North Eastern Geological Society
Click here for the Official NEGS website
Lectures will be held at 7:30 pm
in the Arthur Holmes lecture theatre, which is Room No. CG91 and is downstairs from the Porter's
Lodge on the Science Laboratories site, South Rd., University of Durham.
They will be followed by coffee or tea, to which all speakers and audience
members are cordially invited.
2019 - 2020 programme
2018 - 2019 programme
2017 - 2018 programme
2016 - 2017 programme
2015 - 2016 programme
2014 - 2015 programme
2013 – 2014 programme
2012 – 2013 programme
2011 – 2012 programme
2010 – 2011 programme
2009 – 2010 programme
2008 – 2009 programme
2007– 2008 programme
2006 – 2007 programme
2005 – 2006 programme
Christian Schiffer, Dept. Earth Sciences, Durham University, Science Labs., South Rd., Durham DH1 3LE, UK, firstname.lastname@example.org, 20th January, 2017.
The present-day North Atlantic is the result of subduction of a former ocean (Iapetus Ocean), subsequent continental collision and mountain building (Caledonian mountains), and final rifting and formation of new oceanic crust. Because this was suggested by Tuzo Wilson in 1966 it is known as the Wilson Cycle. This concept significantly added to plate tectonic theory up to the present day. Although the North Atlantic region is one of the best studied areas, some details of its geodynamic evolution remain poorly known.
Recent seismic imaging using broadband seismometers across the coast of East Greenland detected an east-dipping structure in the upper mantle to a depth of 80 km or more. The seismic signature, the large scale geometry and its location relative to North Atlantic geology suggests this structure is an old fossil subduction zone. Similarities to the Flannan structure beneath northern Scotland suggest that the two formed a coherent, eastward-dipping Iapetus subduction zone before the opening of the North Atlantic. This discovery may be an essential piece of information that helps us to decipher the tectonic evolution of the North Atlantic. This includes the relationship of Iceland and the volcanic rocks of Britain, Scandinavia and Greenland to Iapetus geology, and to hydrocarbon resources around the Atlantic margins.
Alex Peace, Dept. Earth Sciences, Durham University, Science Labs., South Rd., Durham DH1 3LE, UK, email@example.com, 21st October, 2016.
Continental breakup between West Greenland and North Eastern Canada produced the small oceanic basins of the Labrador Sea and Baffin Bay, which are connected via the Davis Strait, a region mostly comprised of continental crust. In this study seismic reflection data from the Davis Strait constrained using exploration wells, gravity and crustal thickness data was analysed to produce a series of seismic surfaces, isochrons and a new offshore fault map. The results have been integrated with plate reconstructions and onshore structural data to build a two stage conceptual model for the offshore fault evolution in which early rift basin formation was controlled primarily by reactivation of pre-existing basement structures. While this control diminished into the postrift, the location of synrift basins still exerted some control on the location of sedimentation probably due to differential sediment compaction.
Michael Lim, Dept. Geography, University of Durham, Science Labs., South Rd., Durham DH1 3LE, UK firstname.lastname@example.org 17th November, 2009.
Geology plays a fundamental role in shaping our rocky coastlines, interacting with destabilising processes to control the rate and nature of cliff erosion. Recording, interpreting and predicting coastal cliff erosion is a critical component in coastal policy, assuming even greater significance in the context of global sea-level rise and forecast increases in the occurrence of extreme weather phenomena. Much of our understanding of cliff change is based on patterns in the mapped historic position of the cliffline. These surveys provide a valuable insight into landform behaviour but the levels of error that occur often exceed the absolute changes recorded, casting considerable doubt over the validity of results; results that hold far reaching implications for coastal communities. This lecture presents the results from an ongoing seven year research plan conducted by Durham University into rock cliff erosion on the North Yorkshire coast. The main aim of this work is provide a new quantitative understanding of the 3D nature of coastal cliff erosion and the processes driving it, re-evaluating current rates of retreat established along the coast and consequently providing better tools with which to assess future behaviour.
Andrew J. Dugmore, Geography, School of GeoSciences, University of Edinburgh, Drummond Street, Edinburgh EH8 9XP, Scotland, UK email@example.com, 12th December, 2008
Tephrochronology, a dating technique based on the identification and correlation of layers of volcanic ash, can make key contributions to our understanding of human-environment interactions. This is because the isochrons defined by tephras permit accurate spatial and temporal correlations of environmental data and have such precision that effective integration with historical records and human timescales are possible. In this talk the principles, practice and application of tephrochronology are assessed as a part of a wiser discussion of human environment interaction and the Norse settlement of the North Atlantic. The end of Norse Greenland settlement is widely associated with the climate changes of the ‘Little Ice Age’, environmental destruction and an inability to adapt, but there is evidence in Greenland and across the Atlantic islands for both Norse sustainable practice and successful adaptation to climate change. As a result we propose that the choices made during the initial Norse colonization and settlement of Greenland, followed by a rising level of connection, intensification, and investment in fixed resource spaces, social and material infrastructure, increased the effectiveness of adaptation but at a cost of reduced resilience in the face of variation. When confronted by culture contact, rapid natural, social and economic changes the limitations of the pathway chosen by the Norse in Greenland seem to have been too great and social collapse could have been the result. The lessons drawn from a multidisciplinary assessment of the Viking settlement of the Atlantic islands in general and Norse Greenland in particular are disturbing in a modern context. It is possible to creatively adapt to new environments, build up centuries of community-based managerial expertise, wisely conserve fragile resources for communal benefit, codify the results, maintain century-scale sustainable patterns of life and society- and yet still face ultimate collapse and extinction.
Andy is a Professor of GeoSciences at the University of Edinburgh, and an Adjunct Research Professor on the Doctoral Program in Anthropology at the City University of New York, USA. His research is focused on understanding environmental change over timescales from decades to millennia, and their significance for human society. A key theme is the development and application of tephrochronology, a dating technique based on the identification and correlation of volcanic ash layers. Between 2002-7 Andrew co-directed a Leverhulme Trust Programme Award for the study of ‘Landscapes circum- Landám: Viking settlement in the North Atlantic and its human and environmental consequences’. He is currently embarking on two follow up programmes, ‘Footsteps on the edge of Thule’ which will assess the interactions of Norse and indigenous peoples in Greenland and Arctic Scandinavia (also funded by the Leverhulme Trust) and an NSF Office of Polar Programs IPY project on ‘Human ecodynamics in the Norse North Atlantic’.
Dr. Rob Chapman, 23rd February, 2006
The importance of Au to ancient societies has encouraged many archaeologists to search for the sources exploited in antiquity. These projects generally involve detailed studies of artefacts and comparison of their chemical characteristics with those reported for natural Au. However, descriptions of natural Au are frequently inadequate for provenancing studies, and the compositional variability of the material is not widely recognised. The present study describes a new approach to gold provenancing using the technique of microchemical characterization in which populations of gold grains are classified according to the alloy compositions and the assemblages of micro-inclusions of other minerals. This technique, originally developed to identify sources of alluvial gold during Au exploration, has proved applicable to provenancing studies in four main areas. Firstly, microchemical characterization of artefacts grouped according to archaeological criteria can indicate the number of sources exploited in relation to time and artefact taxonomy. Secondly, knowledge of the total variation in chemical characteristics of natural Au from a particular region provides an excellent database for provenancing and reduces the need for exhaustive sampling. Thirdly, it is possible to predict how Au alloys were modified during fabrication as a consequence of assimilation of mineral inclusions. Finally, identification of inclusion phases in artefact Au can provide information on metallurgical practices.
These principles have been applied to the search for the source of Au used for the unique traditions of prehistoric Irish metalworking. Studies of 180 Irish Au artefacts belonging to 4 major metalworking traditions dating from the Early Bronze Age (2400 BC) to the Iron Age, (150 BC) show that each group exhibits distinctive Ag and Cu contents. Parallel studies of 2267 natural Au grains from 58 alluvial localities and 4 bedrock localities throughout Ireland reveal a broad pattern of alloy compositions consistent with style of mineralization and host geology. The ranges of Ag contents of Early Bronze Age and Middle Bronze Age artefacts suggests that the Au source lies within Lower Palaeozoic sedimentary rocks of the Southern Uplands Terrane and significantly, that the same source (or sources) were used in both periods. A different source of relatively Ag-rich Au, (most probably at Croagh Patrick, Co. Mayo), was exploited in the Late Bronze Age. Iron Age artefacts have Ag contents higher than natural Irish Au. Evidence for evolution of metallurgical practice during the Bronze Age is provided by the increasing Cu content of the gold alloys (to levels far in excess of natural gold) and the nature of inclusions in artefacts of different ages. Elevated Sn in Cu-rich alloys suggests deliberate or accidental alloying with bronze.
This approach has provided the first clear indication that only a few individual indigenous Irish sources of Au were used during the Bronze Age and that their relative importance changed over time. Future archaeological investigations may adopt a geographical focus that was not previously possible.
Dr. Claire Fialips, 17th November, 2006
Clay minerals are abundant in soils and sediments and generally contain significant - if not high - concentrations of structural ferric iron (Fe(III)). Reducing conditions, even for a short period of time, can strongly affect the chemistry, structure and surface properties of iron-bearing clays. In particular, the chemical reduction of Fe(III) to Fe(II) in Fe-rich smectites results in structural rearrangements and dramatic changes in the swelling behaviour and cationic exchange capacity of the clay. Such changes can dramatically and adversely affect the fate of pollutants or the availability of nutrients in natural or artificial systems. However, in some cases, these changes could as well play in our favour in pollution remediation.
Dr. Anthony Cooper, 15th March, 2013
Gypsum (CaSO4.2H2O) is attractive as satin spar, beautiful as carved alabaster and practical as plasterboard; rock salt (NaCl) is an essential mineral, but both cause geological hazards capable of swallowing houses. Gypsum and salt can dissolve rapidly in flowing water and caves can form where this happens underground, sometimes resulting in catastrophic subsidence at the surface. In Northern England, around Ripon, Darlington and in parts of Cheshire, large holes have appeared, often without warning. Beneath Ripon there is a complex maze cave system formed in the gypsum with large breccia pipes leading upwards to collapse features at the surface. It has been suggested that Lewis Carroll’s vision of Alice falling down a deep vertical hole into an underground land was inspired by this subsidence at Ripon. There is a connection between the author, Croft near Darlington, the city of Ripon, and dramatic subsidence at the house where "Alice" is thought to have lived. Salt dissolves very rapidly causing subsidence problems and salt springs; in Cheshire these springs have the local name of “wich” hence the local place names such as Nantwich, Northwich and Middlewich. Gypsum and salt karst subsidence are geohazards that need to be considered in planning and development. They are difficult to investigate, but techniques including airborne multispectral remote sensing, stereo air photography, microgravity, ground probing radar, resistivity tomography and the use of drilling have all helped. The hazards require careful consideration, but can be addressed through the use of Geographical Information Systems (GIS), planning and novel construction techniques. The English soluble rock subsidence problems are not unique and similar problems also occur in Spain, Germany, France, Italy, Switzerland, Turkey, Lithuania, Ukraine, Russia, China, Canada, the USA and many other countries.
Dr. Brian Young, 21st March, 2014
This talk will look briefly at the geology of the Durham city site and it will explore the uses of stone, both local and imported, in what Bill Bryson described as "the best cathedral on planet Earth". As a Cathedral Guide & Steward the speaker obviously agrees with him! Particular emphasis will beplaced on how the site's geology and the varied properties of the main stones used in the building have been employed and how these have influenced the design and appearance of the building.
Darren Grocke, 21st November, 2014
The application of stable isotope geochemistry in understanding the Earth System has been applied for over 50 years, and yet many topics are still poorly understood. In this lecture I will provide a biography of my adventures as a stable isotope geochemist for 20 years. Topics covered include: isotopes in kangaroos as a recorder of precipitation; ancient DNA and isotopes as a tracer of diet and migration; isotopic effects in modern and fossil plants; methane events recorded from a Jurassic Park using carbon isotopes; and understanding carbon burial events in shales. These are only a taster of the types of projects that have passed through my laboratory. This informal lecture is aimed at giving the audience a journey on how stable isotope geochemistry can help understand various aspects in the Earth System – or to reveal how little we still understand...
Certainly old stagers like me from the former BGS field staff have a fairish repertoire of observations of the rough and tumble of field mapping and subsequent compilation. Some of these might well be of interest - perhaps even amusing in some cases - but I think might work best if included in a talk on what is actually involved in the process of putting together a BGS map and, perhaps more interesting still, why we re-mapped some areas as many as 3 times over the past century or so. I was once asked to put together a short article on this for a NERC publication some years ago. It is a question that was often asked of field staff, especially by curious/suspicious landowners. It can be illustrated with some extremely persuasive explanations.
There is something of an air of mystique over geological mapping in some quarters and even many geologists nowadays do not quite grasp what we were about and how we went about it. The process is a lot more involved, and a lot more interesting, than that touched upon in some of the brief taster sessions on mapping offered in some short field courses.
Honorary Research Fellow, Department of Earth Sciences, University of Durham, Retired District Geologist, Northern England, British Geological Survey
“I’ve got a geological map of this area. The rocks can’t have changed so why are you mapping it again? ”. This, one of the most frequently asked questions posed by farmers and land owners to field geologists of the British Geological Survey, in some places on an almost daily basis, might seem a perfectly reasonable query. Yet it betrays an all too common, though in some instances perhaps understandable, misconception of what geological maps are, how they are compiled, what they can and cannot tell us, and what purposes they are intended to serve. Sometimes seen, wrongly, as simply brightly coloured versions of Ordnance Survey maps, geological maps are commonly underappreciated and misunderstood, even by some geologists! This talk will give some insights into the complex and varied disciplines of geological mapping, will de-bunk some of the myths and, above all answer the question of why re-mapping is so often both necessary and ground-breaking 200 years after the pioneering efforts of William Smith.
Associate Professor & Director of the International Volcanic Health Hazard Network, Department of Earth Sciences, University of Durham
During volcanic eruptions, and their aftermaths, communities may be very concerned about inhaling fine-grained ash, which can be rich in the deleterious mineral crystalline silica. Dr Claire Horwell, Director of the International Volcanic Health Hazard Network (www.ivhhn.org) will lead us through her interdisciplinary career journey, from trying, for a decade, to answer the question “Is it harmful to breathe this ash?”, by mineralogical, geochemical and toxicological analyses of ash samples from around the world, to her realisation that this question cannot easily be answered in the timeframe of acute community exposures. In 2015 she embarked on the Wellcome Trust/DfID-funded project Health Interventions in Volcanic Eruptions (HIVE; http://community.dur.ac.uk/hive.consortium/) which aimed to answer a more pertinent question: “How can I protect myself from breathing this ash?”. The HIVE project has built the first evidence base on the effectiveness of common materials used to protect communities in volcanic crises including cloth, surgical and industry-certified masks. The key finding is that industry-certified facemasks are more effective than any other type of protection, even with no fit training. Incorporating laboratory analyses, on the filtration efficiency and fit of 17 forms of respiratory protection, with psychological (questionnaire-based) and anthropological (interview-based) social surveys in Mexico, Japan and Indonesia, and a review of ethical considerations for agencies, the project has culminated in the development of a variety of audio-visual and printable public informational products for IVHHN which are already being widely used in Indonesia.