Urban geology: Productid brachiopods in Amsterdam and Utrecht

Stephen K Donovan (The Netherlands) and David AT Harper (UK) The most obvious manifestations of geological materials in the urban environment are building and facing stones, and similar rocks used in street furniture, such as kerbstones. As a Londoner, SKD was impressed as a boy by the massive kerbstones that he saw in the City and locally where he lived. It was only as his knowledge of geology grew that he discovered such stones to be truly exotic, being largely crystalline rocks (mostly granites in the broad sense) and probably derived from the southwest or the north of the British Isles. A field guide to the kerbstones of London would have accelerated his education in geology at that time. More satisfactorily to palaeontologists, such as the authors of this article, are building stones that are fossiliferous. We have particular interests in the palaeontology of Palaeozoic limestones. These are common building stones and street furniture in many cities in the Netherlands (and elsewhere). These rocks are all imported (Van Ruiten and Donovan, 2018; Dr Bernard Mottequin, email to DATH, 9 May 2018) and are mainly Mississippian, although there are some limestones of Devonian age here and there (Van Roekel, 2007; Reumer, 2016). However, the Mississippian limestones are the more widespread and contain abundant fossils, from the well-known, such as bryozoans (Donovan and Wyse Jackson, 2018), brachiopods, crinoids, and rugose and tabulate corals (Van Ruiten and Donovan, 2018) to the more exotic, such as rostroconch molluscs (Donovan and Madern, 2016). This article … Read More

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Urban geology: The Boxtel wall game

Stephen K Donovan (The Netherlands) The Netherlands is a land of museums, approximately 1,200 of them in a country the size of southeast England. Although the major cities have an ample supply – about 30 in Amsterdam, for example – there are many and varied museums dotted throughout the country. (I remember, in 2003, being driven to Arnhem and seeing a German Panther tank parked outside a small military museum – be ready for the unexpected.) For the geologist, one of the gems is Het Oertijdmuseum (= The Prehistoric Times Museum; formerly De Groene Poort) in Boxtel, in the province of Noord Brabant, north-north-west of Eindhoven. As may be deduced from Fig. 1, the museum has a specialist collection of dinosaurs and other saurian – replicas in the gardens around the main building and mounted skeletons inside. Fig. 1. Welcome to Het Oertijdmuseum! I presume any visitor spots the glass fibre Tyrannosaurus before reading the notice on the right. Other saurians are lurking in the undergrowth around the main museum building, much to the delight of children of all ages. I am a walker and I prefer to saunter from the station through the attractive town of Boxtel to Het Oertijdmuseum rather than take a bus. The walk is a long 30 minutes. As you near the museum, the route passes a most extraordinary building, Bosscheweg 107, ‘Den Daalder’. This appears to be an entirely conventional office block until you reach the end closest to the museum, when all is … Read More

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Urban geology: Gabions in the Dutch townscape

Stephen K Donovan (The Netherlands) Gabions are tools of the engineering geologist, facing elements that are used to stabilize over-steep slopes, such as sea cliffs or railway/roadway cuttings; they also have military applications. The word is derived from the French, gabion, and Italian, gabbione, and originally referred to “A wicker basket, of cylindrical form, usually open at both ends, to be filled with earth, for use in fortification and engineering” (Little et al., 1983, p. 823). A modern gabion used in engineering geology is a cage, box or cylinder, commonly infilled by rocks or concrete, and sometimes sand or soil (https://en.wikipedia.org/wiki/Gabion). Fig. 1. A gabion wall, lacking subtlety, outside the restaurant, ‘De Blausse Engel’, at Amsterdam Zuid railway station. A: General view of castellated wall, separating restaurant patrons (chairs and tables to left) from passers-by. B: Detail of one cobble in the gabion, showing a vein (sphalerite?). Essentially, gabions provide a stable retaining wall that is semi-permanent. That is, they can be more easily removed, modified or replaced than a permanent structure made in concrete, brick or steel. Although they may be aesthetically unpleasing, gabions provide stability in situations where serious erosion problems may exist, which cannot be controlled by alternatives such as re-vegetation (Freeman and Fischenich, 2000). This is a simplification and studies such as that of Druse (2015) explain something of the complexities. So, in the low-lying Netherlands, what uses might be and are found for gabions? It is reasonable to suggest that they might be used in … Read More

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Homotherium: A saber-toothed cat of the North Sea

Dick Mol (Netherlands)and Wilrie van Logchem (Netherlands) Somewhere around the Dutch coast, a mammoth herd, led by an experienced matriarch strolls along a trail on the cold, dry and treeless steppe – the mammoth steppe – typified by tall, tough grasses and Artemisia. The impressive herd numbers about thirty animals, reflecting several generations, young and old, trailing each other on their way to the river (the paleo-Meuse) for a drink. Meanwhile, far off in the background, we notice a stampeding herd of large steppe buffaloes, chased by a pack of lions. Some hyenas are watching the scene with interest from their hideout in the tall, dry grass, eagerly hoping for some leftovers from the anticipated feast. Also hidden by the tall grass, another, strange and unknown predator observes the panorama – a saber-toothed cat. The head of the animal looks fierce. Incredibly long, flattened canines, sharp as daggers, are exposed when this Homotherium opens its mouth… This drama is set in the Netherlands, some 28,000 years ago and it is quite plausible that such a scenario happened in the last part of the ice ages of the Pleistocene epoch. The North Sea is being fished intensively today and Dutch fishermen not only collect flatfish like sole and plaice, living on the sea floor. They also retrieve the weirdest objects – fragments of shipwrecks from days gone by or bombs from World War II, jettisoned by the bombers in the dark days of the previous century. But, the most intriguing discoveries … Read More

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Triassic reptiles from the Lower Muschelkalk of Winterswijk

Henk Oosterink (Netherlands) The Lower Muschelkalk (from the Anisian age of the Middle Triassic) of the quarry at Winterswijk in The Netherlands is well known for its beautiful and sometimes abundant finds of reptile footprints and bones. A few, almost complete, skeletons have even been found. Most of the bones come from marine reptiles within the Sauropterygia (that is, ‘winged lizards’, referring to their paddle-like flippers) group. The quarry is one of the most important sites for Triassic reptiles in the world. Every year, between 2,000 and 3,000 people visit this quarry on excursions and during open days, most being fossil collectors. Many new forms of life The Triassic Period is characterised by an explosive development of many reptile groups. For instance, at the end of this period, the dinosaurs appeared. Many new forms of life developed in terrestrial and marine environments. In the Tethys Ocean and its epicontinental seas, some reptiles adopted a semi-aquatic lifestyle allowing them to be functional in the sea as well as on land. Many of these reptiles belonged to the Sauropterygia. Sauropterygians are diapsids – reptiles are divided into two groups, anapsids that include turtles and diapsids that have two holes in the skull behind the orbit. Their skulls have upper temporal openings and, on the back of the skull, the quadrate is immovable and is connected to the squamosal. The sauropterygians lived mainly in the sea, but they did come ashore, for instance, to lay their eggs. This reptile group appears for the … Read More

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