Caught between two mass extinctions: The rise and fall of Dicroidium

Chris Mays and Stephen McLoughlin (Sweden) In the aftermath of Earth’s greatest biotic crisis 251.9 million years ago – the end-Permian mass extinction – a group of plants arose that would come to dominate the flora of the Southern Hemisphere. Recovery of the vegetation from the end-Permian crisis was slow;… … Read More

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… … Read More

Very down-to-earth Vasquez rocks portray the surface of alien planets for the media

Deborah Painter (USA) They have become associated with stark alien or other-dimensional landscapes since the 1960s, when the popular American television programme Star Trek used them as dramatic backdrops in two episodes, “Arena” and “Friday’s Child”. Prior to that, the Vasquez Rocks of Agua Dulce in California were a favoured… … Read More

Pistol shrimps: How to recognise them in the fossil record

Matúš Hyžný (Slovakia), Andreas Kroh (Austria), Alexander Ziegler (Germany) and John WM Jagt (The Netherlands) Alpheid shrimps, colloquially referred to as “pistol shrimps”, exhibit a remarkable anatomical adaptation. These tiny marine crustaceans use their enlarged and highly modified claw to ‘shoot’ at their prey – hence their name. It is… … Read More

Wealden insects: An artist’s update (Part 4)

Biddy and Ed Jarzembowski (UK) An ‘artist’s impression’ of Wealden insects, inspired by the original work of Neil Watson, appeared in a three-part mini-series in Deposits issues 47 to 49. Since then, the discovery of a number of species new to science (belonging to diverse groups) has meant that an… … Read More

Duria Antiquior: A nineteenth-century forerunner of palaeoart

Steven Wade Veatch (USA) In a breath of inspiration in 1830, English geologist, Henry De la Beche (1796–1855), while exploring new intellectual territories in the emerging fields of palaeontology, painted Duria Antiquior (meaning “a more ancient Dorset”), a representation of a prehistoric Dorset coast. De la Beche’s work was ground… … Read More

Concretions in sandstones of the Inner Hebrides, Scotland

Mark Wilkinson (UK) Concretions are a common feature in many sedimentary rocks, yet they seem sometimes to be misunderstood. So, how do concretions form? As well-studied examples, let’s look at the ones found in some of the sandstones of the Scottish Inner Hebrides, notably the islands of Eigg and Skye.… … Read More

Important Green River Formation fossils come to New York

Stuart Wilensky and Douglas Miller (USA) In the early Eocene Epoch, drainage from the newly uplifted Rocky Mountains filled an inter-mountain basin to form what geologists call Fossil Lake. The climate of Fossil Lake was subtropical, similar to the climate of Florida today. The lake persisted for about two million… … Read More

Jade: Imperial green gem of the East (Part 2) – decorative and ornamental jade

Sonja McLachlan (UK) In the second part of this five-part series of articles, I will be exploring the beautiful examples of ornamental and decorative jade carvings that can be found in many places around the world. Ancient peoples collected and sculpted jade into unique symbolic items representing their own cultures… … Read More