The origin of the Kinnekulle tephra, a huge volcanic ash layer spread across Norway, Sweden, the Baltic region, Belarus and Poland, has long been a mystery but new evidence may have uncovered the source of the ash for the first time.

Scientists at the 51���� (BGS) and the University of Oslo have studied tiny crystals, smaller than the diameter of a human hair, extracted from boreholes 65 km apart in Lincolnshire and Norfolk. The analysis uncovered evidence of a 454 million year old supervolcano, now concealed beneath The Wash on the east coast of England.

Volcanic rocks of comparable age comprise the rugged topography of Eryri (Snowdonia) and the Lake District. A belt of arc volcanism extended from the Lake District towards Belgium in late Ordovician times, when England was separated from Scandinavia by an oceanic basin. The geography was probably comparable to the West Pacific region (Korea–Japan–Indonesia) today.

Using cutting-edge analytical techniques at BGS laboratories, scientists have been able to examine zircon crystals, which form within molten magma before a volcano erupts. Over time, uranium within the zircon slowly decays into lead isotopes, analysis of which enables the age of eruption to be precisely determined. The research reveals that the zircon crystals at both sites were formed at approximately the same time, about 454.4 million years ago. Researchers at the University of Oslo had previously obtained an almost identical age for the Kinnekulle tephra in the Oslo region.

The scientists believe that the near‑identical ages suggest that ash from the eruption plume in what is now eastern England was blown across the Tornquist Sea, which separated England and Scandinavia, and settled on the sea floor of ancient Scandinavia. Further support for this hypothesis is provided by chemical analysis of apatite crystals in both the proposed source and the tephra. During the highly explosive ‘super-Plinian’-type eruption, hundreds of cubic kilometres of rock were launched into the stratosphere by the force of the blast. One of the samples also contained younger zircon grains, dated to 453.70 million years, reflecting a further eruption associated with the collapse of the volcanic caldera.

More than 454��million years ago, a supervolcano now hidden beneath some of England flattest landscapes, produced some of the biggest eruptions in recorded Earth history. We believe that, thanks to cutting edge-analysis, we have been able to provide evidence that the source of the ash layer in Scandinavia originated from this supervolcano, reshaping our understanding of England deep geological past.

Tim Pharaoh, BGS, principal author of the paper.

The research paper, ‘, is now available to read.

The analytical work for the the supervolcano project was funded by The  is an integrated analytical platform funded by the , part of UK Research and Innovation ().

In chemistry student Dorontina Domi first couple of months of her placement at BGS, she has rotated between different laboratories including organics, collagen extraction and modern environmental gas analysis. This has provided her with a broad experience of the different instruments and sample preparation techniques that are required within BGS Stable Isotope Facility (SIF). In this blog, Dorontina tells us about some of her experiences so far. 

Carbon and nitrogen isotopes in organic materials

A wide array of instruments in the SIF can be used to analyse the carbon (C) and nitrogen (N) isotope composition of organic materials found in sediments, soils and plant materials. The bulk of the analysis is carried out using an Elementar isoprime precisION isotope ratio mass spectrometer (IRMS) with a vario ISOTOPE cube elemental analyser (EA). The samples are combusted in the EA and are then passed onto the IRMS on a continuous flow of helium carrier gas, selected for its inertness and separation efficiency for measurement.

While learning sample preparation, I gained experience in using microbalances to weigh samples down to 200 micrograms (or 0.0002 grams), which is a miniscule amount that is challenging to see with the naked eye. I compacted the weighed sample material into either crucibles or capsules, depending on the instrument and their auto sampling methods.

When analysing these sample materials for C isotopes, it is important to understand whether the results are representing organic or inorganic C fractions contained in the material. Organic carbon consists of compounds sourced from living organisms and their remains, and inorganic carbon, such as from carbonates, is formed from biological and geological processes. The two forms of C have very distinct isotope compositions (inorganic C typically has more carbon-13 compared organic C) and even a small amount of inorganic C contamination in samples can offset target organic C isotope values.

Samples must therefore be treated to remove inorganic C prior to isotope analysis. I acidified samples using hydrochloric acid (HCl) and rinsed them with purified water, using a centrifuge to ensure thorough washing, until the pH tested neutral. This process dissolves the inorganic C fraction and isolates the organic C fraction.

SIF houses 13 mass spectrometers, so I have also gained experience in how staff conduct maintenance, such as on the Elementar IRMS. I assisted in replacing the consumables to ensure that the analyses are performed with a high precision and accuracy.

Carbon, nitrogen and sulfur isotopes in prehistoric bone samples

Comparing carbon, nitrogen and sulfur isotope ratios from carnivores and their prey allows us to distinguish the palaeo-diet of animals and the of different species. This allows us to interpret their relationships during different ages and draw inferences from the data on changes associated with climate differences. For example, the higher the nitrogen isotope composition (δ¹⁵N) the more ‘carnivore-like’ feeding habits took place, therefore the main prey for each species can be identified.

Statistical tools called Bayesian mixing models will be used as a framework to integrate the large proportion of data from throughout modern and Pleistocene times and to infer the relevant data. Through this, the project will assess how changes in climate and environment influenced the feeding behaviour of the wolves and their resilience during reductions in prey availability. This information is crucial to understand the influence climate change will have on the endangered species in the future and help conservation strategies.

As part of the sampling programme, I was given an opportunity to spend a day at the laboratories in London, where I observed the meticulous drilling process used to cut small pieces of material from a variety of different fossil species for later analysis. The samples were cut from areas that will minimise damage of the structural integrity of the bone for conservation purposes.

As well as fossil samples, the project is also analysing contemporary wolves from Croatia and their prey as a comparison. These samples are less than 100 years old and required an initial solvent treatment in the geomicrobiology lab before collagen extraction could begin.

I have also helped to prepare the samples for isotope analysis, where a multi-step process takes place to extract the collagen, before it is purified and analysed via the EA-IRMS.

Carbon isotopes in methane samples

Another aspect of my training covers��analysing methane (CH₄) gas samples for their carbon isotope composition using a Sercon HS2022 with CyroGas.

This instrument works by purifying the sample gas via carbon dioxide (CO₂) traps and a cryogenic gas trap to remove any other sources of carbon present that are not from CH₄, thus reducing potential sources of contamination. The sample gas then flows through a combustion tube, where the CH₄ is converted to CO₂ and cryogenic trapping takes place, ensuring that the CO₂ is concentrated in the final trap and can be released to the mass spectrometer rapidly. This allows for a narrow, sharp peak that can be analysed and replicated with a high precision. I also hope to help with the analysis of hydrogen (H) isotopes via the pyrolysis of CH₄ to H₂.

Working at BGS as a student

If you are an undergraduate student looking for an opportunity within stable isotopes, I highly recommend BGS. Not only is it the largest UK producer of stable isotope data, but it is also a supportive workplace to be a part of. There are a variety of clubs to involve yourself in such as the BGS Wilding Group. Staff and volunteers maintain the natural areas at BGS to promote wildlife biodiversity, as a commitment to sustainability.

I would like to extend a massive thank you to everyone at the Stable Isotope Facility for welcoming me with such support and excitement. It has been an incredible start to the placement and I am looking forward to the rest of the year!

About the author 

Dorontina Domi is an undergraduate chemistry student at the University of Surrey, completing her industrial placement at SIF, which is located at BGS headquarters in Keyworth, Nottinghamshire. 

Soil reference materials (RMs) are critical to ensuring the accuracy and consistency of analytical results across laboratories and research institutions. BGS has produced ten new soil RMs, which have been developed by its inorganic geochemistry team to offer a cost-effective alternative to traditional certified reference materials (CRMs), while maintaining confidence in analytical data. The RMs have been released at a lower price point to help improve access to high-quality materials for researchers and laboratories with limited budgets, enabling them to enhance measurement controls and increase confidence in analytical results across a variety of sectors worldwide. 

Developed from a broad selection of parent materials and incorporating a diverse range of textures and organic carbon contents, reference soils BGS110 to BGS119 have each been characterised by a select group of international laboratories using a variety of analytical techniques. The RMs are also accompanied by data sheets that include for 64 major, minor and trace elements, including rarely measured bromine and iodine. More information about the ten new RMs can also be found in the new report, .

Reference materials are the backbone of geochemical analysis, providing confidence in the measurements that a laboratory produces. Our RMs offer reliable benchmarks for analysing samples with similar matrices. Due to their diverse concentrations of economically and environmentally significant elements, these RMs will enable laboratories, PhD��researchers and industry professionals to calibrate instruments, validate analytical methods and ensure data comparability across studies.

Dr Michael Watts, head of BGS Inorganic Geochemistry.

51���� now has 18 soil RMs (including one for use in and seven for the analysis of ) and five mineral RMs available for purchase through its website.

The inorganic geochemistry team also remains actively engaged in global initiatives to harmonise soil analytical data across laboratories. These efforts support enhanced health outcomes and food security worldwide. BGS produces custom proficiency testing (PT) materials for international PT schemes coordinated by the Food and Agriculture Organization of the United Nations’ (GLOSOLAN). As part of its collaboration with the FAO-UN and other organisations, BGS has delivered laboratory training around the world, including guidance on producing RMs and PT samples. A free, publicly available is accessible via the GLOSOLAN website.

In addition, BGS prepares geological PT samples and CRMs for a number of commercial distributors, supporting both UK and international PT schemes.

To place an order or for more information on our bespoke RM and PT preparation services, please contact the inorganic geochemistry team (inorganicgeochemistry@bgs.ac.uk). (Gamma irradiated soil RMs are available on request for shipping internationally.)

The Stable Isotope Facility (SIF) at BGS has just welcomed a new arrival to its mass spectrometer contingent: Elementar isoprime preciSION with iso DUAL and iso MULTI PREP instrument. It is designed to analyse carbon and oxygen isotopes from carbonates as well as oxygen isotopes in waters for scientific research.

The instrument

We have nicknamed our new instrument ‘Gemini’ to reflect both its nature as a and its dual purpose to analyse both small carbonates and water isotopes. Since being installed in April 2025, it has already analysed over a thousand samples and is able to run a range of in-house and international standards with better than 0.1 per mil reproducibility down to a sample size of 20 μg (potentially even less than 5 µg! It is very difficult to see materials at this weight). Gemini has already successfully analysed a range of sample materials including tooth enamel, foraminifera, brachiopods and clam shells for various research questions.

Testing the Gemini

As part of the initial setup, we ran a series of tests to ensure the Gemini was running well. This included a size test that looks at what the values are for one standard if we weigh it out across a range of sizes. For this test, we used an in-house standard Keyworth Carrara marble (KCM), which is a calcite. Carrara marble has been used for building since ancient Roman times because of its beauty and it present in many notable structures, including Marble Arch in London, Peace Monument in Washington DC, the Pantheon in Rome and grave headstones across the world — we are currently using an offcut from a stone mason. Our batch is a valuable standard for oxygen and carbon carbonate analysis not just in SIF but also in many laboratories across the UK.

Figure 3 shows the data produced during the size test. The reproducibility was better than 0.1 per mil for both δ¹³C and δ¹⁸O across a range of sample sizes, which is excellent news and conforms with the precision required for internationally reporting of stable isotope data.

Research focuses

We use carbon and oxygen isotopes in carbonates (CaCO₃) to understand more about our environment both today and in the past. Recent published work on carbonates that the stable isotope team have been involved with include:

• using brachiopod isotope composition  to reconstruct environmental variation in the (past) oceans ()
• identifying changes in rainfall over thousands of years using cave stalagmites in Iraq ()
• describing changes in oxygen levels in ancient oceans ()

If you are interested in reading about other research done by the Stable Isotope Facility, please visit our for our publications.

If you are a potential user of Gemini, please contact the Stable Isotope Facility. UK-based researchers can apply for access through the (NEIF), which is a NERC Service and Facility and free at the point of access for successful UK applications. The next deadline for NEIF applications is 8 October 2025. Before submitting your application, it is important that you first seek the advice of staff at the facility. Further information can be found on .

Carbon and oxygen isotopes in carbonate are a useful tool that can tell us about our environment. For example, oxygen isotopes in tooth enamel are useful in archaeology when researchers want to find out where individuals they are working on are from, or to track animal movement and husbandry. We can also use this technique to analyse modern-day shells of molluscs such as whelks or scallops, to see how they are adapting to rising sea-water temperatures as a result of climate change. ��

Stable isotope analysis at BGS

The Stable Isotope Facility at BGS can analyse a range of carbonate types, including tooth enamel, speleothems, calcite minerals and a wide range of shells, for carbon and oxygen isotopes. We currently have several instruments that can analyse carbonate materials including very small samples down to 5 micrograms — which would fit on the head of a pin!  

During analysis, laboratory staff need to check whether the sample data produced is accurate. We do this by analysing standard materials that have a predetermined value in every sample batch. Both the samples and standards are analysed using the same method, so if the standard data is accurate and precise, the sample data should be correct. Standards are also used to correct data if there is a measurement offset from the known value. We use multiple standards to cover the range of our sample isotopic values.   

Why do we need in-house standards? ​  

We are developing new in-house (internal) standards to use in our laboratory for three reasons. Firstly, we analyse thousands of samples each year, which means we need a lot of standard material. International standards provided by external bodies can be expensive and can run out, so creating our own standards internally helps decrease costs and makes sure there always enough standard material available.  

Secondly, because we analyse some unusual carbonates, it is best to have a standard that matches the sample material we are measuring. Finally, there are very few oxygen isotope standards currently available for carbonates, especially carbonate in tooth enamel. This is because carbonates in powder form exchange oxygen with the atmosphere, causing carbonate isotope values to change over time, meaning materials used for standards do not last long.   

What are we testing?

We are currently working on developing three new internal carbonate standards that we can use as a reference material for our work.

The first is Bahamian oolite aragonite, which we call BOA for short, which comes from a beach composed of oolitic sand in the Bahamas. BOA is composed of round and tiny, egg-shaped ‘ooids’, which form in warm shallow seas and are then deposited on the beach.

The second is made up of fragments of whelk shells, (sometimes known as sea snails). The shells we have are waste from the fishing industry, where the whelk is removed and sold as food and the shells are repurposed for decorative use and in gardening.

The third and final material is from a high-temperature skarn (HiTS) rock that has come from western Romania. This rock formed when magma heated limestone bedrock from below, producing a skarn punctuated with calcite veins, which we extracted. ​This material is probably the most valuable to us as it has a very low oxygen isotope composition, making it useful as a reference material for archaeological tooth enamel samples, as they tend to have low values. 

Creating the internal standard

To use these new materials as an internal standard, we need to ensure that they meet certain requirements:  

• they have homogenous​ carbon and oxygen isotope values   

• there is an isotopic and chemical match to routine samples​  

• they are affordable, available, accessible and abundant  

• they are chemically and isotopically stable over time  

To make sure we meet these requirements, we have been working with other teams within BGS to help characterise our materials. So far, we have analysed them using our scanning electron microscope and X-ray diffraction, which tell us about what elements  make up these materials to check for impurities.  

We are currently analysing our three new standards at the Stable Isotope Facility over an extended period of time, to ensure that they produce consistent isotope values. So far, we have values with an error of less than 0.2 per mil, which is great news for the possibility of the Stable Isotope Facility laboratories and others in the organisation using these materials as an internal standard in future carbonate research. We hope to make these new standard materials available to other stable isotope facilities soon!

Contact

Please get in touch with either of the authors if you are interested in participating in an interlaboratory comparison, to enable us to certify the values of these new standard materials. 

About the authors

The 51���� Inorganic Geochemistry Facility (IGF) provides high-quality analytical expertise and specialist services for the production and interpretation of inorganic geochemistry data for commercial, academic and public sector clients worldwide. This year marks the facility 25th ������/������ 17025 accreditation, a gold standard that fosters trust in the quality of the facility work.  

What is ISO/IEC accreditation? 

This accreditation is the formal recognition by the UK Accreditation Service (UKAS) that an organisation meets the specific requirements of a standard; in our case, . Our accreditation ensures that all staff operate according to internationally recognised standards, underpinning our credibility, impartiality and confidentiality, whilst instilling confidence in our customers that the services provided by BGS conform to the highest quality. 

Fundamentally, it is the core quality system framework and its management that is accredited, ensuring that all analytical techniques are performed under the same quality assurance requirements. The technical scope of accreditation has evolved over the years, adapting to changes in demand and availability, and currently includes the determination of cation, anion and aqueous parameter concentrations in natural and experimental water samples. 

Maintaining accreditation for 25 years highlights the commitment and consistency of high-quality outputs of the IGF and its staff.  

How it all started 

In August 1999, the then BGS Analytical Geochemistry Laboratory was awarded ������/������ 17025 accreditation by UKAS, making the laboratory one of the very few organisations within the UK research community to hold UKAS accreditation at that time. The initial drive to acquire accredited status came from working on samples provided by the Nuclear Industry Radioactive Waste Executive (NIREX), as robust quality assurance was essential for the project. This requirement essentially established the working practices from which the laboratory was able to derive its management system. The work for NIREX heightened the laboratory staff’s appreciation of the benefits of having a comprehensive management system, so it was simply a case of taking small steps to gain formal recognition against ISO/IEC 17025.  

As BGS provides global public-good science and work for commissioning bodies and legislators, it is of paramount importance that we can provide credible, impartial data. The accreditation status of the IGF has proved instrumental in receiving long-term, large-scale projects and will continue to do so where credibility and confidence in results are of the utmost importance. 

What does it mean for BGS? 

The IGF conducts internal audits on all activities as well as having independent experts from UKAS carry out an external audit on an annual basis. Overall, the culture in an ISO/IEC 17025-accredited facility is one of professionalism, accountability and a commitment to excellence, creating an environment that supports high-quality data outcomes used by academics and industry.  

51���� has always been highly regarded in the geoscience community and we often set the standard on how to conduct research. Accreditation to an international standard provides formal recognition to wider industry and the UKAS accreditation is a key part of the IGF identity, instilling a culture that emphasises quality, reliability and continuous improvement. This strong focus on quality at all stages is one of our key strengths and all members of the team understand and adhere to protocols to ensure compliance and the production of high-quality outputs. The culture of continuous improvement encourages feedback and ensures processes are regularly reviewed and updated. 

The accredited status of the IGF has significantly contributed to overseas science partnerships, facilitated BGS-hosted training of laboratory technicians and enhanced capacity-strengthening projects across the globe including Afghanistan, Kenya, Kyrgyzstan, Nigeria, Liberia, Malawi, Saudi Arabia, Tajikistan, Zambia and Zimbabwe.  

Due to our accreditation status, the IGF is a highly sought-after industry placement for undergraduate chemistry students who want to specialise in environmental chemistry. The 12-month industry placement we offer to students from the UK, New Zealand/Aotearoa and Australia equips them with the skills they need to excel in both academic and commercial workplaces, with many of the students going on to work in other accredited laboratories and highly regulated industries. Read more about the success of previous students.  

How will it continue to be relevant in the future? 

The IGF accreditation against ������/������ 17025 demonstrates our ongoing commitment to quality assurance, the reliability of results and regulatory compliance, which is crucial for environmental monitoring. The IGF remains adaptable to ensure we can meet future requirements and regulations, and maintains a level of preparedness for future, national-scale programmes. 

About the author

On a global scale, laboratories are responsible for around two per cent of global plastic waste (Urbina et al., 2015) and use three to ten times more energy than a typical office. The Laboratory Efficiency Assessment Framework (LEAF) is an initiative developed by University College London (UCL) and is a standard awarded to laboratories that can successfully demonstrate practical steps towards improved efficiency and sustainability.

51���� is committed to reducing its impact on the environment and this involves participation across the whole organisation. We identified LEAF as a driving tool to be able to do this within our laboratories; making them more sustainable is a commitment within the overarching 51���� Environmental Sustainability Strategy, which identified the labs as an energy-intensive area. It has allowed us to drive behavioural change and provide awareness to continue to reduce our environmental impacts.

Leah Crosby, BGS Environmental and Sustainability Advisor.

The LEAF accreditation

— bronze, silver and gold — all of which contain actions that laboratory users can take to improve sustainability, such as reducing waste and energy use, recycling more and improving laboratory practices so laboratories can operate in an increasingly sustainable way.

LEAF at BGS

Bronze accreditation, which BGS achieved in 2021, involves raising awareness of the actions people can take, for example switching off laboratory equipment when it is not in use. The silver award, which BGS received in 2022, is awarded for advancing procedures and policies and following best practice in laboratory sustainability. The new gold award, which BGS is the first in 51���� to receive, has been given following implementation of the LEAF principles across thirteen laboratory groups from our Keyworth and Wallingford sites.

The gold accreditation included embedding sustainability in all aspects of our laboratories and expanding the LEAF principles across the office spaces shared by the labs. Gold LEAF accreditation has enabled us to promote a wider sustainability culture in BGS and a vehicle to share good practise across our laboratories and with our stakeholders.

Angela Lamb, BGS Stable Isotope Research Scientist.

Following the framework principles ensures that these practices, such as structural changes in our data storage and laboratory management systems, will continue to be effective in the long term.

Instead of throwing away single-use nitrile gloves — one lab group alone used over 15��000 in one year — we now recycle them. We also employ ‘greener’ practices around solvent use, such as accelerated solvent extraction in the organic geochemistry lab to reduce the amount of solvents we use.

Nicola Atkinson, BGS Isotope Support Scientist.

Acknowledgement

Laboratory staff collaborated and worked with other areas in BGS, including the estates and facilities team, BGS Informatics and the workshops, to achieve the gold accreditation and embed sustainability in all ways of working within our labs.

More information

About the author

51���� has attained silver LEAF status for sustainable laboratory practices.

Laboratories are integral to the work undertaken at BGS, from core scanning to mass spectrometry work. The LEAF (Laboratory Efficiency Assessment Framework) accreditation is an independent standard that is awarded to laboratories that can successfully demonstrate practical steps towards improved efficiency and sustainability.

51����’s laboratories received the second-highest level of certification for following best practice in laboratory sustainability, including waste management, increased energy efficiency and recycling.

As some of our labs include large specialist infrastructure, there are limitations on what can practically be made more sustainable, but we are committed to doing as much as we can to invest in green energy solutions.

This includes researching and implementing the sustainable use of accessories such as IT equipment, consumables, waste streams and reducing the energy requirements for laboratory heating and cooling.

Leah Crosby, BGS Energy and Environmental Advisor

It is estimated that, on a global scale, laboratories are responsible for around two per cent of global plastic waste and use three to ten times more energy than a typical office, according to University College London, which developed the LEAF initiative.

To achieve the award, 16 laboratories across BGS were audited, including engineering geology and thin sections as well as traditional wet chemistry laboratories, which were required to meet a set of criteria.

Attaining LEAF accreditation is an important factor in our organisation transition towards net zero and part of the 51���� Environmental Sustainability Strategy.

We have increased our use of supplier recycling schemes such as zero waste boxes for disposable gloves, disposable lab coats and soft plastics.

We are also looking to reduce the number of plastics coming into BGS, rather than just recycling these products.

Nicola Atkinson, BGS Isotope Support Scientist.

The initiative was led by Leah Crosby, BGS’s energy and environmental advisor, and Angela Lamb and Nicola Atkinson, both of whom work within the BGS laboratories.

51���� is now on course to apply for the gold LEAF accreditation, in line with its environmental sustainability targets.

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