~60 mm length
are exposed by removal of the top part of a
limestone block
FUTURE DEVELOPMENTS/STRATEGIC FORWARD LOOK
Analytical developments:
The Nu Instruments plasma ionisation mass spectrometer (MC-ICP-MS) now has fully developed protocols for U, Th
and Pa analyses where its sensitivity is essential.
TIMS will be used when mass-dependent isotope fractionation and instrument drift, which are both an order of
magnitude better, is a requirement for high precision (for high resolution) and when concentration or availability are not
limiting factors. This includes ‘certification’ of the bracketing standards used with the Nu Instruments.
A disadvantage of MC-ICP-MS is that isotope fractionation in plasma ionisation is an order of magnitude larger than for
TIMS, although it is fairly constant, to within a few ‰ in an analysis period. Mass-dependent isotope fractionation can be
corrected in various ways, we have opted for the bracketing approach where a standard of comparable composition and
concentration is analysed between samples. The standards that are interspersed with the samples are characterised using
TIMS and results from both instruments are fully compatible. This technique works well but is time consuming. Therefore,
we are currently exploring the use of a pre-calibrated, high purity 233U-236U double-spike from IRMM (IRMM 3636). The
addition of the spike will allow us to correct directly for instrumental mass-fractionation, calculate the U concentration and
measure the 234U/238U ratio with negligible spike correction, providing improved data quality and eliminating the need for
‘bracketing’. Preliminary measurements on standards spiked with the double-spike indicate that we can already produce
measurements that are as precise as the standard-sample bracket technique we currently use. Further testing will take place
over the next few months. Th and Pa do not have internal invariant isotope ratios or certified double spikes and the standard
bracketing technique produces data of excellent quality.
OUUSF is continuing the implementation of mass spectrometric analysis of 231Pa. The gamma spectrometry system
makes it possible to ‘track’ spiked samples through the chemical separation and spike preparation procedure. The gamma
spectrometer is now calibrated using a certified multi-nuclide standard and the GammaVision software. Adjustments have
been made to the chemical separation procedures to improve sample recovery and this has greatly improved our confidence
in the efficiency of the separation protocol and we now have data that we confidently consider to be correct.
Strategic look forward:
OUUSF believes that from an analytical and scientific collaboration perspective, our performance is good; we are
improving communication with collaborators and will aim to provide better turn-around time estimates.
A new Agreement to fund OUUSF for 3 years from 2011 is provisionally approved through the SRG process, the
submission contained succession planning upon PvC retirement in 2012, and his continued involvement till 2014 as a
consultant. Ian Parkinson is taking over as lead PI and LET is expanding her role to take on more user contact. Moreover,
OUUSF is confident that our technician will be with us for the duration.
Non-Mandatory Facility-specific OPMs: utilisation, allocation of capacity etc
OUUSF Mission Statement:
OUUSF is hosted by the Isotope Geochemistry Research Group, Earth and Environmental Sciences,
The Open University.
OUUSF is providing U-series methodology through collaborative projects to researchers within the
NERC remit to further the goals in NERC strategy 2007-2012: Next generation science for planet Earth,
Science-based Archaeology and responsive mode (‘blue skies’) research.
OUUSF provides web-based training material and one-to-one training for post-graduates and research
scientists in U-series laboratory techniques, underlying theory and data evaluation.
OUUSF pursues an ‘open door’ attitude and will share methods and protocols with collaborators and
the wider scientific community.
OUUSF aims to expand and improve analytical techniques for chemical preparation in a state-of-the-art
laboratory, using the latest mass spectrometric instrumentation, to support innovative collaborative
projects.
NERC Isotope Geoscience Facilities Steering Committee, 2008
Chair:
Prof Julian E Andrews
School of Environmental Sciences
University of East Anglia
Norwich, NR4 7TJ
Tel: +44 160 359 2536
E-mail: j.andrews@uea.ac.uk mailto:j.andrews@uea.ac.uk
Members
Prof SA Bowring
Department of earth, Atmospheric, and Planetary Sciences
MIT Building 54-1126
Cambridge, MA 02139 USA
Tel: +1 0617 2530 3775
E-mail: sbowring@mit.edu
Prof. A Chamberlain
Department of Archaeology
The University of Sheffield
Northgate House, West Street
SHEFFIELD S1 4ET
Tel: +44 114 222 2906
E-mail: a.chamberlain@sheffield.ac.uk
Dr Sarah Davies
Room E21d, Institute of Geography and Earth Sciences,
Llandinam Building
Penglais Campus, Aberystwyth
Ceredigion SY23 3DB, Wales, UK
Tel: +44 1970 622585
E-mail: sjd@aber.ac.uk
Dr Colin Mcpherson
Department of earth Sciences
Durham University, Science Labs
Durham, DH1 3LE
Tel: +44 191 334 2283
E-mail: colin.mcpherson@durham.ac.uk
Dr RA Mills
School of Ocean and Earth Sciences
National Oceanography Centre, Southampton
Southampton, SO14 3ZH
Tel: +44 23 8059 2678
E-mail: ram1@noc.soton.ac.uk
Prof Clive M Rice
College of Physical Science
School of Geosciences
Geology & Petoleum Geology
Meston Building, King’s College
Aberdeen, AB24 3UE
Tel: +44 1224 273433
E-mail: c.rice@abdn.ac.uk
Prof Jim Marshall
Earth and Ocean Sciences,
University of Liverpool
Tel:+44 1517945177
E-mail: isotopes@liv.ac.uk
Administration:
Béatrice Bullock-von Moos
NERC Isotope Geosciences Laboratory
British Geological Survey
Kingsley Dunham Centre
Keyworth, NG12 5GG
Tel. + 44 115 936 3425
bbullock@bgs.ac.uk
Ex-officio:
Dr Ian Millar, Secretary
NERC Isotope Geosciences Laboratory
British Geological Survey
Kingsley Dunham Centre
Keyworth, NG12 5GG
Tel: +44 115 936 3402
Email: ilm@gbs.ac.uk
Dr R Lin F Kay
Science and Innovation Funding
NERC
Polaris House, North Star Avenue
Swindon, SN2 1EU
Tel: +44 179 341 1500
E-mail: rlfk@nerc.ac.uk
Dr Adrian J Boyce
SUERC
Rankine Avenue
East Kilbride, G75 0QU
Tel: +44 1355 270143
E-mail: a.boyce@suerc.gla.ac.uk
Dr Fin M Stuart
SUERC
Rankine Avenue
East Kilbride, G75 0QU
Tel: +44 1355 270139
E-mail: f.stuart@suerc.gla.ac.uk
Prof. Melanie J Leng
NERC Isotope Geosciences Laboratory
British Geological Survey
Kingsley Dunham Centre
Keyworth, NG12 5GG
Tel: +44 115 936 3515
E-mail: mjl@nigl.nerc.ac.uk
Prof. Randy R Parrish
NERC Isotope Geosciences Laboratory
British Geological Survey
Kingsley Dunham Centre
Keyworth, NG12 5GG
Tel: +44 115 936 3427
E-mail: r.parrish@nigl.nerc.ac.uk
Dr Peter van Calsteren
Department of Earth Sciences
The Open University
Walton Hall
Milton Keynes, MK7 6AA
Tel: +44 1908 652889
E-mail: p.v.calsteren@open.ac.uk
NIGF Steering Committee: Remit
The NERC Isotope Geosciences Facilities Steering Committee exists to:
review applications for use of:
the NERC Isotope Geosciences Laboratory;
the Argon Isotope Facility at the SUERC;
the Isotope Community Support Facility at the SUERC; and
the Open University Uranium Series Facility
monitor outputs from these Facilities;
provide advice to the Director, Science and Innovation Funding on aspects of the operations of these
Facilities.
The Director, Science and Innovation Funding, in turn, provides advice to the Science and Technology Board
of Council on Services and Facilities relevant to their remit.
Terms of Reference
1. To review applications and to establish priorities for the Heads of these Facilities in the allocation of those
of the Facilities’ resources funded from the Science and Innovation Funding allocation, taking into
account NERC Strategy and recommendations made through the NERC peer-review mechanisms.
2. To review the scientific quality of work undertaken by users utilising these Facilities, based on reports and
publications.
3. To monitor the level of user-satisfaction with the Facilities, and to analyse the user-base.
4. To give guidance to the Heads of these Facilities on improvement of the Facilities’ equipment and on their
service function.
5. To advise the Director, Science and Innovation Funding on:
5.1. the level and direction of the internal R & D programme for these Facilities;
5.2. the anticipated levels of future demand and any consequential anticipated changes in resource
requirements from these Facilities.
5.3. on other matters, as appropriate and reasonable.
6. To receive annually a report from the Heads of these Facilities, and comment through the Chair on them
before passing them to the Director, Science and Innovation Funding.
1. Equipment Inventory
OUUSF does not own any equipment but uses instruments, facilities and infrastructure of The Open
University
2. Future Developments.
2.1. In situ analysis:
MC-ICPMS can be hyphenated to the Excimer laser ablation system to measure (234U/238U) and
( Th/232Th) in situ but stalagmites with sufficient U concentration and age, are fairly rare. However, the
technique also has important applications in marine climate change studies because pristine corals have
sufficiently high U concentration. We are assessing a project which involves cladocora corals with
sufficiently high U concentration for a pilot study.
The energy of the laser at the ablation point is such that a short-lived Laser-Induced Plasma is produced
and this adds another process by which mass and element fractionation takes place. The use of appropriate
standards with similar matrix is essential and it is not simple to find a suitable standard that is homogeneous
at the spatial resolution that is required. However, age variation patterns are much easier to resolve and this is
frequently the main purpose.
The defunct TUI laser of our NewWave laser ablation system has been replaced with a 50% funding
contribution from NERC S&F. The new excimer is a Coherent Compaq 50 and early tests show that the
ablation pit ‘quality’ is even better than before, this is probably achieved by the thorough adjustment of the
beam homogeniser that was part of the commissioning process, rather than the inherent characteristics of the
new laser.
We will be re-applying for a NERC Standard Research Grant in July 1st round to work with colleagues at
NOC, S on sulfides from Mid Ocean Ridge hydrothermal vents. It is anticipated that these will contain high
enough levels of U to allow the use of laser ablation. We will also re-apply with colleagues from Durham to
re-visit the MAR at 13ºN where our involvement will again be the dating of newly-extruded pillow lavas.
230
2.2. Protactinium
OUUSF now has methods for mass spectrometric analysis of 231Pa, the daughter of 235U with a half-life of
~35,000 y. The analytical method to purify protactinium from silicate rocks that was published recently
(Regelous et al., 2004, Thomas et al., 2007), has been adapted for the chemical separation of protactinium
from carbonate-rich samples. This adaptation requires the separation of the Ca-rich fraction from the
remaining solid fraction before the solid is dissolved using HF and the subsequent thorough elimination of
any fluoride. When the current project is completed, we will investigate a better method of spike ‘milking’
using TEVA resins, rather than a silicagel column.
The gamma spectrometry system makes it possible to ‘track’ spiked samples through the chemical
separation procedure and to track the presence of 237Np in the purified 233Pa spike, hence enabling full
recovery of 237Np and avoiding the potential contamination of the ion counters on mass spectrometer.
Adjustments have been made to the procedure to improve sample recovery and this has greatly improved our
confidence in the efficiency of the separation protocol and we now have data that we confidently consider to
be correct. The gamma spectrometer will also be used in the preparation of the new Ra spike.
231
Pa dating can provide confirmation of ages obtained by 230Th dating. Two independent estimates of the
age from the same sample would be useful for dating of speleothem carbonate and particularly in
archaeological bone using the Oxford U-uptake model (Millard and Hedges, 1996), recently further
developed for U-series (see Pike et al., 2002).
231
Pa has found application in coral dating (Mortlock et al., 2005, Edwards et al., 1997). In open oceans,
231
Pa and 230Th are removed from the water column by a process of reversible scavenging (Moran et al.,
2002, Moran et al., 2005) which quickly removes 230Th to the sediment. 231Pa is less efficiently scavenged
onto particles than 230Th and is therefore more effectively transported via advection and diffusion before it
reaches the ocean sediment. The equilibrium partition coefficients for particulate versus dissolved matter
may vary with particle type and the (231Pa / 230Th) activity ratio can be of great use in paleo-oceanographic
studies.
231
Pa/235U is part of the project to study an Axial Volcanic Ridges AVR, in the Median Valley of the
Mid-Atlantic Ridge, 700km north of the Azores (IP/929/1106: Prof R Searle, Durham). Glass samples are
being prepared using ‘hand picking’ under the binocular microscope and is making good progress, but it
remains very time consuming.
2.3. Radium
The U-series sub-system 230Th-226Ra has a half-life of 1602y which makes it highly appropriate for
systems with millennial ages. Using TIMS with ion counting we can analyse <4 femtogram 226Ra routinely
and this is essential because 226Ra is present at the femtogram/gram level in geological materials. The age of
a sample is calculated from the 226Ra/Ba ratio in the sample relative to present day 226Ra/Ba. The uncertainty
in 226Ra/Ba ages depends mostly on the assumption that 226Ra/Ba has remained constant. This is a reasonable
assumption because Ra and Ba have very similar geochemical characteristics. Radium dating is one of the
aims of the AVR project. TIMS 226Ra dating has not previously been applied to speleothem samples and an
application in conjunction with lamina counting that would re-enforce confidence in both methods and
confirm the validity of the 226Ra/Ba dating method in young authigenic carbonates in Holocene speleothems,
is being developed. Ra dating will also be applied to the MAR glass samples from the MAR at 45ºN.
2.4. Lead
The energy range of our new gamma spectrometer is such that
exploit this dating tool with a range of 0-120y tentatively.
210
Pb can be detected and we plan to
2.5. Authigenic minerals precipitates from groundwater.
Long-standing assumptions in U-series dating of authigenic minerals are that all accumulated 230Th is
from in-situ decay of 234U and only U and no Th is transported in ground water. The concentration of trace
elements in water is determined by temperature, pH, redox conditions, concentration of anionic ligands and
complex ions formation. Residence time in groundwater is a function of the rate of leaching, stability of
complex ions, and adsorption onto particulate matter or incorporation into authigenic minerals. The resulting
U/Th in groundwater is usually > 10,000.
Contrary to expectations, recent work at The Open University has shown that Th and U have similar
concentrations in oxygenated ground water in the Great Artesian Basin, Australia. Recent results from the
Naukluft project confirm the existence of ‘hydrogenous’ Th in this area as well. It is likely that U and Th
speciation is the determining factor for this unexpected behaviour and furthermore this makes the longstanding U-series dating assumptions questionable. Any 230Th that is not derived from in-situ decay but is
transported in ground water must therefore be accounted for before meaningful ages can be calculated.
The theoretical framework for the behaviour of U and Th in ground water can now be tested due to recent
advances in analytical technology. These recent advances allow the speciation of U and Th to be determined
at the low concentration levels encountered in groundwater.
To assess the effects of 230Th transportability in groundwater is is necessary to:
1.
determine the speciation of U and Th isotopes in groundwater;
2.
develop a thermodynamic framework for the speciations;
3.
evaluate the importance of these findings for U-series dating of authigenic minerals.
OU-IGL has a High-Performance Liquid-Chromatography (HPLC) for speciation research and this
instrument can be hyphenated to our MC-ICPMS.
3. Summary of Performance Information
3.1. Active projects
IP number
University
Institute
PI name
title
Sample type
IP/867/1105
IP/911/0506
IP/912/0506
IP/929/1106
IP/938/1106
IP/1025/0508
IP/1075/1108
IP/1067/1108
IP/1099/0509
IP/1109/0509
IP/1143/1109
IP/1140/1109
Liverpool
Bristol
Southampton
Durham
Leeds
UEA
Zoological Soc
Durham
Birmingham
Manchester
East Anglia
Manchester
E&O science
Archaeology
SOES,NOC,S
Earth Sciences
Geography
SES
Inst of Zoology
Earth Sciences
SGEES
SE&D
SES
SED
Marshall
Zilhao
Mills
Searle
Lawson
Andrews
Turvey
Baldini
Baker
Hughes
Turner
Woodward
Hawes Water
Iberian Peninsula,Neanderthal
Feni Drift N Atlantic
MORB
Ioannina, Greece
Gulf of Corinth
Puerto Rico
Niedzwiedzia, Poland
Ethiopia
Velebit Mountains, Croatia
Perachora, Greece
Macedonia
lake marls
speleothem
ooze
Reykjanes Ridge
laminated lake sediments
cement
nesophontes jaw-bone
stalagmites
stalagmites
speleothem
lithophaga
flowstone
3.2. U112a standard data
U112a
234
U/
238
U = 0.00005298 ± 0.00000012 (2rsd = 0.22%)
5.315
238
U x 10
-5
5.310
5.305
5.300
234
U/
5.295
5.290
5.285
5.280
0
5
10
15
20
25
30
35
4. Papers published and in preparation since 2007, IP code, PI, Science area,
number since 1998 and publication details.
IP/754/0302 Manchester – Woodward, GC
41. Hughes, P.D., Woodward, J.C. and Gibbard, P.L. (2007) Middle Pleistocene cold stage climates in the Mediterranean: new
evidence from the glacial record. Earth and Planetary Science Letters,253(1-2), 50-56.
IP/672/0900 Liverpool – Marshall, GC
42. Marshall, J.D., Weedon, G.P., Lang, B., Kiriakoulakis, K., Fisher, E.H., Crowley, S.F., Ball, J.D., Jones, R,T., Calsteren, P.
van, Bedford, A., Brooks, S,J., Muscheler, R., Johnsen, S. (2007). Early Holocene climate in NW Europe - abrupt events,
centennial variability, and solar influence. Geology, 35( 7), 639–642.
IP/932/1106 Birmingham – Baker, GC
43. Asrat, A., Baker, A., Umer, M., Leng, M.J., van Calsteren, P. and Smith, C.L., (2007). A high-resolution multi-proxy
stalagmite record from Mechara, Southeastern Ethiopia: Paleohydrological implications for speleothem paleoclimate
reconstruction. Journal of Quaternary Science, 22, 53-63.
IP/1115/0509 UEA – Andrews, GC
44. Turner, J.A., Leeder, M.R., Andrews, J.E. and Rowe, P.J.. (2008) Comment on "A comparison of 103 - 105 year uplift rates
on the South Alkyonides Fault, central Greece: Holocene climate stability and the formation of coastal notches" by Cooper et.
al., (2007). Geophysical Research Letters 35 L19314 doi:10.1029/2008GL034854.
IP/578/0998 Birmingham – Baker, GC
45.0Caseldine, C.J., McGarry, S.F., Baker, A., Hawkesworth, C. and Smart, P.L. (2008). Late Quaternary speleothem pollen in
the British Isles. Journal of Quaternary Science, DOI: 10.1002/jqs.1121.
IP/878/1105 Manchester- Woodward, GC
46. Woodward, J.C., Hamlin, R.H.B., Macklin, M.G., Hughes, P.D., Lewin ,J. (2008). Glacial activity and catchment dynamics
in northwest Greece: long-term river behaviour and the slackwater sediment record for the last glacial to interglacial transition.
Geomorphology 101, 44-67.
IP/787/0902 – UCL- Roberts, GC
47. Roberts, G. P., Houghton, S.L., Underwood, C., Papanikolaou, I., Cowie, P.A., van Calsteren, P., Wigley, T., Cooper, F.J.
and McArthur, J.M.(2009), Localization of Quaternary slip rates in an active rift in 105 years: An example from central Greece
constrained by 234U-230Th coral dates from uplifted paleoshorelines, Journal of Geophysical Research., 114, B10406,
doi:10.1029/2008JB005818.
IP/932/1106 – Birmingham – Baker, GC
48. Jex, C., Baker, A., Fairchild, I.J., Leng, M., Sloane, H.J., Eastwood, W. and Thomas, L.E. (2009) Calibration of speleothem
δ18O with instrumental climate records from Turkey. Global and Planetary Change. Accepted for publication.
IP/932/1106, IP/1099/0509 Birmingham – Baker, GC
49. Baker, A., Asrat, A.,Fairchild, I., Leng, M., Thomas, L., Widmann, M., Jex, C., Dong, B., Calsteren P. van, Bryant, C.
(2009) Decadal-scale rainfall variability in Ethiopia recorded in an annually laminated, Holocene-age, stalagmite. Accepted The
Holocene
(IP/998/1107; IP/977/0507) UEA – Andrews, GC
Mason, J. E., Rowe, P. J., Andrews, J. E., Marca, A. D., Thomas, L., van Calsteren, P., Jex, C. N., Vonhof, H. B., Al-Omari, S.
(2009) Precessionally-Forced Seasonality and Climate Teleconnections in a Late Quaternary Turkish Speleothem. Submitted to
Science.
(IP/1115/0509) UEA- Turner, GC
Turner, J.A., Leeder, M.R., Andrews, J.E., Rowe, P.J. van Calsteren, P. and Thomas, L. (2009) Neo-tectonic regional scale
uplift of a failed rift basin in a continental forearc setting, Lechaion Gulf, eastern Corinth rift. submitted to Journal of the
Geological Society. GC
IP/1025/0508 UEA – Andrews, GC
Andrews, J.E., Turner, J.A, Leeder, M.R., Portman, C., Rowe, P.J., van Calsteren, P. and Thomas, L. (2009) Sea level and
climate indicators, Perachora peninsular (Gulf of Corinth, Greece) MIS 5 to MIS 7. Submitted to Sedimentology.)
(IP/937/1106) Oxford – Thomas, GC
Stone, A. E. C., Viles, H. A., Thomas, L., van Calsteren, P. (2009) Quaternary tufa deposition in the Naukluft Mountains,
Namibia, Submitted to Journal of Quaternary Research.
5. Targets & Milestones
instrument utilisation;
The OUUSF Agreement is for the utilisation of 25% of the U-series laboratory capacity, equivalent to
approximately 150 samples per year and this target has been achieved. 22 ‘rock’ standards mainly our
homogenised stalagmite YS, were analysed as Total Procedure Standards to assess the full analytical
protocol. 65 Total Procedure Blanks, reagent blanks and shelf standards traceable to Certified Reference
Materials were analysed to monitor routine performance for Quality Control purposes in the spirit of
ISO:9001. On the MC-ICPMS >400 traceable standards were analysed in Sample-Standard-Standard
analysis ‘bracketing’ protocols. Dozens of test solutions were devised and tested as part of the 231Pa analysis
protocol developments
allocation of capacity and effort;
Instrument and laboratory time for OUUSF operations were scheduled in consultation with other users and
there was no friction.
throughput;
The analytical workload was significantly above average, partly because activity associated with PGRS
working in the lab and our usual turn-around times have not always been maintained.
response times and data delivery to customers;
Analytical results have mostly been submitted to PI’s within the agreed time-frame with a few exceptions.
‘Teething trouble’ with the protactinium method and the large number of samples for which a ‘detrital’
correction is required, have resulted in delays. Communications regarding interpretations and publication are
always conducted with the highest priority.
user satisfaction;
Our new and improved collaborator contact strategy includes 3-monthly emails (this has been done twice now)
updating each collaborator on what has been happening at OUUSF and updates on their samples.
We have not undertaken a ‘customer survey’, because we feel that the relatively small number of projects at OUUSF
is not very suitable for such a ‘statistical’ approach. However when we requested letters of support from our
collaborators for the SRG proposal in December (all letters were included and none were edited), we left it open and
asked for full opinions (both positive and negative) on the projects, from proposal writing, through postgraduate
training (if applicable) to data QA/QC, and we are proud that the letters of support all showed that collaborators
were happy.
From now on, we propose to undertake an ‘exit survey’ of each collaborator when we finish the analytical stage of a
project. This will enable us to close that aspect of a project and gain important feedback on our performance,
including areas that need improving. Collated ‘exit surveys’ will provide us with data for the next SRG proposal.
The ‘exit survey’ will also provide us with an opportunity to gauge the state of manuscript preparation, especially
regarding the relatively large number of collaborations involving PGRSs.
Details of the complaints procedure are on the OUUSF website; no complaints were made.
scheduled maintenance, calibrations, planned contingency, down time due to external factors
etc.;
Instrument maintenance is scheduled such that impact on availability is minimal, calibrations are part of the
analytical ‘continuum’ and not separately accounted. Downtime due to external factors is minimised, mainly
by the use of an Uninterruptable Power Supply that keeps the mains working on all our instruments. The
working relationship with our Estates Division staff is such that maintenance on the Air Handling Units, Air
Conditioning Plant and any other activity, is scheduled to fit with our needs.
summary of internal R&D output;
Our spreadsheets for data evaluation are constantly under review and minor improvements have been
implemented. Especially the Naukluft Project required efforts for the modelling of allogenic Th, if only to
ascertain that the (230Th/234U)>1 cannot be due to mixing with a detrital component but has to be caused by
hydrogenous Th.
The Pa spreadsheet-based model to evaluate Pa isotope ratio data is still in a quite simple form and
expanding rapidly.
6. Finance
Details are included in the accounts filed by The Open University: Finance Division.
7. Service Management
Dr Peter van Calsteren is Principal Investigator and Manager of OUUSF as Senior Research Fellow, Dr
Louise Thomas is Project Officer and is OUUSF-funded through the NERC-OU Agreement. Dr Sam
Hammond has left OUUSF and is now the IGL laboratory manager. Andrea Kwateng was appointed from 15
February 2010 and is Part-Time (50%) Grade 6 Technician, OUUSF-funded through the NERC-OU
Agreement till 31 March 2011. Andrea also has a 50% appointment running the Agilent 7500 ICPMS in
EES. All OUUSF staff are employed in Department of Earth and Environmental Sciences, Faculty of Science
at The Open University on its standard Terms and Conditions.
8. Outreach
We aim to better promote the U-series facility in the wider academic community through the attendance at
conferences and giving talks to other universities, and we are also taking part in local ‘Outreach’ activities.
We have been involved in visits to local schools. Both LET and PvC are trained as STEM Ambassadors.
9. Projects for which the analytical work has been completed
OUUSF#46, IP/864/0505, Plymouth, Geography, PI: Prof Roberts. Turkey: Eski Acigol volcano lake marl: An ultra
high resolution record of Late Quaternary climate change in the Eastern Mediteranean: TIMS U-series dating of
crater lake authigenic carbonates. Sample results did not meet expectations and sample supply has stopped, despite
repeated communications.
OUUSF#50, IP/878/1105, Manchester, Geography, PI: Dr Woodward. Montenegro calcrete: Pleistocene glacier
dynamics and palaeoclimate in the eastern Mediterranean. Results submitted and papers in prep.
OUUSF#70, Pilot, Cambridge, Earth Sciences, PI: Prof Bush. Peru stalagmites: Do millenial scale events in tropical
Andean speleothems record northern high latitude climate changes? Results submitted and these have been used to
prepare OUUSF#72
OUUSF#72, IP/1114/0509, University of Cambridge, Earth Sciences, PI: Prof Hodell. Peru stalagmites: Do
millenial scale events in tropical Andean speleothems record northern high latitude climate changes? Results
submitted and these will be used in the preparation of the next NIGFSC proposal, probably autumn 2010.
OUUSF#73, IP/1115/0509, University of East Anglia, SES, PI: Dr Turner. Perachora, Greece: Potential new Useries dating application: analysis of lithophaga shells. Results have been submitted and a paper is being written.
OUUSF#78, Pilot, University of Nottingham, Geography, PI: Dr Jones. Iran: Holocene lake sediments, ‘hard
water' lake, check 14C date. Results submitted and used to prepare a proposal to NIGFSC for the spring 2010
meeting.
OUUSF#79, Pilot, University of Wales, Aberystwyth, Geography, PI: Dr Tooth. Crete: Dating calcrete in river
incisions in Crete. Results submitted but samples in secular equilibrium. Publication unlikely.
10. Extended Science Highlights
A potential new U-series dating application:Analysis of Lithophaga shells. Dr J Turner, UEA. IP-1143-1109
Mediterranean limestone coastlines often contain L. lithophaga shells and reliable U-series ages from these can be used to
establish the chronology of raised palaeo-shorelines.
Dating raised palaeo-shorelines, that are represented in rocky coastlines by features such as notches, is desirable to resolve
palaeo-geographic questions, but this is currently problematic due to a scarcity of material suitable for dating. One method
applicable to Holocene timescales is determining chronology from 14C analysis of L. lithophaga shell material recovered from
sub-littoral zone holes bored into limestone substrate. Shells associated with older shorelines (pre-Holocene) have not been
dated beyond the ~40 ka limit of the 14C method. Researchers at the School of Environmental Science, UEA, formed a
collaboration with the OU to test the reliability of dating Lithophaga shells by the U-Th method and so extend the application of
these shells for establishing chronologies beyond the Holocene. U-series dating can provide absolute ages for palaeo-shorelines
back to the age range of this method (~350 ka), thus identifying MIS 5, 7 & 9 shorelines.
L. lithophaga as a palaeo-shoreline proxy.
Whilst Lithophaga are widespread in warm marine waters, the species L. lithophaga is indigenous to the Mediterranean area.
This genus secretes acid mucous into limestone substrates and rotates their shelled bodies to bore sub-horizontal holes into the
chemically softened CaCO3 substrate (Lithophaga means "stone eater"). The bivalve shell remains recessed in the hole, while
extruding the soft body part beyond the aperture when feeding (Figure 1). Populations are typically concentrated in the first few
metres below sea level, with the more mature individuals inhabiting the zone between mean and low water mark, the upper bore
holes thus delineating mean sea level to ±0.5 m. Bored holes may contain preserved shells where relative sea-level fall is abrupt
(Pirazzoli et al 2005), placing the shells above the littoral zone where they would be otherwise prone to degradation by
encrusters and bio-eroders.
Figure 1. Lithophaga shells ~60 mm length are exposed by removal of the top part of a limestone block. Lithophaga
preferentially occupy the upper 1m of sea level, after a relative fall in sea level a row of bored holes define palaeo-sea level
(inset).
L. lithophaga shells as a datable material.
Dating of molluscs by U-series methods is not new, but problems have been extensively reported, eg. (Kaufman et al 1971;
McLaren and Rowe 1996). Shells recovered from porous substrates that allow percolation of meteoric water after uplift into subaerial environments are geochemically ‘open system’, resulting from post-mortem uranium exchange with the groundwater.
However, where water flow is minimal, (in arid climates, or within impermeable substrates), shell material can remain a closed
system and yield reliable ages (e.g. Belluomini et al 2002; Causse et al 1989, 2003; Hillaire-Marcel et al 1996; Ivanovich et al
1983; Kaufman et al 1996). The unique bore hole habitat of L. lithophaga in impervious limestone ensures ‘closed system’ and
makes these shells suitable for U-series dating. Shells need to be carefully cleaned and evaluated for evidence of open system
conditions with SEM, (see Figure 2) and XRD analysis. The (234U/238U)initial is used as a filter for separating pristine and
diagenetically altered samples.
First results of U-series analyses
 A modern shell contains ppb concentrations of U, indicating that most U in fossil shells is taken up post-mortem.
 Holocene shells from impermeable limestone have marine ( 234U/238U)init ratios, and ages close to control 14C ages,
suggesting U uptake is from seawater.
 MIS 5e shells from partly-lithified Late Pleistocene coraliferous marls have higher Uconc than Holocene samples, and
give low ages relative to the control age, probably reflecting uptake of U mobilised from the semi-permeable substrate and
strongly suggesting that the nature of the substrate is important when selecting samples.
 Fossil shells contain variable but low levels of 232Th incorporated during growth or post-mortem.
 Shells from the semi-lithified substrate, with high 232Th, may contain fine clastic detritus. When 230Th/232Th ratios are
low, particularly in Holocene shells which have very low authigenic 230Th, the observed 232Th levels would not compromise
U/Th dates >60 ka.
 A sample with a 230Th/232Th of 5.7, significantly higher 232Th, and (234U/238U)init just below that of seawater, probably
incorporated U from sea water post mortem since concentrations in live samples are an order of magnitude lower.
The results for shells recovered from impermeable CaCO 3 bedrock are very similar to 14C ages of Holocene samples and U/Th
ages of coral stems used as control ages.
Figure 2. SEM image of aragonite crystals
forming L. lithophaga shell material.
Summary
U-series dating of L. lithophaga shows promise of a major advance in establishing pre-Holocene chronologies for
Mediterranean sealevel and tectonic studies. The method may be extendable to other Lithophaga species, offering a new
mid- and low-latitude dating tool.
References:
Belluominini G. et al., 2002 Quat. Sci. Rev. 21, 525-47.
Causse C. et al., 2003 Ap. Geochem 18 1691-703.
Causse C. et al., 1989 Geology 17, 922-5.
Hillaire-Marcel C. et al., 1996 Quat. Sci. Rev. 15, 53-62.
Ivanovich M. et al., 1983 Nature 302, 408-10.
Kaufman A. et al., 1971 Geochim. Cosmochim. Acta 35 1155-83.
Kaufman A. et al., 1996 Geochim. Cosmochim. Acta 60 3735-46.
McLaren S.J. & Rowe P.J. 1996 Quat. Sci. Rev. 15, 709-17.
Pirazzoli P.A. 2005 Quat. Sci. Revs, 24, 1989-2001.