Friday, 8 June 2018

From lab to Lake Victoria, Kenya: a student learning experience...by Kelsey Ferris

Kelsey standing on floating Tilapia cages on Lake Victoria, Kenya.
My name is Kelsey Ferris, a Biotechnology student from the University of Waikato, New Zealand. I am half way through my one-year placement with the British Geological Survey, working in the Inorganic Geochemistry Laboratories in Keyworth, Nottingham.

I have been supporting Dr Andy Marriott in his project - Aquaculture: Pathway to food security in Kenya, looking at the link between anthropogenic pollution in Lake Victoria and the geochemical content in caged and wild fish, sediments and lake water. We are investigating the impact this has on health and nutritional quality of aquaculture farmed fish, and the potential of aquaculture to strengthen food security and sustainability for the region. My main role as an analyst in this project is to test the total mercury content of sediments and wild and caged fish tissue, and the water quality parameters taken from key locations in the Winam Gulf of Lake Victoria.

Andy and I partnered with Dr Tracey Coffey from the School of Veterinary Science (University of Nottingham), Professor Odipo Osano from the School of Environmental Sciences (University of Eldoret) and key stakeholders in Kenya’s aquaculture industry, including an excellent research team from the Kenyan Marine Fisheries Research Institution (KMFRI) led by Dr Chris Aura and local aquaculture cage owners.

I was lucky enough to be a part of the fieldwork aspect of the project, and have recently returned from a 10 day trip to Kenya for sampling. We spent 3 days and nights on the largest tropical lake in the world, surrounded by locals in their traditional canoes and floating plant islands which are home to monitor lizards, birds and even hippos. Whilst on board the KMFRI research vessel R.V. Uvumbuzi, we conducted transects of Lake Victoria to be sampled for waters, sediments, and wild and caged Tilapia.

Visual examination of the waters highlighted possible causes of  pollution into the lake indicated by their colouration, which ranged from a vivid green (algal blooms) close to the city of Kisumu and also Siaya County (where intensive cage culture was observed), brown water rich in particulates throughout Winam Gulf, and clear water as we entered the main Lake Victoria basin. This trend was consistent with the strong H2S aroma from sediment samples, an early indication of possible eutrophic conditions due to human interactions. One of my tasks was collecting and filtering water for elemental analysis by ICP-MS and anions by Ion Chromatography in the Inorganic Geochemistry labs, so it was a relief to enter the clear waters so that my thumb could have a rest from the filtering.



From L-R: The RV Uvumbuzi crew, KMFRI researchers with Kelsey preparing to collect water and fish samples;
Assisting in the subsampling of caged Tilapia fish tissue.
As a placement student I have travelled all the way from the University of Waikato to work at The British Geological Survey, and have now had the chance to do fieldwork on Lake Victoria and at the University of Eldoret. The student programme that BGS offers is extremely beneficial because of the combination of routine analytical testing and hands-on fieldwork, which contributes to important real-world research projects. My placement has been very valuable to my studies, allowing me to apply my theoretical knowledge into a practical work environment, and strengthen my initiative and drive to contribute to the scientific community. From wearing a lab coat to a life jacket, you never know where a science degree may take you!



Wednesday, 6 June 2018

Continental Drilling and a visit to China...by Melanie Leng


The ICDP Executive Committee and Assembly of Governors in Guilin, China
In early summer each year the International Continental scientific Drilling Program (ICDP) committee meets to assess applications for drilling deep holes in the Earth. This year the meeting was held in Guilin, China. Here Melanie Leng explains a bit about ICDP, the UK’s geoscience ICDP community, and her trip to China as the UK’s representative on the ICDP Executive Committee…

The UK is a member of the ICDP and this enables consortiums of geoscientists from the UK (in collaboration with other member countries) to apply for funding to drill deep holes into the Earth through many kilometres of sediments and rocks in order to get cores of pristine material for scientific study. There are many reasons we want to take long cores through the Earth and like many applications we assessed in China, they often involve assessing natural hazards including volcanos and earthquakes, natural resources and understanding palaeoclimate. Both workshop proposals and full drilling proposals were assessed at the meeting in China and the outcomes will be published on the ICDP website in the coming weeks. The UK has a past history of successfully obtaining ICDP funding.

As part of the meeting (and a rest day after 3 days around a conference table) the ICDP committee also visited the Lijiang River (the Guilin state “AAAAA tourist attraction” and one of the most famous tourist regions in China). The Lijiang river travels hundreds of kilometres passing through a karst region around Guilin where the “jade ribbon winds through thousands of grotesque peaks”. The reported 2,600m of Devonian and Carboniferous limestones, that form the karst terrain within the Guilin Basin, gives the area its dramatic landscape which formed over the past 10-20 million years. The limestone towers have near vertical sides ranging from tens to hundreds of meters in height. The towers have evolved by slow and continuous tectonic uplift of the karst along with slow rates of erosion.
The spectacular karst and towers scenery along the Lijiang River, Guilin

Our visit along the Lijiang River by boat was quite spectacular. The tourist cruiser (twisting and turning along the river amongst the beautiful scenery) was very peaceful despite the hundreds of boats and tourists (this is one of China’s top tourist destinations)! It rained for most of the time we were on the river although that did not detract from the wondrous landscape.

Many thanks to our gracious Chinese hosts lead by Dr He Qingcheng of the Chinese Academy of Geological Sciences for hosting the ICDP committees this year...

Back to ICDP, the UK has key personnel within the program. Lizzie Garratt (NERC) currently sits on the assembly of Governors, I sit on the Executive Committee and Dr Kathryn Goodenough (BGS) is the Chair of the Science Advisory Group. Please feel free to contact us about ICDP activities. The next deadline for ICDP drilling and workshop proposals is January 2019. You can also keep up to date with ICDP-UK through our website.

For more information, please contact Melanie Leng

Friday, 1 June 2018

Unseen video footage: The Holbeck Hall landslide 25 years on... by Catherine Pennington

This weekend, it will be 25 years since the Holbeck Hall landslide and, while searching through our archives, we found some unseen video footage taken at the time from an aeroplane (drones hadn't been invented yet).  There is no sound and the images are a little hazy due to the weather, but you can get a good idea of the scale of this landslide and some of the damage it caused.


The Holbeck Hall landslide in brief

On the night of 3rd June 1993, a rotational landslide began in cliffs near Scarborough, Yorkshire, that destroyed part of the four star Holbeck Hall Hotel two days later.  Fortunately, the hotel was evacuated before anyone was hurt, despite the alleged reluctance of the guests to leave, even when there was "a gaping chasm 10 m from the hotel"[1].

It involved an estimated 1 million tonnes of glacial till that flowed across the beach forming a promontory 200 m wide, projecting 135 m from the foot of the cliff.  This famous landslide attracted the attention of the national and international press and has been used to demonstrate landslide processes and slope remediation to schools and university groups ever since.

More about the Holbeck Hall landslide

The Scarborough Coastline

The coast is a dynamic, ever-changing environment and landslides of this size will have been evolving these cliffs over the last five thousand years or so, when sea level roughly reached its present position.  In fact, numerous landslides have been recorded along this section of coast over the last few hundred years.  One such landslide (described as an earthquake at the time) took place in December 1737 where an acre of pasture with five cows grazing on it subsided.  The cows, apparently unperturbed, were rescued unharmed two days later[1].  You can find out more about landslides along this section of coast, and elsewhere in Great Britain, in our National Landslide Database.

During the development of Scarborough as a seaside resort, the Victorians regraded and landscaped large sections of cliff (including the landslides) to make public areas with gardens and promenades.  They also built large hotels and private dwellings in many cliff top areas.  Managing this legacy has been the job of Scarborough Borough Council who, along with the North East Coastal Observatory, monitor the cliffs and landslides.  They have been assessing and maintaining this coast for decades and much of their work is freely available on their websites, including a great source of data and reports.

Photograph Archive

Here are some more photos from the BGS archive...

The Holbeck Hall landslide 1993.  P707132. BGS Copyright NERC.
The Holbeck Hall landslide 1993.  P707132. BGS Copyright NERC.

The Holbeck Hall landslide.  P707131. BGS Copyright NERC
The Holbeck Hall landslide.  P707131. BGS Copyright NERC.

Holbeck Hall landslide.  Wreckage of the Hotel, Scarborough. P509016. BGS Copyright NERC.

Holbeck Hall Hotel landslide, Scarborough - Damage to hotel and gardens. Extensional features and rotated blocks. P509023. BGS Copyright NERC.
Holbeck Hall Hotel landslide, Scarborough - Damage to hotel and gardens. Extensional features and rotated blocks. P509023. BGS Copyright NERC.
Holbeck Hall Hotel landslide - damage to the hotel. BGS copyright NERC.
Holbeck Hall Hotel landslide - damage to the hotel. P509025. BGS copyright NERC.

Holbeck Hall Hotel landslide - damage to the hotel. BGS copyright NERC.
Holbeck Hall Hotel landslide - damage to the hotel. P509027. BGS copyright NERC.

Holbeck Hall Hotel landslide - damage to the hotel. BGS copyright NERC.
Holbeck Hall Hotel landslide - damage to the hotel. P509028. BGS copyright NERC.

The damaged Holbeck Hall Hotel after the landslide. P509209.  BGS copyright NERC.
The damaged Holbeck Hall Hotel after the landslide. P509209.  BGS copyright NERC.

The damaged Holbeck Hall Hotel and landslide. P509030.  BGS copyright NERC
The damaged Holbeck Hall Hotel and landslide. P509030.  BGS copyright NERC.
The damaged Holbeck Hall Hotel and landslide 1993.  P509049.  BGS copyright NERC.
The damaged Holbeck Hall Hotel and landslide 1993.  P509049.  BGS copyright NERC.


More photos and information

The full Holbeck Hall photograph archive

For more information, contact landslides@bgs.ac.uk


[1] Clements, M. (1994). "The Scarborough experience - Holbeck landslide, 3/4 June 1993." Proceedings of the Institution of Civil Engineers, Municipal Engineer 103(June): 63-70.

Thursday, 31 May 2018

Tracking the life signature of Britain: The Biosphere Isotope Domains GB dataset and web portal

Strontium isotope biosphere domains of Britain
We have released a new website that enables users to input their own data and compare it with the reference data from three isotope systems (Sr, O and S) that characterize the contemporary British biosphere, in order to assess the likely geographic origins of their sample. 

The data has been derived from the analysis of modern plants and waters and some ancient skeletal material. The method has its roots in archaeological studies of human migration and is used extensively at the NERC Isotope Geosciences Laboratories (NIGL) to, for example, establish the likely place of origin of our ancestors.  However, it is likely to be applicable to other research areas, such as forensic and food traceability studies or environmental baseline and pollution monitoring studies. 

The maps have been constructed from 1km hexagons that contain the data for the different domains and is based on the 1:50K geological and Parent Material maps.  

The best way to appreciate this is to open the website and have a go; maybe try these examples? 
  • Where in Britain might these beans have been grown: 87Sr/86Sr = 0.7087?
  • Which of these people spent their childhood nearest the coast:  Individual A: δ34S (VCDT) = 17 or Individual B: δ34S (VCDT) = 5.2?
  • Is this sheep, bought in a farmers market in Kent, really as local as the seller suggests:  87Sr/86Sr = 0.717?
  • Did this Viking Age individual, excavated in Dorset, originate in the UK: δ18O human enamel (VSMOW) =  15.3?

Use is free and all data is accessible and downloadable. We would be very interested to hear from potential users about any applications, development ideas or comments they have. This is version 1.  We hope to collaborate with users to develop this resource over the next few years. Suggestions for other useful layers would be welcome. The database and map has been created by staff from NIGL (Jane Evans and Carolyn Chenery) and GeoAnalytical and Modelling Programme (Katy Mee, Clive Cartwright and Katy Lee) with web development by Andy Marchant and web deployment by Lina Hannaford.

Wednesday, 30 May 2018

Aquaculture: Pathway to food security in Kenya...by Andrew Marriott and Odipo Osano

Photograph of the team and stakeholders
In late December we were successful in obtaining funding through a Newton International Links bid with the British Council. This project aims to investigate problems of food insecurity and the implications of anthropogenic pollutants for food safety, the impact on the health and nutritional quality of aquaculture farmed fish, and the potential of fisheries aquaculture to boost food security and sustainability in Lake Victoria, Kenya.

Having been successful in the bid, I was looking forward to working with fish again and using the knowledge gained from my years as a Marine Biologist at Bangor University. The project brings together my experiences working on fisheries aquaculture and from knowledge gained working within the Inorganic Geochemistry team in exploring micronutrients, pollution pathways and the associated problems of food security and nutrition in Aquaculture fish. 

This collaborative project involves the Inorganic Geochemistry team (IG) at BGS with our old friend Prof Odipo Osano from the School of Environmental Sciences at the University of Eldoret (UoE) with whom we have worked closely for over 4 years. This grant funded project also collaborates with Dr Tracey Coffey and Dr Sharon Egan from the School of Veterinary Science (University of Nottingham), and the experienced research team led by Dr Christopher Mulanda Aura at the Kenyan Marine Fisheries Research Institution (KMFRI) based in Kisumu, Kenya. 

Stakeholder discussions were hosted at KMFRI headquarters between the project team and aquaculture producers explaining how the project will address questions related to pollution pathways (Food Safety-human and ecological health), through studying problems associated with sedimentation rates in water from erosion, or changes in land-use and water quality, as well as the effects of toxic metals as drivers of antimicrobial resistance (AMR). Expanding on this, and linking to other BGS activities and interests of the Ministry for Agriculture, Livestock and Fisheries, data will be generated to understand the potential for aquaculture to address ‘hidden hunger’ (deficiencies of essential micronutrients for human and animal health). Questions came quick and fast from those attending, with the fisheries-licence holders and the cage-culture representative being extremely interested in what we were intending to do. However, transparency and open talks through public engagements such as this alleviated any concerns they may have had, and their subsequent assistance in locating sites and communicating with local cage managers proved invaluable .

Attention turned to the fieldwork, which was based on KMFRIs main research vessel R.V. Uvumbuzi (Discovery) based on the Winam Gulf in Kisumu. This allowed us direct access and quicker travel between sampling sites within the Winam Gulf to view and sample the intensity of aquaculture cages along the shores of Lake Victoria (Kenyan side).

Photograph of one of the larger aquaculture cages along the shores of Lake Victoria (Kenyan side)
Cage sizes ranged from a few meters (2x2) to the medium 6x4 meters up to the larger 20x20 meters and housing fish from a few thousand to over 20,000 for the larger 20x20 m cages. Most of the fish (Tilapia) are sold at local markets after growing for 6 months (plate size) or in the case of the larger cages (>10m) sold to merchants after growing for up to 8 months for re-sale as fillets..

Involving the representative for the aquaculture operators in the stakeholder meeting hosted by KMFRI, provided invaluable as they were able to help in the design of sampling locations, and assist in gaining the trust and co-operation of the managers of each cage site. With the local manager informed in advance of our visit, sampling fish from both within the cages, and from the wild went smoothly and efficiently.

Sampling involved all the experience of the project team. Water parameters such as pH, temperature, conductivity and dissolved oxygen were measured either directly from the vessel or from the small canoe brought along for closer inshore work. After measurements of the water were obtained, the process of collecting water samples from just below the surface (approx. 1m), and from depth, was completed using a niskin water sampler system. The collected water was then filtered using 0.45 um filters.

Water samples were observed to be slightly discoloured around the shores of Winam Gulf which is a possible indication of high sedimentation rates from land erosion. This colouration cleared when we moved further out to the main channel at Rusinga in the Lake. Finally the collection of a sediment sample was taken using the Van Veen Grab Sampler for both biogeochemical analysis in the UK, and benthic microbiological analysis by the team at KMFRI. Most of the sediment collected near the Winam Gulf area near the shore had a strong H2S aroma indicating possible eutrophic conditions in that area.

Photograph of Andy Marriott sub-sampling muscle tissue.
Fish were sampled both from the cages and also where possible from the wild, using fish locally caught by the local fishermen. Fish were processed on board the R.V. Uvumbuzi, and measurements were taken to record the biological data. Finally sub-samples of muscle tissue were taken and vacuum sealed for subsequent analysis of trace metals, and tissue for DNA extraction and Anti-Microbial Resistance studies.

After 3 long days working on the Lake, the water, sediment and fish tissue samples were finally off-loaded from the RV Uvumbuzi and transported to the School of Environmental Sciences (University of Eldoret). Here sediment samples were partially dried and excess water removed for transportation back to the Inorganic Geochemistry labs in the UK for ICP- MS analysis. Similarly, fish tissue will be measured for trace metals and DNA and AMR analyses at the School of Veterinary Science (University of Nottingham).

Water, fish tissue and sediment geochemistry data in addition to on-going studies by UoE and KMFRI will help to identify possible pollution pathways from anthropogenic activities, and sediment loading from erosion or changes in land-use for design of further investigation in the Winam Gulf and shores of Lake Victoria. Bio-geochemistry data from this and subsequent investigations will be invaluable to KMFRI in advising on the future siting of aquaculture cages to ensure food safety for human and ecological health. Given that ‘wild’ fish catches are unsustainable in Lake Victoria, aquaculture/farming of fish through sustainable methods is an important approach to food sufficiency and in addressing ‘hidden hunger’ along the shoreline of Lake Victoria and further inland.

Acknowledgements:

I would like to thank the Newton International Links programme and the British Council for funding the project. I would also like to thank the BGS-ODA programme and Center for Environmental Geochemistry for financial support and technical expertise.

Thursday, 17 May 2018

Understanding methane dynamics: working towards dual isotope analysis at the BGS…by Andi Smith

A recent collaborative venture between the stable isotope facility at the BGS and UK based mass spectrometer company Sercon Ltd has resulted in the development of the UK’s first automated system for the analysis of both hydrogen and carbon isotopes in methane. Here Andi Smith tells a bit more about the new instrument and potential applications…

Understanding subsurface methane dynamics is something that is going to become increasingly important to several areas of BGS, especially with ongoing developments with UKGEOs and groundwater monitoring projects in the Vale of Pickering, North Yorkshire and Fylde, Lancashire. One of the most promising tracers for understanding methane sources in groundwater is duel isotope analysis of the dissolved gas. Most surface methane is produced by methanogenic bacteria within the near subsurface, large isotope fractionations are associated with this process lead to very negative isotope values for both carbon and hydrogen (δ13C –70 to –110‰; δ2H –160 to –340‰).

Thermogenically produced methane on the other hand is formed by the thermal decomposition of kerogen, a process which is normally associated with isotope values of δ13C between –20 to –50‰ and δ2H between –110‰ to –250‰. These differences allow us to provenance where methane collected during monitoring projects was formed and start to understand potential migration pathways within the subsurface.

Whilst this dual isotope tracer technique has been undertaken many years, traditional systems require very labour intensive/ expensive sample clean up and preparation methods. This has meant that the number of samples that can be analysed has been very limited for most studies. To overcome this limitation staff at the stable isotope facility and Sercon Ltd embarked on a joint innovation project to develop a sample preparation and mass spectrometer system which is capable of running far greater numbers of samples at a reduced cost.

The developed instrument is now on site at the BGS and is being put through its paces. Once the system is fully functional it will be able to analyse large numbers of samples at very high precision. This will be ideal for baseline investigations at a number of BGS research sites and should help us identify if subsurface activities have any impact on methane release into aquifers.

There are many other potential applications for this instrument, if you think you may have an interesting application for this technique get in contact with me andrews@bgs.ac.uk.

Monday, 14 May 2018

Brazilian Bahia Blues...by Clive Mitchell


Clive presenting at the Global Stone Congress
BGS Industrial minerals geologist Clive Mitchell ventured to Brazil for the Global Stone Congress where he made many new friends, saw some amazing geology and learnt approximately 12 words of Brazilian Portuguese… 

Ola! (there that’s the first word!) Towards the end of April I was lucky enough to travel the 6000 or so miles to Brazil to take part in the 6th Global Stone Congress in the coastal resort of Ilhéus in the north-eastern state of Bahia.

I was an invited speaker at a conference I had never heard of, in a place I’d never been and with people I didn’t know. Yes you may have picked up a little apprehension. It wasn’t the presentation I was worried about (I actually enjoy that bit) but the travelling to a big, new, slightly scary sounding place. Anyway I went, otherwise this would be a very short blog…

En route (Nottingham – Heathrow – Sao Paolo – Ilhéus) I met some other delegates who quickly became my new best friends and were pretty much in the same boat as me (in the sense they were new to this, not an actual boat). Thirty hours after leaving home I arrived at the conference venue, the Jardim Atlantico Beach Resort in Ilhéus, approx. 800 miles NE of Sao Paolo.

Over the next 4 days I got to know everyone at the conference, was made to feel very welcome and quickly became part of the natural stone family. We took over the resort for a week – the conference venue was a marquee set up in the grounds. A large rain cover was hastily set up when the rain proved too much for the marquee (yes it rained every day, typical!)

The beach at the Jardim Atlantico Beach Resort in Ilhéus
The Global Stone Congress has been held every few years since 2005, when it was first held in Brazil as the International Congress on Dimension Stone. The objective is to gather internationally renowned natural stone experts in order to share knowledge, promote technical cooperation and discuss the latest advances in the industry. Since 2005 it has travelled to Italy (2008), Spain (2010), Portugal (2012) and Turkey (2014).

The 2018 congress attracted 165 delegates from 11 countries – 70% from Brazil with the remainder mostly from Portugal, Italy and Spain, and a small representation from Chile, the Czech Republic, Finland, Iran, Saudi Arabia, Sweden and one from the UK (me!). For my part, I gave a presentation on ‘Dimension stone in the United Arab Emirates’ – the UAE is an important market for natural stone in the Middle East and is one of the largest importers per capita in the world. It also has the potential to produce its own natural stone. It has mountains of limestone resources equal to that imported from neighbouring Oman.

After the conference, we spent a couple of days visiting dimension stone quarries, which turned out to be a very long way from Ilhéus! The state of Bahia it turns out is twice the size of the UK, with a quarter of the population.

The blue granite of Potiraguá is a sodalite-rich syenite worked as a dimension stone by Somibras and marketed as ‘Azul Bahia’. This is probably the most famous naturally blue stone from Brazil. I have come across it in use in the new terminal building at Dubai International Airport.

Field trip delegates at the Macarani pegmatite dimension stone quarry
The Precambrian Macarani pegmatite is hosted in a metavolcanosedimentary sequence of banded and strongly folded biotite paragneiss. The pegmatite is mostly coarsely crystalline feldspar and quartz often displaying graphic texture, with occasional crystals of aquamarine and beryl. Both the pegmatite and host rocks are worked as dimension stone by Ouro Campo.

An important phrase to learn for those tea drinkers out there: chá com leite frio, por favour or tea with cold milk please (not that you will get black tea of course, you’ll need to take that out with you I learnt!).

The congress social programme introduced me to the three C’s: Caipirinha (the Brazilian national drink), Capoeira (a form of mock-fight dancing) and Cerveja (beer of course, I knew that one as I am a geologist after all!).

The 6th Global Stone Congress took place from 27th to 29th April 2018, and was followed by two days of dimension stone quarry visits. Further information: www.globalstonecongress2018.com.br/ing/

Obrigado e tchau!

Tuesday, 8 May 2018

My first paper about improving methodologies in ostracod research…by Lucy Roberts

Ostracods, small animals which live in all aquatic environments, build shells (see image) that reflect the temperature and salinity of the water in which they formed. When the shells fossilise they can be used to understand past conditions of the lake or climate at that time. The ratio of certain trace elements (magnesium and strontium) to calcium (Sr/Ca and Mg/Ca) and the oxygen and carbon isotopes (δ18O and δ13C) within the shell is used to relate to the water conditions. The magnesium, strontium and oxygen isotopes relate to the past temperature and salinity of the water; carbon isotopes relate to the productivity of the lake. Here PhD student Lucy Roberts from UCL tells about her research on improving cleaning methodologies…

To obtain the most accurate reconstructions of past conditions, the ostracod shells must be cleaned of mud and/or remaining parts of their internal limbs. There are, however, a range of methods used across different laboratories. All the methods used have been proven to effectively clean the shells, but until now it has not been clear if the methods are also removing parts of the shell surface and causing an alteration to the trace element and/or isotope signal that is preserved in the shell.

A valve of the species Cyprideis torosa. A carapace is formed
of two valves – left and right held together by hinge along the
top of the shell. The species was used in the study because
it is found in a range of habitats across Europe, Asia and
Africa and has been used extensively for trace element and
 isotope based reconstructions
Alongside the BGS stable isotope laboratories, we designed an experiment to test this using a range of cleaning methods. For isotopic work, cleaning was performed using chemical oxidation, vacuum roasting and plasma ashing; for trace element work we used sonication, chemical oxidation and reductive cleaning. These methods were compared to simple ‘manual’ cleaning using a paint brush to remove visible material. Cleaning methods were compared by undertaking analyses on a single ostracod carapace (two separate ‘valves’, similar to a mussel, which together form the ‘shell’); in modern ostracods, the two valves should have identical trace element and isotope ratios. One valve was cleaned using one of the methods above, and the other was manually cleaned using a paintbrush. Any difference between the two valves after cleaning could be assigned to the effect of the treatment method.

We found that some cleaning methods have the potential to cause alteration to the signal and can therefore affect the values obtained for climate reconstructions. For trace element reconstructions we calculated that reductive cleaning can alter the Mg/Ca temperature reconstruction up to −12°C and the Sr/Ca conductivity reconstruction up to +4.5 mS cm−1 by removing parts of the surface of the shell. Isotope-based reconstructions are less affected by the cleaning method. However, the concentration and length of exposure to chemicals was an important factor in the extent of alteration.

The naturally smooth surface of the shell after cleaning with a paintbrush and no
chemicals is pictured in A and C. After exposure to hydrogen peroxide for 30 minutes,
the smooth surface shows evidence of being removed (D) altering the trace element
and isotope signal of the shell. After 15 minutes, there is no evidence of the
treatment affecting the shell (B).
To establish a universal method which allows comparison between reconstructions, we recommend sonication for trace element analysis and oxidation by hydrogen peroxide for stable isotope analysis. We believe these methods are effective at cleaning the shells, but do not significantly alter the signal preserved in the shell.

For more information on the study and the recommended methods, the open access paper is reference is: Roberts, L.R., Holmes, J.A., Leng, M.J., Sloane, H.J., Horne, D.J. Effects of cleaning methods upon preservation of stable isotopes and trace elements in ostracod shells: Implications for palaeoenvironmental reconstruction. Quaternary Science Reviews, 189, 197-209. The paper can be download for free here.

Wednesday, 2 May 2018

A new Post Doctoral Research Associate in shale gas geochemistry at the BGS…by Joe Emmings

Joe Emmings presenting research at the European
Geosciences Union General Assembly
Joe Emmings is the new Post Doctoral Research Associate in shale gas geochemistry at the British Geological Survey’s Stable Isotope Facility and Centre for Environmental Geochemistry. Here, Joe tells us about his PhD at Leicester University and future research at the British Geological Survey…

The world is gradually turning to renewables, such as wind and solar, as the main source of energy. This is great news for the environment, particularly for reducing greenhouse gas emissions. Yet all sources of energy, such as natural gas, nuclear energy, but even renewables, have pro’s and con’s. The expansion of renewables and batteries used to store this ‘green’ electricity is increasing the demand for metals, such as Co and Ni. These will need to be mined somewhere in the world.

Renewables cannot entirely replace the demand for hydrocarbons, either. For example, hydrocarbons are used as fertilisers and gas central heating in UK households, will be difficult to replace. So the transition to renewables must proceed now, but gradually – if it is done too quickly, the environmental and economic costs are large.

It is in this context that locally extracted natural gas is potentially a ‘bridge’ between coal, oil and gas and sustainable sources of energy. In a global context, locally extracted gas is preferable over imported gas, because in the UK we have strict regulations which protect the environment, and the fugitive emissions by long gas pipelines is significant. The method of extracting natural gas from shale, hydraulic fracturing, is contentious. Yet much of the science that informs our understanding of the pro’s and con’s of this technique has not been conducted.

I have been and will be continuing to work on the science that contributes to this debate, by shedding light on the composition of black shales in the UK that are of interest to exploration companies. On a microscopic scale, black shales are incredibly varied. No two shales are the same; the amount of gas stored in the rock varies substantially. This ultimately comes down to the environment of deposition – in other words – what did the environment look like millions of years ago?

Through my PhD research, we know Mississippian black shales in the UK were deposited in shallow seaways. By studying the geochemical composition of UK black shales, we know these were deposited in seawaters that lacked oxygen (termed ‘anoxic’), an environment that is similar to the modern Black Sea. Understanding when and how seawaters became oxygenated is important for understanding the amount of gas that is now trapped in the shale. The geochemical proxy record also shows that seawaters were also rich in hydrogen sulphide (H2S), a gas that is highly toxic to aerobic organisms. H2S is produced when other ‘electron acceptors’, such as oxygen, are absent. Anaerobes that live in the water instead respire using dissolved sulphate (SO4) and produce H2S as a product. This means UK black shales contain lots of pyrite (FeS2, ‘fools gold’) and are enriched in many ‘redox-sensitive’ metals, including Co and Ni. So black shales in the UK may represent an important resource of metals, which are used in renewable technologies, and this is something that I will be looking at.

Overall, Joe is interested in understanding ancient marine biogeochemical processes, by integration of sedimentology and organic and inorganic geochemistry. Please contact Joe if you are interested in his research field at josmin65@bgs.ac.uk


Friday, 27 April 2018

A trip to Vienna for the European Geosciences Union General Assembly ... by Dr Jack Lacey


Catch up with #EGU18 on Twitter
This month, over 15,000 scientists from more than 100 countries took part in the European Geosciences Union (EGU) General Assembly in Vienna, Austria.  The EGU programme was diverse with over 17,000 presentations that detailed novel and exciting geoscience research from around the world, and beyond!

Dr Jack Lacey from the British Geological Survey Stable Isotope Facility attended the conference to share new results from two projects that look at human impact on lakes. Here, Jack tell us about his week and the work presented…

Jack Lacey presenting research on human impact at Tasik Chini, Malaysia
The EGU General Assembly provides a fantastic opportunity for geoscientists to network and discuss their latest findings, as well as meet with representatives from industry and publishing. It was a very busy week indeed. The large number of scientific presentations were organised into 22 broad-scale topics, such as ‘Natural Hazards’ or ‘Atmospheric Sciences’, which were subdivided into 666 subject-specific sessions each consisting of talk, poster, and PICO sessions. This was in addition to the medal lectures, great debates, town hall meetings, short courses, and educational and outreach events. Thankfully, the timetable for the whole week is available online and through the EGU app, so you can plan your week in advance and make sure you get to all relevant sessions.

The two papers I presented look at the scale and timing of human impact on lake systems, specifically Rostherne Mere in the UK and Tasik Chini in Malaysia. Using sediment core records we are able to find out how these ecosystems behaved in the past before major human disturbance (e.g. deforestation, pollution, dams), which can then act a baseline for understanding when and in what way human activity has influenced the lake and its biota. This information is essential for putting in place conservation strategies to help manage and reduce our impact on natural environments.

Overall, the meeting was very successful and it was great to share this research with the wider scientific community. Find out more about the Tasik Chini project on GeoBlogy, and read about tracing human impact on Rostherne Mere (UK) in Anthropocene.


EGU is hosted at the Vienna International Centre, Austria
Contact Dr Jack Lacey or via Twitter @JackHLacey