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.
Megan Jacobs (UK) For centuries, the creatures of the past, from the terrifying theropod dinosaurs to the tiny early mammals, have captured the imaginations of millions. However, the people who put those beasts into the limelight are rarely acknowledged for their work and, in many cases, remain unknown. So here is a short account of some of the first prominent names in the world of vertebrate palaeontology, their contributions to the field, and an insight into the often eccentric behaviour that came with it. Georges Cuvier (1769-1832) Fig. 1. Georges Cuvier.Georges Cuvier was a French naturalist and zoologist, and is regarded as the ‘’father of palaeontology’’. He was one of the finest minds in history, founding vertebrate palaeontology as a scientific discipline. For example, in 1800, he identified Pterodactylus as the first known pterosaur from a print published by Alessandro Collini. Shortly after, he described the first mosasaur, a giant marine reptile that was brought to France by Napoleon after he conquered the Netherlands. Going against his old Christian (Catholic) upbringing, Cuvier believed the Earth was immensely old and, during its history, underwent abrupt changes that Cuvier called ‘revolutions’, in which large numbers of species were wiped out. This was the first recognition that extinctions were facts. Cuvier also rightly speculated that there had been a time where reptiles had been the dominant animals on the planet. Indeed, the decades after his death yielded spectacular finds that confirmed his theory. After a study comparing modern elephant species, he worked on … Read More
Dr Paul D Taylor (UK) We are very fortunate in Britain to host one of the most remarkable deposits in the entire geological record, the Chalk. The Late Cretaceous Chalk (with a capital ‘C’) is an extremely pure limestone, famous for the White Cliffs of Dover and responsible for the landscape of rolling hills and dry valleys, forming the ‘downs’ and ‘wolds’ that stretch through England from Devon in the southwest, to Yorkshire in the northeast. The economic importance of the Chalk to the early human inhabitants of Britain was enormous because the flints contained within it could be fashioned into axe heads and hard cutting tools. Why is the Chalk so special geologically? It is a rare example of a pelagic sediment – an open ocean sediment – that was deposited over the continental shelf. This occurred at a time when global sea-level was high and the supply of terrigenous clastic sediment into the sea was minimal. The Chalk is an oceanic ooze composed mainly of the disaggregated plates – coccoliths – of coccolithophores, planktonic microalgae with exquisitely engineered skeletons of calcite. Unfathomable numbers of coccolithophores sank to the seabed over a period of some 35 million years to produce the thick accumulation of Chalk that today extends over northern Europe and into western Asia. The Chalk is a favourite hunting ground for fossil collectors, yielding beautifully preserved specimens, especially of echinoids. But closer inspection of the Chalk shows that the dominant macrofossils are often bryozoans. These colony-forming invertebrates … Read More
Bob Markham (UK) In the early part of his evolution, man made great use of rock and stone to assist him in his activities. The term ‘Stone Age’ has been given to the period of time during which stone was the main material used for the manufacture of functional tools for daily life. It is generally thought to have commenced about 3.3Ma and was the time when man firmly established his position on earth as a ‘tool-using’ mammal. However, it should be remembered that stone was not the only material used for this purpose. More perishable materials, such as wood, reeds, bone and antler, were also used, but very few of these materials have survived to be found today (but see the box: Non-stone tools). Non-stone toolsA notable exception to the general rule that non-stone tools have not been preserved is the Palaeolithic wooden spear shaft that was recovered in 1911 from a site in Clacton in Essex. At 400,000 years old, the yew-wood spear is the oldest, wooden artefact that is known to have been found in the UK (see http://piclib.nhm.ac.uk/results.asp?image=001066).A number of wooden spears dating from 380,000 to 400,000 years ago were also recovered between 1994 and 1998 from an open-cast coal mine in Germany (see https://en.wikipedia.org/wiki/Schoningen_Spears). Other items are found from time to time from peat-bog conditions, which offer the most favourable medium for the preservation of such material.The stones used to make tools Being a non-perishable material, stone has survived the ravages of time and is … Read More
Joe Shimmin (UK) Flint is a very hard-wearing rock from the chalk of the Upper Cretaceous. Whole beaches made of flint pebbles can be found many miles away from the chalk strata that the nodules originated in, owing to the rock’s ability to withstand the processes that destroy other rocks quickly. Flint sea urchins are especially hard-wearing, as their rounded shapes require a lot of force to damage, while less-rounded flints tend to break up over time if subjected to high-energy environments, such as beaches and fast-flowing rivers. Because of this robustness, it is possible to find flint urchins, which have undergone some very interesting journeys before being collected, adding to their interest for fossil hunters. Fig. 1. The hardness of flint and the rounded shape of flint urchins make them extremely robust fossils. All flints start off within chalk strata. Where these strata are exposed at the coast or in quarries and cuttings, it is possible to collect flint sea urchins, which, at first, look very much as if they are preserved like every other urchin found in chalk. They have a white calcite-replaced test and all that can be seen of the flint within is a slight blueish tint or maybe a glimpse of the nodule through the anal or oral apertures. Of course, flints can also be found that partially or fully envelop an urchin and, in these cases, highly aesthetic display pieces can sometimes occur. Fig. 2. Two of these pristine fossil urchins, extracted straight from … Read More
Dr Trevor Watts (UK) This is the second and final part of an article on the volcanic highlights of Northern Ireland’s Giant’s Causeway and surrounds. For the first part, see Giant’s Causeway (Part 1): An introduction.) We were in the area for several days and the weather was fairly mixed, but there were glorious skies between the showers, and the high winds brought the waves up beautifully. Of the six highlights discussed below, we visited the first three in one day, as all were a few kilometres to the west of The Giant’s Causeway. Those to the east, we visited on another day. Fig. 1. A map of some of the highlights. They are all supremely interesting and give an idea of the range of volcanic features to be seen. You cannot see an actual, traditional volcano in Antrim, with its classic shape. However, you can visit many scattered and varied elements of the area’s vulcanicity, and so gain an appreciation of the overall picture. Fig. 2. Fanciful cross section of highlights. 1. Deep lava flows forming the Causeway Basalts and their columnar basalt features. Found at The Giant’s Causeway and Ballintoy Harbour. 2. Beds of red ‘laterite’ rocks and soils buried by the later lava flows. Seen along the whole coast, especially east of the Giant’s Causeway. 3. Multiple relatively thin lava flows forming the Lower Basaltic Series. Seen at The Giant’s Causeway area and Dunluce Castle. 4. Dykes bringing magma towards the surface through fissures of cracks in … Read More
Stephen K Donovan (The Netherlands) The Isle of Wight is a marvellous place for the geologist on holiday, but there must be a suspicion that it has all been done before. When I first visited the island in 1999, my late wife Trina said that, of course, I would want to geologise at some point. She was surprised at my immediate and emphatic reply of ‘no’, until I explained that every square inch of the island was already ‘claimed’ by so many geologists and groups of geologists that I could not possibly get involved without starting a priority war. I was there to relax, not fight. Fig. 1. Outline map of the Isle of Wight, showing the positions of the principal settlements and villages mentioned in the text, and Sites 1-3. Key: CP = Chessell Pottery; EC = East Cowes; OH = Osborne House; 1-3 = collecting sites mentioned in the text. Today, I have a different approach. The family Donovan goes to the Isle for their summer holidays most years and I still go to the island to relax, not fight. But I am now working on a range of projects on the Island that are unlikely to impinge on other peoples’ research, while informing my own interests. These have included identifying borings in fossil wood from the Cretaceous greensands that have been misnamed since the nineteenth century (Donovan and Isted, 2014) and exploring closed railway lines using a geological field guide published a hundred years ago (Donovan, 2015). … Read More