Parting Shots
Remembrance of Carbonatites Past
The Oxford English Dictionary defines ‘vector’ as a quantity having direction as well as magnitude, and ‘scalar’ as a quantity having only magnitude, not direction. Much geological research starts with fieldwork, manifestly a vector activity. In Figure 1A, the geologists are exploring the intersection of a complex, 3-D body, the layered Klokken syenite, a 4 × 3 km igneous intrusion in the Gardar alkaline province of SW Greenland, with a mountainous 3-D land-surface. I described the unusual layering in Elements v10n1 (Parsons 2014). The igneous rocks were emplaced 1,166.3 ± 1.2 million years ago, and the 650 m of 3-D topography, which reveals the inner workings of the magma chamber, was carved by the advance and retreat of the mighty Greenland ice sheet in the last few thousand years. Only the age (a U–Pb age from baddelyite, ZrO2) is a scalar quantity.
Read MoreVectors, Scalars, and How Science Works
The Oxford English Dictionary defines ‘vector’ as a quantity having direction as well as magnitude, and ‘scalar’ as a quantity having only magnitude, not direction. Much geological research starts with fieldwork, manifestly a vector activity. In Figure 1A, the geologists are exploring the intersection of a complex, 3-D body, the layered Klokken syenite, a 4 × 3 km igneous intrusion in the Gardar alkaline province of SW Greenland, with a mountainous 3-D land-surface. I described the unusual layering in Elements v10n1 (Parsons 2014). The igneous rocks were emplaced 1,166.3 ± 1.2 million years ago, and the 650 m of 3-D topography, which reveals the inner workings of the magma chamber, was carved by the advance and retreat of the mighty Greenland ice sheet in the last few thousand years. Only the age (a U–Pb age from baddelyite, ZrO2) is a scalar quantity.
Read MoreHow Far to Glencoe?
In their doomed attempt to keep me near the cutting edge of technology, one of my sons recently bought me a grey cylinder that, when connected to an electricity supply, answers (literally) to the name of Alexa. She speaks BBC English with a mellow, alto voice and can, sometimes, answer my questions. Early in our relationship, to see how smart she really is, I asked her a question with three answers, ‘How far is it to Glencoe?’
Read MoreNooks and Crannies — Mountains and Clouds
I must explain the extension to my title. I wrote a Parting Shot with the title ‘Nooks and Crannies’ for Elements, 8 (2), 2012, in an issue on ‘Minerals, Microbes and Remediation’, devoted to nooks and crannies on weathered alkali feldspar surfaces. For international readers, I explained that (according to the Concise Oxford English Dictionary) a ‘nook’ is ‘a corner or recess; a secluded place’ and a ‘cranny’ is ‘a chink, a crevice, a crack’. The reactivity of complex mineral surfaces is a complicating factor in ‘reactive transport’, particularly near Earth’s surface. The present issue provides me with an opportunity to dust-off a few old micrographs, images of considerable beauty in themselves, to remind readers that minerals are not just chemical compounds. It also allows me to introduce an intriguing discovery of the last five years. Some, but not all, feldspars are extremely effective at nucleating ice in clouds, and this may be related to nooks and crannies, not just to chemistry.
Read MoreSpot the Dot …
Can you locate Mercury
as it hovers over the Sun during its 2016 transit?
What’s Your Next Dream?
While working on extinct volcanoes in Germany, I always wanted to see Hawaii. This dream came true in 1984 when I was on my way to study volcanoes in Antarctica when we passed through Hawaii … and I got the thrill of seeing Pu‘u ‘O¯ ‘o¯ erupt. Later, over a beer, I was telling my friend, Russ Harmon, how my fieldwork adventures had fulfilled a long-held dream. “So, what’s your next dream?”, he asked. “I want to work on the volcanoes of the Atacama in South America”, was my answer, not realizing that he and his colleagues were planning a field campaign to work on Parinacota Volcano in northern Chile the next year. I was invited to join.
Read MoreThe Chemical Precipitates of Henry Sorby
Henry Clifton Sorby (1826–1908) is best known to geologists for his pioneering use of the petrological microscope and for instigating the systematic study of fluid inclusions. He also introduced microscopy to many other areas of science. Sorby belongs to that great tradition of amateurs who have made substantial contributions to science. Being unhindered by the needs of funding bodies, Sorby’s research ranged widely and touched on many topics that are still current today.
Read MorePeace and War
At the end of July, I had a very special holiday, with some of my family, in Orkney, the cluster of small, wind-swept islands (Fig. 1) that stand bravely between the Atlantic and the North Sea off the extreme north-east corner of Scotland. I had always wanted to visit Orkney because my great-grandmother, Isabella Allan, was born on the tiny island of Stronsay in 1843. By any standards, these islands have an extraordinary human history, stretching from Neolithic times, some 5,000 years ago to the two great wars of the 20th century.
Read MoreNew Caledonia: Land of Nickle
New Caledonia (strictly Nouvelle Calédonie) is the most distant French overseas territory. Located in the southwest Pacific Ocean, this small archipelago (18,575 km2) is about 1,200 km from the east coast of Australia and 1,600 km northwest of New Zealand. The name was given by the famous English navigator and explorer James Cook, who published the first map of New Caledonia in 1774. Caledonia was the Roman name for Scotland, and it is said that the coasts of New Caledonia reminded Cook of Scotland, of which his father was a native.
Read MoreTribute to Paul H. Ribbe 1935–2017
Paul Hubert Ribbe, a giant in the field of mineralogy, passed away 24 June 2017 at the age of 82. Just eight weeks earlier, he was preceded in death by Elna Ribbe, his wife of almost 59 years. Paul was born 2 April 1935 in Bristol, Connecticut (USA), to the Reverend Walter and Grace Ribbe. He obtained his BS from Wheaton College (Illinois, USA) and his MS from the University of Wisconsin, Madison (USA), both in geology. He was the first American Fulbright Scholar admitted to Magdalene College, University of Cambridge (UK), where he worked at the Cavendish Laboratory with the legendary crystallographer Helen Megaw. He was awarded a PhD in 1963 for his research on the crystal structure of plagioclase feldspars. Following a short post-doc (University of Chicago, USA) and an assistant professorship (University of California, Los Angeles, USA), in 1966, Paul and Elna moved to Blacksburg (Virginia, USA) where he joined the Department of Geology at Virginia Tech. Paul became part of a powerhouse of talent in mineralogy and petrology that included Donald Bloss, Gerald Gibbs, Charles Gilbert, and the late David Wones.
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