This category can only be viewed by members. To view this category, sign up by purchasing Annual subscription, 12 Month Subscription or Monthly subscription.

Stones that illustrate themselves

Deborah Painter (USA) Earlier in the month of September 2022, my friend David and I spent an afternoon with a fellow named Ellery, a long-time member of a rock collecting club we joined a year ago. Ellery allowed me to photograph some of his rock and mineral specimens, including a rough piece of ‘wonderstone’ of approximately 30cm in length and 19cm in width, from southern Utah, USA (Fig. 1). Fig. 1. Shinarump Wonderstone is a variety of chalcedony that features swirls and other decorative patterns. (Credits: Deborah Painter; specimen from the collection of Ellery Borow.) The piece contained what looked like a painting of the flanks of a slot canyon one might see in the very area where it is found (Fig. 2). Fig. 2. A slot canyon in Page, Arizona USA, just 180km to 185km from known sources of Shinarump Wonderstone. It reminds one of the ripples and swirls in the Wonderstone in Fig. 1. (Credits: Brigitte Werner, Pixabay.) On the opposite side of the same specimen was a fish’s head, complete with an ‘eye’ (Fig. 3). Fig. 3. This ‘fish head’, complete with a fishy ‘eye’ is the image that greets you when you turn over the Shinarump Wonderstone specimen in Fig. 1. (Credits: Deborah Painter; specimen from the collection of Ellery Borow.) None of the images were artificial or cut in a particular way to bring out these ‘images’. I was instantly reminded of the pietra paesina stones of the Florence area of Italy. The latter have … Read More

To access this post, you must purchase Annual subscription, 12 Month Subscription or Monthly subscription.

It doesn’t always have to be dinosaurs – a short review of rauisuchian archosaurs

Stephan Lautenschlager (Germany) and Dr Julia Brenda Desojo (Argentina) Fig. 1. Reconstruction of Batrachotomus kupferzellensis. (Museum of Natural History, Stuttgart, Germany.) Among the multitude of fossil animals, dinosaurs have always been the most popular and fascinating. Loved by six-year-olds, Hollywood directors, toy-designers and scientists alike, they not only dominated most of the Mesozoic Era, but still dominate our understanding of palaeontology. However, only a few people are aware that, before the dinosaurs started their 150-million-year-long global dominion, there was an equally successful and remarkable group of fossil reptiles – the ‘rauisuchians’ (Fig. 2). In this article, we will try to shed some light on these enigmatic and commonly unknown tetrapods, which were as adapt and predominant in their time – and, to be honest, as cool – as the dinosaurs. Fig. 2. Occurrence and evolution of the major archosaur groups. A history of rauisuchian research The first rauisuchian fossil was found in 1861 by the German naturalist Hermann von Meyer. It consisted of a single maxilla of Teratosaurus suevicus and was identified as an early dinosaur. The same happened to the next to be found, Poposaurus gracilis, after its discovery in Wyoming in 1915. This specimen was subsequently described as a theropod dinosaur, a primitive stegosaurid and also an ornithopod. Only when the German palaeontologist, Friedrich von Huene, collected numerous Triassic fossils from the Santa Maria Formation of Brazil in 1928, did things begin to change. His detailed studies of the material revealed that most of it did not belong … Read More

To access this post, you must purchase Annual subscription, 12 Month Subscription or Monthly subscription.

Fossil from Denmark (part 2)

Niels Laurids Viby (Denmark) The first half of the Palaeocene in Northern Europe belongs, more or less, to the Danish! On 16 November 1846, Edouard Desor held a lecture in Paris with the title ‘Sur l’étage Danien, nouvel étage de la crai’ (‘On the Danien, a new stage of the Cretaceous’) – the Danien was, at that time, seen as being the final stage of the Cretaceous period. Nowadays, in most parts of the world, including most of Europe, ‘Danien’ is the recognised name for the geological age stretching from the end of the Cretaceous (somewhere between 64 and 65mya, depending on what book you read) to some five million years later. Danien deposits are widespread in Denmark, apart from in the southern part of Jutland, and even here you can find flint and blocks of chalk from hardened Danien beds on every stony beach. For fossil collectors from countries that do not have these sediments, Denmark is a good place to visit – it is virtually impossible to come home without at least some Danien fossils, although probably not a great variety unless you visit Fakse Chalk Quarry (which is discussed below). Danien chalk – a lot of different sediments: Stevns Klint The layout of the Danien is best seen at Stevns Klint on Zealand, which has some 20km of cliffs, averaging 20m in height. Fig. 1. Stevns Klint – southern end. Here, the bottoms of the cliffs are, in most places, Cretaceous, being from the very top of … Read More

To access this post, you must purchase Annual subscription, 12 Month Subscription or Monthly subscription.

Building stones of the Ancient World

By Ken Brooks (UK) Local stone was an essential element in the development of early civilisations, as its availability and quality determined the building styles that they created. The effective working and use of stone as a building material was a skill acquired by man at an early stage of history in many different regions of the world. Today, we can identify their methods of working stone by studying the buildings, quarries and the tools that have survived them. Egypt For thousands of years, the River Nile has carved its way through areas of sandstone, granite and limestone on its 750-mile journey through Egypt to the Mediterranean. From very early times, and even to the present day, the Egyptians have built their homes with bricks made from mud – an abundant raw material along the banks of the River Nile. It was around 5,000 years ago, as organised religion became established, that they began to use locally available stone to construct temples and pyramids. Between 2590BC and 2500BC, the ancient Egyptians built three huge pyramids on the Giza plateau (near present-day Cairo). Fig. 1. The pyramids at Giza. The bedrock in this area is a nummulitic limestone dating from the Eocene period, 34 to 55mya. It is an interesting thought that some of the largest man-made structures on earth were constructed from the fossil remains of tiny organisms (foraminifera). Work on a pyramid began with the extraction of limestone blocks at a nearby quarry. The only tools the Egyptians had … Read More

To access this post, you must purchase Annual subscription, 12 Month Subscription or Monthly subscription.

Fossils from Denmark (part 1)

By Niels Laurids Viby Denmark – why on earth should anybody in the UK go to such a strange place – where people, among other things, drive on the wrong side of the road and speak a funny language? And why write something for Deposits on the subject at all? You can find fossils from almost every time period apart from a few in the UK. For example, you can find them from the very top of the Cretaceous period (Maastricien) and the Lower Palaeocene period (Danien). However, these particular geological periods, especially the Danien that was, after all, named after a site in Denmark are also found in many places in Denmark. Moreover, at one site, you can actually access the KT border and get a sample from the famous (but thin) band with high concentrations of iridium. Of course, most fossil collectors concentrate on what is found close to home, and for good logistical reasons. However, for those who want a broad collection covering the development of life or for that matter a mass extinction, a holiday in Denmark is a good option for filling a gap without having to drive long distances – Denmark is a rather small country! In this first article on Danish geology, I will provide the reader with two things. Firstly, a short description of Danish geology, including what is legal to collect and what is not and secondly, a description of a Danish speciality – Lower Eocene diatom clay, the ‘moler’, which … Read More

To access this post, you must purchase Annual subscription, 12 Month Subscription or Monthly subscription.

Iceland: Classic Geology in Europe (3rd edition), by Thor Thordarson and Ármann Höskuldsson

reviewed the 2nd edition of this guide a while ago and, as I said then, Iceland seems to set the hearts of certain geologists racing and, reading this field guide and that previous incarnation, it is abundantly clear why. Iceland’s fascinating geology is clearly set out in this concise and authoritative book. The island, astride the Mid-Atlantic Ridge, is a ‘natural laboratory’ where the earth sciences can be watched in real-time. Rifting of the crust, volcanic eruptions and glacial activity are among a host of processes and features that can be observed in this fascinating land.

Book review: Fossilien im Alpstein: Kreide und Eozän der Nordostschweiz (Fossils in the Alpstein: The Cretaceous and Eocene of north-eastern Switzerland), by Peter Kürsteiner and Christian Klug

This is clearly one for our German speakers, of which I am glad to say there are many. However, this glossy and excellently produced hardback, covering the fossils of the Alpstein region of Switzerland, may have general appeal to anyone interested in the identification and study of fossils from various parts of the world, despite being written in German.

Three dimensional photography of fossils (Part 3): Ammonites from the Northern Limestone Alps of Austria

Dr Robert Sturm As a result of their great diversity in shape and long-lasting occurrence in earth history (from the Devonian to the Cretaceous), ammonites are equally fascinating objects for the professional and amateur palaeontologist. By definition, ammonites exclusively comprise a group of extinct marine cephalopods that, according to the … Read More

The “thick-shelled mussel” Pycnodonte (Phygraea) vesiculare: Germany’s “Fossil of the Year” 2017

Jens Lehmann (Germany) Thick-shelled oysters of the species Pycnodonte (Phygraea) vesiculare (Lamarck, 1806) are among the most common fossils of the late Cretaceous period of Europe. They are also known as “thick-shelled mussels” in the popular wisdom and the reason for this name is obvious when you have a look … Read More

Cameos from Ancient Greece and Rome: Small but precious treasures

Dr Robert Sturm (Austria) When talking about precious or semi-precious gemstones, most people think of the diamonds they cannot afford or rubies, agates and similar well-known minerals. But, only a few people know that gemstones have been subjected to various carving techniques since ancient times, making from them small but … Read More