Climate England Geology

The lost lakes of Britain (Part 3): Landscapes that vanished, rivers that remain

This final part of the series brings together the two very different lake worlds explored so far. In Part 1, we reconstructed the long-lived Devonian lakes of the Orcadian Basin; in Part 2, we examined the short-lived but dramatic ice-dammed lakes of Glen Roy. Here, we broaden the view to consider the wider pattern of lost lakes across Britain – how they formed, how they drained, and how their influence persists in modern landscapes, particularly in the behaviour of rivers and the shape of valleys.

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The weird and wonderful of the Ordovician (Part 8): Nemagraptus gracilis — the elegant index fossil of the Middle Ordovician

Jon Trevelyan (UK) This is the eighth in my series of short articles on fossils of the Ordovician. Nemagraptus gracilis is one of the most important and visually distinctive graptolites of the Middle Ordovician, widely known from the black shales of Britain, Scandinavia and North America. Dating to around 463-460 … Read More

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Geology museums of Britain: Dudley Museum at the Archives – from Silurian seas to Carboniferous forests

Jon Trevelyan (UK) A geological museum in the heart of the Black Country Dudley is one of those places where geology is difficult to separate from almost everything that followed. The rocks beneath the town and the surrounding Black Country provided coal, ironstone, limestone and fireclay; their exploitation transformed the … Read More

Climate England Fossils Geology Palaeontology Plate Tectonics

The lost rainforest of the West Cumberland Coalfield (Part 5): The ferns return – Pecopteris and the first colonisers of the drowned swamp

When a Carboniferous swamp drowned, its towering lycopsids collapsed, its peat surface disappeared beneath mud, and the forest that had stood for decades, or at most a few generations, abruptly ceased to exist. Yet within surprisingly little time, new vegetation reclaimed the abandoned lake floor. The first wave of this recovery is written across the roof shales of the West Cumberland Coalfield district in thousands of beautifully preserved fronds, most commonly those of Pecopteris, the characteristic tree ferns of the Westphalian wetlands.

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The weird and wonderful of the Ordovician (Part 7): Maclurites bigsbyi – the open-coiled oddity of the Ordovician

Jon Trevelyan (UK) This is the seventh in my series of short articles on fossils of the Ordovician. Of all the Ordovician gastropods, few are as visually striking as Maclurites bigsbyi. With its large, open-coiled shell and broad, planispiral whorls, the species represents a unique experiment in molluscan shell architecture … Read More

EDITORIALS

Making Deposits easier to explore

One of the great advantages of publishing Deposits online is that an article does not disappear once the next issue comes along. Everything we publish remains available on the website, creating an ever-growing archive of articles, covering geology, palaeontology and the wider Earth sciences. However, as that archive grows, there … Read More

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Geology museums of Britain: Hastings Museum & Art Gallery and a window into the Wealden world

Jon Trevelyan (UK) A museum built on fossils Hastings is usually associated with history rather than prehistory. Its name is inseparable from 1066, while its fishing beach, old town and cliffs are familiar features of the modern resort. Yet the rocks beneath and around the town preserve evidence of a … Read More

Climate Geology Scotland

The lost lakes of Britain (Part 2): The ‘parallel roads’ of Glen Roy – a vanished Ice Age lake system

In Part 1, we reconstructed the long-lived Devonian lakes of the Orcadian Basin from their sedimentary record. Here, we turn to a much more recent and far more fleeting landscape. At the end of the last Ice Age, ice-dammed lakes formed across parts of Britain, leaving behind traces that are often subtle – but in Glen Roy, they are spectacular. The famous ‘parallel roads’ provide one of the clearest records of changing lake levels anywhere in the country, preserving the story of a landscape shaped over centuries, rather than millions of years.

Fossils Geology North America Palaeontology

The weird and wonderful of the Ordovician (Part 6): Isotelus maximus – one of the giants of the trilobite world

Jon Trevelyan (UK) This is the sixth in my series of short articles on fossils of the Ordovician. Trilobites reached their zenith in diversity during the Ordovician, but few species are as impressive as Isotelus maximus. Renowned for producing some of the largest articulated trilobite specimens ever found, this North … Read More

Fossils Geology North America Palaeontology

The weird and wonderful of the Ordovician (Part 5): Flexicalymene meeki – the classic enrolled trilobite

Jon Trevelyan (UK) This is the fifth in my series of short articles on fossils of the Ordovician. If one fossil trilobite has achieved near-universal recognition among collectors, it is Flexicalymene meeki. Abundant, beautifully articulated and famous for its perfectly enrolled specimens, this species offers a remarkably complete view of … Read More

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Geology museums of Britain: Grime’s Graves – ancient mining and the stone beneath the Chalk

Jon Trevelyan (UK) A landscape full of holes Grime’s Graves does not announce itself with the drama of a great cliff, cave or quarry. On a low Chalk ridge in the Breckland of Norfolk, the most immediately striking feature is instead the ground itself. Across the grassland are hundreds of … Read More

Fossils Geology Glaciers Palaeontology Scotland

The lost lakes of Britain (Part 1): The Orcadian lakes – reconstructing Scotland’s lost Devonian world

This is the first of a three-part series exploring Britain’s lost lakes – landscapes that once existed across very different timescales, from the Devonian world of the Orcadian Basin to the fleeting ice-dammed lakes of the last Ice Age. In this opening article, we go deep into the Devonian, reconstructing the Orcadian lakes from the evidence preserved in Caithness and Orkney. Here, finely layered sediments, exceptional fossil preservation and subtle environmental clues allow us to rebuild not just the organisms that lived there, but the structure and behaviour of the lakes themselves.

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The weird and wonderful of the Ordovician (Part 4): Echinosphaerites aurantium – the grapefruit-shaped cystoid

Jon Trevelyan (UK) This is the fourth in my series of short articles on fossils of the Ordovician. Among the diverse and often bizarre echinoderms that flourished during this period, Echinosphaerites aurantium is one of the most distinctive. A rhombiferan cystoid with a rounded, grapefruit-like body, it embodies the experimental … Read More

England Fossils Geology Glaciers History & biographies Museums & societies Palaeontology Plate Tectonics

Geology museums of Britain: Cromer Museum, the West Runton Mammoth and the Cromer Forest-bed Formation

Jon Trevelyan (UK) A small museum with a remarkable geological story Tucked away behind the parish church in the centre of Cromer, Cromer Museum occupies a modest site that visitors could easily overlook. Entering through a modern reception building, the museum opens into a narrow courtyard surrounded by a terrace … Read More

England Fossils Geology Palaeontology Plate Tectonics

The lost rainforest of the West Cumberland Coalfield (Part 4): After the drowning – the roof-shale succession

Every coal seam in the West Cumberland Coalfield district records the accumulation of peat in a mature lycopsid swamp. But just as revealing as the coal itself is what lies immediately above it – the roof shales. These fine-grained sediments record the moment when the forest drowned, the swamp surface subsided or flooded, and a new ecological phase unfolded above the buried peat. In the West Cumberland Coalfield, roof shales are exceptionally well developed and preserve a full sequence of the events that followed each catastrophic rise in water level.

Fossils Geology History & biographies Minerals Mining Museums & societies Palaeontology Wales

Geology museums of Britain: The Blaenavon Industrial Landscape (Part 2) – Big Pit, Blaenavon, Monmouthshire

Jon Trevelyan (UK) Rising above the hills near the town of Blaenavon is the distinctive headgear of Big Pit, one of the most recognisable symbols of the South Wales Coalfield (Fig. 1). Today, the site forms part of the National Coal Museum of Wales, but for nearly a century it … Read More

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The weird and wonderful of the Ordovician (Part 2): Didymograptus murchisoni – a classic marker of the Middle Ordovician

Jon Trevelyan (UK) This is the second in my series of short articles on fossils of the Ordovician. Among the many colonial organisms that chart the course of Ordovician seas, Didymograptus murchisoni remains one of the most recognisable. A key graptolite of the Middle Ordovician, it combines elegant morphology with … Read More

Geology History & biographies Minerals Mining Museums & societies Wales

Geology museums of Britain: The Blaenavon Industrial Landscape (Part 1) – the Iron Works, Blaenavon, Monmouthshire

Jon Trevelyan (UK) The ruined furnaces of Blaenavon rise unexpectedly from the Welsh hillsides like the remains of some vast industrial fortress. Massive retaining walls, towering masonry structures and steep charging ramps still dominate the landscape, despite the silence that now surrounds them. Grass and wild flowers spread across terraces … Read More

Palaeontology Plate Tectonics

The lost rainforest of the West Cumberland Coalfield (Part 3): Beneath the giants – Stigmaria and the swamp floor

The trunks of Lepidodendron and Sigillaria (Part 2) dominate most people’s mental image of the Carboniferous swamp, but to understand how these forests actually functioned, you need to look beneath the surface, into the layer that supported and anchored the entire ecosystem. In the West Cumberland Coalfield, this means one thing above all – Stigmaria, the distinctive rooting systems of the giant lycopsid trees.