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Book review: Introducing Geomorphology: A Guide to Landforms and Processes (2nd edition), by Adrian Harvey

As I said in my review of the first edition of this guide, I love geomorphology. In fact, I have loved it since my school days and deeply regret not having studied it at university. However, as I said in that review, I suspect many people are discouraged by its scientific name, but all it means is the study of the earth’s landforms and the processes that create the landscapes we see today.

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Fossils re-united

Brandon Lennon (UK) My kind of collecting requires collectors to be in the right place at the right time. Science directs fossil collectors to the right place, but it is good luck that puts them there at the right time. The latter is often referred to as “serendipity” and what happened on one of my fossil walks last year can certainly be described that way. I have been collecting fossils in the Lyme Regis area of Dorset for decades. One morning in early July 2005, I took a group of visitors to the Black Ven area between Lyme Regis and Charmouth to search the Lower Lias landslip materials. One of the participants on the walk was Lija Flude, then a 21-year-old geology student from Toronto, Canada who was visiting the UK with her father, Greg. Fig, 1. Lija Flude with the completed Dapedium after preparation work. It was not long before Lija had found a nice piece of fossil bone loose in the beach shingle. However, it was another of her finds that was to provide the most excitement – a flat nodule approximately 20cm in diameter. Round the edge of the nodule could be seen shiny, black fossil fish scales. It was clear that more of the fish lay within the nodule but also apparent was the fact that the nodule had been broken at some time and some of it was missing. Because of the interesting nature of Lija’s find, I advised her to show them to Paddy … Read More

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Book review: River Planet: Rivers from Deep Time to the Modern Crisis, by Martin Gibling

I think the reason why this book is such a success is that River Planet not only introduces readers to the fascinating palaeo-history of the world’s rivers (both existing and disappeared), but also reveals the author’s personal account of his experience of rivers, together with a bit of history and interesting (and relevant) anecdotes, in the most entertaining of ways.

Granite: Its physical, geochemical general properties

Alister Cruickshanks (UK) Granite rocks are igneous rocks that were formed by slowly cooling pockets of magma that were trapped beneath the earth’s surface. Granite is used all over the world in the construction industry due to its unique properties and versatile range of colours and textures. One common characteristic of granite is it has a visible crystalline texture formed of quartz and orthoclase or microcline. Quartz makes up 10% to 60% of the composition, with feldspar accounting for between 65% and 90% and biotite between 10% and 15%. As a result, its hardness makes it not only ideal for building construction, but also for sea and river defences. Fig. 1. Adamellite granite. As a building material, granite is often used for cladding walls, and for roofing and flooring, with a range of other interior and exterior applications. In this respect, one of the biggest advantages it has is its hardness. In fact, granite is actually the hardest building stone available and leads to excellent wear. On the Mohs hardness scale, granite is between 5 and 8, with an abrasive hardness of 37 to 88. Its density can range between 2.54 to 2.66g/cc. Fig. 2. A beautiful grey granite. It is also impermeable with a porosity ranging from 1e-009 and 1e-006. Another important property is it is highly thermally stable, showing no alteration with changes in temperature, which provides excellent fire protection. It is also often used in the construction of tanks for storing caustic material simply because it is … Read More

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Book review: The Chalk of the South Downs of Sussex and Hampshire and the North Downs of Kent (Geologists’ Association Guide No 74) (vols 1 and 2), by Rory N Mortimore

I have to admit, I was beginning to wonder where Prof Rory Mortimore’s update of his excellent Chalk of Sussex and Kent was. And now I know. It wasn’t a second edition he was working on, but this magnificent magnum opus in two volumes covering a vastly greater area than that other guide. And the wait was more than worthwhile. The thoroughness, writing quality, content and publication standards are superb.

Geology museums of Britain: The Museum of Somerset, Taunton

Jon Trevelyan (UK) I’ve been meaning to go to the Museum of Somerset for a long time, not just because it is situated in a castle, but also because of its lovely collection of fossil. Taunton castle (Fig. 1) was created from twelfth century by powerful bishops and welcomed distinguished (if not always particularly pleasant) guests, including King John and Henry III. It was also here that Judge Jefferys presided over the Bloody Assizes from 1685 to try prisoners from the failed Monmouth Rebellion. Since 1958, the museum has been run and funded by Somerset County Council, and now showcases exhibits going back 400 million years and it is about these that I am writing. Fig. 1. The dramatic entrance to the museum: over the bridge, through the fortified gatehouse and into the castle. The exhibits are displayed in magnificent glass cabinets in the ‘Foundation Stones’ gallery and are a feast for the eyes (Fig. 2). This is largely because Somerset has some magnificent geology, giving rise to some splendid examples of palaeontology. Fig. 2. Visitors to the museum are greeted by a stunning display of three large ammonites: (top) Titanites giganteus; (middle) Asteroceras; and (bottom) Phylloceras. The geology of Somerset explored by the museum started (at least for our purposes) some 400 million years ago, when Somerset was on the southern edge of a large, mountainous continent, with active volcanoes. Later, during the Upper Carboniferous (Pennsylvanian), it was a tropical rainforest, where generations of plants lived and died, decomposing … Read More

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The George C Page Museum of La Brea Discoveries and “Project 23”

Deborah Painter (USA) Los Angeles, California features among its many long boulevards a street that trends north to south for 34km: La Brea Avenue. This boulevard is named for a tranquil park a few city blocks from it, on Wilshire Boulevard. The park boasts animal statuary and the Pleistocene Garden, a recreation of the native vegetation that grew here during the Pleistocene epoch of the Quaternary period. This park also has a museum containing thousands upon thousands of animal and plant fossils preserved over a period of tens of thousands of years. This is the George C Page Museum of La Brea Discoveries at Hancock Park, 5801 Wilshire Boulevard on the site of the old “Rancho La Brea”, known more popularly as the La Brea Tar Pits (Fig. 1). The flora and fauna thus preserved represent a time from 50,000 BP (Before Present) to 10,000 BP. Fig. 1. La Brea Tar Pits is located in Hancock Park, Los Angeles, CA. (Photo by Gina Cholick. Credits: Courtesy of the Natural History Museums of Los Angeles County (NHMLAC).) “Brea” is Spanish for “tar”. Asphalt or petroleum seeps are crude oil deposits that are released at the earth’s surface. The volatiles dissipate, leaving asphalt (Fig. 2). Another interesting site not far away from the La Brea Tar Pits, readily accessible to visitors, is Carpinteria State Beach at 5361 6th Street, Carpinteria, California, near Santa Barbara, and the adjacent Tar Pits Park. Both are 135km northwest of the George C Page Museum. Fig. 2. … Read More

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Jathika Namal Uyana: Sri Lanka’s Rose Quartz Mountain Range

Khursheed Dinshaw (India) When I was a child, my mother gifted me a pink pendant. At the time, I didn’t know that it was pink (or rose) quartz. The colour fascinated me and I wore the pendant for many years. As an adult, I learnt that pink quartz is regarded worldwide as the stone signifying unconditional love. It is also widely used for its healing qualities and is believed by some to heal feelings of pain, loss and grief. Other than this, it is a popular semi-precious ornamental stone in jewellery. Poor quality quartz is also used in the glass making industry, and has been mined for centuries. In fact, the semi-precious stone is part of Egyptian and Roman history. Fig. 1. The Rose Quartz Mountain Range of Sri Lanka. Recently, I got an opportunity to visit Sri Lanka and the highlight of my trip was the visit to the Rose Quartz Mountain Range, which is apparently South Asia’s largest pink quartz mountain range (Figs. 1 and 2). Known as Jathika Namal Uyana by Sri Lankans, the range can be reached after a simple hike through the Ironwood Forest from the ticketing counter, from where I purchased my entry ticket. Fig. 2. South Asia’s largest pink quartz mountain range. The entry to the forest was across the road from the counter, with a board mentioning that the forest is the largest in Sri Lanka. The Ironwood Tree (Mesua ferrea) is the national tree of Sri Lanka, where it is known … Read More

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Geology museums of Britain: Watchet Market House Museum, Somerset

Jon Trevelyan (UK) Watchet is a charming little coastal town on the north coast of Somerset. It is also smack in the middle of some of the best Triassic and Jurassic geology in Britain. Therefore, it is no surprise that, in the centre of town, there is a lovely little museum, Watchet Market House Museum, containing a lot of geology (and quite a lot of local history). In fact, along with some magnificent palaeontology, there are artefacts, paintings, photographs and so on, depicting Watchet’s history, which can all be seen in the museum. Fig. 1. Watchet is a lovely harbour town on the north coast of Somerset. Fig. 2. Watchet harbour was the inspiration for the poem The Ancient Mariner by Coleridge in 1797. As part of the Watchet Regeneration Programme, the Watchet Market House Museum Society commemorated the between Coleridge and the town by commissioning a statue as an attraction for local people and visitors. A seven-foot high effigy of the mariner was designed and created by sculptor Alan B Herriot. As any fossil collector will know, Watchet and its surrounds are very fortunate in their geology. Watchet itself lies on Lias rocks, laid down 200 to 215 million years ago during the Lower Jurassic, in which there are a plethora of fossils. The Lower Liassic sedimentary beds were formed during the end of the earlier Upper Triassic period into the first part of the Jurassic. As a result, the museum is able to display a wide selection of … Read More

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Nautiloids from the Red Chalk Formation of Hunstanton

S M Bowerman (UK) Nautiloid specimens from the Red Chalk Formation of Hunstanton are rare but can occasionally be collected. Most specimens found are incomplete and are generally collected from beach level rather than in situ, so determining from which unit and zone (unit A, B and C depending on which author is referred to) within the formation a specimen originated from is problematical. Comparison of the lithology of the matrix surrounding a specimen with samples from known levels within the horizon may be possible. For example, one may carry out a clast count or sediment colour comparison, although the latter is dependent on the degree of weathering the specimen has been subject to. It seems unlikely, based on the lithological evidence of the specimens I collected that any originate from the lowest unit, bed C, which is a soft, dark red marly unit. This suggests that a Middle Albian provenance for these specimens may be ruled out. Therefore, it is apparent that all of these are from Upper Albian Age and originate from either bed B or Bed A. Fig. 1. Geological timescale. The specimen in Fig. 2 demonstrates complete whorls and is involuted with a small umbilicus and some suture lines are visible. Preserved shell material is also evident. Another specimen I have examined consists of approximately three-quarters of the original, although the specimen is extremely water worn. A third specimen was the least complete and the state of preservation is poor. The two latter specimens do not … Read More

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Geology museums of Britain: Staffin (Dinosaur) Museum, Isle of Skye

Jon Trevelyan (UK) I had the good fortune recently and rather delightfully to spend a week on the beautiful Isle of Skye, the largest of the Inner Hebrides. The weather was surprisingly good for September and a good time was had by all. In terms of geology, there are some exceptionally old rocks on Skye. We were staying on the east coast of the Sleat Peninsula, which consists of Lewisian gneiss, which is some 2.8 billion years old, and nearby is Torridonian sandstone, which is a mere 550 million years old. There are also Triassic rocks, from a time when Skye was part of a vast desert and there are the much younger, Palaeocene rocks of the Skye volcano, whose gabbros makes up the glorious Cuillin ridge (Fig. 1). Fig. 1. A classic view of the gabbro of the mighty Cuillin Ridge. So, while I was there, I took the opportunity to leave the family in their respective beds early one morning (none of whom are really interested in geology) and drive to the little Staffin Museum (known also as Staffin Dinosaur Museum), in the northeast of the island. This also provided me with the opportunity to drive past and visit some of Skye’s other geological highlights, namely the Storr (Fig. 2), the impressive Mealt Falls cascading directly into the sea and the equally impressive Kilt Rock (Fig. 3). Fig. 2. The Storr. Fig. 3. Mealt Falls, with the basalt columns of Kilt Rock in the background. However, it is … Read More

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Miocene-Pliocene shallow water marine fossils at Chippokes Plantation State Park, Virginia, USA

Deborah Painter (USA) On a cool, early December day in 2020, my friend David Hawk and I decided we simply had to search for fossils after not doing so for months, and also not be stopped by the chill or the coronavirus. Rather, we would prepare for both. We set off from Norfolk, Virginia USA and drove west to Smithfield, using our GPS to find Chippokes Plantation State Park in Surry County. We found the intersection of Business Route 258 and US Route 10 west of Smithfield, and followed the latter for approximately 22km, before turning right off US Route 10, Virginia to State Route 634. From this intersection, we travelled on 634 for a few kilometres, then right onto State Route 633, and then turned left, which took us back to State Route 634. We then had to climb a steep and winding road through a forested area. “This had better be worth it”, I grumbled, mostly to myself. After about 15 minutes, we reached the intersection with State Route 665 and saw the sign for Chippokes Plantation State Park. We paid our seven dollars daily parking fee at the entrance gate and we soon found the car park for the visitors centre. A family with young children arrived at about the same time and quickly took one of the trails. The car park was only about 40 or so meters from the edge of the bluff overlooking the James River, an estuarine tributary of the Chesapeake Bay. Here, … Read More

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Crusty old fossils

Paul D Taylor (UK) Many fossil collectors will have been disappointed to discover mollusc and brachiopod shells ‘disfigured’ by crust-like coverings of oysters, serpulid worms, barnacles or bryozoans so firmly cemented to the shells that they cannot be removed. However, rather than discarding these encrusted shells, it is worth considering what they can tell us about the ecology of the host animals and the fate of their shells after death. Furthermore, the surfaces of the shells were battlefields for encrusters fighting for living space, allowing a rare opportunity to observe the effects of biological competition millions of years ago. The key palaeoecological advantage offered by encrusters over most other fossils is that they preserve their original life positions. For example, a fossil barnacle encrusting a fossil bivalve (Fig. 1) is located on the shell exactly where the barnacle larva settled and the adult spent its life. Encrusters are not transported or displaced from where they originally lived, although of course the shells themselves may have been moved. Fig. 1. Field photograph of two barnacles, one large and one small, attached to an articulated bivalve shell. Like other encrusters, the barnacles preserve their original life positions on the bivalve. Pleistocene, Nukumaru Brown Sand, near Whanganui, New Zealand. Encrusters are sclerobionts, a collective term for organisms colonizing all kinds of hard substrates, including shells, bones, wood, rocks and sedimentary hardgrounds (Taylor and Wilson, 2003). Other types of sclerobionts bore into hard substrates, leaving trace fossils as evidence of their former presence, or … Read More

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The ‘trident’ trilobites of Morocco

Dr Kendal Martyn (UK) Spectacular “spiny” adaptations of the Devonian (about 380Ma) trilobites of Morocco are well known. Free-standing spines, sometimes up to one hundred on a single specimen, make for spectacular (if fragile) specimens. Historically, similar species were first recognised way back in the 1880s by the classic work of Barrande on the fossils of Bohemia (in what is now the Czech Republic). Fig. 1. Walliserops issimourensis. More recently, the large-scale commercial digging of trilobites in the Anti-Atlas of Morocco, coupled with improved preparation techniques, has produced a wealth of information and new forms. As the digging around Djebel Issimour got tougher during the mid-late 1990s, this lead to people digging further afield. Near Foum Zguid, they found something new – a trilobite with a trident. Fig. 2. Walliserops issimourensis. Now called Walliserops trifercatus (Morzadec, 2001), many features relate this trilobite to more widespread asteropygid trilobites such as Comura bultynki and Quadrops flexuosa (also known as Phyllonix phyllonix). Fig. 3. Quadrops flexuosa. Walliserops trifurcatus is hard to find: one person, one week (full time) for one specimen (often incomplete). In fact, getting hold of a complete specimen is hard: getting it out of the rock without butchering it is harder still (see an unprepared trilobite and you’ll see what I mean). Fig. 4. Walliserops sp. Debate started almost immediately on the purpose of the trident: hood ornament; antler; defensive spear; sensory organ or feeding aid. Discovery of a smaller, short-trident form at the same locality, Walliserops sp., suggested sexual … Read More

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Identifying North African (Moroccan) mosasaur teeth

George Corneille (Ireland) I have been a collector of marine reptile and dinosaur fossils for many years and started to sell on a small scale a few years ago. This editorial is specifically to help collectors identify teeth that they may have in their collections and to better understand these giant ocean going reptiles that dominated the oceans from the middle to late Cretaceous. Many mosasaur species have been identified by isolated teeth. This is extremely difficult, because, ideally, to describe a new taxon, you need skull elements, jaw hinges, flipper digits and so on. This fossil material is of course not easily available for the most part and we have to rely on isolated teeth. However, both French palaeontologist, Camille Arambourg, and Belgian palaeontologist, Louis Dollo, have relied on isolated teeth to identify a new taxon. The first mosasaur was discovered in Holland in 1780 by Dr Johann Leonard Hoffman. Since that time, at least another 40 species have been identified worldwide from Sweden to Africa and Israel to New Zealand as well as the USA, especially in Kansas. Mosasaurs dominated the world’s oceans at the end of the Cretaceous. Here, we concentrate on the Moroccan species, specifically from the Oulad Abdoun Basin and Sidi Daoui in the Moroccan Sahara. There are currently six identified species of mosasaur from the marine deposits in Morocco. Arambourg (1952) was the last comprehensive study of marine fossils. In Mosasaurus beaugei (Arambourg 1952), the tooth crowns are described as robust with both carinae … Read More

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Megalodon shark ancestry

Steven A Alter (UK) Imagine a shark three times the size of the modern Great White  shark charging with reckless abandon into a pod of enormous 30 foot Sperm Whales. The mighty fish opens its gaping jaws and crunches into the side of one of the swimming mammals, slicing through flesh, blubber, ribs, and vertebrae. A single 6˝ long ivory-white tooth is pried loose from the shark’s lower jaw and flutters down to the bottom of the ocean, stained red from the assault. The tooth hits the bottom and soon settles down in the soft mud. The tooth is slowly covered by the sediment until it is deep enough where it is cut off from the water and any oxygen that might creep through. Ten million years later, a diver probes into the bottom of a relatively modern river and uncovers this magnificent tooth, now brown from the minerals that have penetrated it over the years. This tooth, now a fossil but almost as sharp as the day it was lost, becomes a prized possession for the lucky finder who hurries up to the boat to show his friends. This tooth is from the largest predator to ever inhabit the world’s oceans – Carcharocles megalodon. Fig. 1. Carcharocles megalodon. This ancient story relives itself day after day all over the world. Evidence of the megalodon shark can be found in fossilised teeth and vertebrae (even fossilised  whale bones still showing bite marks from the attack) all over the world. The … Read More

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Baltic amber from Kalingrad

E R Matheau-Raven (UK) Amber is the hardened resin of coniferous and angiosperm trees. Resin should not be confused with sap, which is a product of photosynthesis that consists of sugars, water and dissolved minerals. The sticky extrusive mass that comes from a cut on a pine tree is resin. Under the proper conditions, it undergoes certain physical and chemical changes that turn it into amber. If resin has hardened in recent times, it is called copal. Columbia, in South America, has extensive copal deposits. Presently, certain trees produce large quantities of resin; the Kauri gum from New Zealand (Agathis australis), the Sundarac from Australia (Tetraclinis articulata), the Gum Arabic tree from Africa (Acacia arabica)and the Algarroba tree from South America (Hymenaea courbaril. It was trees like these that produced the resin that often trapped unsuspecting insects and even some slightly larger animals. Like fly paper, the more the animal struggled to get free, the more entangled it became. Fig. 1. Caddis fly: Order – Diptera. Often, the origin of the amber can be derived visually from the amber itself. Baltic amber may have a cloudy appearance, due to air bubbles and also has a high percentage of Succinic acid, as much as 8% by weight. It is a high-molecular compound of organic acids and has been produced as a result of fossilisation of the resin from the pine, Pinus succinifera. This tree was prospering in the Baltic area 40 to 45 million years ago. Fig. 2. Ant (worker): Order … Read More

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Hexanchus gracilis: A shark from the Lower Chalk of Hunstanton

S M Bowerman (UK) Sharks of the genus Hexanchus belong to the family Hexanchidae and are more commonly known as six gilled sharks or cow sharks. They are well known for the difference in shape between teeth of the upper and lower jaw. They are first recorded in the Jurassic. Smart (2001) states that Hexanchidae are represented in the English late Cretaceous by two species: Hexanchus microdon and H. gracilis, both species being known only from rare isolated teeth. I collected a single specimen of H. gracilis, which is the subject of this short article. It was found at Hunstanton, in Norfolk in the UK (TF 673414), from the Upper Cretaceous Lower Chalk, Middle Cenomanian, Varians Chalk, Schloenbachia varians zone. Fig. 1. The striking cliffs at Hunstanton (picture courtesy of Andrea Clark). It is an incomplete specimen from the lower jaw. The specimen shows only two cusps of a possible seven. These appear to be accessory cusps. The posterior aspect of the specimen is not preserved therefore the principle cusp is not seen. The cusps show no signs of serration and the specimen remains in chalk matrix with the lingual aspect uppermost. The root is rectangular and slightly convex. Tooth width is 5mm, and its height is 3mm. Fig. 2. Hexanchus gracilis (Ref. No. H/619). Further reading Fossils of the Chalk: Palaeontological Association Guide No 2 (2nd edition), edited by Andrew B Smith and David J Batten, The Palaeontological Association, London (2002), 374 pages (Paperback), ISBN: 0901702781 References Smart, P. … Read More

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Panning for gold at Baile an Or in Northeast Scotland

Alister and Ian Cruickshanks (UK) During the year of 1818, a nugget of gold weighing around ten pennyweights was discovered in the river Helmsdale, in Northeast Scotland. The find sparked national interest and the Scottish local newspapers were soon headlining the discovery. It was then in 1968 that Scotland ensured its place in the history books following the discovery of further gold nuggets at Kildonan, in the river Helmsdale by a local man Robert Gilchrist, who had spent 17 years in the gold fields of Australia. Fig. 1. Gold panning at Baile an Or. Gilchrist was granted permission from the Duke of Sutherland to pan the gravels of the river Helmsdale. Shortly after, word started to spread into London and, within just six months, over 600 people made their way to Kildonan, creating its own miny gold rush. A whole series of temporary living quarters started to appear along the riverbanks forming the small town, Baile an Or (meaning ‘Village of the Gold’). Fig. 2. The equipment you will need. Today, Baile an Or (Grid Reference: NC 91136 21380) continues to provide fun for all for those wishing to try their luck at gold panning. The original nugget from the river was said to have been made into a ring and is in possession of the Sunderland family, but there have been recent stories too of a couple who panned for gold twice every year over a number of years, who had their wedding ring made from the gold of … Read More

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Fossils from Florida, USA

E R Matheau-Raven (UK) Florida has one of the world’s richest fossil deposits of both terrestrial and marine origin, encompassing over 2,000 known fossil locations. The state is famous for its Pliocene/Pleistocene fossil fauna but also has a rich and diverse Miocene heritage, plus its coastal waters abound with giant Carcharocles megalodon shark teeth, much prized by fossil divers for their value. Fig. 1. Tapir lower jaw. The Thomas Farm site in Gilchrist County, North Central Florida has the largest Miocene mammal deposits east of the Rocky Mountains. It was discovered in 1931 after locals reported what they thought was an Indian burial site and has, for the last 70 years, continually given up its secrets. The fossils from here are dated at 18 million years old and are typified by many types of mammal, such as the early three-toed horse Nanippus. Fig. 2. Horse upper molar: Equus sp. Florida began to form by a combination of volcanic activity and marine deposition along the northwest portion of Africa over 500 million years ago during the latter part of the Cambrian Period. At about 300 million years ago (during the Upper Carboniferous), the time of the formation of the supercontinent, Pangaea, Florida was sandwiched between what were to become North and South America and Africa. Near the Triassic/Jurassic boundary (210 million years ago), Pangaea began to divide into two major continents, Laurasia (North America, Europe and parts of Asia) and Gondwana (South America, Africa, India, Australia and Antarctica). Fig. 3. Tapir … Read More

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Travelling through time: The roadmap for Namibia is in the rocks

Patricia Vickers-Rich , Peter Trusler, Steve Morton, Peter Swinkels, Thomas H Rich, Mike Hall and Steve Pritchard (Australia) The “road map” allowing (time) travellers to move across more than 1,000 million years in Namibia is recorded in the rocks of this land. And, it is on display in several museums in Namibia – in Swakopmund, Windhoek, Rosh Pinah and Farm Aar. The old part of the road In drafting the early section of this map, Southern Namibia has been a key region for understanding some of the sights our time traveller will come into contact with, some being the weird organisms called Ediacarans. Since the early days of the twentieth century, when geologists, such as Paul Range, and German soldiers occupying isolated outposts in the Aus region of Southern Namibia, some of these strange fossils were reported. These were the first ‘large’ multicellular organisms that prospered on planet Earth before the development of true animals, and amongst them were the tiny cloudinids. Their fossils are preserved in the thick rock sequences that can be seen along the “time road” in Southern Namibia. These showcase a time in the history of life when there were fundamental and pivotal changes in life occurring, with life transitioning from an enigmatic biota to what we consider normal today. And, at a number of museums in Namibia, including the Swakopmund Museum and the Namibian Geological Survey in Windhoek, several of these intriguing organisms are on show – such as the soft-bodied Ernietta, Pteridinium and Rangea,and … Read More

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Environmental scientists and geology (Part 3): Geology and soil science in the ‘National Environmental Policy Act document’ process in the USA

Deborah Painter (USA) I am an ecologist and general environmental scientist, specialising in transportation, energy and industrial development planning to minimise deleterious environmental impacts. I live in the United States and have also written several articles for this magazine. I appreciate just how important local geology and soil science are in one of the aspects of work I do: researching and writing National Environmental Policy Act documents. This is the third of three articles on how environmental scientists apply this knowledge. Part 1 detailed geology and the hazardous materials site assessment of a property (Fig. 1; see Environmental scientists and geology (Part 1): The first phase of an environmental geology investigation). Part 2 dealt with wetland and water permitting and how geology is important in that process (Fig. 2; see Environmental scientists and geology (Part 2): Geology and soil science in the ‘Wetlands and Waters Permitting’ process in the USA). Fig. 1. Hazardous material releases can have a tremendous impact and must be documented along with plans for remediation. (Credits: Deborah Painter.) Fig. 2. If wetlands are to be impacted, permits must be obtained, along with avoidance and minimisation measures put in place. The impacts must not be significant ones. (Credits: Deborah Painter.) Both of these areas of environmental due diligence are parts of every National Environmental Policy Act document, or “NEPA” document. When I write one of these, I must thoroughly document that these two potential issues – and twenty more – have been examined, and that any remediation … Read More

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Hastings (Part 3): When Dinosaurs Roamed

Ken Brooks (UK) The beach from Rocka-Nore to Pett Level is rich in fossil evidence. Even the most insignificant fossils are important because they provide clues that enable us to reconstruct the ancient environments of this area. Between 100 and 140 million years ago, much of southern England was covered by lakes and lagoons. Rivers flowing from the London area and the west deposited great quantities of sand and silt on extensive flood plains. Molluscs, fish and freshwater sharks lived in the lakes and rivers, while the land was dominated by crocodiles, turtles and dinosaurs. Fig. 1. The Hastings coastline today. Eventually, their fossilised shells, scales, teeth, bones and footprints were preserved in the layers of sediment. Carbonised plants, such as horsetails, ferns, cycads, conifers and tree ferns, indicate that the summers were hot and dry (with frequent fires), followed by wet and humid conditions in wintes. Millions of years later, when Africa collided with the European plate, southeast England was pushed upwards into a vast dome-shaped structure, known as the ‘Wealden anticline’. Since then erosion has removed many layers of rock and exposed the sandstones and clays which now form the cliffs between Hastings and Pett. Fig. 2. Hastings during the Lower Cretaceous (© Stuart Handley). Bones and footprints of Iguanodon are among the most common dinosaur remains, although other very interesting fossils have recently been found in the Hastings area. These include the spines and vertebrae of Polacanthus, a tooth from Baryonyx and quillwort plants still in their … Read More

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Walrus of the Norwich Crag: Alachtherium cretsii

Alister Cruickshanks (UK) The Norwich Crag at Easton Bavents, Southwold in Suffolk is one of the only locations where mammalian remains from the Pleistocene Epoch can be found, in situ, at an accessible location in the UK. The Norwich Crag splits the Antian and the Baventian. At Easton Bavents South Cliff, the Norwich Crag Shell Bed is missing. Instead, there is a fine gravel layer with laminated clay and sand, which yields occasional remains. This bed is equivalent to the Lower Shell Bed of the North cliff at Easton Bavents, One of the latest theories suggests that this was once a pre-historic fast flowing river, which flowed into a larger estuary that was present at the North Cliff during the Pliocene Era. The North Cliff itself has a stone layer above the Norwich Crag Shell Bed. This bed comprises three main bands: the upper, middle and lower beds, but varies considerably along this stretch of cliff. The Norwich Crag Stone bed is directly below the Baventian Clay, both of which are from the Baventian stage which is 1.55 to 1.6 million years old, from the Pliocene Era. The Norwich Crag Shell Bed is Antian in age, which is 1.6 to 1.7 million years old. Fig. 1. Fine gravel layer with laminated clay and sand. A complete lower mandible of a walrus was discovered in situ after high tides during 1993, by my father and me. At this time, the specimen could not be fully identified and spent ten years at … Read More

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Fossil hunting in Oxfordshire, UK

Mike Thorn (UK) If you ask someone to think of Oxford, they will not usually picture warm tropical beaches and azure coral seas. However, go back to the middle Jurassic and you would be hard pushed to find a dreaming spire or student on a bicycle anywhere. At that time, around 160 million years ago, Oxfordshire lay beneath a shallow, tropical seaway at about the same latitude that the southern Mediterranean occupies today. Over the course of the middle Jurassic, this seaway varied in depth, but remained close to nearby land masses from which a lot of sediment was derived (Fig. 1). A great thickness and variety of limestones, sandstones and clays were deposited over several tens of millions of years. Fig. 1. Southern England during the middle Jurassic, 160 million years ago. During the nineteenth and early twentieth centuries, there were many working quarries in the Oxford area, exploiting the abundant clay and limestone for the brick and building stone industries. Quarrymen were frequently paid to look out for fossils and these turned up in abundance, fuelling the academic debates on evolution taking place at the time. Fig. 3. Geological Context for Kirtlington Quarry and Dry Sandford Pit. Sadly, many of these quarries have now been filled in and, for the casual fossil hunter in Oxfordshire, it might seem that there are now few opportunities to collect. However, Kirtlington Quarry and Dry Sandford Pit are two old quarries which are open to the public and at which there is … Read More

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Hastings (Part 1): Field trip from Rock-A-Nore

Ken Brooks (UK) This is the first of three articles on the geology and fossils in the cliffs and foreshore to the east of Hastings. This one is intended as a field trip. The geology here is all Lower Cretaceous and is some of the best in Britain if you are interested in this period of time. Follow the Hastings seafront eastwards to the ‘Old Town’ and the famous ‘net shops’ in Rock-A-Nore Road. Below the high, sandstone cliffs of the East Hill, you will find the Fishermen’s Museum, the Blue Reef Aquarium (a sea-life centre), a large car park and public toilets. This field trip begins at the last stone groyne and continues along the beach towards Ecclesbourne Glen, nearly one kilometre (half a mile) to the east. The massive sandstone cliffs of the Upper Ashdown Formation are overlain by the shales and sandstones of the Wadhurst Clay. A distinct junction between one horizontal bed of rock and another often marks a period of erosion. This may have been followed by a change in the environmental conditions where a different grade or type of sediment was deposited. In this area, the lower part of the cliff is hidden under a scree slope of broken rocks, but there is one small exposure in situ at beach level. Here, there are flattened branches of carbonised wood lying horizontally within a silty mudstone. These were probably washed into a river or lake, then later covered and compressed by sedimentary layers. The leaves … Read More

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Environmental scientists and geology (Part 2): Geology and soil science in the ‘Wetlands and Waters Permitting’ process in the USA

Deborah Painter (USA) I am an ecologist and general environmental scientist specialising in transportation, energy and industrial development planning to minimise deleterious environmental impacts. I live in the United States and have also written several articles for this magazine. One of the things I really appreciate is just how important local geology and soil science are in one of the aspects of work I do: delineating wetlands and obtaining permits from regulatory agencies for work in wetlands and waters. This is the second of three articles on how environmental scientists apply this knowledge. The first is entitled Environmental scientists and geology (Part 1): The first phase of an environmental geology investigation. The discharge of dredged or fill material into waters of the USA and most categories of work in navigable water bodies require US Army Corps of Engineers authorisation under Section 404 of the Clean Water Act of 1972. These activities also require Section 401 Clean Water Act permits from their state governments. The Federal definition of “waters of the United States” includes rivers, small streams, bogs, most nontidal wetlands, many lakes, mud flats, bays, the US territorial sea, and even many drainage ditches (Figs. 1, 2 and 3). They do not include isolated, nontidal wetlands with no connection to interstate commerce. However, a state may assert jurisdiction over these isolated wetlands under its Section 401 program, if it chooses. Fig. 1. In New York State, northern white cedar (Thuja occidentalis) is a common nontidal wetland tree. (Credits: Deborah Painter.) … Read More

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Quartz is more than silicon dioxide

Dr Kendal Martyn (UK) This article describes several processes producing the shape of crystals. Such processes are illustrated in the most common mineral from the Earth’s surface, quartz. Quartz or “simple” silicon dioxide, is made up of interlocking atoms of silicon and oxygen, arranged into various symmetrical structures depending on pressure and temperature conditions. Such variation in the structure accounts for most of the different minerals discussed below. The presence of these different SiO2 minerals in rocks gives important information about the conditions those rocks were exposed to. Starting rules Minerals are classified by their distinctive structure (atomic arrangement), as well as their chemistry: all the mineralsdescribed below have the same chemical composition but different physical forms, known as polymorphs.Different physical structures are favoured by specific conditions of temperature and pressure (Fig. 1).If conditions favour a change in structure, the old structure may be preserved or a new structure formed,depending on the amount of energy available, the energy needed to make that change and the time available to make that change. Quenching (very rapid cooling) may “freeze in” the old structure. Kinetics (the physical re- arrangement of atoms and bonds) triumphs over thermodynamics (theoretically the energetically most favourable structure).Fig. 1. Diagram showing the stabilities of some (not all) of SiO2 polymorphs under different temperature and pressure conditions. (From the Cambridge University website.) Breaking and reforming atomic connections, a radical rearrangement, needs more energy and requires material to diffuse across the crystal. Such reconstructive transitions will only happen if there is … Read More

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Hastings (Part 2): Geology and fossils

Ken Brooks (UK) During the Lower Cretaceous period, between 110 and 145 million years ago, Britain was part of the European land-mass. Southeast England was covered by meandering rivers, extensive flood-plains, lakes and lagoons which extended across to central France. Rivers flowing from the London Uplands and the west brought huge quantities of sand, silt and mud, which were deposited over the whole area. Fig. 1. Starlight Cove These sediments later became the sandstones and clays of the Ashdown Sandstone and Wadhurst Clay within the Hastings Beds. Structures in the rocks, combined with fossil evidence, can be used to reconstruct the ancient environments and communities of this period. For example, the siltstones, clays and sandstones have preserved features such as river channel and flood plain deposits, as well as a rich variety of fossilised plants and animals. Fig. 2. An infilled river channel. The carbonised remains of horse-tails, ferns, cycads, conifers and tree-ferns indicate that Southern England had a sub-tropical climate with seasonal rainfall, perhaps like the Mediterranean today. Freshwater sharks and shellfish lived in the lakes and rivers, while the land was dominated by crocodiles, turtles and dinosaurs. Today, their scales, teeth, bones and footprints may be found along the stretch of beach between Rock-a-Nore and Pett Level. Fig. 3. Crocodile tooth: Goniopholis. Around 100 million years ago, the great weight of the sediments, combined with geological faulting, resulted in a gradual subsidence of the southeast. As a warm, shallow sea began to cover most of England and northern … Read More

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