Our bubbling Earth

In several places on earth large volumes of gas are seen to escape. These gases are usually dominated by CO2. The emissions are associated with volcanic activity, and are attributed to magma degassing. It will be shown that in the case of Milos this explanation is unacceptable for quantitative reasons. An alternative explanation will be given, and its consequences for the thermal evolution of certain sections of the crust will be discussed

Olivine to Combat Climate Change

Weathering of basic rocks, containing magnesium and calcium silicates, is the main mechanism to capture CO₂ in a sustainable way, with storage of organic carbon a distant second. The CO₂ emission by Man, due to the combustion of fossil fuels is at least ten times larger than the natural CO₂ emission from the Earth. Emission and capture are no longer in balance, and the concentration of CO₂ in the atmosphere is steeply rising. It is a logical step to investigate whether we can stimulate the natural process of weathering in such a way that the balance is restored. Weathering takes place at the surface of rocks, so we must increase the available surface area. This can be done by mining and milling suitable rocks, and spread the powder over land and in shallow seas. Factors that influence the rate of reaction, apart from grain size, are temperature, pH and water. This means that soils in tropical countries are best suited. Soil atmospheres are on average hundred times richer in CO₂ than air. This is caused by the decay of plant material and the respiration of soil fauna. A high CO₂- pressure causes a low pH, which is favorable for weathering. The most suitable rock type is dunite, which consists for more than 90 % of olivine. Dunite massifs are found in many countries on each continent. Large massifs occur among others in Guinea, Sierra Leone and Ivory Coast. By mining the olivine there, milling it and spreading a thin layer over the surroundings, climate change can be counteracted. Weathering is a natural process, that has kept the CO₂ level of the atmosphere within bounds for billions of years, thus no short term or long term negative ecological consequences are to be expected.Вивітрювання основних порід, що містять магнієві і кальцієві силікати, є основним механізмом поглинання СО₂ протягом тривалого часу з тривалим збереженням органічного вуглецю. Виділення СО₂ під час спалювання викопних паливних матеріалів, щонайменше, вдесятеро вище, ніж виділення СО₂ Землею. Рівноваги між виділенням і поглинанням вже не існує і концентрація СО₂ в атмосфері поступово зростає. Необхідно з’ясувати, чи можливо стимулювати природний процес вивітрювання так, щоб відновити цю рівновагу. Вивітрювання відбувається на поверхні порід, отже, необхідно збільшити наявну площу поверхні. Це можна зробити, видобуваючи і подрібнюючи придатні для цього породи і розсіюючи порошок над землею і мілководними морями. Чинники, що впливають на швидкість реакції, без урахування розмірів зерен, — температура, рН і вода. Отже, найбільш придатні для цього ґрунти тропічних країн. Атмосфера ґрунтів в середньому в сотні разів більше збагачена СО₂, ніж повітря, що обумовлено розпадом рослинного матеріалу і диханням ґрунтової фауни. Високий тиск СО₂ знижує рН, що є сприятливим фактором для вивітрювання. Найпридатнішим типом порід є дуніт, складений більш ніж на 90 % з олівіну. Масиви дуніту знайдені в багатьох країнах на кожному континенті. Великі масиви цих порід поряд з іншими країнами розташовані у Гвінеї, Сьєрра-Леоне і на Березі Слонової Кості.Выветривание основных пород, содержащих магниевые и кальциевые силикаты, служит основным механизмом поглощения СО₂ в течение продолжительного времени с длительным сохранением органического углерода. Выделение СО₂ при сжигании ископаемых топливных материалов, по меньшей мере, в десять раз выше, чем выделение СО₂ Землей. Равновесия между выделением и поглощением уже не существует и концентрация СО₂ в атмосфере постепенно растет. Необходимо выяснить, возможно ли стимулировать естественный процесс выветривания таким образом, чтобы восстановить это равновесие. Выветривание происходит на поверхности пород, следовательно, необходимо увеличить имеющуюся площадь поверхности. Это можно сделать, добывая и измельчая пригодные для этого породы и рассеивая порошок над землей и мелководными морями. Факторы, влияющие на скорость реакции, без учета размеров зерен, — температура, рН и вода. Следовательно, наиболее пригодны для этого почвы тропических стран. Атмосфера почв в среднем в сотни раз более обогащена СО₂, чем воздух, что обусловлено распадом растительного материала и дыханием почвенной фауны. Высокое давление СО₂ понижает рН, что служит благоприятным фактором для выветривания. Наиболее подходящим типом пород является дунит, состоящий более чем на 90 % из оливина. Массивы дунитов обнаружены во многих странах на каждом континенте. Большие массивы этих пород наряду с другими странами расположены в Гвинее, Сьерра-Леоне и на Берегу Слоновой Кости

Pyrolusite-rich tailings from Nikopol against anoxia?

Anoxia in marine basins is a problem, or is feared to become a problem in several locations. A straightforward remediation would be to blow large volumes of oxygen (or air) into those sub-oxic waters, but that is a tiresome and costly affair. By introducing a solid oxygen donor, it should be possible to attack the anoxia problem for a reasonable period of time in a single and simple operation. An obvious and cost-effective choice would be the use of the mineral pyrolusite (MnO₂). This is one of the commonest manganese ore minerals, and hundreds of millions of tons of manganese tailings containing this mineral are stored in tailings near manganese mines all over the world. A well-known example of such tailings can be found in the manganese mining district near Nikopol/Ukraine. Its use has no harmful effect, as the mineral contains no heavy metals, and even its pore waters are of drinking water quality. The major problem is probably that the reaction of MnO₂ is rather sluggish.Аноксія є проблемою морських басейнів деяких регіонів. Найкращим запобіжним заходом могло б бути закачування великих об’ємів кисню (або повітря) у збіднені киснем води, але це надто складна і дорога операція. Найпростіший метод — введення твердого джерела кисню як окремої операції. Очевидним і ефективним може бути використання піролюзиту (MnO₂) — одного з найпоширеніших марганцево-рудних мінералів. Сотні мільйонів тонн марганцевих хвостів, що містять його, зберігаються в околицях марганцевих шахт у всьому світі. Зокрема, у районі видобування марганцю поблизу Нікополя (Україна). Їх використання не матиме шкідливої дії, оскільки мінерал не містить важких металів і навіть якість його порових вод відповідає якості питної води. Основна проблема полягає у тому, що реакція MnO₂ проходить дуже повільно.Аноксия является проблемой морских бассейнов некоторых регионов. Наилучшим средством могло бы быть закачивание больших объемов кислорода (или воздуха) в обедненные кислородом воды, но это довольно хлопотная и дорогостоящая операция. Наиболее простой метод — введение твердого источника кислорода как одиночной операции. Очевидным и эффективным выбором может стать использование пиролюзита (MnO₂) — одного из наиболее распространенных марганцево-рудных минералов. Сотни миллионов тонн содержащих его марганцевых хвостов хранятся в окрестностях марганцевых шахт во всем мире. Хорошо известны примеры таких хвостов в районе добычи марганца под Никополем (Украина). Их использование не оказывает какого-либо вредного воздействия, поскольку минерал не содержит тяжелых металлов и даже его поровые воды соответствуют по качеству питьевой воде. Основная проблема заключается в том, что реакция MnO₂ проходит очень медленно

The Hormuz Strait Dam Macroproject— 21st Century Electricity Development Infrastructure Node (EDIN)?

Ocean gulfs offer a means of artificially creating a depression, which can be used for a regionally significant hydroelectric macroproject. We examine here the case for a dam at the Strait of Hormuz that blocks a large gulf situated in an arid region. A 35 m evaporation of this concentration basin will reduce its watery surface area by ~53% and allow generation of ~2.050 MW (or possibly ~ 2.500 MW) of electricity. Our conclusion is that the proposed Electricity Development Infrastructure Node (EDIN) is a feasible and desirable macroproject. If the macroproject starts in the near-term future, it would require a significant change in the logistics of oil and gas transport from this region. Alternatively, it can be considered as an attractive future solution for the energy requirements of the region after the exhaustion of its oil and gas reserves

Climate change and CO2 removal from the atmosphere

Several methods have been proposed in recent years to counteract climate change and ocean acidification by removing CO2 from the atmosphere (Carbon Dioxide Removal). The most versatile and widely applicable of these methods is enhanced weathering of olivine, which is capable of removing billions of tons of CO2 from the atmosphere at moderate cost compared to the high cost of Carbon Capture and Storage (CCS). Despite its disadvantages, CCS is still the favored solution of many governments. Many misunderstandings of the potential of enhanced weathering persist. This paper addresses some of these misunderstandings, mainly caused by models which ignore established facts

Metallogenetic and geochemical provinces : book review

In November 1972 a symposium on metallogenetic and geochemical provinces was organized in Leoben by Prof. W.E. Petrascheck; the proceedings of this symposium have now appeared. The book is recommended to all those who want to combine their interest in economic geology with a somewhat wider outlook in order to place the ore deposits in their geologic context. The quality of the contributions is uneven, but some are outstanding, and Prof. Petrascheck can be proud of his initiative

Olivine and climate change

The greenhouse effect, thanks mainly to the water vapor in our atmosphere, has created a livable climate on Earth. Climate change, however, may potentially have dire consequences. It is generally assumed that the rise in CO2 levels in the atmosphere is the main culprit, although several other greenhouse gases (GHG) also play a role. Next to limitation of CO2 emissions by higher efficiency, developing alternative energy sources or changing our wasteful style of living, there are two general approaches to combat climate change. Both fall under the heading ‘Geo-engineering the Climate’, a report submitted to the Royal Society in 2009. These include methods to fight: 1. symptoms, or 2. causes. The first group encompasses attempts to change the Earth's albedo, for example by spreading aerosols of SO2 in the stratosphere, or painting all our roofs white. Among methods to remove CO2 from the atmosphere, the best known are CCS (carbon capture and storage) and ‘geological storage’, which has nothing to do with geology, except for the receptacle being of natural origin [1]. There are two processes by which CO2 has been removed from the atmosphere throughout geological time, primarily by weathering reactions of Ca- and Mg-silicates, and to a lesser extent by storage of organic carbon in coal beds, oil and natural gas, and carbonates. Thus, enhanced weathering is a logical step to remove CO2 from the atmosphere. To that purpose, abundant rock types available in large volumes are ground to increase reactivity, possibly mix with pyrolized wood known as ‘biochar’ (Brazil: ‘terra preta’), and spread the mix in climate zones that favor rapid weathering, that is the wet tropics. Industrializing nations like India, China or Brazil would not need to limit their CO2 emissions by restricting industrial production, and thereby slowing their economic development, but could instead compensate their emissions by enhanced weathering

Troodos: a giant serpentinite diapir

Troodos is a classical ophiolite complex. It is proposed that the serpentinized harzburgites that now form the top of the mountain and represent the originally lowest part of the ophiolite sequence rose as a diapir. This diapiric rise is caused by the pervasive serpentinization of a suboceanic harzburgite, due to rock-sea water interaction. The serpentinization caused a 44% expansion of the rocks. Contrary to salt diapirism, the driving force for this diapiric rise is not so much the difference in density, but the volume increase asscociated with the transformation of harzburgite into serpentinite. The overlying gabbros, sheeted dike complex and pillow lavas were pierced by this serpentinite diapir but barely deformed. Their interaction with sea water was li- mited to some pyroxenes in the gabbros being transformed to amphiboles, and epidotisation of some of the dikes in the sheeted dike complex. The location of steep faults in the Troodos massif is determined by the contrasting expansion behavior of different rock-types on both sides of the fault

Capturing CO₂ from air

Schellnhuber proposed some well-known solutions to the climate problem: •i) Phasing out of CO₂ in the next decades; •ii) Energy efficiency; •iii) Emission reduction; •iv) Systematic decarbonation; •v) Efficiency and renewables. These suggestions are commendable, but their suggested time scheme lacks realism. The emerging economies (China, India, and Brazil) want to develop their economies and raise the standard of living. A prerequisite is access to abundant and cheap energy. They want to realize their objectives by using their large coal reserves

Geochemie : K.H. Wedepohl. Sammlung göschen - Walter de Gruyter, Berlin, 1967, 220 pp., 26 illus., 37 tables, DM.7.80

When a geochemist of international renown like Professor Wedepohl writes a book on geochemistry in the Sammlung Göschen, one logically entertains high hopes that this book will be the long-awaited introductory textbook on geochemistry to be recommended to beginning geochemistry students. Next to this it should give the interested layman a clear understanding of the aims and methods of geochemistry, and still be sufficiently detailed to be of interest to the professional geochemist as well. Maybe all these goals are unattainable in one single volume, and in fact the book falls short of these in several respects.The author has tried to give too much, and instead of limiting himself to a smaller number of problems, he has saved space by merely mentioning several geochemical concepts, without explaining them, or else by presenting many factual data, without trying to bring these together into one framework. The book is therefore inaccessible to laymen without an ample background in geology and petrography. The student who is just beginning his studies in geochemistry might also, on first reading, get the wrong impression that geochemistry is mainly concerned with the collection of analytical facts on all kinds of geological material, without much regard for the ultimate purpose, the unraveling of past or present geological processes. Given these limitations, one should in all fairness point out that Wedepohl has brought together from a prodigious knowledge of the geochemical literature, as well as from his own extensive geochemical work, a wealth of data, touching on all possible fields of geochemistry