Dean R Lomax (UK) Introduction Ichthyosaurs are extinct marine reptiles that superficially resemble dolphins and sharks, but are neither. They are most definitely not ‘swimming dinosaurs’. In fact, they were fully aquatic marine tetrapods that lived in the seas, while their more famous counterparts – the dinosaurs – roamed the land. They achieved a worldwide distribution and remains have been discovered from the late Early Triassic to the early Late Cretaceous, and hundreds of species have been described (McGowan and Motani, 2003). The coastal town of Lyme Regis, situated on the Dorset coast, is often seen as the birthplace of ichthyosaurs. Many ichthyosaurs were collected from here during the early nineteenth century and were first brought to the attention of the scientific world by a fantastic young woman called Mary Anning (see below). The focus of this article is based on the most famous ichthyosaur genus, Ichthyosaurus, which lends its name to the group. The first species, I. communis, was described in 1821; the second, I. breviceps, was described in 1881; and the third, I. conybeari, was described in 1888. Since then, lots of ‘Ichthyosaurus’ have been described and all have since been found to represent distinct ichthyosaur genera and species, until now. No-body-saurus In 2008, I began researching the collections of my hometown museum, Doncaster Museum & Art Gallery. One specimen, the key ichthyosaur of this study, was shown to me as “an exceptional cast” (this was as part of an exhibition I created at the museum; see my … Read More
Robert Sturm The Isle of Skye is a part of the Inner Hebrides in the north-west of Scotland. It has a total area of 174,000 hectares and has an irregularly shaped coastline that is typical of the British Isles. Since the early nineteenth century, the island has become a centre of geological research, because rocks of different geological periods are exposed there. For instance, the gneisses of the Lewisian complex were formed in the Proterizoicum, 2,800Ma and, therefore, are some of the oldest rocks in Europe. On the other hand, intrusive and extrusive igneous rocks can be assigned to magmatic events that covered wide parts of the island during the Tertiary. This event, which took place about 60Ma, resulted in the development of the Atlantic Ocean in its present form. In more recent times, two ice ages, which affected the island 26,000 years ago (the Dimlington glacial) and 11,000 years ago (the Loch Lomond glacial), resulted in the formation of a partly spectacular glacigen landscape (a landscape formed by the ice) with sediments that are of high interest for geological research. Fig. 1. Geological map of the Isle of Skye (modified after Anderson & Dunham 1966) illustrating the high variability of rocks that can be found on the island. Impressive evidence for the Tertiary volcanism is provided by the plateau lava series (these are horizontally stacked layers of lava), mainly exposed in the north and west of the island. These extrusive rock formations probably reached a thickness of 1,200m before … Read More
Scotland has been the source of many important fossil discoveries, from the first ever soft body parts of the conodont animal, to Devonian fishes and early tetrapods. Yet, there has been little published for the popular market on Scottish palaeontology.
David M Martill (UK) After several gruelling years of working in the sticky wet Jurassic clay pits of the Peterborough district for their gigantic marine reptiles and even more massive fishes, it was a refreshing change to fly south and investigate the sun-baked Caatinga of South America. The Chapada do Araripe, on the borders of the Brazilian states of Ceará, Pernambuco and Piaui, had always fascinated me (Fig. 1). Fig. 1a (left). A map showing the location of the Chapada do Araripe in the northeast of Brazil. Fig. 1b (above). Detail of the Chapada do Araripe. This is one of the most important sites in the world for Cretaceous Gondwanan fossil fauna and flora. I had seen specimens of the fabulous fossil fishes (I hope you like the alliteration) in limestone concretions (Fig. 2) that kept turning up in European fossil shops, but what had really caught my eye was a short letter to the scientific journal Nature that described fossil ostracods from those very same concretion horizons. Fig. 2. A typical concretion from the Santana Formation, with a not so typical fish. This is one of the rare fossil rays. I am not an aficionado of ostracods: who is? They mostly look like small baked beans, and it is so tedious trying to mount them on stubs so that you can see them under the electron microscope. No, it was the remarkable quality of their preservation that caught my eye. The specimens in question were described by Ray Bate, … Read More
Jens Lehmann (Germany) The recent find of a big slab of Early Cretaceous lumachelle limestone of the Wealden facies containing a bone (Figs. 1 and 2) made for a time-consuming and technically ambitious preparation process. (Lumachelle limestone is a compact limestone or marble containing fragments of shells, encrinites and other fossils, which are sometimes iridescent, and display a variety of brilliant colours.) The specimen looked disappointing at first sight, but the end result made the hard work worthwhile, as I discuss below. Indeed, the following is intended as an example of the technical aspects of palaeontology, which are too often forgotten or ignored. The specimen was discovered in a loose, but very heavy slab on the beach. Therefore, efforts were made to reduce the size of the rock in the field to make it easier to carry, but, unfortunately, it broke into two pieces (Figs. 1 and 2). Fig. 1. A bone in a limestone from the Early Cretaceous (Barremian, Wealden facies), broken while preparing the slab in the field. Fig. 2. Reverse side of the limestone slab, with masses of freshwater bivalves making up most of the boulder. The original surface of the bone was completely worn – with no details preserved (Fig. 3A) and therefore a transfer preparation had to be planned. On the other side, the cross section (Fig. 3B) gave me a pretty good idea of the shape of the bone before preparation and the exact thickness of the rock that would have to be removed … Read More
Jens Lehmann (Germany) Plate tectonics drove the continent-continent collision of Euramerica and Gondwana, roughly 280 to 380mya. This mountain-building phase of the late Palaeozoic era is referred to as the Variscan Orogeny and eventually formed the supercontinent Pangaea. This was largely complete by the end of the Carboniferous and many of today’s secondary mountains in Europe are ascribed to the Variscan phase. In the UK, this event formed a couple of spectacular places for geotourism at the boundary between Devon and Cornwall. When visiting southwest England, you should not miss these spots – they are surely among the most impressive places in the world showing the effects of tectonics. A tiny settlement but tremendous in geology A tiny settlement on Cornwall’s coast gives the name for surely the most famous spot for folded sedimentary rocks in the UK – Millook Haven. A narrow, winding road leads down the hillside, with a gradient of 30° (Fig. 1). Fig. 1. At the top of the winding road down to Millook Haven. But, after surviving the journey downhill, you are rewarded by a cliff with spectacularly folded Carboniferous sediments (Fig. 2). Fig. 2. A group of geology students visiting the spectacular Millook Haven cliffs. On a global scale, coal swamps are typical of the late Carboniferous period. However, in Cornwall and Devon, no economically viable coal was deposited. In southwest England, alternating sand- and claystones, which had been transported by submarine currents with material mainly in suspension, were formed in an environment far … Read More
John P Green (UK) The Ampthill Clay Formation of the UK, of Late Jurassic (Oxfordian) age, represents a series of highly fossiliferous marine mudstones that form part of the Ancholme Clay Group in North Lincolnshire (Gaunt et al, 1992); but are almost unexposed in the county other than at an excellent exposure of the Ringsteadia pseudocordata zone at South Ferriby Quarry (SE 992204). Therefore, this shortage of natural exposures means that any information, which can be obtained from other exposures in this county, is of the utmost significance. Minor stream exposures at Kingerby Beck, North Owersby in North Lincolnshire (TF 0519 9340) have revealed a rich and well-preserved fossil fauna. These minor exposures have been placed by Gaunt et al (1992) within the Amoeboceras glosense zone, therefore lying at a differing stratigraphical horizon to the South Ferriby Quarry. Also, in contrast to the latter locality, the fossils exhibit a much higher degree of preservation and are therefore easier to collect. Fig. 1. Kingerby Beck, North Owersby. Minor exposures of the Jurassic Ampthill Clay. Unfortunately, biostratigraphical bed-by-bed collecting is largely impractical at Kingerby Beck, due mainly to the very minor nature of the exposures; indeed, the majority of fossils have been collected from patches of clay exposed on the stream bed. The Ampthill Clay Formation, where exposed, is present as undifferentiated pale grey mudstones, with scattered calcareous concretions. It is these that are the major source of the prolific and well-preserved fossil faunas, particularly ammonites. Some of these concretions are very … Read More
John P Green (UK) The large, disused quarry at North Ormsby [O.S. grid ref. TF2893], north of Louth in Lincolnshire, displays an important sequence of beds of the Burnham Chalk Formation (Upper Cretaceous, Upper Turonian stage) and, at present, constitutes the best exposure of the beds in the county. Similar beds exposed at Ulceby Vale Pit [TA104133] in North Lincolnshire have described in terms of both stratigraphy and palaeontology, by Wood (1992) and, more recently, by Hildreth (1999, and in press). Fig. 1. North Ormsby disused quarry; an important sequence of beds of the Burnham Chalk Formation. The North Ormsby section was measured and described in stratigraphical terms by Wood and Smith (1978), although little information on the macrofauna was published. Hill (1902) was the first to identify the S. plana biozone of the Burnham Chalk Formation in this area, and Rowe (1929) provided an admirable macrofaunal list in his account. Therefore, my aim is to build on the work of previous authors, and place the recorded macrofossils in a stratigraphical context. In addition, Wood and Smith (1978) established important flint and marl marker horizons for the chalk of Lincolnshire and Yorkshire, and these shall be referred to in this account. Fig. 2. Closeup of the Burnham Chalk Formation. The Burnham Chalk, as exposed at this locality, consists in general terms of thick bedded chalk, interbedded with marl seams and marl layers, and beds of predominantly tabular and semi-tabular flint bands. About halfway up the sequence, above the level of … Read More
I don’t normally review BGS memoirs – they are excellent publications, but largely written for the professional or the seriously committed amateur geologist. (I have to admit to owning several, which cover my favourite fossil collecting areas of the UK.) However, this is one ‘Special Memoir’ that I am quite willing to make an exception for.
John P Green (UK) The Early Cretaceous succession in Lincolnshire consists of a series of shallow water marine sandstones, ironstones, clays and limestones, not unlike those deposited elsewhere in the UK during early Jurassic times. In the north of the county, at Nettleton Hill, near the village of Nettleton, minor exposures of the Claxby Ironstone Formation are present. Fig. 1. Nettleton Hill, showing former site of workings for Spilsby Sandstone and the overlying Claxby Ironstone, now restored. This deposit, approximately 5.7m thick, rests unconformably on the eroded Late Jurassic Spilsby Sandstone Formation of Volgian age. The age of the ironstone ranges from the Lower Valanginian to the Lower Hauterivian stage, and is of particular interest due to the ammonite and belemnite faunas it contains. My studies over a number of years have brought to light a series of cephalopod faunas that are also prevalent in Speeton, East Yorkshire, as well as northern and southern Europe. Prominent contributors to the study of the cephalopod faunas of this formation include Lamplugh (1918), Swinnerton (1935), Casey (1973), Wright (1975) and Kemper et al (1981). The ironstone is divided into two members: the Lower and Upper Claxby Ironstone Formations. Both these formations are characterised by a brown to purple clay matrix, rich in prominent iron ooliths, and which is highly fossiliferous. Excellent exposures were formerly present in opencast and deep mines around Nettleton (TF 1140 9868, TF 1164 9870). However, these sections are now unfortunately filled in. The current exposures at Nettleton Hill, while … Read More
Anthony Rybek (UK) Having lived on the Isle of Skye since 2007, I consider myself to be very fortunate to have every day opportunities to fulfil my hunger for the wilderness, natural world and two of my greatest passions, fossil hunting and geology. So, it was of no surprise to me that, during these times immersed in this dramatic and mostly unspoiled landscape, yet another passion would evolve – oil painting. Fig. 1. Anthony Rybek, working on a painting. Like all my pursuits, I am self-taught and, as I began to learn and practice painting techniques, it soon became clear that I had a degree of aptitude for this art form. I found it similar to my earliest fossil hunting trips where, once I tasted success and the thrill of discovering new and amazing fossils, the desire to learn more and improve my skills grew deeper and deeper. My painting is no different. It wouldn’t take long before the subject matter for my landscape paintings would cross paths with fossil hunts and geology. Skye has an abundance of iconic geological landmarks and I feel privileged to have a basic understanding of the geological processes that help shape these formations. And it is these dramatic scenes that are the main influence of many of my paintings. The Trotternish Ridge In the northern half of Skye, this is the dominant feature of the Trotternish Ridge, which runs like the spine of an ancient creature between the islands capital Portree and the infamous … Read More
Dr Trevor Watts (UK) In the first part of this article, I discussed the Middle Jurassic environment in the region of Whitby, on the northeast coast of England at the time when dinosaurs roamed there. In Part 2 (see The dinosaur footprints of Whitby: Part 2 – problems matching footprints to dinosaurs), I looked at how the footprints were formed and preserved, and at the problems in identifying and classifying them. And in Part 3 (see The dinosaur footprints of Whitby: Part 3 – a brief look at the six footprint groupings), I discussed the six major forms of footprints to be found in the area. In this fourth and final part, I will describe each of the four locations close to Whitby, and hope to give an idea of what footprints are there to be searched for. Fig. 1. Reproduced from the first part of this article – the four sites around Whitby where dinosaur footprints are commonly found. 1. East Cliff Beach Fig. 2. East Cliff Beach, with four minor headlands and five bights. Even on a much-visited beach such as East Cliff in Whitby, dinosaur footprints can be found without a lot of difficulty. This is a variable beach with ever-changing areas of rock platform, masses of sand and boulder fields, punctuated by frequent cliff falls and slumps. Every summer weekend, it is home to hundreds of curious fossil-searching families. It is very easily accessible down a slippery concrete ramp during the lower half of the tide … Read More
Dr Trevor Watts (UK) In my previous articles in the series, I looked at the environments that allowed dinosaurs to flourish in the Whitby area during the Middle Jurassic and to leave their footprints. Then I considered the factors and problems in trying to match the footprints to particular species of dinosaurs. In this part, I will look at the six different forms that dinosaur footprints mostly take in the region. 1. Theropods Fig. 1. A Squabble of Theropods. The toes of theropods tend to be quite slender, they are longer than the heel and the foot is longer than it is wide. Theropods, meaning “beast-footed”, include well-known dinosaurs such as Megalosaurus, Velociraptor, Tyrannosaurus, Allosaurus, Tarbosaurus, Troodont, Deinonychus, Coelophysis and a great host of turkey-sized raptors. Most of these species were not around at this specific time and place (although Megalosaurus may well have been). However, they were principally fast-moving carnivores that hunted or scavenged. They all had sharp, serrated, meat-ripping teeth; and were mainly bipedal – that is, they ran on two strong rear legs, with much shorter and weaker forelimbs. Figs. 2, 3, 4 and 5. Examples of small and large theropods, and their feet. Their footprints are said to be “tridactyl” – a word somewhat pretentiously created in the early nineteenth century from the ancient Greek for three fingers. It loaned scientific credence and academic gravitas to this new field of study. Most of the early footprints found in the UK and along the Connecticut Valley in … Read More
Dr Trevor Watts (UK) In the first part of this article (The dinosaur footprints of Whitby: Part 1), I considered the immediate surroundings of Whitby as a seemingly unlikely place to find many dinosaur footprints; and I looked at the environments that existed here in mid-Jurassic times; and finally discussed how the footprints came to be shaped as I find them. In this part, I look at the problems that are encountered in trying to match the footprints to particular dinosaur species, and at the idea of ‘ichno-species’. I also suggest a simple compromise in classifying the footprints. Matching a footprint to a particular species of dinosaur isn’t easy, for several reasons. 1. Relatively few dinosaur species have been identified as living at this time or in this region In many parts of the world, the relevant rocks have been eroded away, or are deeply buried under later beds, or no beds were laid down, or the environment was marine. On a worldwide scale, there are remarkably few places where footprints coincide with skeletal remains that might be matched with them. The Middle Jurassic is a time about which very little is known with regard to the variety, numbers and development of dinosaurs, anywhere in the world. In fact, it is the least understood part of the Jurassic. Fig. 1. Replica foot and footprint photographed at both Dinosaur Valley State Park, Texas and Springfield Science Museum, Connecticut. In this particular area, it is extremely rare to find any skeletal remains … Read More
Dr Trevor Watts (UK) Introduction I recall reading a sentence in a book some time ago that went something like, ‘Occasionally a dinosaur footprint may be found along the coast.’ In fact, dinosaur footprints are superabundant along the Yorkshire Coast. On a day’s visit to any of 15 or 20 beaches, we (my wife, Chris, and I) would consider finding less than a dozen footprints to be a little disappointing, unless they were especially clear, part of a track or an unusual type. More commonly, we would expect to find two dozen or so recognisable prints. Fig. 1. Map of the UK showing the position of Whitby on the coast of Yorkshire. The outline map of the UK is reproduced by courtesy of d-maps at http://d-maps.com/carte.php?num_car=2557&lang=en. This article is intended to give an impression of how common they are, what to look for, what might have made them and where exactly they can easily be found. It is not meant to be a technical, profoundly scientific paper: it’s a discussion. I hope it will provide an idea of what they might look like when you’re out on a beach (that is, the sort of things to be looking for on the rock surfaces, so you can recognise a footprint – they aren’t always clear at first sight). It is largely a case of seeing the ridges and bumps – the curves and angles, and the grooves and depressions on a rock surface – for what they are. This is a … Read More
The Jurassic Coast Trust is certainly producing some good books these days. I have alraedy reviewed one (The Jurassic Coast: An Aerial Journey through time by Peter Sills) and I think these two might even be better. As is well known, in recognition of its wonderful geology, the coast between Orcombe Rocks in southeast Devon and Old Harry Rocks in south Dorset was granted World Heritage status in December 2001.
Mark Wilkinson (UK) Scotland has a number of sites of historical interest to geologists. I described one of these, Hutton’s Unconformity at Siccar Point near Edinburgh (see Hutton’s unconformity and the birth of ‘Deep Time’). James Hutton described several Scottish unconformities in his book of 1795 and, while the one at Siccar Point is easily the most dramatic and most easily accessible, there is another unconformity on the Isle of Arran that is well worth a visit if you are on the island. There is a third unconformity in the Scottish Borders that is sufficiently well known to be actually called ‘Hutton’s Unconformity’, but is on private land and is thought to be presently inaccessible. There are also a number of other locations that Hutton described, but which have sunk in the mists of time back into obscurity. It would make an interesting project to resurrect these. It was on the Isle of Arran that Hutton first observed an actual unconformity surface, in 1787. Arran is the seventh largest Scottish Island at around 32km long, lying in the Firth of Clyde some 64km to the southwest of Glasgow. Sometimes described as ‘Scotland in miniature’ due to the range of scenery, Arran has both highland and lowland landscapes. This is because the varied scenery reflects the underlying geology, with rocks typical of the Highlands of Scotland, and the lowlands. There is a good range of sedimentary, igneous and metamorphic rocks, many of which have well-exposed field relationships, as well as areas … Read More
This is an odd little book. Produced by the Craven & Pendle Geological Society and edited by Paul Kabrna, it sets out to cover the geology of Craven Lowlands through a series of chapters written by different contributors.
Diana Clements (UK) The Geologists’ Association (GA) was formed in 1858 and, from its inception, was an inclusive organisation set up to embrace both professional and amateur geologists, unlike the Geological Society, some 50 years older, which was only intended for professionals. Women were accepted from the beginning – similar organisations of the time were habitually men only. It was intended as a meeting-place for like-minded people and fieldtrips were always an important part of the Associations’ activities. As early as 1895, Local Groups around the country were set up to extend activities nationwide; now we have 17 Local Groups with a further 72 other geologically-related societies that are affiliated with the GA. The aims that we adhere to now were developed gradually and foremost among them is to make geology available to a wider public. The Proceedings of the Geologists’ Association first appeared in 1859, only a year after its formation, and included written papers presented first to members at the Friday lectures and the write-ups from the early fieldtrips. These are often important historical documents of geology in a bygone age, no longer visible, particularly in urban environments. Fig. 1(a) A fieldtrip to Gilbert’s Pit, Charlton in 1913, when the quarry was operating. Fig. 1(b) The same face in 2016, with steps erected to view the remaining exposure of geological interest. As well as the images in the write-ups, the GA possesses a large archive of photographs and associated ephemera documenting the activities of the Association since the … Read More
If you can see past the somewhat robust title (a reference to James Hutton’s discomfort riding around Scotland on horseback during his geological investigations), this is an interesting read, combining both geological science and humour in just about the right measures.
The Geologists’ Association has produced yet another great guide, this time on the geology of Wales. However, this is a slightly different beast from most of their other publications.
Jens Lehmann (Germany) Plagiostoma – a record of about 200 million years Are there any boring fossils out there in the ground? I do not think so and to demonstrate this, an “ordinary” fossil find is focussed on here. We are talking about “just” a mussel, but one that belongs to an extinct group and even this alone makes it exciting. Plagiostoma is a member of the file clam family. This genus is only known from the fossil record and appeared probably in the Permian and certainly by the Mid-Triassic period, about 240 million years ago. This genus became extinct at the Cretaceous-Palaeogene boundary – according to the most recent timescale dated 66 million years ago. At least two dozen of species have been described so far. The shells of Plagiostoma are moderately inflated and can reach the size of a hand, with an oblique oval outline. It is a common fossil, for example, in the Muschelkalk (Middle Triassic) in the Germanic Basin and quite a few continental countries. It is also well known from the Blue Lias of Southern England and stratigraphic equivalents, and can be frequently found at Monmouth Beach in Lyme Regis, a world-famous spot for fossil hunting. The giant Plagiostoma The species frequently encountered at Lyme Regis is Plagiostoma gigantea and the name already suggests that it is a giant amongst the representatives of the genus. The specimens figured here (Fig. 1) are of moderate size, with a total length of each about 8cm, but there … Read More
Jon Trevelyan (UK) This is the much anticipated 4th edition of the GA’s Yorkshire Coast guide and it was well worth the wait. From personal experience, I was aware that the previous editions were extremely good for any geologist – professional, academic or amateur – who is attracted by the wonderful scenery and fascinating geology of this part of the UK coastline. However, this new edition is altogether an even better product. The full colour photographs, diagrams and maps make for an entertaining and informative read, and a new chapter using seismic profiles provides additional information not in previous editions. Like all GA guides, this introduces the geology of the Yorkshire Coast in an accessible and readable style, including coverage of its structure, stratigraphy, palaeogeography and environments, and its industrial history. It then provides 17 excursions covering areas from Staithes in the north to South Holderness in the south. This takes in all the obvious areas that any fossil collector in the area will know – like Staithes to Port Mulgrave, Saltwick Bay to Whitby, Speeton and Flamborough Head – but also includes some new locations, such as Betton Farm Quarries, which is a SSSI. I was lucky enough to visit this fascinating site with the authors, who showed us why this excellently exposed localised, coral reef from the Upper Jurassic was worth including in the guide. (There is also an excellent charity-run tearoom and restaurant to visit after looking at the rocks.) Pete Rawson spent his academic career in … Read More
The long awaited PalAss guide to Wealden fossil flora and fauna has finally arrived and what a magnificent tome it is. At 769 pages and 35 chapters, it is by far the most ambitious and complete of their guides, covering various vertebrate groups, together with invertebrates, plants and stratigraphical descriptions of what can be found on the coast and in the quarries of southern England and the Isle of Wight.
Martin Simpson (UK) Newly unearthed documentary evidence substantiates the classic story that Mary Ann Mantell found some worn down Iguanodon teeth in Cuckfield, Sussex, before 1822 in some rocks by the roadside, while her husband Gideon was elsewhere. She was accompanied by a friend and purchased the specimens from a workman. We now have the who, what, where and why in this discovery, but the precise when remains unclear. It is suggested in this article that the event took place on 21 May 1821 and the fossils were passed to Gideon the following day. Subsequently, the ‘later to be’ dinosaur was formally named in 1825. Introduction One of the benefits of the government’s 2020 social lockdown policy, introduced to combat the spread of the Coronavirus pandemic, has been the increase in reading, researching and publishing amongst many scientific academics. There will no doubt be a corresponding increase in productivity for the individual scientists themselves and a forthcoming ‘paper boom’. In my own case, I have spent proportionately more of my time preparing, cataloguing and researching fossils, and less on actual field collecting due to the travel restrictions, resulting in a significant catch-up of jobs that needed doing, but were otherwise confined to the back burner. In particular, with precious little television worth watching, I have been trawling the internet in search of obscure references to check the synonymies of umpteen species of interest, and to add to their historical background. Whilst googling a topic somewhat off at a tangent from … Read More
Rory Mortimore (UK) Flint in the Late Cretaceous Chalk: links across the European platform In a recent issue of this journal Paul Taylor wrote “We are very fortunate in Britain to host one of the most remarkable deposits in the entire geological record, the Chalk” (Deposits Issue 55, 2018, p.35, see Bryozoans in the English Chalk). Perhaps equally remarkable are the bands of flint associated with the pure white chalks (Figs. 1 to 3). Flints have attracted human attention since pre-historic times with some flint bands providing the preferred source rock for manufacturing stone-age tools (for example, the Late Turonian Floorstone Flint at Grimes Graves near Brandon in Norfolk, England (Figs. 4 to 6a and b; Mortimore and Wood, 1986), or the geologically much younger Early Campanian flints in the Harrow Hill Flint Mines in Sussex, England Fig. 7). Subsequently, Brandon flints were used as the vital spark for guns (that is, gun-flints, Skertchley, 1879; Shepherd, 1972) and these have been found as far afield as eastern North America (used in weapons of the American revolution) to the Fijian Islands in the Pacific (from Royal Navy guns). In the modern era flint remains a material of concern in engineering causing damage to core-drilling operations, tunnelling machines (Fig. 8) and cable trenching machines onshore and offshore northwest Europe. Flint also impacts the ease with which piles can be driven into chalk. To fully appreciate flint as a material and to assess the impact of flints on engineering operations has required establishing … Read More
I have stood several times in front of an (apparently) plain white, chalk cliff-face along with others, while Prof Mortimore discussed the implications of what we were seeing. And, every time, I left not just thinking but knowing this was the most fascinating piece of geology I had ever seen.
Jan Willem van der Drift (The Netherlands) Historic finds In 1900, nobody knew what kind of tools man used before the handaxe. Some scholars assumed that early-man used ‘eoliths’ – handy natural forms. That theory turned out to be false. The earliest tools were manmade flakes and cores, and this is now called Mode-I. James Reid Moir was one of the first to make claims about such tools and Fig. 1 shows a flake on which Reid Moir wrote that it came from below the Weybourne Crag near Cromer. Fig. 1. This flake was found over a century ago by Reid Moir (drawing from reference 1). However, the flaking angles, the form of the bulb and other fracture-signals on Reid Moir’s flakes differ slightly from what we see on flakes found in Neolithic sites or in connection with handaxes. This led most archaeologists to believe that Reid Moir’s flakes were not manmade. Rediscovery In the 1980s, Dutch collectors found pebble tools in aggregate that was dredged from the sea, offshore from Norfolk. A group of four collectors (Ab Lagerweij, André Cardol, John de Koning and Herman van der Made) decided to visit East Anglia and search for sites on land. They hoped to find pebble tools in the Cromer Forest Bed, which is a freshwater deposit dated to the Cromerian, which contains fossils from steppe mammoth, rhinoceros and horse. The Anglian glaciers covered this formation with sand, gravel and till, but it lies exposed on the coast. The four did … Read More
The Jurassic Coast Trust has produced a truly fascinating little picture book illustrating the geology of this World Heritage Site.
It has the shape, form and feel of a holiday souvenir book – the sort you buy in tourist information shops to commemorate your visit with pictures of the sites you didn’t have time to see – and there is also plenty of information for the curious visitor who wants to learn more about the earth science of the area.
Dr Neale Monks (UK) The Gault Clay is an Albian (Lower Cretaceous) deposit of blue-grey clay exposed primarily in Southeast England. At the classic exposure at Copt Point, Folkestone, the Gault Clay is sandwiched between the Lower Greensand underneath and the Upper Greensand on top. Fig. 1. Folkestone is the most productive location for collecting Gault Clay fossils in the UK. It is a stiff clay that preserves fossils extremely well. In particular, aragonite is sometimes preserved on fossils such as bivalves and ammonites, resulting in much more attractive and detailed fossils than those found in limestone or chalk. As well as providing excellent preservation, the Gault Clay is highly fossiliferous at many localities. Unsurprisingly, these two factors have ensured that the Gault Clay has always been extremely popular with fossil collectors. In terms of what was going on during the Albian, the Gault Clay represents a phase of sea level rise, something known as a “marine transgression”. Compared with the preceding Lower Greensand, this clay was deposited in a deeper, less energetic environment in what is sometimes known as the “Gault Sea”. This was a shallow, warm sea with a muddy bottom. Corals were notably absent, but animals that were adapted to muddy conditions, such as clams and pelican’s foot snails, were common. The sediment particles were finer and less disturbed by water currents and benthic animals (that is, animals living on the sea bottom), resulting in the high-quality fossils so characteristic of this deposit. At this time, the … Read More