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Kimberlite volcanism typically involves the formation of diverging pipes or diatremes (see image below), which are the locus of high-intensity explosive eruptions. The talk will first provide an overview of diatreme formation. I will then focus on a conspicuous and previously enigmatic feature of diatreme fills known as ‘pelletal lapilli’ — well-rounded clasts that consist of an inner ‘seed’ particle with a complex rim, thought to represent quenched juvenile melt. Such clasts are widely documented in a range of pyroclastic successions on Earth, yet are not fully understood. New observations of pelletal lapilli in kimberlites show they coincide with a transition from magmatic to pyroclastic behaviour, thus offering fundamental insights into eruption dynamics and constraints on vent conditions. We provide strong evidence that pelletal lapilli form by fluidized spray granulation — a coating process used widely in industrial applications, including the chocolate industry. We propose that pelletal lapilli are formed when fluid volatile-rich melts (akin to molten chocolate) intrude into earlier volcaniclastic infill close to the diatreme root zone. Intensive degassing produces a gas jet in which locally-scavenged particles are simultaneously fluidized and coated by a spray of low-viscosity melt. Most fine particles are either agglomerated to pelletal coatings or elutriated by powerful gas flows. The origin of pelletal lapilli is important for understanding how magmatic pyroclasts are transported to the surface during explosive eruptions, where they can be asociated with high diamond grades. A similar origin may apply to pelletal lapilli in a range of alkaline volcanic rocks including carbonatites, kamafugites and melilitites.
Most people associate nature conservation with rare plants and animals – certainly not with rocks! However, Britain is now widely regarded a world leader in geoconservation, so how did the need to conserve Britain’s geological heritage come to be recognised and acted upon? Who pioneered geoconservation in Britain, who convinced government to include geoconservation in the first national nature conservation legislation, who suggested which sites to conserve, who implemented the legislation, and what challenges did they face?
This talk explores the 19th Century origins of geoconservation, the planning by geologists during the Second World War, the post-war decision making and the work undertaken up to the 1990s that saw Britain become a world leader in this field. It touches on the threats to our geological and geomorphological heritage, the conservation legislation and tools used to conserve it, the Geological Conservation Review and the increasing levels of local participation. This look back at the history of geoconservation provides context for conservation today, explaining the link between boulders, lunacy, ‘robot planes’ and an Honorary Member of the Geologists’ Association in the process.
Ichthyosaurus was the first ichthyosaur to be described, in 1821. Thousands of Ichthyosaurus fossils have been found in the UK, with most coming from the Jurassic Coast, Dorset, and from inland quarries in Somerset. By 1900, over 50 different species of Ichthyosaurus were described from fossils across the globe, but most of these were subsequently identified as different types. Within the last 30 years, only three species of the genus were identified, Ichthyosaurus communis, I. breviceps and I. conybeari, but they were poorly defined. In recent years, palaeontologist Dean Lomax, in collaboration with Prof. Judy Massare, have begun to thoroughly revise Ichthyosaurus by examining hundreds-to-thousands of specimens held in museums in the UK, Europe and North America. In doing so, they have provided a better understanding of the previously recognised species and have identified at least three new species to science. In this talk, Dean will share with you his extensive research on Ichthyosaurus.
Although the Gamburtsev Subglacial Mountains in the interior East Antarctica are thought to be a key nucleation site for the largest ice sheet left on Earth, their geological origin has remained an unresolved enigma ever since their first discovery in 1958. How did this presently completely ice-covered mountain range that resembles the European Alps form in the centre of an assumed "stable" Precambrian East Antarctic craton?
Seven nations, including the UK pooled their resources during the International Polar Year to tackle this question, which has major implications for understanding the interactions between mountain building and ice sheet formation and the process causing intraplate mountain building.
Here I review some of exciting findings of our major challenging international geophysical expedition (AGAP) over central East Antarctica that sheds new light into the enigma of the Gamburtsev Mountains and poses several new questions.
The geophysical data reveal that the Gamburtsevs are surrounded by one of the longest rift systems on our planet and are underlain by a remarkably well-preserved thick crustal and lithospheric root. With the aid of flexural models I show that the combination of Permian to Cretaceous rift-flank uplift, root buoyancy and isostatic responses to Cenozoic fluvial and glacial erosion can reproduce both the remarkable elevation and relief of the Gamburtsev Subglacial Mountains.
Two major implications stem from this study. Firstly, our models challenge the paradigm of a stable East Antarctic continent since Precambrian times, by revealing that much more recent Mesozoic tectonic and isostatic processes played a key role in triggering mountain building and aiding subsequent East Antarctic ice sheet development. Second, the proposed evolution of the Gamburtsevs, demonstrates that even modest amounts of crustal extension along the boundaries between cratons and orogens, coupled with isostatic responses to fluvial and glacial erosion can potentially cause major intracontinental mountain building, even in the absence of significant changes in the underlying Precambrian crust and lithosphere.
Tantalising new questions remain unanswered, however. How was the thick crust created in the first place? Did this occur during Rodinia supercontinent assembly or was this linked to Gondwana amalgamation, or both? If rifting did occur in Permian times, was the rift system later inverted? What was the role of deep mantle dynamics (i.e. “dynamic topopgraphy”) in supporting the remarkably high elevation of the entire East Antarctic plateau and the Gamburtsev Mountains? These and other open questions may be tackled in the future with new international research in several still largely unknown East Antarctic frontiers.
February 5 - Dr Imran Rahman
A Virtual World of Palaeontology
March 11 - Dr Nick Longrich
Giant marine reptiles and whales during the Eocene-Oligocene cooling event
What images are evoked with the phrase ‘super-volcano’? Large explosions? Catastrophic damage? Perhaps even the extinction of species? Many television programs preach the devastating effects of an eruption of the Yellowstone ‘supervolcano’. In this talk I will guide you through the discovery and critical importance of the Earth’s largest volcano (and it's not Yellowstone...). It is in a rather unfamiliar location and its discovery required years of concerted effort from a group of scientists from diverse backgrounds. It has, and continues to yield invaluable information about the deep interior of the Earth.
May 6 - Dr Haydon Bailey
AGM and Presidential Address
Foraminifera II: Planktonics - The free floating story
The Chiltern Hills are underlain by Chalk, predominantly what was traditionally called the Middle Chalk (now the lower part of the White Chalk Group) capped by the Top Rock - Chalk Rock complex (Kensworth Member of Mortimore et al., 2001). It is this series of chalk hardgrounds which effectively forms the spine of the Chilterns. The Chalk dips gently into the London Basin, and the overlying basal Tertiary succession provides minor outliers around this northern rim of the basin. The other major geological event we have to recognise in this area is the re-routing of the Proto-Thames River during and following the Anglian glaciation, some 450,000 years ago. This created the landscape we currently see in much of the southern parts of the Chilterns. The planned route of the HS2 fast rail link passes straight across the Chilterns Area of Outstanding Natural Beauty (AONB) and the geology underlying this region needs to be considered carefully before any tunnelling is carried out; some concerns will be raised regarding the tunnelling proposed under the Chilterns, the geology it will encounter and it’s impact on the surrounding AONB.
*POSTPONED*October 7 - Dr Antonio Ferreira
Radon, a silent GeoHazard
Radon (Rn) is a unique chemical element, as it is a geogenic, radioactive, noble, heavy gas with no colour, taste or smell. The element Radon is an intermediate decay product in the solid radioactive decay chain of Uranium (U-238 or U-235) or Thorium (Th-232); often known as Radon gas, Rn-222 (from) is the Radon’s most stable isotope with a half-life of 3.8 days, directly decaying from Ra-226 (half-life of 1602 years), in the U-238 decay chain.
Radon gas is geogenic and ubiquitous, as it is permanently produced from Uranium-bearing minerals which is one of the most common radioactive elements on earth and which is present in all type of rocks and soils. Radon gas production at a global scale has been constant in the past and will remain for the next millions of years as U-238 have a very long half-life (4 468 millions of years). However, Radon emanation from the ground can be highly variable from place to place, depending on Geology. Uranium enriched rocks (such as some granites, black shales, phosphate rocks, limestones, etc.) emanate higher Radon levels which are also favoured by a high permeability.
A difference in atmospheric conditions between indoors and outdoors favours Radon gas to accumulate inside houses, coming from the ground and getting in through gaps in the floor. In the UK the outdoor average level is 4 Bq/m3, while indoors it is five times higher (20 Bq/m3). Values as high as 10 000 Bq/m3 have already been measured indoors.
Radon is considered a health hazard due to its radioactivity. Radon exposure is reportedly the second cause of death by lung cancer in the UK (about 1100 per year1, 2), thus, possibly the deadliest Geohazard in the UK. This is a result of inhalation of Radon gas and its decay into solid short-lived isotopes (ex.: Po-218, Po-214), which easily attach to the lungs tissue while continuing to emit alpha particles.
Radon risk mapping in the UK is carried out through a joint project between Public Health England and the British Geological Survey. Maps showing the probability of dwellings exceeding the Radon Action Level (200 Bq/m3) are produced, by using a method that takes into account both the Radon indoor measurements and the Geology. These maps are produced with the aim of identifying Radon affected areas (figure 1), so that preventive or remedial measures (such as radon sumps, under floor ventilation) can be taken and the potential health impacts avoided.
1 Darby, S., et al. (2004) Radon in homes and risk of lung cancer: collaborative analysis of individual data from 13 European case-control studies. BMJ, 6 pp. doi:10.1136/bmj.38308.477650.63. 2 EPA (2009) RCE-11: Radon and Public Health. Report of the independent Advisory Group on Ionising Radiation.
December 2 - Prof. Julian Dowdeswell
The Polar Oceans and Climate Change
Subduction zones are located where one of the Earth's tectonic plates slides beneath another - this motion is controlled by the plate boundary fault zone. These plate boundary faults are capable of generating the largest earthquakes and tsunami on Earth, such as the 2011 Tōhuku-oki, Japan and the 2004 Sumatra-Andaman earthquakes, together responsible for ~250,000 fatalities. Although some plate boundary faults fail in catastrophic earthquakes, at some subduction margins the plates creep past each other effortlessly with no stress build-up along the fault, and therefore large earthquakes are not generated. Determining what controls whether a fault creeps or slips in large earthquakes is fundamental to assessing the seismic hazard communities living in the vicinity of plate boundary faults face and to our understanding of the earthquake process itself. In the last 15 years a completely new type of seismic phenomena has been discovered at subduction zones: “silent earthquakes” or slow slip events. These are events that release as much energy as a large earthquake, but do so over several weeks or even months and there is no ground-shaking at all. Slow slip events may have the potential to trigger highly destructive earthquakes and tsunami, but whether this is possible and why slow slip events occur at all are two of the most important questions in earthquake seismology today. Importantly, there is recent evidence that slow slip preceded and may have triggered two of the largest earthquakes this decade, the 2011 Tohuki-oki and 2014 Iquique, Chile earthquakes. Therefore, there is an urgent societal need to better understand slow slip events and their relationship to destructive earthquakes.
In this talk we will discuss the various types of fault slip behaviour that have now been discovered at subduction margins and delve into the new techniques that we are using to learn more about them in an attempt to ultimately crack the code of why some subduction megathrust faults slip in devastating earthquakes and some slide silently.
For many years, it has been accepted that the fossil record of animals can be traced back to the base of the Cambrian Period, around 541 million years ago. Prior to this point in Earth history, evidence for the presence of animals was scarce. Recent fossil discoveries, combined with new molecular analyses, have suggested that the earliest animals evolved in the Neoproterozoic Era, perhaps as much as 200 million years before the Cambrian. Fossils of large, complex, soft-bodied multicellular organisms that lived in the interval just prior to the Cambrian, and widely termed the "Ediacaran biota", are a key line of evidence in this debate. However, the unusual body plans of many of these fossils have defied classification, and there has been much discussion about whether they represent animals or entirely different groups, or even their own extinct Kingdom.
In this talk I will outline the current state of knowledge surrounding the Ediacaran biota, and will discuss the new findings and discoveries that are finally shedding light on what these enigmatic organisms may have been. Rather than being a confusing assortment of ultimately failed biological 'experiments', the Ediacaran biota record a diverse, thriving ecosystem that likely contained algae, bacterial colonies, protists, and some of the earliest animals. Such ecosystems thus paved the way for the complex animal-dominated marine communities of the Cambrian.
The Jurassic Kimmeridge Clay Formation is the UK’s single most important stratigraphic unit, being the source rock for most of the North Sea oil reservoirs. The oil is a consequence of the breakdown of buried organic matter, which, in Dorset, may make up to 30% of the Kimmeridge Clay at some horizons. This high organic carbon content reflects high productivity in the surface water during the Jurassic with super abundant phytoplankton feeding an equally abundant zooplankton, of which we know very little. Exposures of the Kimmeridge Clay Formation along Dorset’s World Heritage Jurassic Coast provide a unique window to the phytoplankton, and also to the other end of the food chain, where giant pliosaurs and crocodiles were the dominant carnivores. In between these microscopic algae and giants was an extremely diverse assemblage of invertebrates (molluscs, echinoderms and many more) and vertebrates, including more than thirty different fish species, ichthyosaurs, turtles and long-necked plesiosaurs. Every component of the assemblage was eating another. Waiting for the droppings below was a sedimentary soup inoculated with a cocktail of bacteria that, with the aid of a bit of heat and pressure, turned it all to gas and oil.
Numerous micropalaeontologists initially encounter single celled organisms through their early biological studies and it’s only when they’ve subsequently discovered the benefits of a geological education that they’re introduced to the wealth of micropalaeontological information available to them. Nevertheless, the initial biological understanding remains critical and Charles Lyell’s founding remark that “the present is the key to the past” is still an essential guide in modern day studies of foraminifera.
Over the last forty years enormous strides forward have been made in the various applications of foraminifera, from biostratigraphy and its uses in modern hydrocarbon drilling techniques through to biofacies studies and how these can be used in our understanding of the relationship between sedimentology and structural growth. The increasing knowledge of their genetics and their applications in palaeo-oceanographic, palaeotemperature and climate change studies, as well as their value in environmental monitoring, cannot be underestimated.
But - the basic techniques are still required if we’re to take this research further. Micropalaeontologists still need to know how to describe and identify what they’re recording and how their records can be made meaningful to their co-workers. So fundamental teaching is a major requirement. Having put this in place, it’s apparent that there are still gaps in our foraminiferal knowledge and that the evolutionary story of these microscopic organisms is still not fully understood.
From a Mineralogical perspective, a seemingly fairly innocuous region of the Carboniferous Limestone in the Mendip Hills, Somerset is perhaps the UK’s most scientifically important mineralogical location. It is unique in a world-wide sense, sharing only minor characteristics with deposits in Sweden and Namibia. Approaching 100 different minerals have been recorded in the area, making it now the most mineralogically diverse place in the British Isles. Amazingly, ten of the minerals so far discovered were recognised as being entirely new to science and several have never been found anywhere else. Although mines have worked in the area since ancient times, the deposits of Lead, Copper and Zinc, were eclipsed by the famous mining districts of Cornwall and the Northwest and unfortunately the area is often forgotten by those interested in the geology of mineralisation and the extractive industries, there are no books published on the importance to science of the minerals found here and most papers regarding the deposit are found in some of the less common or historic geological literature sources.
I will present a quick overview of the history of mining in the region and go on to cover in depth the progression of mineralogical discovery in this area - exploring how both professional and amateur geologists/mineralogists have been fundamental in our understanding of minerals from the area by discovering new materials to science since (probably) the late 17th Century. Research is still ongoing using mineral specimens from the area and some of the newer materials found here may have significant material science applications and may even question our concept of how we define a mineral. What is perhaps most surprising is that even after over 300 years of study, there is no consensus as to the origin of the unusual and unique suite of minerals preserved here - It is the UK’s mineral location that just keeps on giving scientists more and more things to think about!
The production of William Smith’s famous 1815 geological map, A Delineation of the Strata of England and Wales, with part of Scotland ..., was far from straightforward. Encouraged by his friends in Bath, Benjamin Richardson (1758-1832) and Joseph Townsend (1739-1816), to publish his discoveries on the sequence of strata and their contained fossils, Smith issued a prospectus for a work on the strata of England and Wales in 1801. But John Debrett (1753-1822), who had agreed to publish it, was declared bankrupt and it was over ten years before the cartographer John Cary (1755-1835) offered to publish Smith’s map. Th e map and its accompanying Memoir were eventually published in early September 1815, and i ts distribution began to the 410 subscribers listed in the Memoir. However, few had paid in advance, some refused to take their copies, and at least ten had died during the map’s ten-year long gestation. Those who did purchase a copy were not all sold the same map; in addition to complaining to Cary about the variable quality of some of the colouring, Smith continually revised and altere d the map, which must have been a source of irritation to Cary. Despite this, Cary continued to support Smith’s publishing of his cross sections, reduced map of England and Wales, and county maps into the 1820s. Although publication of the Geological Society’s map in 1820 must have impacted upon the sales of Smith’s map, sheets of the map were still being printed in the 1820s and several maps were produced in the late 1830s, just a few years before Smith’s death in 1839.
Salt is not simply for fish 'n' chips or icy roads. It is a unique and perhaps underappreciated rock type, living in the shadows of its more glamorous carbonate and clastic neighbours. For example, not only is salt one of the economically most important rock types on Earth, forming the seals to super-giant hydrocarbon accumulations, but it is also responsible for forming some of the most complex geological structures observed on the Earth. In this talk I will celebrate salt, highlighting its unique physical properties, it's role in the generation of complex geological structures, and it's importance in terms of hydrocarbon exploration.
December 11(2nd Fri) - Dr Helen Dacre
The largest airspace shutdown since WWII: Volcanic ash prediction and its challenges! The presence of widely dispersed volcanic ash clouds in the atmosphere can
disrupt air travel, resulting in serious global economic consequences. For
example, the eruption of Iceland's Eyjafjallajokull volcano in 2010 closed
European airspace for six and a half days, grounding over 95,000 flights and
affecting roughly 10 million passengers. The International Air Transport
Association stated that the total loss for the airline industry was around
£1.1. billion. The event highlighted an incomplete understanding of the
impact of volcanic ash on aircraft engines, poor communication between
scientists from different disciplines and deficiencies in the volcanic ash
Since 2010, progress has been made to address these issues with the ultimate
aim of improving volcanic ash cloud predictions. In this seminar I will
provide an overview of volcanic ash cloud prediction, discuss the challenges
involved in making accurate volcanic ash predictions and present results
comparing observations and model simulations of the Eyjafjallajokull
volcanic ash cloud.
December 5th - Andrew Bloodworth, British Geological Survey, Keyworth, Nottingham NG12 5GG, United Kingdom email@example.com
A once and future extractive history of Britain: The rise, fall and resurgence of UK domestic mineral supply
Geology, geography and human affairs have combined to give Britain a rich history of mineral extraction which stretches back several thousand years. Changing technological, economic and social factors means that the character and scale of domestic extraction have varied enormously over this time span. These same factors have also influenced our level of trade in minerals and metals with the rest of the world. Cornish tin established Britain as a supplier of metal across the ancient world. Norman masons utilised huge quantities of dimension stone to build cathedrals and castles. Wooden ships sheathed with copper from South West England, Wales and the Lakes secured a global empire for Britain in the 17th and 18th Century. Indigenous coal and iron were the basis of Victorian and Edwardian prosperity. Aggregates for road building literally formed the foundation of the post-war ‘great car economy’.
Economic globalisation, technology shift and changes in societal attitudes in the late 20th and early 21st Century caused a precipitous decline in domestic output of some minerals, notably metals and coal. The British seemed content to let the global market provide their material needs and happy to export the impacts of mineral extraction to other countries. However, by 2050 it is likely that human population will be close to 9 billion, economic power will have shifted from the West, environmental change will be accelerating and global competition for resources will be intense. In the face of this enormous challenge, will indigenous minerals make a comeback and increase their contribution to our security and prosperity?
October 3 - Hugh Torrens
The Incredible Story of the Stone Pipe Company 1805-1815, London, Manchester and DublinThe Incredible Story of the Stone Pipe Company 1805-1815, in London, Manchester and Dublin.
The Stone Pipe Company (SPC) was set up to supply these three, rapidly enlarging, British cities with water, through pipes of clean, solid, and thus pure, stone. Previously used elm pipes had proved both to leak and be all too short-lived. Cast iron pipes were regarded as equally unsuitable, and more expensive, as all too often these produced only bad, iron-stained, water. When production targets shot up, Guiting Stone, high up in the Cotswolds, was chosen as the company's source of stone. This was because of the large-sized blocks which Guiting Stone alone could yield. Here, deep in the Cotswolds, for a few frantic years, was a massive manufacturing enterprise, with 30 tons of pipes leaving the works each day. Many of Britain's most famous engineers were involved; James Watt senior (the steam engineer), William Murdoch (the pioneer of gas lighting), John Rennie (the famous civil engineer, who was the SPC's chief engineer and a share-holder) with tramroad wagons supplied, but never paid for, from the famous Butterley Company in Derbyshire. Expensive plans to run first a major canal, and then a long tram road, into the works to facilitate transport of pipes were set afoot. But, in July 1812, the pipes failed, at first in London, on a massive and terminal scale. The pipes had proved unable to withstand the, steam-engine driven, water pressures now being used. These were needed to provide 'high service', up to the tops of the fashionable houses it was hoped to supply. Back-biting and bankruptcy, including one major London bank, followed, in one of the first cases of "systems failure" in British history. This failure helped initiate the systematic testing of geological and other materials here, for a first time. This lecture explores the complex story of this amazing enterprise, one of the most remarkable happenings ever to involve Cotswold geology. Previous, and continuing, claims that this whole enterprise was simply 'fraudulent', ignore the abundant historical record, which cannot simply be googled in these newly idle days.
July 4 - Ed A Jarzembowski BSc PhD FGS FRES
In search of the Silk Road- late Mesozoic insects from the ends of Eurasia
Visiting Professor Chinese Academy of Sciences Nanjing
Scientific Associate The Natural History Museum London
The late Mesozoic of northeastern China has become famous for the exceptional preservation of fossil vertebrates unearthed by local people in recent decades. The fauna, however, also includes diverse invertebrates, especially insects, which are now being actively studied and described. The fossils usually occur as sporadic, intact, articulated specimens in fine-grained siliciclastic sediments deposited in volcanic lakes (Yanliao and Jehol biotas). Insects remains are also common in contemporary non-volcanic, more fluviatile deposits in southern England (Purbeck-Wealden biotas). A number of genera in different orders are found in both regions. Thus the deposits complement each other in our understanding of late Middle Jurassic and early Cretaceous insect life and environment. This illustrated talk will explore ancient colour, song, sex and vertebrate parasitism as well as silken artefacts revealed in this ancient Palaearctic palaeoentomofauna. And did their world end with a bang- or a whimper?
Pics: late Middle Jurassic, Daohugou, Inner Mongolia; Lower Cretaceous basal beetle Cionocoleus from Purbeck Limestone Group (left), Yixian Formation (right).
June 6 - Susan Evans
Big, bad and bizarre, the devil frog from the Late Cretaceous of Madagascar
Madagascar is one of the largest islands in the world and, as a result of both its isolation and geological history, is home to a diverse and unusual collection of animals and plants. The extant frog fauna of the island is exceptionally rich and almost completely endemic. Understanding of the history and relationships of these frogs has been greatly advanced by molecular studies, but very little is known of their fossil history. Until recently, the fossil record of frogs on Madagascar was limited to a single specimen of the Early Triassic proto-frog, Triadobatrachus. However, over several decades, palaeontologists from Stony Brook University, New York, have led field work in the Upper Cretaceous (Maastrichtian) rocks of the Mahajunga Basin in the north west of the island. These deposits have produced a diverse fossil assemblage including dinosaurs, crocodiles, turtles, rare lizard remains, mammals and primitive birds. In 2008, we named the first fossil frog from the deposit, based on a small collection of distinctive skull fragments. The large size, heavy ornamentation, and inferred predatory nature of this frog led us to name it Beelzebufo. Beelzebub, lords of the flies, seemed rather appropriate. More recently, new material of the skull and postcranial skeleton has shown Beelzebufo to have been even more bizarre than we originally interpreted. Various features of its anatomy, including the absence of an eardrum, suggest it may have survived periods of seasonal aridity underground. Oddly, phylogenetic analysis continues to place it with South American ceratophryid ('Pacman') frogs rather than African ones, posing something of a palaeobiogeographical conundrum.
May 9 AGM and Presidential Address - Rory Mortimore
A walk on the Chalk Side Part 2: Flint, basins and the end of the Chalk in the British area
The magic of flint a never ending story. Flint is inextricably interlinked with chalk in many parts of the World including North West Europe. Continuing last year’s theme of trying to answer the seemingly simplest yet most difficult questions relating to the origin of Chalk this year’s talk illustrates the role of flint in helping to unravel some of these mysteries.
In this quest some the topics to be covered include:
1. Nature of flint in bedding. What controls the apparently ‘cyclic’ recurrence of flint bands?
2. Recurrence of types of flint and do these reflect large-scale sedimentary cycles?
3. Some remarkable flint bands (Criel Paramoudras, Lewes Tubulars, Cuilfail Zoophycos, Seven Sisters Semi Tabular).
4. Preservation of fossils (uncrushed) trace fossils (unsquashed), and early fractures illustrate the early onset of flint formation.
5. Correlation of flint bands and flint types (long distance – thousands of kilometres). How do we identify the same flint band in widely separated areas?
6. Distribution of flint and basin analysis (shelf to deep-water). What controls the absence of flint in some areas and lots of flint bands in other areas?
7. Fragmented flints such as the ‘Mish-Mash’ Flints and the flints of Etretat and Hope Gap occur in bedding plane slips and in slump bedding. How can strong flints fragment in very weak, soft chalks?
8 In areas where intra-chalk reworking has occurred flints are absent. What happens to the host sediment to prevent flint formation.
9. Flints as a pain in the tunnel face.
10. Flints as impermeable water flow horizons and development of cave systems.
Flint and the end Cretaceous in the British area.
Flint bands continue into the youngest Maastrichtian chalk of Norfolk and Northern Ireland and siliceous chalks and reworked flints are a feature of end Cretaceous deposits of the Inner Hebrides.
April 4 - Vladimir Zholobenko
Zeolites – just boiling stones?
“Among the minerals I have collected and whose properties I have sought to investigate, two specimens exhibit so strange and peculiar behaviour in a blowpipe flame that it is impossible to identify them with any other family. I have boldly, but I trust not too presumptuously, designated these minerals zeolites.” In 1756, when the Swedish mineralogist Axel Cronstedt coined the name for these newly found minerals (zeolite is a Greek word meaning boiling stone), he could not know that it would take two centuries for these materials to demonstrate and realise their potential. But when it did happen in the second half of the 20th century, their success was overwhelming. Largely unknown to the general public, zeolites have become essential for a host of major industrial developments, and scientific studies into zeolite science have increased dramatically over recent decades, reflecting the growing understanding and application of these versatile materials. It is estimated that 5 million tons of natural zeolites are mined and 2 million tons of synthetic zeolites are produced annually. Thanks to the unique combination of their exceptional properties, zeolites are utilised as molecular sieves and sponges, as nuclear waste clean up materials and as water softeners in washing powders, as well as essential catalysts in oil refining for the production of petrol and diesel and in petrochemical industries making plastics and synthetic fibres.
This presentation aims to give a brief overview of zeolite science and practice, as well as to demonstrate the natural beauty of zeolite structures and their remarkable properties.
March 7th - Note: Change of Lecture - Dr. Haydon Bailey, with input from Liam Gallagher and Matt Hampton,
Network Stratigraphic Consulting Ltd.
Provenance – the search for a source.
As micropalaeontologists, once we’ve put an age onto a sample, one of the next most frequently asked questions is “where did it come from?” The answer to this can have considerable implications and a variety of applications. These may be archaeological or historical, just as much as geological. They may have implications in criminal investigations and therefore need to stand up to forensic scrutiny. Microfossils can often occur in their thousands; they are frequently morphologically very distinctive and they can be restricted in both their age range and their provenance. This presentation includes a variety of examples, ranging from the origins of building stones and Tudor paintings through to the detailed analysis of material directly used as evidence in murder cases.
February 7th - Prof. Gina L. Barnes, SOAS, University of London
Japan: volcanic soils and agriculture from prehistory to present
Every inch of the Japanese Islands has been covered with tephra from its 108 active volcanoes and inactive volcanoes dating back to the beginning of Quaternary volcanism 700,000 years ago. Much of this tephra has been transformed into clay, but considerable amounts remain as volcanic ash loam and pumice. Traditional Japanese rice agriculture has been concentrated on the lowland alluvial plains, but what about upland areas and their potential for agriculture? We will discover that the Japanese story is quite different from the Mediterranean where fertile volcanic soils support rich farmland.
January 3 - Ian Watkinson (Teaching Fellow at Royal Holloway University of London)
Virtual fieldwork using Google Earth: exploring global tectonics from your armchair
Since its release in 2005, Google Earth has provided free and accessible imagery of the entire surface of the earth, something previously only available to those with access to expensive datasets and complex processing software. As a tool for gaining rapid, global-reaching and often detailed views of the earth’s surface (left: Fig. 1, Thrust fault near Borah Peak, Utah) it is unsurpassed – leading to its widespread use by non-scientists, the media, industry as well as academia.
To the geologist it provides a ready method of visualising surface processes, lithological characteristics and structural features in three dimensions (Fig. 2) comparable to the traditional method of using stereopairs of air photos. In its early days much of the imagery was based on relatively poor resolution Landsat data, but blocks of high resolution data including those acquired by the QuickBird and SPOT satellites are progressively being added, so that it is now possible to undertake ‘virtual fieldwork’ almost anywhere on earth without leaving home (Fig. 3). The imagery can also be used as a reconnaissance tool to plan real fieldwork, to identify large-scale structures (Fig. 4), pinpoint potential field locations and produce synoptic overviews previously only possible using an aircraft (Fig. 5).
(from left to right), Fig 2: xxx; Fig. 3: Antiformal fold, Iran; Fig. 4: Mekong River strike-slip displacement, Myanmar-Lao PDR border.
(from left to right), Fig. 5: The San Andreas Fault at San Francisco, California; Fig. 6: Conjugate strike-slip fault pair, Kazakhstan; Fig. 7: Indian Ocean crust ages (http://nachon.free.fr/GE/Welcome.html)