Take me to the rocks

Dr Sebastian Lüning (Germany) I am a geologist by profession. Everyday of my working life, I have worked with rocks, from nine to five, for 19 years, looking for oil and gas in the Sahara. Sometimes this is stressful, sometimes really enjoyable and sometimes simply annoying – just like any other job. However, I’ll tell you a little secret about what I do in my limited spare time to refresh my mind and recharge my batteries for another day. I am so in love with my rocks that I am also a hobby geologist. I just cannot keep away from the rocks. There are plenty of interesting fields open to amateur geologists and palaeontologists to indulge in. Most popular are probably collecting minerals and fossils, including visiting quarries and searching beaches for new specimens. However, my hobby is focused on regional geology. I love to understand the earth history of a particular area, by visiting its outcrops and reading the regional geological descriptions that have been published about it. That is, I like to look behind the scenes of a modern landscape to understand how it was shaped and what lies underneath. I drive and walk through my object of study to understand its dimensions, distances and height. At one moment, I can pay attention to millimetre-sized fossils and, a few minutes later, be enjoying a panorama across kilometre-scale valleys shaped by ice. I am convinced there are many other amateur geologists, who share my passion for an integrated view … Read More

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

Dinosaur mines of the Kem Kem

M’Hammed Segaoui and Dr Charlie Underwood (UK) The great transgressions that occurred in the mid part of the Cretaceous have had a profound influence on the geology of many parts of the world. In North America, the seas flooded the central part of the continent to produce the Western Interior Seaway, while, in northern Europe, the incoming of the Chalk seas saw much of the continent disappearing below the waves. Across the northern part of Africa, the transgression was more gradual, but on a scale as large as that seen anywhere else. In the period preceding the great marine flooding, huge coastal plains developed across a vast tract of land that extends from what is now Niger to Egypt. These coastal plains were criss-crossed by great braided river systems and provided the perfect habitat for a huge range of fresh water and terrestrial animals. Vertebrate fossils have been known from the coastal plain, fluvial rocks of the African Cretaceous for a long time; excavations in Egypt in 1912 recovered the remains of several species, including the unusual theropod, Spinosaurus. Subsequent expeditions to other areas of north and northwest Africa have yielded many additional species of dinosaurs, as well as a host of other fossils. In the early 1990s, the southeastern part of Morocco was just starting to open up to tourism and, with it, the great geological wealth of the region was becoming better known. In addition to the rich and diverse fossil faunas from the sandstones and limestones of … Read More

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

Shedding light on an isolated skull: A new elasmosaur from the Late Cretaceous of Morocco

Dean Lomax (UK) The bodiless plesiosaur In 2011, a plesiosaur specimen, consisting of an isolated and crushed skull, was described. The collected skull sadly lacked any postcranial remains, but was identified as an elasmosaurid plesiosaur and considered to be something new. Therefore, it was given the name Zarafasaura oceanis. The skull was collected in the Sidi Daoui area, near the city of Oued Zem, situated within the Khouribga Province of the northeast Oulad Abdoun Basin in Morocco. There, the phosphates date to the Maastrichtian Stage of the Cretaceous, the last stage of the Mesozoic Era, famous for many fossils, such as Tyrannosaurus rex from the USA. The study suggested that Zarafasaura shared close connections with other elasmosaurids from the Late Cretaceous of North America and Japan. The elasmosaurs had the longest necks of any plesiosaurs and flourished during the Maastrichtian. It was hoped that future discoveries of more complete remains would shed light on the general appearance and understanding of Zarafasaura. Fig. 1. Mounted skeleton of Zarafasaura oceanis (WDC CMC-01) at the Wyoming Dinosaur Center. (Photograph by Dean Lomax.) ‘The body that fits the head’ In April 2004, seven years before the description of Z. oceanis, an almost complete plesiosaur skeleton was discovered in the Sidi Daoui area in Morocco, at the same location as the skull discussed previously. The specimen (museum number WDC CMC-01) was excavated by a small team and covered by five large plaster jackets (to protect the fragile bones). It was largely articulated, consisting of a … Read More

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

Triassic salt in the High Atlas of Morocco

Chellai El Hassane (Morocco), Ghanmi Mohamed (Tunisia) and Doblaas Miguel (Spain) The Triassic terrestrial deposits at the northern edge of the High Atlas near Marrakech are mainly represented by thick sequences of massively layered, red sandstone. These are topped by a formation of silt and pink-brown clay containing large deposits of evaporites consisting mainly of rock salt and gypsum. The silt and clay formations form domed structures characterised by intruded gypsum and irregular (disharmonic) folds capped by fine sandstone beds, as well as by small, isolated anticlines only a few metres in scale. The direction of folding shows no relationship to that of the major tectonic folding that gave rise to the Atlas Mountains. In contrast, the folding is closely linked to the deposition of rock salt and gypsum in the High Atlas near Marrakech during the Late Triassic. The same phenomenon is observed in the passive margins of the Atlantic of western Morocco. Lithostratigraphy These Triassic formations are the most prominent features of the landscape, with thicknesses that can reach up to 400m. They consist essentially of two formations: F5 (the Oukaïmeden sandstone) and F6 (the Superiors Silts), which correspond to the uppermost part of the Triassic, as defined in the Ourika valley by Biron (1982). The first formation consists of thick (400m) beds of detrital sandstones with fine to medium-sized, diamond-shaped sedimentary bodies, interbedded with layers (a few centimetres to several metres thick) composed of red clay as well as red and brown silts. These are overlain by … Read More

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

Aetosaurs: An introduction

Stephen Lautenschlager (Germany) The Triassic Period was one of the key episodes in the evolutionary history of life. It marks the transition from the Palaeozoic to the Mesozoic Era, preceded by the Permian/Triassic mass extinction – the greatest extinction event of all time. A conclusive explanation for it has still to be found, but it is presumed that massive eruptions of flood basalts in Siberia were a key factor. The resultant release of green house gases, such as carbon dioxide and sulphur dioxide, into the atmosphere may have led to a catastrophic rise of the global temperature and oxygen depletion. While other causes may have contributed to this extinction, its effects are clearly visible in the fossil record. Over 90% of marine species and about two thirds of terrestrial species died out. Among the tetrapods, amphibians and therapsids (mammal-like reptiles) suffered the most and the terrestrial ecosystems were heavily depleted. Fig. 1. Life restoration of Desmatosuchus, a heavily armoured aetosaur from North America. Yet, on the other hand, this mass extinction cleared the way for several new groups of animals. The ecological niches on land, which had been vacated since the Permian/Triassic transition, were quickly occupied by two new groups – the rhynchosaurs and the archosaurs. The latter proved to be most successful, not least for the rapid evolution and diversification of the dinosaurs in the Late Triassic, which eventually gave rise to the birds. However, it was other groups among the archosaurs, which first took advantage of the newly … Read More

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

Natural wonders of the Maghreb in Morocco

Sebastian Lüning (UK) Morocco is a popular tourist destination. Most people travel to the white beaches of Agadir to sunbathe and relax, to watch the magicians on Djemaa el-Fna square in Marrakech, or to go shopping in the UNESCO-protected Osouk of Fes. However, Morocco has much more to offer. Some of the most attractive specimens found at international fossil fairs originate from this country. Morocco is home to exceptionally well-preserved trilobites and attractive Orthoceras assemblages from the Palaeozoic. The beds containing these fossils are systematically mined in the Anti-Atlas. Other fossils, such as goniatites and ammonites, complement the diverse palaeontological national treasure. Fig. 1. Location map of geological sites mentioned in this article. 1) granites near Tafraoute, 2) algal mats near Ouarzazate, 3) Ordovician glaciation, 4) Silurian graptolithic shales, 5) Orthoceras limestones, 6) Devonian mud mounds and Merzouga sand dunes, 7) Triassic Argana river sands, 8) Cascades d’Ouzoud, 9) Friouato karst shaft, 10) Dades Gorge, 11) blowholes near Agadir and Cretaceous oysters, 13) Amesfrane cliff. These fossils are part of an exciting geological past. This article aims to guide you through the highlights of Morocco’s geological history, exploring the stories behind the country’s natural wonders and its multi-million-year-old inhabitants. Concealed in its spectacular mountain chains are some fascinating snapshots from the past. Our trip will commence at the very beginning of this history and will take us gradually forward through time. We will visit various sites on a route starting in the Precambrian of the Anti-Atlas, in the southern part … Read More

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