The Golden Age of Mineralogy: Reflections by Ima Medalists (Part II)
By Rodney C. Ewing, Gordon E. Brown, Jr., and Robert M. Hazen | December, 2022
The International Mineralogical Association (IMA) Medal of Excellence (www.imamineralogy.org/Medal.htm) was established in 2006 as a lifetime achievement award that recognizes the excellence and impact of one’s contribution to knowledge. Here, we present the second half of a twopart series featuring recipients of the IMA Medal of Excellence and their personal reflections and experience of the “Golden Age of Mineralogy.” The first half of this series was presented in Elements vol. 18, no. 3, with insightful passages composed by Distinguished Professor Emeritus Frank C. Hawthorne (University of Manitoba, Canada) and Professor Nikolay V. Sobolev (V.S. Sobolev Institute of Geology and Mineralogy, Russia). This issue features passages written by Professor Rodney C. Ewing (Stanford University, USA), Professor Emeritus Gordon E. Brown, Jr. (Stanford University, USA), and Robert M. Hazen (Carnegie Institution for Science, USA).
On the Path to Decarbonisation
By Andrew J. Stewart | October, 2022
Cement and concrete are the fundamental building materials of the modern built environment. Our cities grow to the sky and into the ground, all based on concrete and its key ingredient, cement. Concretes are changing, but the role of concrete in our world is not. At present, most concrete has significant embodied CO2, but there is growing focus on changing that.
In 2006, I ended my academic career as an experimental geochemist and transitioned to a role at the global technical centre for one of the world’s largest cement companies. I became an expert in the chemistry and mineralogy of the clinker- and cement-making processes. I spent much time in various places around the world troubleshooting factory issues, training teams, and working on novel cements and production methods. In 2012, I left the technical centre and started on a journey within the business side of the industry, having the opportunity initially to lead a concrete division and now today being responsible for a cement business.
Why Study the Cascade Arc?
By Eugene D. Humphreys and Anita L. Grunder | August, 2022
The Cascade subduction zone (also known more generally as Cascadia) is but one of many subduction zones in the world. Why, then, is it so special and study-worthy in the global scheme? For a start, Cascadia represents an endmember setting for continental subduction zones— where compared with other subduction zones, the subducting oceanic lithosphere is young, warm, and subducting slowly. Cascade subduction is also unusual in other respects—for example, episodic tremors and slips are common but large earthquakes are uncommon, and the effects of toroidal mantle flow can be observed at the southern end of the subducted Juan de Fuca slab. Here, we highlight three other aspects of the Cascade subduction zone that we believe make it specifically worthy of study: (1) its interaction with a continental shear zone; (2) its sudden initiation; and (3) its interactive history with an oceanic plateau and a mantle plume. Each of these characteristics provide an unusual opportunity for gaining a greater understanding of subduction zones and associated volcanic arcs around the world.
For the present Perspectives, we have asked the recipients of the IMA Medal of Excellence (www.imamineralogy.org/Medal.htm) to reflect on their personal “Golden Age” experience and share their thoughts on the past, present, and future of mineral sciences.Read More
The Great East Japan Earthquake and Tsunami happened on 11 March 2011, which caused the Fukushima Daiichi Nuclear Power Plant (FDNPP) accident. The accident resulted in a substantial release of radio-nuclides, including 131I, 134Cs, and 137Cs, into the atmosphere, causing signiﬁcant environmental contamination. This was a particular issue in many parts of eastern Japan, especially in the Fukushima Prefecture (Yoshida and Takahashi 2012). Among the above-mentioned radioactive isotopes, 131I is one of the most critical radionuclides to be monitored after an accidental reactor release due to its tendency to accumulate in the human thyroid gland.Read More
During my doctoral studies, in the late 1980s, I realised that the Italian kamafugites (kalsilite melilitites) had to be related to carbonatite magmatism. I started a detailed study of the kamafugitic sites, and I explored remote areas deep in Italy’s Apennine mountains. When I found the Polino carbonatite, I put a few drops of acid on it, and the rock reacted. I have a vivid memory of my heart beating faster. I had found it! My fellow geologists were somewhat sceptical, but the late Professor Giorgio Marinelli (1922–1993) encouraged me and predicted many new carbonatite discoveries. He was right. Overcoming my Latin temperament, I focused on the concept that carbonatites, however unusual as rocks, cannot be dismissed as simple geological oddities but require detailed and comprehensive study. I am fond of all the history that marked my latest 40 years of life, and it reminds me of the many friends and mentors that I have had, especially when I was a young researcher. Sadly, some of them are no longer with us. I am so grateful to them, and I consider it a life-changing experience to have met them.Read More
Lithium, the first element in the alkali metals group of the periodic table, may seem a strange choice as a subject for which to devote a whole issue of Elements. Why should you care about lithium? What can lithium do for you? Well, lots, as it turns out. Not only is lithium a critical metal for modern society, it is also becoming an increasingly important tool for Earth scientists.Read More
Chandrasekhara Venkata Raman (1888–1970) reported the light scattering phenomenon that has become known as the Raman effect in 1928 (Raman and Krishnan 1928). This followed theoretical predictions by Smekal (1923) that such a phenomenon should exist. Raman initially used sunlight, and then the light from a mercury lamp, to excite the spectrum presumably produced when a photon of light lost a small amount of its energy to a molecular vibration.Read More
Hydrogen gas (H2), when combusted, produces heat and water. There is no pollution, just water vapor. When hydrogen combines with oxygen, there is no generation of carbon dioxide, no production of cyclic hydrocarbons, no sulfur oxides (SOx), no nitrogen oxides (NOx), no ozone cogeneration. It seems that hydrogen, along with efficient energy production, solves many of our pollution problems, from urban air pollution to global warming. In the so-called Hydrogen Age of the future (Holland and Provenzano 2007), H2 will be mainly produced by the electrolysis of water using electricity that itself is derived from renewable energy sources or nuclear power plants. Steam methane reforming (a catalyzed reaction at high temperature where CH4 is combined with water to produce CO2 and H2) will only be acceptable as a source of H2 if it is associated with low-cost CO2 storage. But, in this future energy landscape, what is the role of naturally occurring hydrogen, sometimes referred to as native hydrogen?Read More
With all due respect to basalt, and I appreciate a granite as much as the next person, kimberlite is hard to beat. But what is a kimberlite? Kimberlites may be classified as igneous rocks but it is difficult to know how exactly to describe them in terms of magma, at least in any conventional sense of the word. Kimberlites tap the deepest recesses of our planet that we can sample. Propelled by a formidable volatile load, kimberlite melts transit hundreds of kilometers of mantle and crust, perhaps in just a few days, to form unique ballistic deposits at Earth’s surface. Kimberlites accumulate and transport ripped-up bits from throughout most, if not all, of their ascent path, including diamond, that classic gem of desire with its remarkable qualities that have fueled a global market. Indeed, much of our understanding of kimberlite is owed to the intrepid explorers who searched for and studied elusive diamond deposits. Adding to the veil of petrological complexity kimberlites are often pervasively altered by fluids, some of which were magmatic but some of which were not. The study of kimberlites over many decades has revealed glimpses of their origins and the paths by which they have travelled.Read More
The mysteries and promise of the deep ocean rose to attention on the heels of military interest and technology after World War 2. Despite accounting for 70% of the Earth’s surface, almost nothing was known about the deep-ocean seafloor. That changed dramatically over the following 60–70 years, although our knowledge still remains patchy at best.Read More
Last year (2016), when I spoke at the Geological Society of America’s Penrose Conference on “Layered Mafic Intrusions and Associated Economic Deposits” held in Red Lodge, Montana, I noted that I gave my first professional talk some 35 years ago. As a young researcher back then, I had thought that all the interesting questions in layered intrusions were soon to be solved, leaving little room for me to make a name for myself. I was wrong!Read More
Sustainable development is a term that all too often has been hijacked within our society by politicians and business promoters eager to endorse their “green” credentials. Yet human society requires sustainable growth in order to continue. However, in the context of much of society’s mineral resources what does sustainability actually mean?Read More