Abiotic Sedimentary Dolomite Formation: from Nano- to Macro-scale
Abiotic Sedimentary Dolomite Formation: from Nano- to Macro-scale

Author: Yihang Fang

Publisher:

Published: 2022

Total Pages: 0

ISBN-13:

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With over centuries of effort to understand the formation mechanism of dolomite, a common mineral in sedimentary rocks, the geologic community still struggles to formulate a universal mechanism to explain the origin of massive deposition of sedimentary dolomite. Understanding the exact mechanism for dolomite formation at Earth's surface conditions is crucial for investigating economic reservoirs, interpreting sedimentary environments, reconstructing secular seawater variations, assessing potential carbon sequestration reservoirs, and understanding biominerlization processes.One of the main obstacles for dolomite nucleation and growth is the high water affinity of magnesium and the subsequent kinetic energy barrier for surface Mg2+-water complex to dehydrate. Polysaccharides, exopolymeric substances (EPS), and hydrogen sulfides demonstrate the capability to overcome the kinetic barriers and catalyze dolomite growth, which supports the hypothesis that sedimentary dolomite has a microbial origin. However, not all dolomite are formed by microbial life as dolomite is much more abundant in earlier Earth history when microbial activity levels are lower compare to nowadays, and an abiotic mechanism is needed to explain massive dolomite formation. This work applied laboratory and synchrotron X-ray diffraction, high-resolution TEM imaging, Z-contract imaging, and electron microprobe analysis on low-temperature synthesized and natural samples to understand abiotic controls on surface Mg2+-water complex dehydration and dolomite precipitation. Several focused studies were conducted toward exploring this topic, including: (1) Using ethanol-water mixtures to validate the hypothesis that low-dipole moment materials induce the surface Mg2+-water complex dehydrate, thus allowing disordered dolomite precipitation; (2) Demonstrating that dissolved silica, a low dipole moment molecule, in naturally available concentrations can promote disordered dolomite growth; (3) Applying a dissolved silica catalyzed dolomite growth model to decipher Marinoan cap carbonate formation with coupled Ca, Mg Si, and C cycles; (4) Testing dissolved silica driven dolomite growth in modern hypersaline settings (i.e., the Great Salt Lake, UT); (5) Examining the effect of dissolved silica toward catalyzing dolomite formation in Early Silurian dolomite. Results from this research demonstrate that dissolved silica may be a dominating abiotic control for dolomite precipitation in early Earth history, when dissolved silica in seawater is significantly higher prior to the appearance of silica-consuming microorganisms, and modern hypersaline environments. This abiotic mechanism would allow the reconstruction of solution chemistry changes based on abundances, textures, and associated minerals of dolomite. Changes in dolomite abundances might also contain information on weathering intensities, sea level variations, and Wilson cycles both locally and globally from changes in dissolved silica concentration.

Dolomite
Dolomite

Author: Oleg S. Pokrovsky

Publisher: Nova Science Publishers

Published: 2017

Total Pages: 190

ISBN-13: 9781536107807

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Dolomite (CaMg(CO)2) is certainly one of the most enigmatic sedimentary minerals on Earth. Its massive deposits of the past have very little contemporary analogues and today, scientists still do not have a consensus on how hundred meter-thick dolomite deposits of the Precambrian age (>600 million year) were formed across the globe. Recently, the interest in dolomite has risen due to its importance as a major regulator not only of carbon cycle in the past, but also as an important host rock in ongoing projects of CO2 underground storage and sequestration. The growing demand for primary resources also impacted the interest in dolomite and dolomitic rocks, which are now widely used in numerous technological and industrial applications. For these reasons, there is a steady increase of scientific publications linked to dolomite problematics. A Web of Science search (all databases) with "dolomite" as the topic yielded more than 13,000 papers published from 1950-2015; 4,200 of them were published over the last five years and 8,800 were produced during preceding sixty years. The number of publications concerning use of dolomite in the field of engineering and physical science (non-earth sciences) increased five-fold from the mid-1990s to 2000s, and nowadays contributes to more than a half of all publications on dolomite. This clearly illustrates the rising interest in dolomite for technological applications over the past decade. This book incorporates a large number of disciplines, from geology to chemical engineering of catalysts. It illuminates three main aspects of dolomite as a major sedimentary rock and important technological material: (i) natural occurrence; (ii) laboratory study of dolomite dissolution and precipitation and (iii) applications in various technological aspects. The first two chapters address geological and mineralogical aspects of dolomite deposits in the natural environment (Wagner et al.; Marfil et al). The next three chapters cover the reactivity of dolomite in an aqueous solution (Pokrovsky and Schott), the synthesis of dolomite analogues from aqueous solution (Pina et al) and laboratory precipitation of Mg-bearing carbonates and protodolomite from homogeneous supersaturated solutions (Pokrovsky). Finally, the last two chapters (Ivanets et al., Ryabkov et al.) present the application of dolomite for numerous technological and engineering purposes.

Sedimentary Carbonate Minerals
Sedimentary Carbonate Minerals

Author: F. Lippmann

Publisher: Springer Science & Business Media

Published: 2012-12-06

Total Pages: 310

ISBN-13: 3642654746

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and their identification obviates individual thermochemical studies on every genus. The stability relations among sedimentary carbonate minerals are now more or less well known. The common rock-forming minerals cal cite and dolomite are indeed stable phases in the pertinent systems. Most other carbonate minerals of similar composition which are known to occur in the younger sediments are metastable with respect to calcite, dolomite, and magnesite. This implies that the sedimentation of carbon ates is determined only in part by stability relations. Kinetic factors, which allow the formation of metastable minerals, appear to be more important. Although the diagenetic transformations leading to stable minerals take place by virtue of thermodynamic requirements, the reac tions themselves are triggered by kinetic factors as well. Some of the reactions leading from metastable to stable carbonate assemblages are susceptible to simulation in the laboratory; others (e. g. dolomitization) appear to be so slow that they can be studied only in analogous systems characterized by reasonable reaction rates. In all attempts to explain the possible mechanisms of such reactions, we must consider the crystal structures of the final products as well as of the starting materials. This is another viewpoint from which mineralogy is important to carbonate petrology, if we regard the crystal chemistry of minerals as a part of mineralogy. A certain parallelism with clay mineralogy suggests itself.

Negative Emissions Technologies and Reliable Sequestration
Negative Emissions Technologies and Reliable Sequestration

Author: National Academies of Sciences, Engineering, and Medicine

Publisher: National Academies Press

Published: 2019-04-08

Total Pages: 511

ISBN-13: 0309484529

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To achieve goals for climate and economic growth, "negative emissions technologies" (NETs) that remove and sequester carbon dioxide from the air will need to play a significant role in mitigating climate change. Unlike carbon capture and storage technologies that remove carbon dioxide emissions directly from large point sources such as coal power plants, NETs remove carbon dioxide directly from the atmosphere or enhance natural carbon sinks. Storing the carbon dioxide from NETs has the same impact on the atmosphere and climate as simultaneously preventing an equal amount of carbon dioxide from being emitted. Recent analyses found that deploying NETs may be less expensive and less disruptive than reducing some emissions, such as a substantial portion of agricultural and land-use emissions and some transportation emissions. In 2015, the National Academies published Climate Intervention: Carbon Dioxide Removal and Reliable Sequestration, which described and initially assessed NETs and sequestration technologies. This report acknowledged the relative paucity of research on NETs and recommended development of a research agenda that covers all aspects of NETs from fundamental science to full-scale deployment. To address this need, Negative Emissions Technologies and Reliable Sequestration: A Research Agenda assesses the benefits, risks, and "sustainable scale potential" for NETs and sequestration. This report also defines the essential components of a research and development program, including its estimated costs and potential impact.

Bioavailability of Contaminants in Soils and Sediments
Bioavailability of Contaminants in Soils and Sediments

Author: National Research Council

Publisher: National Academies Press

Published: 2003-05-03

Total Pages: 433

ISBN-13: 0309086256

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Bioavailability refers to the extent to which humans and ecological receptors are exposed to contaminants in soil or sediment. The concept of bioavailability has recently piqued the interest of the hazardous waste industry as an important consideration in deciding how much waste to clean up. The rationale is that if contaminants in soil and sediment are not bioavailable, then more contaminant mass can be left in place without creating additional risk. A new NRC report notes that the potential for the consideration of bioavailability to influence decision-making is greatest where certain chemical, environmental, and regulatory factors align. The current use of bioavailability in risk assessment and hazardous waste cleanup regulations is demystified, and acceptable tools and models for bioavailability assessment are discussed and ranked according to seven criteria. Finally, the intimate link between bioavailability and bioremediation is explored. The report concludes with suggestions for moving bioavailability forward in the regulatory arena for both soil and sediment cleanup.

Microbial Evolution
Microbial Evolution

Author: Howard Ochman

Publisher:

Published: 2016

Total Pages: 0

ISBN-13: 9781621820376

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Bacteria have been the dominant forms of life on Earth for the past 3.5 billion years. They rapidly evolve, constantly changing their genetic architecture through horizontal DNA transfer and other mechanisms. Consequently, it can be difficult to define individual species and determine how they are related. Written and edited by experts in the field, this collection from Cold Spring Harbor Perspectives in Biology examines how bacteria and other microbes evolve, focusing on insights from genomics-based studies. Contributors discuss the origins of new microbial populations, the evolutionary and ecological mechanisms that keep species separate once they have diverged, and the challenges of constructing phylogenetic trees that accurately reflect their relationships. They describe the organization of microbial genomes, the various mutations that occur, including the birth of new genes de novo and by duplication, and how natural selection acts on those changes. The role of horizontal gene transfer as a strong driver of microbial evolution is emphasized throughout. The authors also explore the geologic evidence for early microbial evolution and describe the use of microbial evolution experiments to examine phenomena like natural selection. This volume will thus be essential reading for all microbial ecologists, population geneticists, and evolutionary biologists.

Carbonate Sedimentology
Carbonate Sedimentology

Author: Maurice E. Tucker

Publisher: John Wiley & Sons

Published: 2009-07-17

Total Pages: 496

ISBN-13: 1444314165

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Carbonate rocks (limestones and dolomites) constitute a major partof the geological column and contain not only 60% of the world'sknown hydrocarbons but also host extensive mineral deposits. Thisbook represents the first major review of carbonate sedimentologysince the mid 1970's. It is aimed at the advanced undergraduate -postgraduate level and will also be of major interest to geologistsworking in the oil industry. Carbonate Sedimentology is designed to take the readerfrom the basic aspects of limestone recognition and classificationthrough to an appreciation of the most recent developments such aslarge scale facies modelling and isotope geochemistry. Novelaspects of the book include a detailed review of carbonatemineralogy, non-marine carbonate depositional environments and anin-depth look at carbonate deposition and diagenesis throughgeologic time. In addition, the reviews of individual depositionalsystems stress a process-based approach rather than one centered onsimple comparative sedimentology. The unique quality of this bookis that it contains integrated reviews of carbonate sedimentologyand diagenesis, within one volume.

Processes and Phenomena on the Boundary Between Biogenic and Abiogenic Nature
Processes and Phenomena on the Boundary Between Biogenic and Abiogenic Nature

Author: Olga V. Frank-Kamenetskaya

Publisher: Springer Nature

Published: 2019-08-29

Total Pages: 900

ISBN-13: 3030216144

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The book represents a collection of papers presented at VI International Symposium "Biogenic - abiogenic interactions in natural and anthropogenic systems" that was held on 24-27 September 2018 in Saint Petersburg (Russia). Papers in this book cover a wide range of topics connecting with interactions between biogenic and abiogenic components in lithosphere, biosphere and technosphere. The main regarding topics are following: methods for studying the interactions between biogenic and abiogenic components; geochemistry of biogenic-abiogenic systems; biomineralization and nature-like materials and technologies; medical geology; biomineralogy and organic mineralogy; biomineral interactions in soil; biodeterioration of natural and artificial materials; biomineral interactions in extreme environment.