BOSCORF NEWSLETTER ISSUE N°1BOSCORF NEWSLETTER ISSUE N°1 AUTUMN … · 2014-11-20 · BOSCORF NEWSLETTER ISSUE N°1 AUTUMN 2010 The ITRAX corescanner now exists in some twenty leading

BOSCORFNews

BOSCORF NEWSLETTER ISSUE N°1 AUTUMN 2010BOSCORF NEWSLETTER ISSUE N°1 AUTUMN 2010

BOSCORF is the United Kingdom’s national core repository and core analysis facility, and provides a unique and strategic service to the UK sc ient i f ic community. It provides an advanced state-of-the-art non-destructive core logging and analysis capability that is unique in the UK and available for community use.

In our first newsletter, we bring you up-to-date with news on the repository. BOSCORF is changing, a £ 3 million grant from NERC will allow the repository to expand and commission new laboratories, in order to enhance service delivery and expand its training programme. We a lso review our core logging instruments and their capabilities, as well as high-lighting some recent scientific results gained from using our facilities. We h o p e y o u f i n d t h e Newsletter informative and of course we welcome your feedback. Please send any feedback and any ideas for what you would like to see in future issues to [email protected] About BOSCORF B O S C O R F i s t h e U K ' s national deep-sea core repository which also holds lake cores and some cores from archaeological landscapes. As well has providing specialist core

logging facilities for the community, it also provides long-term core storage facilities, so that sediment cores collected by NERC ships, and NERC-funded researchers, can be kept under optimum conditions to ensure long-term preservation and availability to the scientific community. BOSCORF promotes secondary multiple usage of the core material in its care ensuring cost-effective exploitation of an important national scientific resource. It is also responsible for long-term curation of core-based data relating to its holdings and from core-based national programmes in compliance with NERC data management policy. BOSCORF plays a major role in training Ph.D. students and post-doctoral scientists in sediment core analysis and has a wide user base within the natural sciences, including geographers and archaeologists. No other facility offers community use of equivalent advanced logging tools or sophisticated x-ray analytical facilities. BOSCORF core-logging suite of instruments allows researchers to extract maximum high-resolution environmental information from cored sediments. For more information, please visit here (www.boscorf.org). BOSCORF is funded by the Natural Environment Research Council (NERC) and located at the National Oceanography Centre, Southampton.

Welcome to the first issue of the BOSCORF Newsletter.......

In this issue...• Investigating the

largest submarine gravity flows on Earth...

on p3

• ITRAX - high-resolution XRF analysis of sediment cores... p7

• Multi-Sensor Core Logging... p8

• How to find out what cores we have... p12

LATEST NEWSBOSCORF to expand...

BOSCORF has been awarded £3 million by NERC to extend the core repository, in order t o c r e a t e m o r e r e f r i g e r a t e d c o r e storage space as well as new laboratories for c o r e l o g g i n g a n d analysis.

In recent years, the B O S C O R F c o r e repository has become progressively full and n e w r e f r i g e r a t e d storage space is now urgently required... read more p7

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mailto:[email protected]


http://www.boscorf.org


BOSCORF NEWSLETTER ISSUE N°1 AUTUMN 2010

The ITRAX corescanner now exists in some twenty leading institutions, worldwide from the USA, Canada, Sweden, Norway, UK, Ireland, Spain, France, Germany, Turkey, Taiwan, Korea and China, and has become a key analytical tool in palaeoceanography, palaeo-limnology and in the emerging field of environmental forensics. To r ev iew sc i en t i f i c applications and discuss future enhancement of the instrument, an

international user workshop ITRAX 2010 - Applications, i n n o v a t i o n s a n d f u t u r e developments was held on the island of Lipari, Italy, on 12-14 April, 2010. Over 30 senior scientists from ITRAX-owning institutions attended and enjoyed a v a r i e d a n d s t i m u l a t i n g programme of 29 talks and poster presentations. The meeting was judged to be a great success by all and is hoped to be repeated in three years time.

ITRAX users meet in Lipari

Photograph: Participants at the ITRAX 2010 workshop, Lipari, Italy

Abstracts can be downloaded from the BOSCORF website

BOSCORF has been awarded £3 million by NERC to extend the core repository, in o r d e r t o c r e a t e m o r e refrigerated core storage space as well as new laboratories for core logging and analysis. I n r e c e n t y e a r s , t h e BOSCORF core repository has become progressively full and new refrigerated storage space is now urgently required to store new a c q u i s i t i o n s . A d d i t i o n a l laboratory space is also needed to

allow BOSCORF to grow its core logging instrument portfolio, enhance service delivery and develop its training activities. The new extension will more than double BOSCORF's present refrigerated core storage space to over 4000 cubic metres, provide additional teaching and instrument laboratories and enhanced amenities for visitors. Building works are expected to start in January 2011 and be complete by April 2012.

BOSCORF to expand......

BOSCORF to host the 15th Meeting of the International Core Curators Group in May 2011 BOSCORF is to host the 15th Meeting of the US-based Core Curators Group - the first time that the meeting has been held outside of the USA since the meetings inception in 1977. These biennial meetings are i m p o r t a n t e v e n t s i n t h e curatorial calendar, providing opportunities for curators to

share best practise, learn about new technological developments, and improve global accessibility to core datasets. The meeting will be held at t h e B a l m e r L a w n H o t e l , Brockenhurst, in the New Forest, Hampshire, from 15-18 May 2011. It is hoped to use this opportunity to facilitate closer European

involvement in international collaboration in promoting core data accessibility.

For more information, please visit here. (http://www.ngdc.noaa.gov/mgg/curator/curator.html)

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http://www.ngdc.noaa.gov/mgg/curator/curator.html





Submarine gravity flows dominate clastic sedimentation into the deep ocean. In volume they are the most important pathway for sediment on the p lanet , t ransport ing vast quantities of material from the continental shelf to the deep sea abyssal plains. Hence they are crucial in our understanding of the global sediment cycle. These systems are also economically important with many hosting large oil and gas reserves. As unpredictable and highly destructive events they are very difficult to directly measure. Hence our understanding is derived from their deposits. U s i n g c o r e s h e l d a t BOSCORF my research examines deposits of some of the largest submarine gravity flows in the world, within the Moroccan Turbidi te System, offshore nor thwest Afr ica (Fig. 1 ) . Geochemical analysis of the deposits coupled with a suite of remote sensing data collected from Geotek multi-sensor and ITRAX core logging machines it has been possible to correlate individual events for large

distances (up to ~2000 km). The size of the flows is impressive covering areas up to 460, 000 km2 with volumes exceeding 150 km3. Examination of individual flow deposits shows flows can be either laminar, depositing en masse, or turbulent, depositing grains progressively finer as the flow loses energy. Transformations between these two rheological states occur in response to subtle changes in seafloor gradient (0.01º-0.02º; Fig. 2). Seafloor gradient also appears to have a strong control on how the fine silt and mud is distributed within a flow. Individual bed correlations show the mud to pond into topographic low points with marginal slope gradients of 0.0023º (Fig. 3). T h e e x c e p t i o n a l stratigraphic framework and extensive core coverage of the Moroccan Turbidite System has revea led key re la t ionsh ips between deposit character and sea floor gradient. This research has gained unparalleled insights into gravi ty f low structure and evolution crucial in evaluating hydrocarbon prospects and

understanding how sediment is transported around the planet.

Bibliography Wynn, R.B., Talling, P.J., Masson, D.G., Stevenson, C.J., Cronin, B.T. and Le Bas, T.P. (2009) Investigating the timing, processes and deposits of one of the World’s largest submarine gravity flows: the ‘Bed 5 event’ off northwest Africa. Submarine Mass Movements and their Consequences IV, Springer, Dordrecht, 463-474. Wynn, R.B., Talling, P.J., Masson, D.G., Le Bas, T.P., Cronin, B.T. and Stevenson, C.J. The influence of subtle gradient changes on deep-water gravity flows: a case study from the Moroccan Turbidite System. SEPM Special Publication, in press.

Investigating the largest submarine gravity flows on Earth

Figure 1. Map of the Moroccan Turbidite System, o f f s h o r e N W A f r i c a , comprising; the Madeira Abyssal Pla in (MAP) , Agadir Basin (AB) and Siene Abyssal Plain (SAP). From Wynn et al., (2009).

Article by: Chris Stevenson is a Ph.D. student at the University of Southampton, researching the transport and emplacement of mud within submarine gravity flows. The research is funded by the National O c e a n o g r a p h y C e n t r e , Southampton and the industry f u n d e d U K - T A P S g r o u p ([email protected]).

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Figure 2. Transects detailing the depositional architecture of turbidite ‘AB5’. Note the deposit style transforming from turbulent to debris flow across subtle changes in seafloor gradient. Adapted from Wynn et al., (2009).

Figure 3. Transect of turbidites entering the MAP. The marginal sea floor gradient effectively ponds mud into the topographic lows. Adapted from Wynn et al., (in press).

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D11816 (5407m) D10698

(5433m)

D11817 (5417m) D10688

(5428m)

0

2

CoreScale (m)

Flow Direction

D10684 (5436m)

A

A1

B

C

D

D1

E

F

G

?

?

PONDED MUD

Gradient ~0.002o

110 Km

Type Source

Silliciclastic

Silliciclastic

Silliciclastic

Volcanoclastic

Sahara Headwall

Moroccan Margin

Canary Islands

Local Seamounts

KEY

NESW

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A major advance in the analysis of sediment cores in recent years has been the advent of non-destructive, high-resolution, XRF sediment core scanners which provide rapidly-acquired, along-core elemental profiles for many elements in the Periodic Table from Al to U, with minimal sample preparation. Under favourable conditions and depending on the acquisition time, detection limits down to a few ppm can be achieved. Such c o r e s c a n n e r s h a v e revolutionised the analysis of sediment cores and are particularly useful in providing high-resolution geochemical proxy data for measuring environmental change. Other a p p l i c a t i o n s i n c l u d e determining bed provenance and correlation, measuring the distribution of contaminants in polluted sediments, diagenetic studies, and the identification a n d c h a r a c t e r i s a t i o n o f palaeosols, volcanic ash and ice-rafted debris.

BOSCORF operates an ITRAX XRF corescanner for community use. The ITRAX corescanner collects element profiles in the range Si-U downcore from split core sections up to 12 cm in diameter and 1.8 m in length. Core sections are first scanned to achieve a constant working distance for the X-ray detector using a laser distance finder to map the topography of the cut core surface. Core sections are then scanned at a step-size that is defined by the user to obtain an ED-XRF spectrum at each step. A digital continuous-

strip X-radiograph, 22 mm wide, can be collected immediately prior to the XRF scan using a charge-couple device (CCD) line camera located below the core. T h e c o u n t t i m e f o r e a c h measurement is a lso user-definable but should not be less than 30 seconds if minor elements are to be well-detected. The X-ray beam used to irradiate the core is generated using a 3 kW Mo X-ray tube (typically run at 65 kV and 45 ma fo r x -radiography and 30 kV and 30 ma for the XRF scan) and focused through a flat capillary wave guide. (Copper and chromium target tubes are also held for applications where users require enhanced excitation for the lower Z elements, although these tubes result in poorer excitation of the medium Z e lements ) . The recorded spectra are deconvolved in live time to construct profiles of peak area integrals for individual elements and Rayleigh and Compton scattering peaks. The element peak areas will reflect element abundances within the sediment.

The BOSCORF XRF core scanner is available for use by the UK scientific community.

Above: ITRAX-generated x-radiograph, 22 mm wide down the centre of a core.

Above: Summer and winter deposition in a Scottish lake core (within former glacial Lake Blane, a proglacial lake formed during the Younger Dryas stadial) - bright reflectors are clays deposited in winter months and dark reflectors are silts deposited during the summer melt season. Red line is the Fe/Ca ratio (Courtesy Alison MacLeod, Royal Holloway, University of London).


ITRAX - high-resolution XRF analysis of sediment cores

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ITRAXConventional

WD-XRFOptical image and high-resolution X-radiography provided

YES NO

Sample preparation and preparation requirement

Non-destructive, flat exposed surface needed, 6-1.5 µm polypropylene film used to inhibit drying during analysis

Semi-destructive (pellets) or destructive (beads), requires 3g or more of sample, involves subsample removal, drying, grinding and pelletization

Practical scanning resolution > 100 µm 5000 µm

Time to acquire major and minor element data from a 1 m long core at 500 µm scanning increments

16 hours 10 working days

Normal detection limits (100 s)9000 ppm Si

60 ppm Ti5 ppm Sr

50 ppm Si10 ppm Ti0.5 ppm Sr

Above: Integrated optical, radiographic and XRF data for a laminated sediment core from the Newport Deep, Severn Estuary, UK. Note the high levels of anthropogenic pollutant elements Zn, Pb and Cu in the upper 275 mm of the core. The green line indicates a valid ITRAX measurement while the red broken lines are user-defined reference lines (Courtesy Dr I.W. Croudace, University of Southampton).

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Quantifying ITRAX data T h e I t r a x c o r e s c a n n e r c a n p r o v i d e information on elements present i n a s a m p l e n o t o n l y qualitatively (as the size of a spectrum peak corresponding to a given element) but also as a q u a n t i t a t i v e e l e m e n t concentration using built-in software. Using a quantitative approach is desirable because it allows, for example, effects such as d i lu t ion o f de tec tab le elements by organic matter to be eliminated and, for studies of pollution, allows the extent of contamination to be determined. Accurate quantification using the Itrax software requires calibration with a sample similar to that being studied but h a v i n g k n o w n e l e m e n t concentrations - something that is not always readily available and as a result the built-in quantification method has not been widely used.

We have recently been evaluating methods of quantifying Itrax data. The approach built in to t he I t r ax so f tware u se s a 'fundamental parameter' model – that is it attempts to model the phys ica l p rocess f rom the generation of x-rays to their interaction with the scanned sample and their detection. In practice, some quantities such as x-ray tube output and detection efficiency are not easy to predict and so they are set by a calibration process with a sample of known composition. For the Itrax, only a single calibration sample can be used so it must contain detectable concentrations of all the elements of interest. The Itrax software has been compared to a similar but more configurable approach provided by XRS-FP, a general purpose Fundamental Parameter m o d e l l i n g a p p l i c a t i o n , b y CrossRoads Scientific. This

software allows the use of multiple standards for calibration. Calibration based on a linear regression and on a log-ratio relationship between peak areas and concentrations has also been assessed. We have shown that a simple linear calibration can be accurate for elements heavier than silicon, while the log-ratio aproach gives accurate and precise results for a wide range of elements, but requires subsamples to be taken from the sample that is s canned . The fundamen ta l p a r a m e t e r a p p r o a c h e s a r e dependent on the correct choice of calibration sample to give good results.

Article by: Stuart Jarvis - an industy-funded Ph.D. student at the U n i v e r s i t y o f S o u t h a m p t o n , researching analytical enhancement and validation of the high-resolution ITRAX micro-XRF core scanner, and supported by Cox Analytical Systems ([email protected]).

Multi-Sensor Core Logging Multi-sensor core logging i s a n e s s e n t i a l t o o l f o r measuring a number of key sediment parameters, including sediment bulk density, porosity and water content. Such data is important for characterising core lithology and quantifying grain-size variation. It can be especially useful for identifying palaeocl imatic cycles and events, and for assessing core quality. BOSCORF operates two GEOTEK Multi-Sensor

Core Loggers for community use: A standard Multi-Sensor Core Logger (MSCL-S) is fitted with P-wave velocity, gamma density (bulk density), magnetic susceptibility and non-contact resistivity sensors, together with a Geoscan III full colour digital linescan imaging system which produces RGB images and profile data from cores. These sensors produce a stream of precise, accurate measurements at a spatial

resolution as low as a few mm, that can be used by scientists and engineers, both intrinsically for their actual values, or as proxies for changes in lithology, texture or sedimentary origin.

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A XYZ Multi-Sensor Core Logger (MSCL-XYZ) fitted with a Bartington magnetic susceptibility point sensor and a Konica Minolta spectrophotometer that allows the user to mount multiple split core sections and log them in a single operation without further user intervention. A natural gamma spectrometer can also be f i t t e d f o r c o r r e l a t i o n a n d radioactive studies. BOSCORF’s MSCL-XYZ provides t ime-efficient logging of two key p a r a m e t e r s ( m a g n e t i c susceptibility and greyscale reflectance) and is the only instrument of its kind at a UK institution.

Above: BOSCORF’s MSCL-XYZ allows automated unattended collection of key parameter data at a logging rate of 1 hour per 1.5 m core section at 0.5 cm resolution.

InstrumentProperty

measuredEXAMPLE APPLICATIONS

Standard configuration MSCL(Geotek MSCL-S)

gamma ray attenuation

• measurement of sediment bulk density• stratigraphic correlation between cores• porosity measurement• measurement of water content


P-wave velocity

• seismic correlation• stratigraphic correlation• construction of synthetic seismograms• core quality assessment• determination of grain-size variations


magnetic susceptibility

• terrigenous material indicator• stratigraphic correlation between cores• turbidite identification and correlation• glacial-interglacial climatic cycle studies


electrical resistivity • grain-size-related lithological information

XYZ MSCL(Geotek MSCL-XYZ)multiple section measurement

magnetic susceptibility • see above


spectrophotometry

• quantification of sediment lightness and sediment colour variability

• identification of palaeoclimatic cycles and events• detection and quantification of small-scale variability


natural gamma• determination of lithological character• radioactive mineral determination and study• stratigraphic correlation

Table: Scientific applications of multi-sensor core logging

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Above: Magnetic susceptibility (light blue) and grey-scale reflectance (purple) profiles through a core from offshore North-West Africa, data acquired using the GEOTEK MSCL-XYZ logger.

BOSCORF’s Multi-Sensor Core Loggers are available for use by the UK scientific community. For more information, please contact Drs Guy Rothwell or Suzanne MacLachlan, BOSCORF, National Oceanography Centre, Empress Dock, Southampton, SO14 3ZH, tel: +44 (0) 2380 596567/596292, email: [email protected]

The TM-1000 tabletop Hitachi SEM has become an invaluable ins trument at BOSCORF. The imaging alone has enabled detailed analysis of s e d i m e n t a r y g r a i n s a n d foraminifera taken from piston and gravity cores. The imagery has enabled high resolution analysis of grains in 3D without the need for carbon or gold plating, with grains mounted on a single semi-conductor pad. Grain identification has also b e e n a i d e d b y t h e E D S capability of the instrument, supported with Swift software for EDS data analysis. This has n o t o n l y e n a b l e d g r a i n identification through use of the EDS spectra, but has paved the w a y f o r q u a n t i t a t i v e geochemical analysis. The previous geochemical analyses have been hindered by software output options only enabling normalised elemental

weight percentages. Currently efforts have been taken to calibrate the geochemical output to provide quantitative results. A first stage in developing a calibration methodology involved taking 15 international standard reference materials as powders, compacting them on semi-conductor pads and performing an a r e a a n a l y s i s a t 1 0 , 0 0 0 x magnification. Calibration curves from these showed robust results for the lighter elements Na, Mg, Al, Si, and Ca, while results for P, K, Ti, Mn, and Fe indicate that work was still required to refine the methodology. Furthermore in r e g a r d s t o P, K a n d M n measurements were often at or below detections limits, where results increase in standard error exponentially below 1 wt%. A methodological advance involves the production of a homogenous sample to analyse. This will involve the generation of glasses

of the reference materials through total fusion.

Figure 1. TAS major element analysis of volcanic glasses from CD166/27 and /25, and summary chemical fields.

Review of the TM-1000 tabletop Hitachi SEM

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As stated above, the ability t o p e r f o r m q u a n t i t a t i v e geochemical analyses reliably can o f f e r m o r e t h a n g r a i n i d e n t i f i c a t i o n . O n e s u c h application was in the analysis of volcanic glass populations from the Icod turbidite, which was generated by the Icod landslide from northern Tenerife (~160,000 ka). The turbidite is composed of seven upwards-fining sequences interbedded with suspension

f a l l o u t m u d s ( s u b u n i t architecture). These have been proposed to signify a multistage retrogressive failure of the landslide. Chemical variations in the volcanic glass populations have shown that each subunit interval contains volcanic glass populations from the same source, but are disparate enough to indicate subtly different volcanic formations involved in each failure. Thus the subunit turbidite

architecture of the Icod event represents multistage failure, which the composition of the volcanic glasses in each subunit has supported. To date, the TM1000 SEM and EDS has also been applied to study volcanic basalts and phonolites from numerous turbidite sequences around the Canary and Madeira archipelagos to study provenance successfully.

Figure 2. Calibration curves for SiO2 and Na2O.

Article by: James Hunt is a Ph.D. student at the University of Southampton, researching ...... The research is funded by the National Oceanography Centre, Southampton ........ ([email protected]).

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Above: El Hierro basalts image from TM1000 SEM. Above: Volcanic glass from Tenerife.




BOSCORF’s core holdings can be searched online to see w h a t c o re s w e h o l d a n d associated metadata. Static summary maps, showing the location of cores held, are available on the BOSCORF website (http://www.boscorf.org/holdings.html). Further, proactive search capability is provided by a BOSCORF-specific link from the BOSCORF home page to the World Data Center for Marine

Geology and Geophysics, at Boulder, Colorado, USA. This allows BOSCORF holdings to be searched through an interactive ArcIMS map interface, or through a form-based webpage using a variety of search criteria (such as Ship, Cruise, Sampling Device, Water depth, Province, Principal Investigator, Storage, Geologic Age, Core length, Core Diameter and free search strings). Access to actual core samples and analytical data may be subject to agreement

from the PI who collected the core, within 3 years of core collection. But access will be granted to researchers, on receipt of satisfactory science cases, to cores collected over 3 years ago, and sooner with agreement of the PI. BOSCORF’s core holdings m a y b e s e a r c h e d a t www.boscorf.org, from where Sample Request forms can also be downloaded.

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How to find out what cores we

CoreWall - Core data visualisation C o r e W a l l i s a n innovative software solution for visualising and integrating large and diverse core datasets. The analysis of sediment cores involves use of a wide range of tools, involving non-destructive loggers of various types (e.g. XRF scanners, GEOTEK multi-sensor core loggers), photography, grain size analysis, x-radiography and o the r t echn iques . These investigations result in a variety of data types, which CoreWall can integrate and display as a scrollable scalable high resolution image of the core surface with analytical data from different techniques and instruments plotted downcore, together with nested images (e.g. from smear slides and x-radiographs).

Above: BOSCORF uses a multi-monitor set-up to maximise display involving six 23” flat screen monitors driven by a single high performance computer. This facilitates rapid integrated data display, which is ideal for research, training and project workshops and demonstrations.

CoreWall Workshop held in Minneapolis A CoreWall workshop was h e l d a t t h e U n i v e r s i t y o f Minnesota on 16-18 August 2010. The purpose of the workshop was to bring together some experienced

as well as novice users (~20) to gather information on the uses of the CoreWall and ANDRILL applications, provide tutorials on their deployment, and collectively

devise new features and tools. The meeting was regarded as a success by all, and it is anticipated greatly aid the development of the CoreWall applications.

http://www.boscorf.org/holdings.html







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Cruise RegionPrincipal Investigator

No of cores Total metres

James Clark Ross Cruise 157

Antarctic Prof. J. Dowdeswell SPRI, Cambridge

17 44.53 + 7 push cores and 16 bagged samples

James Cook Cruise 34

NE Atlantic Dr. R. Wynn NOC, Southampton

8 61.31

James Cook Cruise 36

NE Atlantic Prof. D. Masson NOC, Southampton

20 117.13 + 12 push and 10 mega cores

- South China Sea Prof. P. Cliff Univ. of Aberdeen

1 2.2

TOTAL 46 225.17

Above: Location of sediment cores held at BOSCORF. Over 1440 sediment cores are held in cold storage (April 2010) and the collection is growing by 100-200 cores per year. Many of the cores are considered internationally important and attract researchers from all over the world. As well as marine cores the collection also holds lake cores and cores collected for archaeological environmental records.

Table: New cores entering BOSCORF from 1 April 2009 - 31 March 2010

For further information on any of the articles within the newsletter, please contact us at:

British Ocean Sediment Core Research FacilityNational Oceanography CentreEuropean WaySouthampton, SO14 3ZHTel: +44 (0) 2380 596292Fax: +44 (0) 2380 596554Email: [email protected]



Documents

BOSCORF NEWSLETTER ISSUE N°1BOSCORF NEWSLETTER ISSUE N°1 AUTUMN … · 2014-11-20 · BOSCORF NEWSLETTER ISSUE N°1 AUTUMN 2010 The ITRAX corescanner now exists in some twenty leading