Sign in with Facebook
Jan Zalasiewicz’s Followers (27)
Jan Zalasiewicz
More books by Jan Zalasiewicz…
“Basalt is the result of basaltic magma that has flowed onto the Earth’s surface, and so has cooled and frozen rapidly. When this happens, there is little time for the atoms and molecules in the magma to make their way, by diffusion, to the surfaces of growing crystals. Hence, basalt is made of a mass of tiny crystals, which can only be really seen using a microscope—geologists say it is ‘fine-grainedâ€�. If cooling is exceptionally rapid (as at the chilled surface of basaltic magma that has come into contact with water) then there is no time at all for crystals to grow, and volcanic glass forms instead. Such glass is inherently unstable, or more precisely metastable, because the atoms and molecules are in higher energy states than they would be if they were locked into the ordered molecular structures of crystals. Hence, over millions of years—and even in the solid state—the atoms and molecules diffuse, very slowly, the tiny distances necessary to lock onto other atoms and molecules, and they begin to form incipient crystals. The rock thus devitrifies and turns from clear to opaque, as a myriad submicroscopic crystal boundaries scatter the light.”
― Rocks: A Very Short Introduction
― Rocks: A Very Short Introduction
“The next stage is a hornfels, a thoroughly recrystallized rock, so named after its supposed resemblance to animal horn. Hornfels has one rather unexpected quality—when suitably shaped, it can produce beautiful musical notes when struck. Indeed, it took central place in an extraordinary narrative of the English Lake District. An eccentric 18th-century inventor, Peter Crosthwaite—a fighter against Malay pirates in his youth and, later in life, the founder of a museum in the town of Keswick—built a kind of xylophone using hornfels from the local Skiddaw mountain. Half a century later, the Keswick stone-maker and musician Joseph Richardson determined to top Crosthwaite’s achievement, and almost ruined his family financially by building an even bigger instrument, which would produce a larger range of musical notes. Once built, though, it was indeed a sensation. Richardson toured England for three years with his sons, playing Handel, Mozart, and dance tunes on his rock creation—though at times restraining the power of the instrument so it would not shatter concert hall windows. Queen Victoria liked the performances so much that she requested extra concerts (although reports from the time do suggest that she was not amused at its imitation of Alpine bells). The harmonious hornfels ‘lithophonesâ€� may still be seen in the Keswick museum—and are to this day occasionally taken on musical tour.”
― Rocks: A Very Short Introduction
― Rocks: A Very Short Introduction
“Bone beds turn up sporadically elsewhere, with spectacular examples in the Dinosaur National Monument in the USA and in Mongolia’s Gobi desert. In eastern England there are several within the early Cretaceous strata, which include, as well as bones, structures termed coprolites, some of which represent the petrified faeces of dinosaurs or marine reptiles. In the middle of the 19th century, when England’s population was booming and the farmers were struggling to feed everybody, it was discovered that these fragments (which, being bone, are phosphate-rich) made a superb fertilizer when crushed and acid-treated. A thriving and highly profitable industry formed to quarry away these ‘coprolite bedsâ€�.
Some considerable figures were involved in this industry. John Henslow, Charles Darwin’s beloved mentor of his time at Cambridge, seems to have first encouraged the farmers of eastern England to use such fossil manure. William Buckland also became involved. An extraordinary combination of early savant of geology at Oxford and Dean of Westminster, he was the first to scientifically describe a dinosaur ( Megalosaurus); carried out his fieldwork in academic gown; reputedly ate his way through the entire animal kingdom; and coined the term ‘coprolite�, using these petrified droppings to help reconstruct the ecology of ancient animals. Later, he energetically collaborated with the celebrated German chemist Justus Liebig (who had worked out how to chemically treat these fossil phosphates to make fertilizer) to show how they could be used by agriculturalists, once demonstrating their efficacy by exhibiting, in Oxford’s Ashmolean Museum, a turnip, a yard in circumference, that he had grown with such prehistoric assistance.
It is related strata (geologically rare phosphate-rich deposits, usually biologically formed) that are still a mainstay—if a rapidly depleting one—of modern agriculture. In a very real sense, these particular rocks are keeping us all alive.”
― Rocks: A Very Short Introduction
Some considerable figures were involved in this industry. John Henslow, Charles Darwin’s beloved mentor of his time at Cambridge, seems to have first encouraged the farmers of eastern England to use such fossil manure. William Buckland also became involved. An extraordinary combination of early savant of geology at Oxford and Dean of Westminster, he was the first to scientifically describe a dinosaur ( Megalosaurus); carried out his fieldwork in academic gown; reputedly ate his way through the entire animal kingdom; and coined the term ‘coprolite�, using these petrified droppings to help reconstruct the ecology of ancient animals. Later, he energetically collaborated with the celebrated German chemist Justus Liebig (who had worked out how to chemically treat these fossil phosphates to make fertilizer) to show how they could be used by agriculturalists, once demonstrating their efficacy by exhibiting, in Oxford’s Ashmolean Museum, a turnip, a yard in circumference, that he had grown with such prehistoric assistance.
It is related strata (geologically rare phosphate-rich deposits, usually biologically formed) that are still a mainstay—if a rapidly depleting one—of modern agriculture. In a very real sense, these particular rocks are keeping us all alive.”
― Rocks: A Very Short Introduction
Topics Mentioning This Author
| topics | posts | views | last activity | |
|---|---|---|---|---|
| Stress Free Readi...: Delta's Part 3 Passport | 115 | 37 | Oct 19, 2017 06:13PM | |
| Around the Year i...: COMPLETED Heidi's mostly fantasy, scifi & classics 2018 plan | 5 | 39 | Dec 31, 2018 09:09AM | |
| Stress Free Readi...: Candy Craze Challenge | 148 | 389 | Apr 20, 2019 08:42AM |
Is this you? Let us know. If not, help out and invite Jan to Å·±¦ÓéÀÖ.
