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Fossil spiders in Baltic amber

Anthonie Hellemond (Belgium) Spiders represent the most diverse group of obligate predators (that is, predators that feed solely on other animals) in terrestrial ecosystems today, with almost 48,000 extant species in 118 families described to date. The number increases annually by approximately 500 species as a result of new discoveries and it has been estimated that the true diversity may number around 160,000 extant species. This great diversity is no doubt at least in part due to their geological longevity, with the oldest known fossil spider dating back to the Carboniferous. In addition, spiders appear to have co-radiated along with their insect prey over geological time and they also appear to have been relatively resistant to extinction during the major events that eliminated many other terrestrial animal groups, such as the dinosaurs (Penney and Selden, 2011). Most people seem to presume that spiders do not have a very good fossil record on account of their very small size and their lack of a mineralised, bony skeleton. However, spiders actually have a very good fossil record, with 1,347 fossil species currently recognised. Fossil spiders occur in rocks of various different types, but the vast majority and best-preserved spiders are found as inclusions in amber from various localities dating back to the Cretaceous, although preservation tends to be better in the younger (for example, Miocene and Eocene) ambers. The best known of these deposits is Baltic amber, with more than 650 fossil spider species recognised (Penney et al., 2012), representing close to … Read More

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Book review: Geology of the South Devon Coast from the Dorset County boundary to the Brixham area: Geologists’ Association Guide No 73, by John CW Cope

Jon Trevelyan (UK) This is the second Geologists’ Association (GA) guide by Professor John Cope to be published in the last two years. The first was the second edition of his excellent Dorset guide, which was reviewed in the last issue of Deposits. And, on the grounds that “if it … Read More

Northern Rocks: Shetland

Neville Martin (UK) Shetland is famous for many things including ponies, knitwear, sheep and sheepdogs, birdlife and fishing. It is less well known for being an excellent attraction for the geologist or that it is currently going through the process of qualifying for European and World Geopark recognition. The rocks of Shetland are too old for fossils with the exception of some fish and aquatic plant fossils at the southern and western extremities. However, what it lacks in fossils it more than makes up for in an abundant variety of minerals and geological structures and, while looking for minerals, the geologist can enjoy some of the most spectacular seascape in the UK. In addition, the islands have a long history of mineral extraction and there has been talk of possible, future platinum and gold mining. Fig. 1. Old Red Sandstone Cliffs, Bard Bressay and Noss. One of the reasons for the geological diversity is that the Great Glen Fault, which formed Loch Ness, also manifests itself in Shetland. This gives rise to a displacement of some 60 to 80km, such that there is a distinct difference between East and West Shetland. The landscape is also the result of sculpturing by glaciers and the sea. The many submerged, glacial valleys are called “voes”, the largest of which is Sullom Voe, the site of the oil terminal where oil from north, east and west of Shetland is landed. The shelter provided by such a large voe (which is sea loch) made it … Read More

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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 and beliefs. Today, modern jade sculpting honours this ancient symbolism whilst introducing contemporary themes, thereby widening the appeal of this ancient art form. Maori Jade Carving The Maoris valued jade for its toughness and it was often made into weapons and tools such as adzes and chisels used for working with wood. Modern jade carving reflects the Maori traditions with new interpretations on fishhooks, circular koru pendants and beautiful double and triple jade twists that represent bonding and friendship. Models of Kiwis, Turtles and Dolphins can also be found carved in jade. Fig. 1. Maori-style Pendant, carved out of solid Jade. Inspired by Maori designs. Spiral – Koru – The fern fronds represent life, new beginnings, life unfolding, growth & harmony. The stylisation of Koru represents the spirit of rejuvenation. Fig. 2. Another Maori-style pendant, fish hooks – Hei Matau. Represents strength & determination. Brings peace, prosperity, abundance and good luck. It also provides safe transport over water. Chinese Jade Carving The highest quality Burmese Jade is sent to China where it is used for the finest objects and religious figures. It is often found in the grave furnishings of high-ranking members of the imperial family. The raw stone is … Read More

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Jade: Imperial green gem of the East (Part 1) – mining the gem

Sonja McLachlan (UK) In this, the first of a five-part series exploring the mineral Jade, I will explore  the various locations around the world in which Jade is found and mined. The world geography of jade mining Imperial jade, in all the colours and forms in which it is found, has appealed to many Eastern cultures since early times. It has been extensively mined and collected across the ages by many different people. However, in 1863, it was finally realised that the name “Jade” was being applied to two different minerals: jadeite and nephrite. Both jadeite and nephrite deposits are found in various places around the world. However, the jadeite mineral is much more rare than nephrite and, therefore, has a greater value to both the miner and collector. Nephrite deposits Nephrite jade deposits have been found in Khotan and Yarkand in Turkestan in China. Khotan is a city oasis and located on the famous “Jade” or “Silk Road”. New Zealand jade or “Pounamu” is found only in river boulders on the South Island. Deposits are also found in the Swiss Alps at Salux, Val de Faller, Poschiaro and the Gottard Range. Nephrite jade has been found in British Columbia, Canada where it is surface-mined. Large-scale mining began in Canada in 1995 and    currently  approximately 100  tonnes  a  year  are  mined and  sent  to  China. The finest jade found here is called “Polar Jade” and is especially translucent and green, which is rare in nephrite specimens. Jadeite deposits The most … Read More

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Mysterious blue orbs of K2 granite

William Wray (USA) K2 granite is found near the base of K2, the mountain it is named after, in the Himalayas from a rarely visited site. K2, also called “Mount Goodwin Austen” is the second highest mountain in the world, rising to 8,611m (28,253 feet). K2 got its name from the British surveyor TG Montgomerie. The “K” comes from the Karakoram mountain range and the “2” means that it is the second tallest peak recorded. Fig. 1. An oval cabochon made from K2 granite found on K2, a mountain between Pakistan and China, revealing several bright blue azurite stains. The blue azurite stains formed after the granite cooled and hardened. (Photo by the author. Specimen from the William Wray collection.) K2 granite has impressive splashes of blue circles or orbs on its surface. The blue circles are azurite inside of white K2 granite rock. The white granite is fine-grained and composed of the minerals: quartz, feldspar, muscovite and biotite. The azurite stained parts of the granite, making blue dots, which range from a couple of millimetres to about two centimetres. Azurite has a relative hardness of 3.5 to 4 on the Mohs hardness scale, but assumes the hardness of the white granite, because the azurite is only a stain. The azurite formed after all the other minerals in the granite had cooled and hardened. With a hand lens or microscope, azurite spheres reveal that the azurite appears along the edges of mineral grains, in tiny fractures in the granite, and … Read More

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Stop the press: The Jurassic Coast starts in the Permian

Mervyn Jones (UK) This Geologists’ Association field meeting followed the publication of Professor John Cope’s Geologists’ Association (GA) Guide No 73, Geology of the South Devon Coast. It is also the companion to GA Guide No 22, Geology of the Dorset Coast. John retired in 2003 after lecturing at Swansea and Cardiff universities. Since then, he has been an Honorary Research Fellow at the National Museum Wales in Cardiff, and has a wide field experience in the UK and Europe, with publications covering many fossil groups over a wide stratigraphical range. Most recently he has been working on redrawing the geological map of South Wales, the subject of an upcoming GA lecture. And, each year, for the past six years, he has provided weekend geological trips to the West Country. Fig. 1. Prof Cope demonstrates bedding and cleavage. We met up at Meadfoot Strand to the east of Torquay Harbour. Our mission for the weekend was to examine the complex Devonian succession in the Torbay area and its unconformable relationship to the Permo-Triassic cover. Of great interest was the marine Devonian, first described by Adam Sedgwick, assisted by Roderick Impey Murchison, who finally realised that these facies were contemporaneous with the familiar Old Red Sandstone found north of the Bristol Channel. Since then, the Devonian Stages have been named after rocks in the Czech Republic, Germany and Belgium. The base of the Devonian was the first ‘Global Boundary Stratotype Section and Point’ (GSSP), defined by graptolite zones at Klonk, in … Read More

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Colourful bluffs in Long Island recall the most recent ice age

Deborah Painter (USA) Imagine a tremendous piece of land moving equipment that scraped up the soil and some of the surface bedrock from four states within the United States’ Eastern Seaboard, carrying and dragging it all the way, before dumping it on a ridge off the shoreline. That is what essentially occurred with the final advance of the Wisconsinian ice sheet, the only one which left glacial deposits visible in New York State today. Long Island is a ridge of Cretaceous bedrock with glacial deposition. The moraines there have not been ground into sandbars and spits along the western end of the north shore as much as elsewhere, because of the sheltered nature of the Long Island Sound. Therefore, shoreline bluffs expose rocks as well as glacial loess. Fig. 1. Fishermen’s Drive takes you to the loess deposits. To park at the beach requires a permit. (Photo by JB Steadman.) If you find that your journeys take you to New York City, one of the world’s largest metropolitan areas, try to make time to visit Caumsett State Park at Long Island Sound. My own visit began when planning a visit to New York State’s Long Island to see my friend, Joyce Raber. She suggested various things that we might do: go to a Broadway play, go shopping and so forth. However, my list of things to do was typically “eco-tourist”. I wanted to visit the famed American Museum of Natural History in Manhattan, then see nearby Central Park, where the … Read More

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La Gomera: A short geological guide

Ken Madrell (UK) The island of La Gomera has an area of 370km2, it is 25km in diameter, has a maximum altitude of 1,487m (Alto Garajonay) and is situated approximately 40km west of Tenerife. Unlike the other Canary Islands, La Gomera has experienced a long and continuing eruptive break and is in a ‘postshield erosional stage’. Carracedo and Troll (2016) describe this as the stage when active volcanism has ceased, and erosive and denudational landforms are predominant (p. 39). The submarine base of the island shows that it rests on a shallower ocean bed than the surrounding islands. The emerged land mass is semi-circular in shape, with a radial drainage pattern from its centre near Alto de Garajonay. The dating of the island has proved problematic, as some of the earlier measurements placing its age between 15 Ma and 19 Ma have since proved to be inaccurate. More reliable estimates now put its age at between 10 and 11 Ma. Fig. 1. Roque Argando viewed from Lomo de la Mulata. La Gomera’s general stratigraphy comprises of three main rock sequences: (1) A Miocene basaltic shield, including a basal plutonic complex (that is igneous rock formed by solidification at considerable depth beneath the earth’s surface); (2) A nested felsic (that is, igneous rocks that are relatively rich in elements that form feldspar and quartz) stratovolcano (which is built up of alternating layers of lava and ash); and (3) The youngest Pliocene volcanism. Fig. 2. Sketch map of La Gomera, showing the … Read More

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Whitby Jet and the Toarcian Oceanic Anoxic Event

Arthur Speed (UK) One hundred and eighty million years ago in the Toarcian Stage of the Lower Jurassic Period, the Earth was very different from the world we know today. The continents were all clumped together in a supercontinent called Pangaea, which was just beginning to split apart. Sea level was approximately 100m higher than at present, such that much of Britain (including Yorkshire) lay beneath shallow seas. At this time, the Earth’s oceans were depleted in dissolved oxygen. The chain of events that caused this are complex, but can be traced back to a major volcanic event (Fig. 1). The eruption of the Karoo-Ferrar Large Igneous Province (LIP) spewed lava over what is now southern Africa and released vast amounts of carbon dioxide into the atmosphere. Just as happens now, the carbon dioxide resulted in global warming, which, in turn, had several effects on the oceans: Fig. 1. Volcanism during the eruption of the Karoo-Ferrar LIP may have triggered the Toarcian Oceanic Anoxic Event (Ulrich, 1983). Seawater became deficient in dissolved oxygen, because oxygen solubility decreases with increased temperature.Plankton thrived as a result of the warmer temperatures and increased nutrient supply, using up even more dissolved oxygen.Oceanic circulation was decreased, reducing the supply of cold oxygenated water to the oceanic basins.Warmer water released the green-house gas methane from the ocean floor, further accelerating global warming.The result was the formation of a layer of water that was deficient in oxygen throughout the Earth’s oceans. Its existence was first postulated in … Read More

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Geological transformation of Sharjah, United Arab Emirates

Khursheed Dinshaw (India) In this article, I will briefly deal with the fascinating and relatively recent geological transformation of the Sharjah region of the United Arab Emirates (UAE). Sharjah needs no introduction in terms of it being a popular tourist destination, especially for families. However, very few know how it was formed and subsequently transformed. In this article, I hope to explain this fascinating aspect of Sharjah. From the beginning At the beginning of the Miocene Period, 23 Ma, Arabia finally split from Africa along the Red Sea and the Gulf of Aden became a separate plate. This new plate moved in a northerly direction and collided with, and was subducted under, the Eurasian continent (Fig. 1). The Strait of Hormuz also closed as the remains of the Tethys Ocean formed a rapidly subsiding basin in which thick layers of salt were deposited. Large scale folding and faulting took place in the UAE producing hills of folded rock, such as Jebel Fai’yah and Jebel Hafit. Fig. 1. Granite from continental drift. In the eastern part of the UAE, uplift of the Al-Hazar Mountains began. This continued into the Pliocene Period, from 5 to 2 Ma. In the late Miocene and Pliocene, the Sharjah region finally rose above sea level and the landscape we see today was formed. Fig. 2. Various rock exhibits at the Sharjah Natural History and Botanical Museum. When the region known as Sharjah rose above sea level, it allowed the area to be covered by the moving … Read More

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Colorado mountain memories

Steven Wade Veatch (USA) While headed for the California Gold Rush of 1849, George Giggey (who was my great-great-grandfather) first made his way through the mountainous and untamed wilderness of what would later become Colorado. He was among a group of young men, who were determined to make a new life, fortune and future in the American West. After working in the Californian goldfields, he turned his attention to Colorado, where he prospected for gold for a while and then returned to the East. In 1865, George Giggey returned to Colorado with his family of ten children and built a homestead in the wilderness near what would become, in just a few years, the town of Caribou. The town developed around the Caribou silver mine that was discovered by Sam Conger in 1868. George Lytle, one of Conger’s partners, was from British Columbia and named the mine after his caribou hunting trips in Canada. By 1870, the Caribou Mine was in full production and was shipping ore down Coon Trail, to the nearby settlement of Nederland for processing. By 1872, the frontier town of Caribou built a much needed schoolhouse. Three of George Giggey’s boys attended Caribou’s first school session. They were: George Leon (my great-grandfather), who was 14 years old; Adelbert, age 7; and Charley, who was only 6 years old. I can feel the boy’s excitement when they took their seats in the one-room schoolhouse, with new furniture, blackboards, maps, globes and a new teacher – Miss Hannah … Read More

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Volancoes of Big Island, Hawaii (Part 3)

Dr Trevor Watts (UK) This is the last of a three part article about the volcanoes of Big Island, Hawaii. In the first part, I discussed their background and explained some of the terms used to describe the lava that can been seen there. In the second, I discussed some of the highlights that my wife and I saw during our several trips to the island, including in October 2014. And in this part, I will continue to describe what we saw. Fig. 1. One of the kipukas (that is, untouchedby- lava areas of forest). The abandoned lava cliff at Kalapana This is a stretch of old cliff face that is now several hundred metres from the sea. It is located among the flows of February 1992 to October 2003, but the area was re-flooded with lava between 2007 and November 2013, when the ocean entry hereabouts was blocked. The site is just under 5km southwest of present-day Kalapana near Poupou, where the Royal Gardens lava flow reached the coast. The walk is well worth the effort for the variety of lava formations, the many tumuli or blisters of lava, and the coastal scenery along the present cliffs. We were guided here by Gary Sleik, who lives on the lava at Kalapana. Fig. 2. The first section of cliff face, with the lens-shaped tube blocked by cindery flow. The cliffs are backed up by a small kipuka, which is an area that was left untouched, as the lava flowed around … Read More

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Volancoes of Big Island, Hawaii (Part 2)

Dr Trevor Watts (UK) This is the second of a three part article about the volcanoes of Big Island, Hawaii. In the first, I discussed their background and explained some of the terms used to describe the lava that can been seen there. In this part, I will discuss some of the highlights that my wife and I saw during our several trips to the island, including in October 2014. A night walk to the flowing lava from Kalapana This was one of the major highlights of our previous trip in 2013. Several local guides conduct walks across the old lava (mostly 1981 to 2013 flows) to wherever the current flow is best viewed. Our lead guide was Dave Ewing (postewing@gmail.com or (808) 315-2256) and our group met up at his house, located on private properties beyond the “End of the road” signs at Kalapana. This house is one of the very few to survive the 2010 flow, which came through the Royal Gardens subdivision and into Kalapana. Fig. 1. A going away party to mark the long-expected event of the house burning at Kalapana on the night of 25 July 2010. My thanks to Darlene Cripps and Gary Sleik for this picture. We began in late afternoon, with around a dozen people in the group. The walk initially passed the remnants of some of the other homes – a corrugated roof, a fridge, some pilings, and so on, before getting onto the fresh lava. It was almost five kilometres … Read More

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Volancoes of Big Island, Hawaii (Part 1)

Dr Trevor Watts (UK) We (my wife Chris and I) enjoyed our fourth visit to Big Island Hawaii in May 2013 so much that we decided to return to the same places in October 2014. We were hoping to see similar events and activities, which we had found particularly interesting and accessible over the years. Every time we visit, something changes or isn’t possible, but this time was a little more changeable than most. The intervention of three ladies altered a few of our plans – Iselle, the hurricane that visited the southeast of Big Island two months before we arrived; Madame Pele, the Hawaiian Goddess of the Volcano; and Ana, the hurricane that hit the area during our stay. The three interventions illustrate the simple fact that we and our little plans have to be adaptable and show that some of the great locations will be discussed in these articles and will be missed if you only make one visit. This is the first of three articles on Big Island in Hawaii. In them, I will talk about the major highlights of our visit in connection with the volcanic activity of this wonderful island. This first part will mostly illustrate the different volcanic concepts that need to be understood to appreciate what can be seen, and will also provide a general background to the location and the significant summer 2014 flow towards Pahoa. About lava Traditionally, lava is described as pahoehoe or a’a. These are taken to mean ropey … Read More

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Dendermonde Mammoth: Fighting pyrite decay and the preservation of unique palaeontological heritage

Anthonie Hellemond (Belgium) Collecting fossil vertebrates is rather popular among amateur palaeontologists. However, little interest is shown in the different stages one should undertake to treat and safely guard these specimens for the future. Loads of fossils from historical collections are currently suffering because of years of storing and neglect. This might seem strange, since the fossils themselves have spent most of their time underground in very humid conditions, but in reality, problems only start right after digging them up. Following-up on the restoration project of the “Dendermonde Mammoth”, we want to give an insight into the problems one can encounter when dealing with the restoration and preservation of Pleistocene vertebrate remains that have remained untreated for the past 20 years. The discovery In the historical Belgian city centre of Dendermonde (French: Termonde), we find the city’s history (including natural history) museum called the “Vleeshuis” museum (the house of meat merchants). It is located in one of the most authentic sandstone buildings in the main market square of “Dendermonde” (a province of East-Flanders). Inside the majestic wooden attic of the museum, the city’s oldest resident watches over the collection, which is packed with fossils and artefacts from the last ice age and prehistory. When walking up the impressive stone stairs that lead to the attic, visitors will encounter the paleontological pride of the “Dender” valley (the river flowing through Dendermonde). When we take a closer look at the information signs, we learn that this mammoth was found between 1968 and … Read More

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Trouble with pyrite

 Fred Clouter (UK) On Wednesday, 26 April 1882, the Queenborough Chemical and Copperas Works were auctioned off, heralding the demise of the copperas industry on the Isle of Sheppey. Green copperas was used to make sulphuric acid or vitriol, chemical manures and dye stuffs. “Being in Queenborough Castle in the year 1579 I found there one Mathias Falconer, A Brabander, who did in a furnace that he had erected there, trie to drawe very goode brimstone and copperas oute of a certain stone that is gathered in great plenty upon the shoure near untoe Minster on the isle”. This extract is from ‘Lambard’s Perambulations of Kent’ and is probably the earliest known reference to a ‘chemical’ factory in Britain. Fig 1. Poster advertising the sale of Queenborough Chemical and Copperas Company. The first reference that I have that links copperas with the collection of fossils is found in the ‘Life and letters of Edward Lhwyd (second Keeper of the MUSEUM ASHMOLEANUM) Oxford March 28th. 1695’. Below is an excerpt from ‘A Museum of the Early seventeenth Century’ By Cyril Edward Nowill Bromhead, BA, FGS, FRGS. (Read 18Th. June, 1947) referring to the Lhwyd letter: “If you could setle a correspondent in the Isle of Shepey to save us all the Crampstones the copras-women pick up for a month or two, I would now fall about a Lithologia Britannica: and so contrive it that the first tome shall consist of onely teeth and bones of fish.” (Sharks’ teeth were called ‘cramp … Read More

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Roman quarries in Austria and Germany: A short sight-seeing tour

Dr Robert Sturm (Austria) This is the third of four articles on the quarries of the ancient world and later, and, in particular, the marble that was quarried there and the works of art made from it. The first is Mining in Ancient Greece and Rome and the second is Marble from the Isle of Paros – a tour of the ancient quarries. The ancient methods used An antique quarry is interesting because it is a place where raw material for buildings and sculptural works was extracted to specific sizes and shapes with the technical methods of that time. The mining techniques did not change very much from the earliest phases of human civilization until the end of antiquity, even though the methods used continuously improved over time. In ancient Greece, single blocks of the stone were separated by smashing several key holes into the rock wall, into which wooden wedges were driven. After that, the wedges were moistened, causing their expansion and the cracking of the block along the line of holes. For a better control of the rock fracture, long groves were carved into the blocks with iron tools, into which key holes were subsequently inserted. Alternatively, the blocks were completely split off from the rock walls by deep cuts in the rock and then separated from the ground using crowbars (Fig. 1). Fig. 1. Separation of single blocks of rock using a crowbar and leverage. Since archaic times, rock saws have also been used. In the Roman … Read More

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Marble from the Isle of Paros in Ancient Greece: A tour of the ancient quarries

Dr Robert Sturm (Austria) This is the second of four articles on the quarries of the ancient world and later, and, in particular, the marble that was quarried there and the artwork that was made from it. The first was Mining in Ancient Greece and Rome. Some introductory words In general, marble represents a coarse-grained metamorphic rock primarily consisting of the minerals calcite (CaCO3) and dolomite ((Ca,Mg) (CO3)2). The word ‘marble’ may be derived from the Greek term ‘marmaros’ (μάρμαρος), which means ‘shiny stone’. The earliest use of the rock dates back to the fourth millenium BC, when it was considered, for the first time, as appropriate material for the construction of buildings and the production of rather primitive sculptures. In the Classical era starting at the beginning of the fifth century BC, its use was subject to a remarkable increase, which, among other things, entailed the prevailance of this shiny material in ancient Greek architecture and sculptural art. At that time, marble was simply termed ‘white stone’ or ‘Pentelic, Hymettus or Parian stone’, thereby indicating its preferential origin from the quarries of Naxos, Paros and Mount Pentelicus. Although these mines attained extraordinary eminence in antiquity, marble was also exploited from the quarries of Eleusis, Tripoli, Argos, Selinus, Syracuse, Skyros and other places. Marble from Paros – a very particular stone Each marble originating from a local quarry is characterised by very specific features. Stone material from Mount Pentelicus is distinguished by its white colour and fine-grained texture, rather high … Read More

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Wieliczka Salt Mine of Poland (Part 2)

Khursheed Dinshaw (India) This the second of two articles on the Wieliczka Salt Mine in Poland. The first (Wieliczka Salt Mine of Poland (Part 1)) covered some of the highlights that can be seen there. This one covers some more of these features, but also deals with the geology of the site. The journey began in the Miocene period, which was about 13.5Ma, when the crystallisation of salt dissolved in sea water occurred. These salt deposits combined with rocks that normally accompany salt that occupied what was known as the Pre-Carpathian Sink. Subjected intensively to the tectonic process, these salt deposits shifted and folded. About 6,000 years ago, the local people of Wieliczka in Poland started to produce salt by evaporating salty water. In the thirteenth century, when the sources of the salty water were almost exhausted, they began to sink wells hoping to find salty water under the ground. In 1289, at the bottom of one of the wells, the first lump of the grey rock salt was found and that was the beginning of the Wieliczka Salt Mine. Today, the mine is divided into two portions. While its upper stratum is the block type, its lower stratum is of the stratified type; and visitors learn about salt, its excavation and types as they walk with their designated guides across chambers, pathways, tunnels, chapels and lakes. In the olden days, the equipment to transport salt from one level to another included wooden carts and trolleys. At Wieliczka, these are … Read More

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Wieliczka Salt Mine of Poland (Part 1)

Khursheed Dinshaw (India) The Wieliczka Salt Mine of Poland was included in the first UNESCO World Heritage list in 1978. It is also on the Polish List of Historic Heritage and, when visiting, provides an interesting way to get to know how salt has been mined underground for almost nine centuries. In the summer, almost 8,000 tourists a day visit Wieliczka, which has 500 tour guides and 400 miners maintaining the mine. After buying your ticket, you are allotted a guide who will take you around the mine. Patrycya, our guide, has been on the job for 20 years and we enthusiastically followed her to explore the beauty, material culture and historic heritage of the mine and its excavated complex. Fig. 1. Kinga – the patroness of the miners, along with other salt sculptures. We opted for the tourist route, which lets you explore chambers, galleries, chapels and lakes. The mine has been opened to the public with this route since the end of the eighteenth century and has more than 300km of galleries and almost 3,000 chambers. It is divided into nine floors at depths varying from 64m to 327m. We went down to the third floor, which is at a depth of 135m. To get to the first level, one has to walk down 380 wooden steps, but the walk is comparatively easy. There are a total of 800 steps that tourists walk in the mine and, after the tour ends, a lift takes you to the exit … Read More

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Pallasites: The meteorite jewels in the crown

David Bryant (UK) Perhaps unsurprisingly (as a professional dealer in space rocks), I find all meteorites equally fascinating and, in their own way, aesthetically appealing. However, I have to admit, the meteorites known as the Pallasites, with their beautiful structure of olivine fragments suspended in a nickel-iron matrix, are probably the most visually exciting, particularly to the non-specialist. In addition to their undoubted beauty and rarity, Pallasites offer us an intriguing glimpse into the interior of a planet that make them among the most scientifically important of all meteorite types. The name Pallasite is derived from that of the German naturalist, Simon Peter Pallas. Pallas was one of those amazingly observant and gifted polymaths, who seem to have been a lot more abundant during the eighteenth century, as well as lending his name to a whole class of meteorite, an eagle, a warbler, two species of bat, a wild cat and dozens of other plants and animals. In 1772, Pallas obtained a 680kg lump of metal that had been found near Kransnojarsk in Siberia. When it was examined in St Petersburg, it was identified as a new type of stony meteorite. In keeping with tradition, it was named after the location where it was found, but, uniquely, the whole class of meteorites was named for Pallas. There is still some debate about the actual origin of Pallasites. Although some meteorologists contend that the stony-iron structure resulted from a collision between a nickel-iron asteroidal core and a chunk of mantle material … Read More

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Urban micrometeorites: A myth?

Jon Larsen (Norway) Is it possible to find micrometeorites in populated areas? The question has been raised for nearly a century and, despite numerous attempts to find them, the answer up to this day has been a very short “no”. Meanwhile, our knowledge about these amazing stones has gradually increased. There is a continuous evolutionary line in the research on micrometeorites, from the early pioneers, John Murray and Adolf Erik Nordenskiöld in the nineteenth century, to Lucien Rudaux and Harvey H Nininger. With Donald E Brownlee and Michel Maurette in the 1960s, micrometeoritics became real science. During the past two decades, this research has accelerated thanks to, among others, Susan Taylor, who extracted micrometeorites from the water well at the South Pole, Matthew Genge, who figured out the classification, and other splendid researchers, in addition to the space probes that have returned to Earth with dust samples from comets and asteroids. Today, there is a growing literature about micrometeorites, but still the answer to the initial question is “no” and urban micrometeorites have been considered an urban myth. Micrometeorites have been found in the Antarctic, but also, to some extent, in prehistoric sediments, remote deserts and in glaciers – places that are clear of the confusing anthropogenic influence. The wall of contamination has been considered insurmountable. It is therefore with pride and joy that I can report here about a project involving the systematic examination of all sorts of anthropogenic and naturally occurring spherules in an empirical search for micrometeorites … Read More

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Great Plains geology: A personal journey

Professor Emeritus Robert F Diffendal, Jr (USA) I grew up in the 1940s and 50s in the eastern US state of Maryland and went to cinemas on my own from the age of six, mostly to see what were then to me exciting western movies. In 1962, I was off to graduate school in the Great Plains state of Nebraska, a place that I pictured in my mind as it had been depicted in some of those films. Imagine my surprise when it looked nothing like the outdoor scenes in most of those films. Silly me, to have thought that films were made as closely as possible to the real subject area. From graduate school in 1962 to now, I achieved my goals and became a geologist and professor, travelling and doing research in the Great Plains and western Central Lowland physiographic provinces, and looking at geology in exotic places like the UK, China, Australia and New Zealand. Fast forward to 2013. I had enough experience and expertise on Great Plains geology by then that I was asked to write a short book of about 35,000 words on the geology of the Great Plains by the director of the Center for Great Plains Studies at the University of Nebraska, Dr Richard Edwards. After visiting and studying sites in Alberta and Saskatchewan in Canada, and in south-western Texas that I had not previously studied, I started working on the book now titled Great Plains Geology that is reviewed in this issue … Read More

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Agate: A mineral that develops with age, water and moganite

Terry Moxon (UK) Agate is banded or variegated chalcedony and this distinctive appearance allows a ready identification from any source. Many agate thick sections from basic igneous hosts are reminiscent of a series of distorted onion-like rings with the initial bands closely replicating the shape of the supporting gas cavity. However, the banding is frequently distorted and this general pattern is known under various names, for example, fortification or wall lining. A second type is less common and demonstrates apparently gravity-controlled horizontal bands. Agate host rocks are varied but the most abundant agate sources are the gas cavities of basic igneous rocks. This article limits discussion to agates from these basic hosts. However, agates can also be found in some igneous acidic hosts (for example, rhyolite), sedimentary rocks (for example, limestone) and in some fossils. Agate is greater than 97% silica (SiO2) and shows little variation between different samples. Under normal earth surface conditions, silica occurs in a number of forms. It is most commonly found as alpha-quartz and this is the major component in agate. A second silica constituent is moganite with a concentration at 2 to 25%. Moganite is found in agate that has not been heated by metamorphism or in the laboratory. Together with alpha-quartz, they are usually the only forms of silica identified in agate. However, other forms of silica such as cristobalite and tridymite have been occasionally identified in agate. In agates from basic igneous hosts, calcite is a rarity, as demonstrated by an examination … Read More

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Pale white dot

Steven Wade Veatch (USA) and Vishwam Sankaran (India) “There’s nothing new under the sun” goes a famous saying and these words are very apt when trying to understand Earth’s climate trends. Thanks to numerous discoveries made about Earth’s ancient past, we now know that our climate has never been static. According to geological and palaeontological records, climate change has affected the Earth throughout geologic time. In this context, this is the second of a series of articles about climate change over geological time. The first is A warming medieval climate supports a revolution in agriculture by Steven Wade Veatch and Cheryl Bibeau. To understand climate change today, researchers study past climates and events that affect climates, such as volcanic activity, solar radiation, sunspot activity, astronomical changes and other factors that influence climate. Once we understand the dominoes that have fallen during the past climate change events, we can understand and predict – to some degree – the kind of patterns that may follow current trends. To do this, scientists piece together clues from past climates provided by rock formations. Scientists likewise examine fossil records that yield climate signals from the past. These fossils range from prehistoric pollen to dinosaurs. Putting both geological and fossil records together reconstructs ancient climates and environments. More recent climate change is studied through climate records held in polar ice caps and ice sheets, ice cores, glaciers, isotopes of elements (like oxygen, carbon and sulphurfur), soil sediments and tree rings. When we think of the term … Read More

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What’s so special about South Devon?

Professor John CW Cope (National Museum of Wales, Cardiff UK) Take a trip to the South Devon coast around Easter time and you are bound to come across student parties from universities engaged in fieldwork. What is it about this area that makes it so popular as a centre for this? The simple answer lies in a single word — variety. There is probably no other area in the UK where such a wide variety of rock types and ages is well-exposed in such a small geographical compass. Let’s have a look at some of the factors. The geological succession The oldest rocks exposed in South Devon are of Devonian age and, unlike many other areas of the UK, the Devonian rocks are in marine facies virtually throughout. Looking back over the history of geology, the age of these rocks had initially proved difficult to identify and it was only after Murchison had seen the marine successions in The Rhineland and Russia that he realised that these marine rocks were the equivalent of the Old Red Sandstone farther to the north. The Devonian rocks present a variety of marine facies, with the Middle Devonian limestones being of particular note. The limestones are a local development whose presence, in an otherwise deeper water succession, is due entirely to local shallowing of the water caused by thicknesses of volcanic rocks extruded along extensional fault lines as the local basins developed. This shallowing allowed reef-building organisms to flourish and the principal ones of … Read More

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Jurassic Coast (or is it?) with the Geologists’ Association

Mervyn Jones (UK) Since 2012, the Geologists’ Association (GA) has put on annual field trips to the Dorset coast led by Prof John CW Cope (of the National Museum Wales), who is author of the definitive Field Guide No 22. The second edition was published in April 2016 (Geology of the Dorset Coast (2nd ed)). In fact, the trips were started to celebrate the publication of the first edition of the guide. The Dorset Coast is often equated with the ‘Jurassic Coast’ when, in fact, the geology stretches from the topmost Triassic, near the Devon border, through Jurassic and Cretaceous successions, to Eocene deposits at Studland. For this and other reasons, it attracts amateur geologists in large numbers. John’s guide provides essential information including descriptions of the succession and practical guidance about access. What’s missing are the entertaining stories that John Cope can provide and the context provided by exploring inland a bit. Day 1 – Saturday (1 October) For our fifth field meeting, we met up in Lyme Regis (in the car park next to the newly-restored house originally owned by John Fowles – see below) – a town to stir the heart of any geologist. Our mission for the weekend was to look at the unconformity below the Cretaceous, as it oversteps the older Jurassic and Triassic strata progressively in a westerly direction. En route, we observed the instability of the cliffs and suffered the same ourselves, as we scrambled over the boulders and shingle. On this occasion, … Read More

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Seeing into the ‘Stone Age’: The stone tools of early man

Bob Markham (UK) In the early part of his evolution, man made great use of rock and stone to assist him in his activities. The term ‘Stone Age’ has been given to the period of time during which stone was the main material used for the manufacture of functional tools for daily life. It is generally thought to have commenced about 3.3Ma and was the time when man firmly established his position on earth as a ‘tool-using’ mammal. However, it should be remembered that stone was not the only material used for this purpose. More perishable materials, such as wood, reeds, bone and antler, were also used, but very few of these materials have survived to be found today (but see the box: Non-stone tools). Non-stone toolsA notable exception to the general rule that non-stone tools have not been preserved is the Palaeolithic wooden spear shaft that was recovered in 1911 from a site in Clacton in Essex. At 400,000 years old, the yew-wood spear is the oldest, wooden artefact that is known to have been found in the UK (see http://piclib.nhm.ac.uk/results.asp?image=001066).A number of wooden spears dating from 380,000 to 400,000 years ago were also recovered between 1994 and 1998 from an open-cast coal mine in Germany (see https://en.wikipedia.org/wiki/Schoningen_Spears). Other items are found from time to time from peat-bog conditions, which offer the most favourable medium for the preservation of such material.The stones used to make tools Being a non-perishable material, stone has survived the ravages of time and is … Read More

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